The Alaska Earthquake March 27, 1964 cEOoLlOG@icAL SURVEY PROFESSIONAL I ‘ The Alaska Earthquake March 27, 1964; Lessons and Conclusions By EDWIN B. ECKEL A summary of what was learned from a great earthquake about the bearing of geologic and hydrologic conditions on its effects, and about the scientific investigations needed to prepare for future earthquakes @EoLoGIcaL sURVEY PROFESSIONAL PAPER 5 4 6 179044 UNITED STATES DEPARTMENT OF THE INTERIOR WALTER J. HICKEL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Congress catalog-card No. 70-604792 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1970 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 75 cents (paper cover) FOREWORD Few of the effects of the Alaska earthquake of March 27, 1964, on earth processes and on the works of man were new to science, but never had so many effects been accessible for study over so great an area. This earthquake has received more intensive study from all scientific disciplines and specialties than any single previous natural disaster. In a series of six Professional Papers, the U.S. Geological Survey has published the results of a comprehensive geologic study that began, as a reconnaissance survey, within 24 hours after the event and extended, as detailed investigations, through several field seasons. Professional Paper 541 de- scribed early field investigations and reconstruction efforts; 542, in seven parts, the effects of the earthquake on Alaskan communities; 543, in 10 parts, the regional geologic effects; 544, in five parts, the worldwide effects on the earth's hydro- logic regimen; 545, in four parts, the effects on Alaska's transportation, communications, and utilities. This volume, Professional Paper 546, "Lessons and Conclusions," is the last of the series; it contains a selected bibliography and an index for the 28 reports. The findings of the Geological Survey study apply not only to documentation of the Alaska earthquake itself, but, it is hoped, toward better understanding of earthquakes in general; their nature, origin, and effects, and of how man may plan or build to avoid or minimize their consequences. W. T. Prcora, Director. CONTENTS Page Effects, ete.-Continued Beneficial effects-Continued 1 Oceanographic effects-Con. Page Scientific benefits-______-_--.- introduction............~..... 2 Seismic sea waves ___. 25 New information..------.-.- Geological Survey reports on Miscellaneous effects...... 26 New and improved investi- the earthquake..--...-.---.-- 6 Audible - and - subaudible gative Acknowledgments... 8 earthquake sounds-_-.--. 26 Conslusions..:...............-. Tectonic§:---...............<~ 8 Magnetic _-_. 26 Scientific - preparation _ for The 8 Visible surface waves.... ._. 26 future earthquakes. Deformation and vibration of Permafrost......-...l..... 27 Fundamental research.. the land surface........__.. 9 Cable breaks.............. 27 Earthquake forecasting and Vertical deformation.... 11 Tunnels, mines, and deep evaluation of earthquake Horizontal deformation __.. -- 11 ll 27 Surface faults............... 12 Archeologic remains.... 28 Geologic mapping of Mechanism of the earthquake. 13 Earthquake effects, geology and communities............ Effects on the physical environ- 28 Instrumentation and meas- 14 Geologic control of vibration urements__.------------ Geologic effects...._..._..... 14 dnmage::..::... 29 Investigations of actual earth- Downslope mass movements. 14 Surface faulles....... !...; 30 Ground fissures........._. 19 L & Need for advance planning. yes. f andslides..............~.... 30 s f Consolidation subsidence... 21 i Py: Geologic, geophysical, and Shore processes.... 21 Vertical ?ect.onlc displacements hydrologic investigations. Hydrologic effects_______ ___.. 21 and seismic ses wihves.--.- - 80 Availability of maps and Olaciers:................. 21 Ground and surface water other basic data____---- Ice breakage.............. 22 hydrology .--------------- 31 Questionnaires. ._._____--._- Ground water-___________. 22 Beneficial effects of the earth- Scientific and - Engineering Surface water....._....... 28 quake.______________-_---- 31 Task Force.:....--.-.-..~. Oceanographic effects___.____. 23 Socioeconomic benefits__..... 31 Selected bibliography.... Local waves.........l._.. 24 Direct geologic 82 ns ILLUSTRATIONS FIGURES Page 1. Map showing extent and nature of the effects of seismic vibrations related to the earthquake.. rentes oan ana nous ao sak o tn casue 4-5 2. Map of south-central Alaska, showing areas of tectonic land-level 10 Page 32 34 37 37 37 3T 38 40 41 41 41 VI "One of the greatest earthquakes of all time struck in south-central Alaska in the late afternoon of March 27, 1964." THE ALASKA EARTHQUAKE, MARCH 27, 1964; LESSONS AND CONCLUSIONS One of the greatest earthquakes of all time struck south-central Alaska on March 27, 1964. Strong motion lasted longer than for most recorded earth- quakes, and more land surface was dis- located, vertically and horizontally, , than by any known previous temblor. Never before were so many effects on earth processes and on the works of man available for study by scientists and engineers over so great an area. The seismic vibrations, which directly or indirectly caused most of the damage, were but surface manifestations of a great geologic event-the dislocation of a huge segment of the crust along a deeply buried fault whose nature and even exact location are still subjects for speculation. Not only was the land sur- face tilted by the great tectonic event beneath it, with resultant seismic sea waves that traversed the entire Pacific, but an enormous mass of land and sea floor moved several tens of feet hori- zontally toward the Gulf of Alaska. Downslope mass movements of rock, earth, and snow were initiated. Sub- aqueous slides along lake shores and seacoasts, near-horizontal movements of mobilized soil ("landspreading"), and giant translatory slides in sensitive clay did the most damage and provided the most new knowledge as to the origin, mechanics, and possible means of con- trol or avoidance of such movements. The slopes of most of the deltas that slid in 1964, and that produced de- structive local waves, are still as steep or steeper than they were before the earthquake and hence would be unsta- ble or metastable in the event of an- other great earthquake. Rockslide avalanches provided new evidence that such masses may travel on cushions of compressed air, but a widely held theory that glaciers surge after an earthquake has not been substantiated. Innumerable ground fissures, many of them marked by copious emissions of By Edwin B. Eckel ABSTRACT water, caused much damage in towns and along transportation routes. Vibra- tion also consolidated loose granular materials. In some coastal areas, local subsidence was superimposed on re- gional tectonic subsidence to heighten the flooding damage. Ground and sur- face waters were measurably affected by the earthquake, not only in Alaska but throughout the world. Expectably, local geologic conditions largely controlled the extent of struc- tural damage, whether caused directly by seismic vibrations or by secondary effects such as those just described. Intensity was greatest in areas under- lain by thick saturated unconsolidated deposits, least on indurated bedrock or permanently frozen ground, and inter- mediate on coarse well-drained gravel, on morainal deposits, or on moderately indurated sedimentary rocks. Local and even regional geology also controlled the distribution and extent of the earthquake's effects on hydro- logic systems. In the conterminous United States, for example, seiches in wells and bodies of surface water were controlled by geologic structures of regional dimension. Devastating as the earthquake was, it had many long-term beneficial ef- fects. Many of these were socioeco- nomic or engineering in nature; others were of scientific value. Much new and corroborative basic geologic and hydrologic information was accumu- lated in the course of the earthquake studies, and many new or improved investigative techniques were devel- oped. Chief among these, perhaps, were the recognition that lakes can be used as giant tiltmeters, the refinement of methods for measuring land-level changes by observing displacements of barnacles and other sessile organisms, and the relating of hydrology to seis- mology by worldwide study of hydro- seisms in surface-water bodies and in wells. The geologic and hydrologic lessons learned from studies of the Alaska earthquake also lead directly to better definition of the research needed to further our understanding of earthquakes and of how to avoid or lessen the effects of future ones. Research is needed on the origins and mechanisms of earthquakes, on crustal structure, and on the genera- tion of tsunamis and local waves. Better earthquake-hazard maps, based on improved knowledge of regional ge- ology, fault behavior, and earthquake mechanisms, are needed for the entire country. Their preparation will require the close collaboration of engineers, seismologists, and geologists. Geologic maps of all inhabited places in earth- quake-prone parts of the country are also needed by city planners and others, because the direct relationship between local geology and potential earthquake damage is now well understood. Improved and enlarged nets of earthquake-sensing instruments, sited in relation to known geology, are needed, as are many more geodetic and hydrographic measurements. Every large earthquake, wherever located, should be regarded as a full- scale laboratory experiment whose study can give scientific and engineer- ing information unobtainable from any other source. Plans must be made before the event to insure staffing, funding, and coordination of effort for the scientific and engineering study of future earthquakes. Advice of earth scientists and engineers should be used in the decision-making processes involved in reconstruction after any future disastrous earthquake, as was done after the Alaska earthquake. The volume closes with a selected bibliography and a comprehensive in- dex to the entire series of U.S. Geolog- ical Survey Professional Papers 541-546. 1 "...and lo, there was a great earthquake... and every mountain and island were m out of their places." dy over so great an. area. A massive relief and recon- struction program began at once- " 9 ~ l'.\ 4A l. p \ il 0. ~ Qh: a program in which the Federal Government played a greater part than for any previous physical dis- aster in the United States. The Alaska earthquake received more intensive study from scien- tists and engineers of all disci- plines and specialties than any major earthquake in history. Much has been, and is still being, learned from these investigations. The findings apply not only to documentation of the Alaska earthquake itself, but toward bet- ter understanding of the nature and origins of earthquakes in gen- eral, of their effects, and of how man can plan or build to avoid or ameliorate those effects. This report is primarily a sum- mary of geologic and hydrologic findings of the U.S. Geological Survey with only incidental excur- sions into the findings of other organizations and disciplines. For this reason, the enormous amount of new information amassed and published by others is not stressed, though references to it appear in the selected bibliography, and all of it was used by Survey authors as it became available in reaching their conclusions. The story of the earthquake is told in a general nontechnical way by Hansen and others (1966). More detailed descriptions of many facets of the earthquake and its ef- fects, treated partly by topic and partly by locality, are contained in other reports in this series; the bibliographies in each report, of course, contain references to many other descriptions. No attempt is made here to repeat all these details or even to summarize them. In- stead, the intent is to sort out that which was significant or different about the Alaska earthquake as compared with previous ones. Em- phasis is given to the lessons learned from it, both technical and philosophic, that can be applied to 859-625 0O-70--z2 LESSONS AND CONCLUSIONS the studies of future earthquakes and to better understanding of the earthquake process. GEOLOGICAL SURVEY REPORTS ON THE EARTHQUAKE The Survey's first report on the earthquake, by Grantz, Plafker, and Kachadoorian (1964), was published only a few weeks after the event. It described in a remark- ably accurate and thorough fash- ion the essential facts about the earthquake and its effects as they were learned during the initial reconnaissance investigations. This preliminary report has been fol- lowed by a series of six Profes- sional Papers, under the overall title "The Alaska Earthquake, March 27, 1964," of which this is the concluding volume. Together, these reports constitute a compre- hensive description of the earth- quake's effects on geologic and hydrologic materials and proc- esses, considerable emphasis being placed on the bearing of those ef- fects on man and his works. They are based primarily on the Geolog- ical Survey's own investigations, but several contributions from other authors were sought out and included for more complete coverage. Each report of the Professional Paper series is liberally illustrated and contains a bibliography. At the end of this volume, the entire series is indexed and complete bib- liographic citations are given un- der the principal authors' names. Parts or all of the series are avail- able for purchase from the Super- intendent of Documents, U.S. Government - Printing - Office, Washington, D.C. 20401. The several Professional Papers and the short titles of their parts are listed here, with a brief state- ment of contents of each. Professional Paper 541, "Field in- vestigations and reconstruction 3 efforts," by W. R. Hansen and others (1966) : This nontechni- cal introductory volume de- scribes the time, duration, and extent of the earthquake, its physiographic-geologic - setting, and its effects on the communi- ties and transportation facilities of Alaska; it also contains a brief description of the sea-wave damages at coastal communities in British Columbia, Washing- ton, Oregon, and California. Biologic, atmospheric, and pos- sible magnetic effects of the quake are outlined. Separate sections note the governmental and private response to the dis- aster and the contribution of both sectors to the reconstruc- tion. The following subtitles indicate the contents of the sections : "A Summary Description of the Alaska Earthquake-Its Set- ting and Effects," by W. R. Hansen and E. B. Eckel. "Investigations by the Greolog- ical Survey," by W. R. Hansen. "The Work of the Scientific and Engineering Task Force- Earth Science Applied To Policy Decisions in Early Re- lief and Reconstruction," by EF. B.. Bekel and W. B, Schaem. "Activities of the Corps of En- gineers-Cleanup and Early Reconstruction," by R. E. Lyle and Warren George. "Reconstruction by the Corps of Engineers-Methods and Accomplishments," by War- ren George and R. E. Lyle. "The Year of Decision and Ac- tion," by Genie Chance. Professional Paper 542: "Effects on Communities," in seven chapters : A, "Anchorage," by W. R. Hansen (1965). Seismic vibra- tion damaged many multistory ALASKA EARTHQUAKE, MARCH 27, 1964 68° 64° 60° FORT RANDA L av“ qn a nS % [s c 9 y+ Q\fi Base from U.S. Geological Survey 1:2,500,000 Alaska Mop E 100 200 390M1LES 1.-Map showing extent and nature of t] LESSONS AND CONCLUSIONS se° EXPLANATION [___] Large area of relatively thick unconsolidated deposits Approximate felt—limit; dashed \< where inferred Approximate limit of fissured ground and cracked ice; dotted where in- ferred Approximate limit of landslides and avalanches Approximate limit of property damage from seismic vibrations; broken | where inferred 200 --- Miles from epicenter YA) 78 SPEER CENTER s \ C ' I \ cas g \ \ \ | EARTHQUAKE “flip? \ \ \ | EPICENTER \ | Q $11”) wee by VaLDEZ { v | ¥ f \ \ . | 0 o CORBPVA -’7 K B® & / | a. "off i So 2 j "<., 5 \ | \\ skagway O xffi )% ALEUTIAN o <4? QQO i 17180 X o° k mic vibrations related to the earthquake. buildings, - caused - extensive ground fissures, and triggered disastrous translatory landslides in some bluff areas underlain by sensitive clays. Because of its size, Anchorage had greater total property damage than all the rest of Alaska. B, "Whittier," by Reuben Kachadoorian (1965). Land subsidence, waves generated by submarine landslides, fire, and seismic vibration wrecked much of the waterfront area in this small port-rail terminal. C, "Valdez," by H. W. Coulter and R. R. Migliaccio (1966). Ground fissures, waves, and fire did much damage, and a gigan- tic submarine slide off the front of the delta town site carried the waterfront away and dic- tated relocation of the town. D, "Homer," by R. M. Waller (1966). Submergence caused by tectonic subsidence and by con- solidation of sediments exposed much of Homer Spit, economic heart of the community, to the reach of high tides. A sepa- rate section by K. W. Stanley describes the beach changes on Homer Spit that resulted from subsidence. E, "Seward," by R. W. Lemke (1967). Seismic sea waves, sub- marine slides, and fires destroyed the town's waterfront and ne- cessitated relocation of the Alaska _ Railroad - terminal. Ground fissures damaged nu- merous buildings, particularly in suburban areas. F, "Kodiak Area," by Reuben Kachadoorian and George Plaf- ker (1967). Seismic sea waves flooded Kodiak, the nearby Naval Station, and several smaller communities in the Ko- diak island group. Regional tectonic subsidence caused fur- ther damage in many places. ALASKA EARTHQUAKE, MARCH 27, 1964 G, "Various Communities," by George Plafker, Reuben Kachadoorian, E. B. Eckel, and L. B. Mayo (1969). Effects on several scores of miscellaneous communities, where there was loss of life or significant physi- cal damage, are described, as are the extensive wave damage in coastal areas and evidence of vi- bration throughout Alaska. Professional Paper 543 : "Regional Effects," in 10 chapters: A, "Slide-Induced Waves, Seiching, and Ground Fractur- ing at Kenai Lake," by D. S. McCulloch (1966). The earth- quake dislodged - subaqueous slides from deltas in Kenai Lake that generated destructive waves. The lake basin was tilted and a seiche wave was excited in it. B, "Martin-Bering Rivers Areas," by S. J. Tuthill and W. M. Laird (1966). Widespread geomorphic changes took place in a large uninhabited area east of the Copper River. Ground fis- sures-some with associated ejections of mud or water- avalanches, and landslides were among the more important effects. C, "Gravity Survey and Re- gional Geology of the Epi- central Region," by J. E. Case, D. F. Barnes, George Plafker, and S. L. Robbins (1966). Gravity stations and reconnaissance geologic mapping in the Prince Wil- liam Sound area provided background for other inves- tigations of the earthquake. A regional gravity gradient, caused by thickening of the continental crust and local anomalies related to differ- ences in lithology were measured. D, "Kodiak and Nearby Is- lands," by George Plafker and Reuben Kachadoorian (1966). Seismic sea waves caused the greatest physical damage throughout the Ko- diak Island area. Tectonic subsidence adversely af- fected much of the shore- line. Vibration, ground fissures, and landslides af- fected unconsolidated ma- terials but not bedrock. E, "Copper - River - Basin Area," by O. J. Ferrians, Jr. (1966). Extensive ground fissures formed in flood plains, deltas, and the toes of alluvial fans. Terrain un- derlain by permafrost be- haved like bedrock and did not crack. Avalanches and rockslides were released in the mountains. F, "Ground Breakage in the Cook Inlet Area," by H. L. Foster and T. V. N. Karl- strom (1967). Ground fis- sures, many of which ejected water or sediment, formed on the Kenai Lowland; most of them were on thick bodies of unconsolidated materials. Zonal concentra- tion of ground fissures may have been - concentrated along a buried fault. G, "Surface Faults on Mon- tague Island," by George Plafker (1967). Two reac- tivated steep reverse faults in Prince William Sound are the only known surface faults caused by the earth- quake. They are probably part of a fault system that extends discontinuously for more than 300 miles from Montague Island past the southeast coast of Kodiak Island. H, "Shoreline Erosion and Deposition on Montague Is- land," by M. J. Kirkby and A. V. Kirkby (1969). Modi- fication of the shore by sub- LESSONS AND CONCLUSIONS T aerial and marine processes ice breakage, seiching, fis- tralia recorded measurable began immediately after suring of streambeds, and seiches, or hydroseisms. tectonic uplift. The effect temporary damming. Such recorders can thus and rate of each process on Ground water was also serve as useful adjuncts of various - materials - were drastically affected, mostly seismograph networks in measured. Evidence was in unconsolidated aquifers. earthquake studies. found of two relative sea- Many temporary and per- Professional Paper 545, "Effects level changes prior to 1964. manent changes occurred in on Transportation, Communica- I, "Tectonics of the Earth- water levels and artesian tions, and Utilities," in four quake," by George Plafker pressures. chapters : (1969). The earthquake B, "Anchorage Area," by R. A, "Eklutna Power Project," was accompanied by crustal M. Waller (1966). Immedi- by M. H. Logan (1967). warping, horizontal distor- ate effects on the Anchorage Vibration-induced consoli- tion, and surface faulting hydrologic system included dation of sediments dam- over an area of more than increased stream discharge, aged the underwater intake 110,000 square miles. Focal seiches on lakes, and fluctu- structure, and permitted mechanism studies, com- ations in ground-water lev- sand, gravel, and cobbles to bined with the patterns of els; water supplies were enter the tunnel. Lesser deformation and seismicity, temporarily disrupted by damage was done by vibra- suggest that the earthquake damming of streams. tion and ground fractures. probably resulted from C, "Outside Alaska," by R. A separate section by L. R. movement along a complex C. Vorhis (1967). The Burton describes the use of thrust fault that dips at a earthquake caused measur- a portable television camera low angle beneath the con- able changes of water levels to locate breaks in under- tinental margin. Radiocar- in wells and surface waters ground communication sys- bon dating of pre-1964 dis- throughout nearly all of the tems. placed shorelines provides United States and in many B, "Air and Water Transport, data on long-term tectonic other countries. A separate Communications, and Utili- movements in the earth- section by E. E. Rexin and ties," by E. B. Eckel (1967). quake region and on the R. C. Vorhis describes hy- All forms of transportation, time interval since the last droseismograms from a well utilities, and communication major _ earthquake-related in Wisconsin and one by R. systems were wrecked or movements. W. Coble the effects on severely hampered by the J, "Shore Processes and Beach ground water in Iowa. earthquake. Numerous air- Morphology," by K. W. D, "Glaciers," by Austin Post ports and all seaports were Stanley (1968). All 003.5131 (1967). Many rockslide av- affected by vibration, sub- features began to readjust alanches extended onto the aqueous slides, waves, fire to 0.1131“ng conditions im- glaciers; some traveled long and tectonic uplift or sub- mediately after the eatrth- distances, possibly over sidence. Aboveground trans- quake. In the subsided layers of compressed air. mission lines were exten- areas, beaches flattened and No large snow and ice ava- sively broken, but buried receded; in uplifted areas, lanches occurred on any of utility lines were virtually they were stranded. Emer- the hundreds of glaciers. undamaged except where gence and submergence Little evidence of earth- the ground fractured or posed problems of land use quake-induced surges of slid. and qwnersh}p and changed glaciers was found. C; "The Highway System," by wildlife habitats. E, "Seismic Seiches," by Ar- Reuben . Professional Paper 544, "Effects thur McGarr and R. C. (1968). Widespread damage on the Hydrologic Regimen," in Vorhis (1968). Hundreds of resulted chiefly from de- five chapters: water-level instruments on struction of bridges and A, "South-Central Alaska," by streams, lakes, and reser- roadways by seismic vibra- R. M. Waller (1966). Sur- voirs throughout the United tion and subsidence of face waters were affected by States, Canada, and Aus- foundations. - Snowslides, landslides, and shoreline submergence also damaged or drowned some roadways. D, "The Alaska Railroad," by D. S. McCulloch and M. G. Bonilla (1970). The rail system - was - extensively damaged; bridges and tracks were destroyed, and port facilities were lost at Seward and Whittier. "Landspreading" (a term for sediments that were mobilized by vibration and moved toward topographic depressions) was the single THE EARTHQUAKE The earthquake struck about 5:86 p.m., Friday, March 27, 1964, Alaska standard time, or, as recorded by seismologists, at 03:86:11.9 to 12.4, Saturday, March 28, 1964, Greenwich mean time. Its Richter magnitude, com- puted by different observatories as from 8.3 to possibly as high as 8.75 (that of the greatest known earthquake is 8.9), has generally come to be described as 8.4-8.6. Its intensity on the Modified Mercalli scale ranged between very wide limits, depending partly on dis- tance from the epicenter but much more on local geologic and hydro- logic conditions and distribution of population; hence isointensity lines are difficult or impossible to draw. The epicenter was instrumen- tally determined to be close to College Fiord at the head of Prince William Sound, on the south flank of the rugged Chugach Mountains (fig. 2). Calculations of the epicenter vary, but all place it within a 9-mile (15-km) radius of 61.1° N., 147.7° W. The focus, ALASKA EARTHQUAKE, MARCH 27, 1964 most important source of trouble. ACKNOWLEDGMENTS Sincere thanks go to all the au- thors whose work is summarized here and to all my colleagues who played parts in publishing the U.S. Geological Survey's series of re- ports on the earthquake. Early drafts of this report were reviewed by the authors of each paper in the series and by many other friends, particularly the members of the Committee on the Alaska Earth- quake Committee, National Acad- emy of Science. All of these were very helpful in correcting factual and interpretative errors. Special thanks are due Wallace R. Hansen, George Plafker, and David S. Mc- Culloch, who went beyond the call of duty in helping to improve this presentation. Catherine Campbell, who had primary responsibility for processing all the reports in the series; and Elna Bishop and her associates, who did the final edit- ing and saw the reports through the press, deserve the thanks of all authors and readers. Robert A. Reilly used imagination, skill, and patience in preparing the line drawings for these pages. TECTONICS or point of origin, was 12-30 miles (20-50 km) below the surface. References to a single epicenter or depth of focus are misleading in that they imply that the earth- quake had a point source. As inter- preted by Wyss and Brune (1967), the earthquake rupture propa- gated in a series of events, with six widely distributed "epicenters" recorded during the first 72 sec- onds. Thus, energy was released by the earthquake itself over a broad area south and southwest of the epicenter; the thousands of aftershocks were dispersed throughout an area of about 100,000 square miles, mainly along the Continental Shelf between the Aleutian Trench and the mainland. The long duration of strong ground motion intensified many of the earthquake's effects and added greatly to its scientific signifi- cance. At the time, there were no instruments in Alaska capable of recording the duration of motion, but many observers timed or esti- mated the period of strong shak- ing as from 114 to ' minutes. In most places the time was between 3 and 4 minutes. The majority of observers reported either continu- ous strong shaking throughout the earthquake or gradually dimin- ishing motion. There is evidence, however, that in Anchorage and possibly elsewhere there were sev- eral pulses of strong shaking, sep- arated by periods of diminished vibration. The earthquake vibrations were felt by people throughout Alaska and parts of British Columbia (fig. 1); they were recorded by seismographs - throughout - the world. The vibrations themselves, or their immediate effects on bod- ies of water, were measured on streams and lakes and in wells throughout the United States and in many other countries. Earth- quake-caused atmospheric pres- sure waves and subaudible sound waves were also recorded by in- struments at widely separated sta- tions in the conterminous States. There is general agreement among seismologists and geolo- gists that shallow earthquakes are caused by sudden release of elastic strain energy that has accumu- lated in the earth's crust and upper mantle. There is no unanimity of opinion, however, as to why the strains are released when and where they are nor as to the details of the earthquake-generation proc- ess or mechanism. The Alaska earthquake of 1964 gave some ad- ditional insight into these prob- lems but did not solve them all by any means. Much has been made by both technical and popular writers of the fortunate circumstances that brought the Alaska earthquake on the late afternoon of Good Friday, or Passover, at a time of low tides, and during the off-season for fish- ing, when there were few people on docks and boats and in near- shore canneries. There is no ques- tion that this combination of cir- cumstances resulted in less loss of life than would have occurred at almost any other time. Wilson and Tgrum (1968) make the interesting suggestion that the timing of the release of strain was perhaps not fortuitous at all, but was the product of astronomic forces. They base their suggestion on the fact that the earthquake oc- curred near the time of the vernal equinox-the date on which the religious seasons of Easter and Passover are also based-when the - (@ * * the timing of the release of strain was perhaps not fortuitous at all, but was the product of astronomic forces. LESSONS AND CONCLUSIONS earth, moon, and sun were in op- position at syzygies and ocean tides were at maximum spring range. Wilson and Tgrum inferred that six other great earthquakes in recent history occurred at or near the lunar position of syzygy either in opposition or conjunction; they concluded that the maximum earth and ocean tides that result from these conditions are perhaps important triggering devices for releasing built-up strain in the earth's crust. Whether or not their hypothesis is correct, the earth- quake could hardly have struck at a time more favorable to mini- mizing damage and loss of life. DEFORMATION AND VIBRATION OF THE LAND SURFACE An earthquake by definition is a shaking of the ground surface and the structures on it, but the shak- ing is really only symptomatic of the great geotectonic events that are affecting a part of the earth's crust. This truism was well dem- onstrated by the Alaska earth- quake. Vibrations from few, if any, earthquakes in history have been felt by people over a wider area, or have persisted for a longer time. Much of the damage was caused by the vibrations them- selves or by their direct results 9 ground cracks, compaction of sedi- ments, landslides and subaqueous slides, and local waves originated by such slides. But perceptible and disastrous as they were, these ef- fects were insignificant compared to the great geologic event that caused them, even though most other effects of that event were not even recognizable as such until long after shaking had subsided. Indeed, the nature and location of the assumed fault along which the main event occurred are still sub- jects for inference and speculation, despite intensive studies by many able investigators. Some other effects were nearly or quite as destructive as were the seismic vibrations. The uplift and subsidence that disrupted ports and navigation routes throughout the affected area had far-reaching, long-term effects (fig. 2). Massive tilting of the ocean bottom un- doubtedly initiated the seismic sea waves or tsunamis that wrecked Kodiak and other towns in Alaska and caused many of the deaths there and as far down the coast as Crescent City, Calif. The hori- zontal seaward movement of the landmass, though not measurable as such without precise geodetic studies and interpretations, may it- self have initiated disastrous slides and waves along the shores of » 10 ALASKA EARTHQUAKE, MARCH 27, 1964 156° 144° (t. Canal na Pa 'big ' Prince William ‘ j): Sound y) Ae » a SIN/fl Achinbrook ”4 Island lle COMTO o ‘ & " island Kayak Island /. #4 fi/Resurrection Cape St. Elias < / Bay / ..° /‘1/ emt T & %D ”PS5 le? AJ y a <, & "a 34 o ;, / f $ , C £ 6 a 4 EXPLANATION [ _ )i sce- s- > / Subsidence-uplift boundary // Highway # # Railroad 0 25 50 75 _ 100 MILES C s LOLOL ___I __ [| e fl 56°15 . \ x _ ue // 2.-Map of south-central Alaska, showing areas of tectonic land-level changes. Prince William Sound and else- where. Perhaps the most significant aspect of the Alaska earthquake was the great expanse of measur- able land dislocation. Most of our knowledge of the crustal deforma- tion that marks large earthquakes comes from analysis of the elastic waves that they generate; more di- rect observations are commonly limited by a lack of critical ground control. In Alaska these deforma- tions were measurable by geodetic and other methods over much of the displacement field (Malloy, 1964, 1965; Plafker, 1965; Parkin, 1966, 1969; Small and Parkin, 1967; and Small and Wharton, 1969). The vast quantity of avail- able facts are interpreted in tec- tonic terms by Plafker (1969), from whose report most of the fol- lowing information is taken. VERTICAL DEFORMATION Over an area of more than 100,000 square miles, the earth's surface was measurably displaced by the earthquake (fig. 2). Dis- placements occurred in two ar- cuate zones parallel to the con- tinental margin, together about 600 miles long and as much as 250 miles wide. West and north of a curving isobase line that extends around the head of Prince William Sound, thence southwestward past the southeast shores of the Kenai Peninsula and the most - southeasterly fringes of Kodiak Island, the land and sea-bottom surface sub- sided an average of 2%%4 feet and a maximum of 7% feet. South- east, or seaward of the isobase line, the surface was uplifted an average of 6 feet and a measured maximum of 38 feet, on Mon- tague Island, where surface faults developed along a zone of severe deformation. There is some evi- dence that the land west of the subsided zone, involving the 359-625 0-10-38 LESSONS AND CONCLUSIONS Aleutian and Alaska ranges, was uplifted a maximum of 114 feet, but less is known about this area. Besides the tsunamis that spread across the entire Pacific Ocean, subsidence and uplift had other consequences, par- ticularly along the seacoasts. Nearly every report in this series describes these effects as observed in some part of the earthquake- affected region. Some effects were immediately apparent to ob- servers; others were not even recognized until hours or days later, when anomalous waves had subsided and new tide levels were affirmed. Only then did people begin to realize the magnitude of the tectonic changes. Real measurements of the dis- tribution and amount of land- level change required geodetic resurveys of previously estab- lished land nets and hundreds of measurements of vertically dis- placed intertidal sessile orga- nisms. The fact that certain marine plants and animals have definite vertical growth limits relative to tide levels has long been known but, following the early lead of Tarr and Martin (1912), its usefulness in determin- ing relative land-level changes resulting from earthquakes was greatly expanded by Plafker (1969) and his colleagues. The potential accuracy of the method is limited only by the number of observations that can be made with available time, energy, and funds; by the accuracy of our knowledge as to the growth habits of these sessile organisms; and by the accuracy of the ob- server's estimates of tide stages at the time of observation. In south-central Alaska it provided far more detailed and reliable information on the nature and size of land deformation than could have been determined from 11 the relatively sparse geodetic, hydrographic, and tide-gage con- trol that was available. HORIZONTAL DEFORMATION Large-scale horizontal deforma- tion also accompanied the earth- quake (Parkin, 1966, 1969; Plaf- ker, 1969). Horizontal movement of the land mass was not noted by observers and could not in any case have been distinguished by human senses from the back-and-forth sensations caused by the seismic waves. Its net results, however, were measured geodetically. Retriangulation by the U.S. Coast and Geodetic Survey over about 25,000 square miles of up- lifted and subsided ground in and around the Prince William Sound region shows definitely that the landmass moved relatively sea- ward, or southeastward. The amount and distribution of the displacement has been determined relatively but not absolutely. Plaf- ker's interpretation shows system- atic horizontal shifts, in a south to southwestward direction, of as much as 64 feet. Parkin, using the same data, found maximum dis- placements of about 70 feet and in slightly different directions. What- ever the differences in detail and interpretation, there is little doubt that a large mass of land and sea floor moved several tens of feet toward the Gulf of Alaska,. The horizontal land movements produced no known direct effects on man and his structures. Malloy (1965), Wilson and Tgrum (1968), Plafker (1969), Plafker and others (1969), all suggest, however, that the sudden seaward land motion may well have caused waves in certain confined and semiconfined bodies of surface water. Too, po- rosity changes that caused tempo- rary water losses from surface streams and lakes, and lowering of water levels in some wells that tap 12 ALASKA EARTHQUAKE, MARCH 27, 1964 "The Alaska earthquake of 1964 produced only two known surface faults, both on uninhabited Montague Island, in Prince confined aquifers, may have resulted from the horizontal land movements (Waller, 1966a, b). SURFACE FAULTS Surface fault displacements ac- company many large earthquakes and are much feared because of potential damage to buildings. The Alaska earthquake of 1964 produced only two surface faults, both on uninhabited Montague Is- land, in Prince William Sound (Plafker, 1967). They are signifi- cant, however, because of their tec- tonic implications, their large dis- placements, and their reverse hab- its. So far as is known, reverse faults rarely accompany earth- quakes. The two faults, called the Patton Bay fault and the Hanning Bay fault, were reactivated along preexisting fault traces on the southwestern part of Montague Island. These faults had been mapped by Condon and Cass (1958). New scarps, fissures, flex- ures, and large landslides ap- William Sound." peared in bedrock and in surficial deposits along both traces. Both strike northeast and dip steeply northwest. Vertical displacements are 20 to 23 feet on the Patton Bay fault and 16 feet on the shorter Hanning Bay fault. Both blocks of each fault are uplifted relative to sea level, but the northwestern block of each is relatively higher than the southeastern one. The Patton Bay fault is 22 miles long on land and extends seaward to the southwest at least 17 miles; in- direct evidence suggests that the fault system extends southwest- ward on the sea floor more than 300 miles (Plafker, 1967). The faults on Montague Island and their postulated extensions southwestward are in the zone of maximum tectonic uplift. Their geologic setting and positions relative to the zone of regional up- lift and aftershocks suggest to Plafker (1969) that they are not the primary causative faults of the earthquake but are subsidiary fractures. The hypothetical causa- tive fault is viewed as a low-angle thrust beneath the continental margin. Inconclusive evidence suggests that ground fissures on the Kenai Peninsula may reflect earthquake- induced movement along an undis- covered buried fault zone (Foster and Karlstrom, 1967). The cracks may, however, have been caused by refraction of seismic vibrations off subsurface bedrock irregularities. Similarly, his bathymetric surveys indicate to G. A. Rusnak of the U.S. Geological Survey (oral commun., 1968) that the earth- quake may have formed fault- bounded grabens on the floor of Resurrection Bay, as well as some- what similar displacements in Passage Canal. Evidence for these suggestions is tenuous, particu- larly because no direct indications of the postulated earthquake- caused structural features have been found on land, despite dili- gent search. MECHANISM OF THE EARTHQUAKE The widespread vertical and horizontal displacements of the land surface, and the surface faults on Montague Island and southwest thereof, were manifestations of a great geologic event-the sudden release of crustal strains that caused movement along a great fault deep beneath the surface. Nearly all seismologists and geol- ogists agree that such a fault exists, but its exact position, orientation, and sense of displace- ment are obscure, and will prob- ably remain so. The elastic rebound theory for the generation of earthquakes states that shallow-focus earth- quakes (at depths less than about 40 km.), such as the Alaska one, are generated by sudden fractur- ing or faulting following slow ac- cumulation of deformation and strain. When the strength of the rocks is exceeded, failure occurs and the elastic strain is suddenly released in the form of heat, crush- ing, and seismic-wave radiation. Most investigators believe that this sequence of events took place in Alaska. Most believe further that the 1964 earthquake was but one pulse in a long history of regional deformation ; this history is sum- marized by Plafker (1969). Geo- logic evidence, supported by num- erous new radiocarbon datings, indicates that most of the de- formed region has been undergo- ing gradual tectonic submergence for the past 930 to 1,360 years; Plafker tentatively interprets this submergence as direct evidence that regional strain with a down- ward-directed component had been accumulating in the region for about that length of time. Intensive studies of the earth- quake, and of its foreshocks and aftershocks, have led seismologists LESSONS AND CONCLUSIONS to agree that movement was ini- tiated on a new or a reactivated old major fault or fault zone beneath Prince William Sound. Seismolo- gists also agree that the fault is elongate, extending several hun- dred miles southwestward from near the epicenter to or beyond Kodiak Island and that it is 12 to 30 miles beneath the surface at the epicenter of the main shock. Focal- mechanism studies are inconclu- sive as to whether the postulated fault dips steeply or at low angles. Either angle fits the available data. Plafker (1969), who considers the focal-mechanism studies by seismologists in conjunction with the regional geologic history and with regional patterns of tectonic deformation and seismicity, be- lieves that the fault is most prob- ably a low-angle thrust (reverse fault). According to his interpre- tation, the earthquake originated along a complex thrust fault that dips northwestward beneath the Aleutian Trench. Subsidiary re- verse faulting on Montague Island occurred in the upper plate. In his postulated model, the observed and inferred tectonic displace- ments resulted primarily from (1) 'relative seaward displacement and uplift of the frontal end of the thrust block along the primary fault and subsidiary reverse faults, such as those on Montague Island, and (2) simultaneous elastic hori- zontal extension, leading to sub- sidence, behind the overthrust block. The concept of a primary low- angle thrust, with the landmass moving relatively toward the Gulf of Alaska, fits most of the known geologic, geodetic, and seismo- logic facts. Stauder and Bollinger (1966) have shown that focal- mechanism solutions of the main shock and numerous aftershocks based on both P and 8 waves favor 13 a low-angle thrust. These same writers, and Savage and Hastie (1966), show that the observed vertical displacements in the major zones of deformation are in reasonably close agreement with the theoretical displacements ob- tained by applying dislocation theory to a low-angle or horizon- tal-thrust model. The low-angle thrust model does not fit all the data, however. For example, Press and Jackson (1965) and Harding and Alger- missen (1969) present alternative interpretations of the seismologic data that favor a steeply dipping fault, rather than a thrust. Savage and Hastie (1966) have shown that the theoretical surface dis- placements from such a model di- verge considerably from the obser- vations, and they point out that the surface-wave fault-plane data cited by Press and Jackson in sup- port of a steep fault would apply equally well to a low-angle fault because rupture propagation was along the null axis. However, P- and S-wave solutions of the main shock suggest to Harding and Al- germissen movement on a steep plane. Von Huene and others (1967), too, present oceanographic evidence from the Gulf of Alaska and the Aleutian Trench which they interpret to preclude over- thrusting of the continental margin. There appears to be no unam- biguous explanation of the me- chanism of the Alaska earthquake. All major arc-related earthquakes, such as this one, are difficult to study because much of the dis- placement field is invariably sub- marine; data on earthquakes with offshore epicenters cannot be ob- tained as readily as for those cen- tered on land. It can be hoped that better seismograph records of long-period motions, together with 14 continuing precise geodetic meas- urements that would give evidence of the strain accumulations and deformations on land, will permit ALASKA EARTHQUAKE, MARCH 27, 1964 less ambiguous interpretations of the causes of future Alaska earth- quakes. These data would require new techniques for determining subsea displacements and the hy- pocentral depths and first motions of offshore earthquakes in are en- vironments. EFFECTS ON THE PHYSICAL ENVIRONMENT The shaking and land deforma- tions had profound and lasting effects on the geologic, hydrologic, and oceanographic environments of a large part of south-central Alaska and, to a lesser extent, of an enormously greater area (fig. 1). These effects in turn had im- mediate and drastic effects on man and manmade structures. The var- ious categories of effects, which were responsible for all the deaths and destruction, are discussed in succeeding paragraphs. Many oth- er effects, such as those on the bird, animal, fish, and shellfish populations and their habitats, are not described here, though they were of outstanding importance to science and to the economy of Alaska. GEOLOGIC EFFECTS DOWNSLOPE MASS MOVEMENTS Of the many downslope mass movements during the earthquake, only four kinds provided much new knowledge about their char- acter and origins. These were (1) the enormous rockslide avalanches on some glaciers, (2) the disas- trous subaqueous slides from lake- shores and sea coasts, (3) the near-horizontal movement of vi- bration-mobilized soil, and (4) the giant translatory slides in sensitive clay at Anchorage. Earthquakes have long been known to cause landslides and rock or snow avalanches, but they are generally subordinate to other more usual causes such as gravity interacting with water or ice (Varnes, 1958). It is not surpris- ing that a great earthquake in a rugged land like south-central Alaska should bring down thou- sands of landslides and avalanches in the mountains and many sub- aqueous slides in the deep lakes and fiords. Property damage from slides in the mountains was generally lim- ited to roads and railroads. Rock- slides contributed to only one known death. At Cape Saint ' Elias, a coastguardsman, seriously injured by a large rockfall, was later drowned by waves (Plafker and others, 1969). Several writers have attributed the relatively small amount of damage done by avalanches and slides to the sparse population in the mountains. That the rockslides were unprecedented in size and number in recent centuries is dem- onstrated by the absence of similar deposits of debris on most glaciers before the 1984 event. Large-scale slides triggered by earthquakes doubtless do present a serious haz- ard in the mountainous regions of Alaska where steep, unstable slopes are present. With a few outstanding excep- tions, most of the slides and ava- lanches were comparatively simple well-known types and, because they caused little physical dam- age, they received little attention by investigators. The landslides along the Patton Bay and Hanning Bay faults on Montague Island (Plafker, 1967) are of interest chiefly because they are related to the only known earthquake-caused surface faults. Although their study added little to general knowledge of landslide processes, Plafker (1967) has noted that, by their very nature, "By far the greatest damage done by slides and avalanches was along the highway and rail net, south and east of Anchorage." active thrust faults tend to con- ceal their traces automatically by initiating linear zones of land- slides. Debris slides and rotational slumps developed in many places in and near Anchorage (Hansen, 1965), but they did far less dam- age and were less important sci- entifically than the gigantic trans- latory slides discussed separately below. Slides and slumps on steep slopes near Whittier (Kachadoor- ian, 1965), Seward (Lemke, 1967), and Homer (Waller, 19662) also did little damage as com- pared to submarine slides, waves, and subsidence. Many landslides occurred on the Kodiak island group in a great variety of geologic settings (Plaf- ker and Kachadoorian, 1966), but aside from temporarily blocking a few roads, they did no significant damage. By far the greatest damage done by slides and avalanches was along the highway and rail net, south and east of Anchorage. The plotted distribution of these fea- tures (Kachadoorian, 1968; Mc- Culloch and Bonilla, 1970) shows how widespread and numerous they were along the roads and railroads. This distribution prob- ably represents fairly well the dis- tribution of downslope mass movements throughout the earth- quake-shaken area, with some al- lowance for the fact that man- made cuts and fills tend to diminish slope stability, hence to increase the number of slides. ROCKSLIDE AVALANCHES Glaciers and snowflelds cover more than 20 percent of the land area that was shaken violently. Al- most 2,000 avalanches and snow slides were seen on postearth- quake aerial photographs exam- ined by Hackman (1965). Most of these he suspected were caused by the earthquake but as Post (1967) "* * * the avalanches initially descended very steep slopes and attained high veloci- ties. * * * These features * * * help substantiate the hypothesis that some large rock avalanches travel on cushions of compressed air." and several others point out, none of these snow and ice avalanches were large enough to materially affect any glacier's regime. As compared with slides of snow and ice, rockslide avalanches were fewer but much larger. The most thoroughly studied of these is on Sherman Glacier in the Chu- gach Mountains, 20 miles east of Cordova. There, an enormous mass of rock and some snow and ice fell from two peaks, traveled at high speed, and spread out over half of the glacier's ablation area (Shreve, 1966; Post, 1967; Plat- ker, 1968). The effects of such de- posits on glacier regimes have yet to be fully assessed, but reduction in ice ablation sufficient to favor positive annual mass balances has already been measured. A future modest advance of the Sherman Glacier's terminus can be expected. Various investigations show that the Sherman and other ava- lanches tend to have certain com- mon characteristics: (a) the areas were cliffs currently under- going glacial erosion; (b) the un- stable rock available for move- ment was hundreds of thousands of cubic yards in volume; (c) the avalanches initially descended very steep slopes and attained high velocities; (d) the rock debris spread out over surficial features of the glacier surfaces without greatly modifying them; and (e) the gradients of the avalanches on the glacier surface were very low, yet the material traveled very long distances (Post, 1967). These features together help substan- tiate the hypothesis that some large rock avalanches travel on 16 cushions - of - compressed _ air (Shreve, 1959, 1966b, 1968; Cran- dell and Fahnestock, 1965). HORIZONTAL MOVEMENTS OF MOBILIZED SOIL The movements of mobilized water-saturated soil toward top- ographic depressions deserve spe- cial mention. These movements took place throughout the strongly shaken part of Alaska and were among the major causes of ground fractures along river banks, deltas, and elsewhere. They were best seen and recorded along the highway and railroad systems and were major sources of damage to both (Kachadoorian, 1968; Mc- Culloch and Bonilla, 1970). Else- where in thinly populated regions like the Martin and Bering River area (Tuthill and Laird, 1966), lateral spreading did less damage but was nevertheless an important geomorphic process. In detailed studies of earthquake damage to the Alaska Railroad, McCulloch and Bonilla (1970) ob- served that ordinary rotational slumps were surprisingly rare and that the elastic response of uncon- solidated sediment was a less im- portant source of damage than were near-horizontal - displace- ments or "landspreading." This phenomenon has been observed in studies of other great earthquakes. McCulloch and Bonilla describe the distension that occurs within the sediments and note that land- spreading takes place on flat or nearly flat ground; thus they dif- ferentiate from landsliding, which connotes downslope movement. Along the railroad, ground fis- sures, loss of bearing strength, and other effects all took their toll ; but in terms of dollars lost, damage caused by landspreading was sec- ond only to the loss of terminal facilities at Whittier and Seward caused by submarine slides, waves, and fire (Kachadoorian, 1965; ALASKA EARTHQUAKE, MARCH 27, 1964 Lemke, 1967). Water-laid satu- rated sediments responded to the earthquake's vibrations by mobil- izing and moving laterally toward free topographic faces that ranged in size from small drainage ditches to wide valleys. The spreading of the mobilized sediments generated stress in their frozen surfaces and caused ground cracking that tore apart railroad tracks and high- way pavements. In addition, streamward spreading of the mo- bilized sediments compressed or skewed numerous bridges by streamward movements of banks. Even deeply driven piles moved toward stream centers, and there was a tendency toward compres- sion and uplift beneath some bridges. Many of the movements took place in areas where surfaces were nearly flat. Some extended as much as a quarter of a mile back from the topographic depression and offset rail lines or other linear fea- tures. McCulloch and Bonilla con- clude that the tendency toward mobilization of sediments should be considered in design of struc- tures in earthquake-prone areas. They suggest that it might be mini- mized by eliminating strong sur- face irregularities and linear fea- tures insofar as possible; skewing of bridges might be reduced by placing crossings at right angles to streambanks. SUBAQUEOUS SLIDES Subaqueous slides, and gigantic local waves that were closely re- lated to them in time and origin, caused high loss of life and prop- erty. A very few similar slides and their associated waves have been known from other earthquakes, but none had received much study. Throughout the earthquake- shaken area, steep-fronted deltas collapsed into many of the deeper lakes. The new fronts were gen- erally steeper and less stable than the old ones (Tuthill and Laird, 1966; Ferrians, 1966; Lemke, 1967). Except on Kenai Lake (McCulloch, 1966), none of these slides did much damage, and they were not studied intensively. The several slides along the shores of Kenai Lake yielded more informa- tion on the mechanics of sliding and the distribution of resultant debris than was available for the seacoast slides. McCulloch (1966) found that sliding removed the protruding parts of deltas-often the youngest and least consolidated parts-and steepened the delta fronts. He suggests that protrud- ing portions should be the least stable, for they contain the most mass bounded by the shortest pos- sible failure surface. Fathograms show that large slides spread for thousands of feet over the hori- zontal lake floor and that some of the debris moved so rapidly that it pushed water waves ahead of it and up on the opposite shores. Because of the presence of coastal communities, submarine slides in the fiords of Prince Wil- liam Sound and along the south coast of the Kenai Peninsula were far more destructive than those on lakes. The most disastrous ones were at Valdez (Coulter and Mig- liaccio, 1966), Seward (Lemke, 1967), and Whittier (Kachadoo- rian, 1965), but there were also" slides at Homer on Cook Inlet (Waller, 19662) and at many other inhabited places. Some of these, and their associated waves, did more damage in proportion to the size of the communities affected than did the better known ones at Seward and Valdez (Plafker and Mayo, 1965; Plafker and others, 1969). In addition to those known to be related to submarine slides, there were numerous destructive waves of unknown origin through- out much of Prince William Sound. Some of the unexplained waves may have been related to unidentified submarine slides, but some are believed to have been generated by permanent horizontal shifts of the land relative to partly or wholly confined bodies of water (Plafker, 1969; Plafker and others, 1969). How much of the sliding was caused by direct pro- longed vibration and how much by the southeasterly shift of the land- mass during the earthquake is unknown. It seems probable, how- ever, that vibration was the pri- mary cause of most of it. All the subaqueous slides that were studied in any detail left new slopes nearly or quite as steep as the preearthquake ones, some even steeper. This is the most significant and ominous finding from the in- vestigations of these features, for it means that the delta fronts are still only marginally stable and hence are subject to renewed slid- ing, triggered by future earth- quakes. The lesson is clear-any steep-faced delta of fine to moder- ately coarse materials in deep water presents inherent dangers of future offshore slides and destruc- tive waves, whether or not it has slid in the past. One somewhat unexpected result of the offshore slides, observed on LESSONS AND CONCLUSIONS Kenai Lake and at Valdez and Whittier, may well have occurred on other narrow lakes or fiords: the wide and rapid spread of slide debris on the bottom. Some of the debris at Kenai Lake crossed the lake, pushed water ahead of it, and caused wave runups on the far shores (McCulloch, 1966). This feature means that, under some conditions at least, the shore op- posite a steep-faced delta may be almost as poor a place for buildings or anchorages as is the delta itself. In summary, the 1964 earth- quake showed that any deep-water delta, such as those in the fiords and many lakes of south-central Alaska, may produce subaqueous slides and associated destructive waves if shaken by a severe earth- quake. Such deltas commonly con- tain much sand or finer grained material, are saturated with water, and have steep fronts; hence they are apt to have very low stability under dynamic conditions. TRANSLATORY LANDSLIDES IN ANCHORAGE All the highly destructive land- slides in the built-up parts of An- chorage moved chiefly by transla- tion rather than rotation-that is, they moved laterally on nearly horizontal slip surfaces, following drastic loss of strength in an al- 17 ready weak layer of sensitive clay. The translatory slides at Anchor- age ranged from block glides, in which the slide mass remained more or less intact, to those that are best classed as failures by lat- eral spreading (Varnes, 1958). Translatory slides, caused by earthquakes or other agencies, are uncommon, but they have long been known, and studied to some extent, in Scandinavia, Chile, and the United States (Hansen, 1965). The Anchorage slides of 1964, however, promise to become a clas- sic reference point in the scientific and engineering literature on near- horizontal mass movement of ma- terial. They had many novel as- pects, and, because facts were needed for far-reaching decisions on the reconstruction of important parts of a thriving city, the An- chorage translatory slides prob- ably received more study by soils engineers and geologists than any comparable group of landslides in history. Several million dollars was spent by the Corps of Engineers in intensive soils studies of all the Anchorage slides: (1) to de- termine - where - reconstruction should be permitted, (2) to build a gigantic stabilizing buttress in the midst of downtown An- chorage, and (3) to experiment "All the highly destructive landslides in the built-up parts of Anchorage moved chiefly by translation rather than rotation-that is, they moved laterally on nearly horizontal slip surfaces, following drastic loss of strength in an already weak layer of sensitive clay." 18 with explosive and - electro- osmotic methods of stabilizing the great slide at Turnagain Heights. The slides at Anchor- age have also sparked other studies of the stability of slopes in sensitive clays, particularly under dynamic conditions. All the Anchorage slides in- volved a hitherto obscure but now famous geologic formation- the Bootlegger Cove Clay of Pleistocene age (Miller and Dobrovolny, 1959). This deposit of glacial estuarine-marine origin underlies much of Anchorage; it is overlain by outwash gravel. All the destructive slides oc- curred where the Bootlegger Cove Clay crops out along steep bluffs. The formation is comprised largely of clay and silt, with a few thin, discontinuous lenses of sand. The middle part of the formation contains zones char- acterized by low shear strength, high water content, and high sensitivity ; these failed under the earthquake's vibrations. The most thorough report on the geology of the Anchorage slides, as distinct from the soils engineering aspects, is that by Hansen in which he recon- structed the highly complex Turn- again slide by maps and cross sections (Hansen, 1965, pls. 1, 2). Many other reports on the mechanics of the Anchorage slides or on theoretical and ex- perimental work engendered by the Anchorage experience have already appeared in the civil engineering literature (Shannon and Wilson, Inc., 1964; Long and George, 19672, b; Seed and Wilson, 1967), and more will appear in the future. As described by Hansen (1965) earthquake vibrations reduced the shear-strength of saturated sensitive zones in the clay. A prismatic block of earth moved ALASKA EARTHQUAKE, MARCH 27, 1964 laterally on a nearly horizontal surface toward a free face, or bluff. Tension fractures formed at the head of the slide and al- lowed collapse of a wedge-shaped mass, or graben. Pressure ridges were formed at the toe of the slide block. In complex slides, and with continued shaking, the process was repeated so that slice after slice moved forward toward or beyond the former bluff face. Seed and Wilson (1967) agree in most respects with Hansen's view of the mechanics of the An- chorage slides. They are much more inclined, however, to ascribe the initial translatory motion to liquefaction of layers or lenses of sand in the clay than to weakening of the clay itself. Seed has found by experiment with modified tri- axial shear devices that laboratory- reconstructed sand, similar to that in the Bootlegger Cove Clay, lique- fies and loses all its shear strength with far fewer vibratory pulses than are required to liquefy the clay. He is doubtlessly correct as to the initiating mechanism, but there is no question that drastic weakening of the clay contributed to the lateral movements once they had begun. Even under static con- ditions prior to the earthquake, the bluffline at Turnagain Heights was being undermined at its foot in a continuous zone of clay slumps and liquefied-clay mudflows. Large-scale field tests were made at Turnagain Heights to determine if remodeling by blasting or treat- ment by electro-osmosis might add to the strength of the jumbled mass of clay that slid seaward during the 1964 earthquake. Neither method produced very promising results, but when the tests were abandoned the Corps of Engineers and its consultants had determined that the landslide material along Knik Arm had naturally regained all its preearthquake strength. The Corps concluded therefore that the new slopes in the Turnagain area now form a natural buttress to the undisturbed bluff behind the slide that should withstand a future earthquake similar to that of 1964, provided the buttress toe is pro- tected against erosion. In 1969 there were no plans for such ero- sion protection. The greatest unanswered ques- tion about the Anchorage transla- tory slides is whether they will recur in the event of another great earthquake, and if so, what can be done to prevent them. There is abundant evidence that repeated similar slides, some in the same places, have been triggered by ear- lier earthquakes or by other causes (Miller and Dobrovolny, 1959; Hansen, 1965; McCulloch and Bo- nilla, 1970). There is also every reason to suppose that new slides will develop if and when another severe earthquake occurs. With present knowledge, the most prac- tical means of avoiding or ameli- orating future translatory slides would seem to be to reduce the slopes on bluffs, to avoid loading the upper parts of slopes or bluffs, or to construct gigantic earth but- tresses like that at the Fourth Ave- nue slide. Other means of slide pre- vention may be developed in the future. Meanwhile, the U.S. Geo- logical Survey, in cooperation with Anchorage Borough authorities, is preparing detailed maps that will show, among other things, the outcrops of the Bootlegger Cove Clay and the distribution of steep slopes (Dobrovolny and Schmoll, 1968). Such maps should be useful to borough and city officials in de- _ termining the general areas where slides are most likely to occur. Very detailed investigations will, of course, be necessary at any spe- cific site in order to determine the soil conditions and to design cor- rective or preventive measures. GROUND FISSURES Ground fissures, also called cracks or fractures by various authors, are formed by nearly all severe earthquakes and by some smaller ones. Possibly more re- sulted from the 1964 earthquake than from any previously recorded earthquake. Certainly they were more noticeable and more in- tensely studied, especially by means of aerial photographs. The ground surface was frozen in nearly all of the earthquake-af- fected area; this condition not only resulted in more fissures but favored their preservation long enough to permit observa- tion, photographing, and map- ping. General distribution of fissured ground throughout the earth- quake-affected area is shown by Plafker and others (1969). Only a very few of the fissures that developed have been mapped, but good examples of their patterns, character, and geologic settings are shown in maps of the Kenai Lake area (McCulloch, 1966) ; along the railroad and highway nets (Kachadoorian, 1968; McCul- loch and Bonilla, 1970) ; at Valdez (Coulter and Migliaccio, 1966) ; at Anchorage (Hansen, 1965; Engineering Geology Evaluation Group, 1964); at Seward (Lem- ke, 196%); and elsewhere. In addition, Ferrians (1966) and Tuthill and Laird (1966) made detailed studies of the fissures and associated landforms in the Copper River Basin and Martin- Bearing Rivers areas. The very extensive ground breakage on the Kenai Lowland was mapped by Foster and Karlstrom (1967). Ground fissures, many marked by copious emissions of muddy or sandy water or by minor local collapse features, were widespread within about 100 miles of the epi- LESSONS AND CONCLUSIONS center, but they were noted as far as 450 miles away (fig. 1). Flood plains, the tops and fronts of deltas, toes of alluvial fans, low terraces with steep fronts, and lake margins were among the geomorphic features most affected. Fissures varied greatly in length but some indi- vidual ones could be traced for thousands of feet. Some open fis- sures were several feet wide; many fissures opened and closed with the passage of seismic waves. Most ground fissures were nec- essarily studied only at the sur- face. Some fissures on the Kenai Lowland, however, and on Kodiak Island and elsewhere are known to have extended at least 20 to 25 feet beneath the surface, because coal, gravel, pumice, and other materials that exist at those depths were brought to the surface by spouting water (Foster and Karl- strom, 1967; Plafker and Kacha- doorian, 1967). Great quantities of water, mixed with varying amounts of sand and silt, were ejected as fountains or sheets of water from ground fis- sures in many places (Waller, 1966b). Most ejections came from linear fractures, but in flat-lying homogeneous sediments some came from point sources. Among the chief consequences of the ejections were local subsidence of the land surface and further cracking by removal of water and material from below. Geologically, most ground fis- sures were ephemeral features and, of themselves, left little perma- nent evidence of their presence. Cracked mats of peat, however, were still preserved in 1967, and clastic dikes formed by sand or mud injections may last for many years. Evidence of local subsidence caused by ejection of water and mud from fissures is somewhat more permanent also, as are a few 19 other minor landforms that result- ed from them. Several unusual geologic-geomorphic features, such as mud-vent deposits, foun- tain craters, subsidence craters, and snow cones, are described by Tuthill and Laird (1966) in the Martin-Bering Rivers area. Most of these are related to the pumping of water and sediments from ground fissures. Similar deposits were left by mud spouts or by melting of snow avalanches in many parts of the earthquake affected area (Waller, 19662, b; Lemke, 1967; McCulloch and Bo- nilla, 1970). All these features are of some scientific interest, but they are ephemeral and are not likely to be preserved in the geologic rec- ord unless they are soon buried by other deposits. Widespread damage resulted from fissures, though on the whole it was minor as compared to that from other sources. Ground fis- sures disrupted buried utility lines and did other damage in Anchor- age (Hansen, 1965; Burton, in Logan, 1967; McCulloch and Bon- illa, 1970). At Seward, remaining parts of the fan-delta whose front slid into Resurrection Bay were severely cracked and left unstable. Fissures also damaged many homes and roads in Forest Acres outside of Seward (Lemke, 1967). At Valdez, 40 percent of the homes and most commercial buildings that were not wrecked by the giant submarine slide were seriously damaged by earth fissures that de- stroyed their structural integrity, broke pipes, and pumped immense quantities of sand and silt into their lower parts (Coulter and Migliaccio, 1966). At the Eklutna Lake powerplant, numerous cracks, some of them damaging, developed in both natural and ar- tificially compacted - sediments (Logan, 1967). At the Cordova airport, the foundation of the 20 FAA office building was split by a ground fissure, and underground utility lines were broken in so many places that most had to be replaced (Eckel, 1967). All fissures were directly related to local geologic conditions. Many of them formed in thick coarse- grained unconsolidated deposits, where the water table was close to the surface and where the topmost layers were frozen, hence brittle. Many others, as on the mudflats of the Copper River Delta, Con- troller Bay, and near Portage, de- veloped in fine-grained deposits. Artificial fills were very suscep- tible. Many cracks followed back- filled utility trenches. Many high- way fills compacted and cracked marginally. Few fissures formed in well-drained surficial deposits, and hardly any in bedrock or in permafrost. Only on the Kenai Lowland was there any suggestion of tectonic control of the fracture patterns (other, of course, than the regional tectonic factors that controlled the general distribution of all the earthquake's effects). On the low- land, and to some extent in the Chugach Mountains north of it, Foster and Karlstrom (1967) noted an alinement of ground fractures that suggested to them that the fractures might reflect earthquake - caused _ movement along hypothetical faults in the underlying bedrock. Seismic vibration was the ulti- mate cause of virtually all the fis- sures. Some were formed directly by the shaking, others by differen- tial horizontal or vertical compac- tion, others by local subsidence. Many formed near slopes or sur- face irregularities when underly- ing materials liquefied or, mobi- lized by vibration, moved toward topographic depressions. The best known examples perhaps are the ground fractures back of the ALASKA EARTHQUAKE, MARCH 27, 1964 translatory slides at Anchorage (Hansen, 1965), the extensive fis- sures on the Resurrection River Delta near Seward (Lemke, 1967), and the thousands of fissures along the rail and road systems (Kacha- doorian, 1968; McCulloch and Bonilla, 1970). Unconfined slopes were not essential to the formation of fissures, however; many formed on flat unbroken surfaces such as that of the Copper River Delta. As a possible explanation for the origin of a certain type of ground fissure that formed in the Copper River Basin in flat-lying areas where there were no free faces to- ward which the materials could move, Ferrians (1966) suggests that surface waves flexing the layer of frozen surficial materials, which was in a state of tension, caused the initial cracking of the surface. The passing surface waves subjected the saturated sediments beneath the seasonal frost to repeated com- pression and dilation in the hori- zontal direction; consequently, large quantities of water and silt- and sand-sized material were ejected from the cracks, and sedi- ment particles were rearranged. The net result of these forces was horizontal compaction, which caused the formation of numerous ground cracks that extended for great distances and formed a sys- tematic reticulate pattern in the flood plains of some of the larger rivers. Permanently frozen ground, be- cause it behaves dynamically like bedrock, had few if any fissures ; in some places, however, where water- bearing layers were perched be- tween the permafrost and the seasonal frost layer at the ground surface, there was extensive crack- ing (Ferrians, 1966). Except in a general way, the oc- currence and distribution of ground fissures would be difficult to predict for any given earth- "All fissures were directly related to local geologic conditions. Many of them formed in thick coarse-grained unconsolidated deposits, where the water table was close to the surface and where the topmost layers were frozen, hence brittle." quake. The conditions under which they develop are now well known, and it is possible to identify bodies of sediments that are susceptible to fissuring during a large earth- quake of long duration (Mc- Culloch and Bonilla, 1970). Formation of individual fissures or fissure systems is so dependent on local geologic and ground- water conditions, however, that highly detailed knowledge of local surface, subsurface, and subaerial conditions would be required for precise predictions. CONSOLIDATION SUBSIDENCE Seismic vibration caused con- solidation of loose granular materials in many places. Rear- rangement of constituent particles, aided by ejection of interstitial water through waterspouts or mud spouts, caused compaction and local differential subsidence of the surface. Lateral spreading, too, caused lowering of surface levels in places. In coastal areas where local subsidence was superimposed on regional tectonic subsidence, as on Homer Spit (Grants and others, 1964; Waller, 19662), Kodiak Island (Plafker and Kachadoorian, 1966), and near the head of Turnagain Arm (Plafker and others, 1969), for example, the likelihood of destructive flooding was heightened. The intake and spillway at Eklutna Lake, which feeds the Bureau of Reclamation's Eklutna hydroelectric plant, provided spe- cial instances of damage by con- solidation subsidence. The concrete intake structure was cracked when the lake sediments beneath it com- pacted and subsided. As a direct result, about 2,000 cubic yards of sand and rock passed through the broken intake and into the main tunnel. The concrete spillway gate at Eklutna Dam was also severely cracked, but not until long after the earthquake. As described by Logan (1967), saturated alluvium below the frozen surface layer subsided as it was consolidated by the earthquake and left a void be- low the frozen layer. Later as thawing progressed, the frozen material collapsed into the void, breaking the gate structure. LESSONS AND CONCLUSIONS SHORE PROCESSES Thousands of miles of coastlines were modified by the earthquake, partly by transitory but highly destructive water waves and, more generally and much more permanently, by uplift or subsid- ence. All but a few reports in this series describe such damage, particularly at inhabited places along the coast. There were, how- ever, comparatively few studies of the coastal processes themselves. The changes in beach-forming processes at Homer Spit, because of their economic importance, were investigated in detail by Stanley (in Waller, 1966a) and by Gronewald and Duncan (1966). Similarly, but for scientific reasons only, stream mouths and beach changes caused by sudden uplift on Montague Island were studied by Kirkby and Kirkby ( 1969), and the shallow deltaic sediments off the mouth of the Copper River were investigated by Reimnitz and Marshall (1965). The Geological Survey itself made few detailed studies of shore processes (McCul- loch, 1966; Waller, 19662, b) but, with support from the Committee on the Alaska Earthquake, Na- tional Academy of Sciences, the Survey persuaded K. W. Stanley (1968) to prepare a general report on this subject based on his own observations and on summaries of the sparse published work of others. Periodic detailed observa- tions over many years would be needed to provide a more complete understanding of the many geol- ogic and biologic adjustments still in progress along the coasts. All along the coasts, the shore- line began immediately to conform to new relative sea levels. Subsided beaches moved shoreward, build- ing new berms and slopes. Rel- atively higher tides attacked receding blufflines. Faster erosion 21 locally scoured source areas for beach nourishment, and thus pro- vided more material to replenish losses caused by - subsidence. Streams whose mouths were drowned began to aggrade their beds. In the uplifted areas, on the other hand, beaches were stranded above tidewater and some surf-cut platforms became terraces or benches. Wave erosion of bluffs was stopped, and bluff recession was slowed to the rate set by sub- aerial processes. Uplift speeded streamflow, with consequent en- trenchment and increased sedi- ment load. New beaches began to form below the abandoned ones. Within the span of a few minutes, the earthquake caused changes in coastal conditions and processes that normally require centuries. In the subsided areas it also wrought changes that are usually associated only with rare severe storms. HYDROLOGIC EFFECTS The hydrologic regimen other than glaciers was studied by fewer investigators than were most other phenomena. Nevertheless, these studies produced much new knowl- edge. Hydrologic effects possibly were more extensive than any pre- viously observed on the North American continent ; quite certain- ly they were the greatest ever re- corded, for fluctuations of surface and ground-water level were meas- ured not only throughout most of North America but in many other parts of the world. GLACIERS Glaciers cover about 20 percent of the land area that was violently shaken by the earthquake. Numer- ous glaciologists and geomorphol- ogists, particularly those who 22, had continuing interests in the life histories of specific glaciers, were eager to study the effects of the earthquake. But aside from the great rock avalanches, surprising- ly few effects were observed within the first several years. Studies added weight to the theory that some rock avalanches descend on a cushion of com- pressed air (Shreve, 1959, 1966b, 1968). It is also quite clear that the avalanche debris will drasti- cally alter the regimens of the glaciers by insulating the ice sur- faces on which they came to rest. Aside from these facts, most of the glacial studies had indecisive re- sults. There were several enormous rockslide avalanches, but no large snow or ice avalanches, and rela- tively few small ones occurred on glaciers, despite the fact that avalanche hazard was already high at the time of the earthquake (Post, 1967). There were no signif- icant changes in the calving of ice- bergs from tidewater glaciers, al- though some glacier fronts were shattered and glacial ico was thrown out onto ice-covered lakes that - fronted them _ (Waller, 1966b). Few changes occurred in glacial streams or ice-dammed lakes. There was no evidence of dynamic response to earthquake shaking or to avalanche loading. The glaciers' response to tectonic uplift, subsidence, or lateral movement was too small to detect, at least during the few years that have been available for study. By far the most significant con- clusion reached by the glaciologists was a refutation of Tarr and Mar- tin's theory (1912) that earth- quakes are likely to initiate rapid advances or surges in glaciers by triggering extraordinary numbers of avalanches in the glaciers' ali- mentation area. Post (1967), on the basis of long-continued studies, thinks that the surges actually ALASKA EARTHQUAKE, MARCH 27, 1964 bear no relation to earthquakes. Many such surges involve sudden advances of ice from the upper to the lower parts of glaciers, with little or no advances of the termini. Knowledge that surges did not immediately result from this earthquake does not remove the danger that sudden advances of glaciers from other causes may in- crease flood hazards to places like Valdez (Coulter and Migliaccio, 1966). ICE BREAKAGE In Alaska and nearby Canada, ice was broken on lakes, streams, and bays over an area of more than 100,000 square miles (fig. 1). The cracked ice afforded an easily ob- served measure of the geographic spread of the earthquake's effects, but otherwise it had minimal sig- nificance (Waller, 19662, b; Plaf- ker and others, 1969). Breakage did little physical damage except to a few beaver houses; in fact, the ice cover on many bodies of water probably diminished the in- tensity of destructive wave action. Some of the cracking was caused directly by seismic vibra- tions, but much more resulted from long-continued seiches, as on Portage Lake (Waller, 1966b) and on Kenai Lake (McCulloch, 1966). Horizontal tectonic move- ments of the landmass may have been a factor in causing ice break- age in some places. Cracking of ice in lakes and fiords was doubt- lessly initiated by subaqueous slides off delta fronts and by the local waves engendered by the slides. Still lacking is a firm ex- planation as to why the ice on a few lakes and stream segments, even near the earthquake epicenter, was unbroken. Possibly the earth- quake vibrations did not coincide with the natural periods of these water bodies, so that there was no buildup of resonance. GROUND WATER The surging of water in wells and the temporary or long-lasting changes in water levels as a result of earthquakes have possibly been known ever since man has had wells. Within Alaska these effects from the 1964 earthquake were not much different from those ob- served in the past, though their magnitudes and durations may have been greater. Over most of the violently shaken area in south- central Alaska, ejection of vast quantities of sediment-laden water through ground fractures lead in places to subsidence of the water- bearing sediments. As described by Waller (19664, b), the water in many shallow wells surged, with or- without - permanent changes in level, pump systems failed, and water became turbid. In some of the subsided areas, coastal salt water encroached into some wells Most of these effects were temporary, but some were permanent or semipermanent. Many artesian wells were also greatly affected. In several of these wells, at Anchorage for example, artesian-pressure levels dropped as much as 15 feet, either perma- nently or for several months. Per- haps this change was caused by porosity-increasing grain rear- rangements in the aquifers, or by material displacements that per- mitted freer discharge of water at submarine exposures of the aqui- fers. Significantly, all such wells were in areas of known or inferred regional horizontal extension and vertical subsidence where porosity - increasing changes must have oc- curred in the aquifers (Plafker, 1969). The observations of the earth- quake's effects on ground water outside Alaska were of tremen- dous scientific significance. Other earthquakes have caused fluctua- tions or disturbances in the ground-water regime at far-dis- tant points, but never before have such effects been noted at as many recording stations and over the en- tire world (Vorhis, 1967; McGarr and Vorhis, 1968). "Hydroseisms" (a word coined by Vorhis to in- clude all seismically induced wa- ter-level fluctuations other than tsunamis) were recorded in more than 700 water wells in Europe, Asia, Africa and Australia, and in all but four of the 50 States. Most records showed only brief fluctuation of the water level, but the fact that about a fourth of them showed either a lasting rise or decline in water level suggests that the earthquake caused a re- distribution of strain throughout North America. Especially sensi- tive well stations recorded both the surface seismic waves that traveled the long way and those that traveled the short way around the globe. Some wells as far away as Georgia were muddied. SURFACE WATER Research into the earthquake's effects on surface waters yielded even more significant information than studies related to ground wa- ter. Within Alaska the effects were widespread, though they taught little that was new (Waller, 1966 a, b). Seiches dewatered some lakes, fissures in streambeds and lakeshores caused water losses, re- gional tilting may have reduced the flow of some rivers, and land- slides or avalanches blocked or diverted some streams. Recording gages on streams measured seiches like those on lakes. Perhaps the most interesting side effect of local surface-water reaction to the earthquake was the realization that some large Alaskan lakes may be useful as giant tiltmeters for future vertical strain measure- ments (McCulloch, 1966; Hansen and others, 1966). LESSONS AND CONCLUSIONS The observations of the effects on surface waters outside Alaska also were scientifically illuminat- ing. The worldwide distribution of these effects was first reported by Vorhis (1967) ; later the find- ings were elaborated by McGarr and Vorhis (1968) to answer some of the theoretical questions that arose earlier. Seismic seiches caused by the Alaska earthquake were recorded at more than 850 gaging stations on lakes, ponds, and streams throughout North America and at four stations in Australia. The seiches are believed to be re- lated to the amplitude distribu- tion of short-period seismic sur- face waves, particularly those having periods that coincide with similar-length oscillation periods of certain bodies of water. They were concentrated in areas under- lain by thick soft sediments or where sediment thickness increases abruptly. Major tectonic features exerted a strong control; the Rocky Mountains, for example, provided a wave guide along which seiches were more numerous than to either side. Preliminary as they are, the findings of McGarr and Vorhis have far-reaching significance in the understanding of the world- wide amplitude distribution of short-period _ seismic - surface waves. Most importantly, McGarr and Vorhis (1968) have shown that records of seiches on surface- water bodies, as measured by the network of water-level recorders that is necessarily much denser than any seismograph network can be, are powerful potential tools in future studies of seis- mic waves and of earthquake intensities. Another lesson learned from the earthquake's effects on hydrology was that long-continued records from properly equipped observa- 283 tion wells and gaging stations are essential to proper interpretation of postearthquake observations. OCEANOGRAPHIC EFFECTS Violent waves of diverse kinds and origins wrought havoc along the shores of south-central and southeast Alaska and on the north- ern Pacific shores from British Columbia to California ; they also took most of the lives that were lost. Had the coast been more heavily populated or had the earth- quake struck at high tide, damage would have been even more exten- sive than it was. The terminology applied to earthquake-generated water waves differs among various authorities, but in this series a general distinc- tion is made between seismic sea waves, or tsunamis, and local waves. Local waves were gen- erated along the coast or in lakes and affected areas of limited ex- tent; they characteristically struck during or immediately after the earthquake. Seismic sea waves, or tsunamis, on the other hand, com- prised a train of long-period waves that spread rapidly over the entire Pacific Ocean and struck the Alas- kan coast, after shaking had sub- sided. Locally, seiches, caused by the to-and-fro sloshing of water in partly or wholly confined basins, complicated the overall wave pic- ture. Within Alaska, there were few instrumentally determined records of the waves, because all nearby tide gages were destroyed or in- capacitated. The nature of both seismic sea waves and local waves, therefore, was deduced from the accounts of eyewitnesses, from di- rect observations of wave effects on shores, and from indirect un- derwater investigations. The wave histories at specific communities, and descriptions of 24 their effects, are discussed in re- ports on Whittier (Kachadoorian, 1965) ; Valdez (Coulter and Mig- liaccio, 1966); Homer (Waller, 1966a) ; Kodiak (Kachadoorian and Plafker, 1967) ; and Seward (Lemke, 1967). Wave effects were also studied along most of the shores of Prince William Sound, along the south end of the Kenai Peninsula, and on the Kodiak island group (Plafker and Kachadoorian, 1966; and Plafker and others, 1969). Con- currently oceanographic studies of the effects of slides and waves were being studied in much of Prince William - Sound, - Resurrection Bay, and Ailiak Bay (G. A. Rus- nak, unpublished data). The history and significance of the seismic sea waves, both near the origin and throughout the Pacific, were investigated by Van Dorn (1964), among others. Though nec- essarily based in large part on a synthesis of facts collected by others shortly after the earth- quake, the exhaustive treatment of all the kinds of waves and of their effects on coastal engineering struc- tures by Wilson and Tgrum (1968) is the most comprehensive that has appeared. ALASKA EARTHQUAKE, MARCH 27, 1964 LOCAL WAVES Knowledge of the origin and im- portance of earthquake-induced local waves, hitherto very sparse, was greatly augmented by studies of the Alaska earthquake. One of the most striking characteristics of the waves was their localized and seemingly erratic distribution, though actually it was the distri- bution of the causative slides that was erratic, rather than the waves. Furthermore, the local waves struck during the earthquake, or immediately after it, and had gen- erally subsided long before the ar- rival of the train of seismic sea waves, or tsunamis. There is much evidence of the genetic relationship of the local waves to subaqueous slides. In general, this evidence consists of (1) wave-damage patterns that radiate from the vicinity of deltaic or morainal deposits, (2) presence of subaerial scarps or oversteep- ened near-shore slopes, and (3) bathymetric measurements that in- dicate removal of material from upper parts of slopes and deposi- tion of slide debris in deeper water. Many of the destructive local waves, however, cannot be attrib- uted with any assurance to sub- aqueous slides. Some formed in shallow - embayments or semi- enclosed basins, where slides are unlikely to have occurred. It seems possible that the horizontal dis- placement of the landmass may have been either a primary Or & contributing cause (Malloy, 1965; Plafker, 1969, and Plafker and others, 1969). Other factors that may have played a part are re- gional tilt, submarine faulting, and seismic vibrations, but none of these should have caused waves as large as some of those observed. Plafker (1969) has suggested that the long-period high-amplitude seiche waves recorded at Kenai Lake may have been caused pri- marily by horizontal shift of the lake basin rather than by regional tilt as originally suggested by Mc- Culloch (1966). u* * * violent local waves * * * generated directly or indirectly by the earthquake at many places through- out the affected area * * * were more destructive than any similar waves ever recorded from previous earthquakes." The origin of many of the local waves must remain in doubt, but it is known, (1) that violent local waves were generated directly or indirectly by the earthquake at many places throughout the af- fected area, (2) that, except for the giant waves of Lituya Bay (Miller, 1960), they were more de- structive than any similar waves ever recorded from previous earth- quakes, and (3) that a basis for predicting the recurrence of some of them exists. SEISMIC SEA WAVES The first of a train of seismic sea waves (tsunamis) struck the shores of Kodiak Island, the Kenai Peninsula, and Prince William Sound from 20 to 30 minutes after the earthquake. Succeeding waves, with periods ranging roughly from 1 to 114 hours, followed dur- ing the night-the highest waves of the series commonly striking around midnight near the time of high tide. These waves were gen- erally much lower in amplitude than the locally generated waves, and in some places resembled high fast-moving tides more than they did breaking waves. They flooded large areas and wrecked many ves- sels and shore installations, par- ticularly where the land had already subsided because of tec- tonic downdrop or compaction of sediments. Outside Alaska, the seismic sea waves were measured instrumen- tally at many stations around the Pacific, even as far away as Antarctica (Donn, 1964; Donn and Posmentier, 1964). The see- ond measurement ever recorded of the passage of a seismic sea wave in the open ocean was made near Wake Island (Van Dorn, 1964). The first such measurement, also made on the gage near Wake Is- land, recorded the tsunami from the March 9, 1957, earthquake in LESSONS AND CONCLUSIONS the Aleutian Trench (Van Dorn, 1959). The seismic sea waves were gen- erated on the Continental Shelf within the Gulf of Alaska. This was shown clearly by the arrival times of initial waves, the distri- bution of wave damage, and the orientation of damaged shorelines. Other evidence, such as tide-gage records outside the area affected by the earthquake, demonstrates conclusively that the violent up- ward tilt of an enormous segment of the sea floor provided the force that initiated the seismic sea waves and oriented the wave train. The waves thus began along the linear belt of maximum tectonic uplift that extends from Mon- tague Island to near Sitkalidak Island, southwest of Kodiak Is- land (Van Dorn, 1964; Spaeth and Berkman, 1965; Pararas- Carayannis, 1967; Plafker, 1969; Wilson and Tgrum, 1968). Most of the shallow Continental Shelf off the coast of south-central Alaska was involved in the up- ward tilting of the sea floor, which forced a great quantity of water to drain rapidly from the shelf 25 and into deeper water. Recon- struction of the source volume from available data on the area and amount of uplift suggests that the potential energy of the seismic sea waves was of the order of 2X10* ergs, or roughly 0.1 to 0.5 percent of the seismic energy re- leased by the earthquake (Plafker, 1969). The source area of a train of seismic sea waves and their orig- inating mechanisms were better defined for the Alaska earthquake of 1964 than for most other earth- quakes that have been studied. As Van Dorn says (1964), "Never be- fore has sufficient detailed knowl- edge been obtained on sea-floor motion, type of motion, and the deep-water spectrum offshore, to permit a convincing reconstruc- tion of the generating mecha- nism." Furthermore, the seismic sea waves generated by the Alaska earthquake largely confirmed em- pirical-statistical data used by oceanographers to relate the size of the source area and tsunami heights and periods to the energy released by the initiating earth- quake (Wilson and Tgrum, 1968). "The first of a train of seismic sea waves (tsunamis) struck the shores of Kodiak Island, the Kenai Peninsula, and Prince William Sound from 20 to 30 minutes after the earthquake. * * * They flooded large areas, and wrecked many vessels and shore installations, particularly where the land had already subsided because of tectonic downdrop or compaction of sediments." jib/é” PPP r 6 6 l///% Ww 26 MISCELLANEOUS EFFECTS The earthquake had many other effects of great economic, soci- ologic, and biologic importance. These are summarized briefly by Hansen and others (1966) and are treated at length by many writers. There remain a few effects, at least partly related to geology, that are worth noting here. AUDIBLE AND SUBAUDIBLE EARTHQUAKE SOUNDS Audible sounds that accompany or even precede the onset of an earthquake have been reported many times in history, but such sounds have never been instru- mentally recorded and seldom have they been scientifically authenti- cated. The Alaska earthquake of 1964 followed the pattern-nu- merous observers reported hearing sounds, but, so far as is known, no instrumental records were made of these sounds. On Kodiak Island, several wit- nesses heard a low-pitched rum- bling noise about 5 seconds before the initial tremors were felt. Many Kodiak people also heard deep rumbles just before some of the aftershocks were felt (Plafker and Kachadoorian, 1966). At Homer, too, and at Portage Lake near Turnagain Arm, some people heard rumbling sounds a few sec- onds before feeling the initial shock. They also heard sounds variously described as rumbling, cracking, and popping during the period of violent earth motion (Waller, 1966 a, b), as well as the windlike noise of rapidly swaying tree branches. Crackling sounds in the ground were heard at South Naknek, 350 miles southwest of the epicenter (Plafker and others, 1969). Observers at Valdez (Coul- ter and Migliaccio, 1965), in the Copper River Basin (Ferrians, ALASKA EARTHQUAKE, MARCH 27, 1964 1966), on the Kenai Peninsula, in Prince William Sound, and at many other places also heard sounds during the quake (Chance, 19662). That the Alaska earthquake pro- duced sounds audible to alert ob- servers over a wide area seems a well established fact, though the cause of the sounds has not been determined. In all probability there were many causes, operating at different places and at slightly different times. Cracking or bend- ing of trees, breaking of ice on water bodies or in glaciers, and ground fractures in frozen near- surface soils all probably made audible sounds. How much, if any, of the sound effects can be ascribed to deeper sources, such as breaking of rock along faults in depth or to crunching of sands and gravels as they were consolidated by vibra- tion or as they formed slides on land or under water, is unknown. It seems possible, however, that some of the sounds, particularly those that preceded recognizable ground vibrations, were caused by processes such as these. It also seems possible that the earthquake tremors, coupled to the overlying air envelope, caused audible vibra- tions. This explanation would apply particularly to the fast- moving, lower amplitude P waves that can often be heard but not felt. Although audible sound waves are not known to have been re- corded, subaudible sound waves were recorded. Waves of very low, subaudible frequencies were re- corded by the National Bureau of Standards at stations in Washing- ton, D.C., Boulder, Colo., and Bos- ton, Mass. These sound waves, gen- erated by the earthquake itself and by seismic waves as they passed through the earth, excited the at- mosphere. In addition, Rayleigh waves (surface seismic waves) that displaced the ground created subaudible sound waves that trav- eled upward, with amplification, to the ionosphere. The resultant oscillation of the ionosphere was detected by means of reflected ra- dio waves (Bolt, 1964; Davies and Baker, 1965; Leonard and Barnes, 1965; Smith, 1966; and Row, £19007). MAGNETIC EFFECTS A recording magnetometer in the city of Kodiak recorded sev- eral magnetic disturbances a little more than 1 hour before the earth- quake struck. Moore (1964) thinks that the magnetic events so re- corded may have resulted from piezo-magnetic effects of rocks un- dergoing a change in stress. He also suggests that magnetic moni- toring may provide a means of predicting major earthquakes in time to save lives and property. VISIBLE SURFACE WAVES As with audible sound waves, the passage of visible waves over the surface of the ground during strong earthquakes has been re- ported by many observers. The Alaska earthquake of 1964 was no exception to the general rule; many observers reported seeing ground waves, but their obser- vations were not substantiated instrumentally. On the Kodiak island group, surface waves reportedly were seen at Ouzinkie and Afognak. These waves, perhaps propagated in ground that had become semifluid with vibration, were estimated at about 30 feet in length and about 3 feet in height (Plafker and Kachadoorian, 1966). Many people reported seeing surface waves in various parts of the Copper River Basin. At a point 100 miles from the epicenter, the waves were said to be about 10 feet apart and 3 feet high. At 165 miles from the epicenter, they were reported as longer and lower, with lengths of 50 to 60 feet and heights of 18 to 20 inches (Fer- rians, 1966). Perhaps the most reliable ob- servation of surface-wave ampli- tudes was made by an experienced geologist at Valdez. As quoted by Coulter and Migliaccio (1966), the geologist noticed a 6-foot youth standing 410 feet away from him. As crests passed the youth, he appeared in full sight, with one trough between him and the ob- server. Passage of troughs caused him to sink partly out of sight. The observations indicate wave heights of 3 to 4 feet and lengths of sev- eral hundred feet. There is no question that many people saw, or thought they saw, waves on the ground surface in many places. Whether all the waves were real or imaginary, and if real, what caused them, must re- main subjects for speculation. PERMAFROST Because it was one of the few well-studied earthquakes that has affected perenially frozen ground, the 1964 Alaska earthquake added much to our knowledge of the re- action of frozen ground to seismic shock. Permafrost, or perennially frozen ground, has long been a perplexing and exasperating engi- neering problem in arctic and sub- arctic regions. The perennially frozen unconsolidated deposits affected by the 1964 quake behaved like solid rock and were far less susceptible to seismic vibration than were similar but unfrozen deposits. The seismic response of perma- frost was studied in detail in the Copper River Basin (Ferrians, 1966). In the basin, most fine- grained sediments are perennially frozen from depths as great as 200 feet to within 1 to 5 feet of the sur- LESSONS AND CONCLUSIONS face, except beneath cleared areas where the top of the permafrost is 10 to 20 feet deep. Coarse- grained deposits along the major streams and deposits close to large deep lakes generally are free of permafrost. There were no ground cracks and little or no vibration damage of any kind where permafrost ap- proaches the surface. Thus ice-rich perennially frozen ground appar- ently behaved much like bedrock in transmitting and reacting to earthquake - shocks. - However, perched ground water between permafrost and the seasonally frozen layer at the surface caused some fissuring and other evidences of vibration. CABLE BREAKS Several underwater cables were broken by the earthquake vibra- tions or by subaqueous slides. The only one broken in the heavily dev- astated area was the Federal Avia- tion Agency cable under Beluga Lake at Homer (Waller, 19662). This break was probably caused by vibration, for the lake is shal- low and there is no evidence of off- shore-slides. The Southeastern Alaska coaxial submarine cable was broken at a point 191% miles south of Skag- way, in Lynn Canal, near the mouth of the Katzehin River; a similar break occurred in this area as a result of the 1958 earthquake. The 1964 break occurred early on the morning of March 28 and was apparently caused by a submarine slide in silt that was triggered by the seismic sea wave (Lt. Col. Alexander A 1v a ra d o , USAF, written commun. to George Plaf- ker, May 1, 1964). Near Port Alberni, British Co- lumbia, the Commonwealth Pa- cific Communication Service cable from Port Alberni to Hawaii was ruptured. This break occurred 27 only 2 minutes after the onset of the earthquake and was evidently caused by seismic vibrations. The cables between Port Angeles, Washington, and Ketchikan and between Ketchikan and Sitka were unaffected (Comdr. H. G. Conerly, U.S. Coast and Geodetic Survey, oral commun. to George Plafker, May 1964). TUNNELS, MINES, AND DEEP WELLS One aspect of the earthquake's effects on manmade structures that deserves further study is the fact that no significant damage has been reported to underground openings in bedrock such as tun- nels, mines, and deep wells, al- though some rocks and earth were shaken loose in places. The Alaska Railroad tunnel near Whittier (McCulloch and Bonilla, 1970) and the coal mines in the Matanus- ka Valley (Plafker and others, 1969) were undamaged. The tun- nel and penstocks at the Eklutna hydroelectric project were dam- aged only by cobbles and boulders that were washed through the in- take structures (Logan, 1967). A. small longitudinal crack in the concrete floor of the Chugach Elec- trie Association tunnel between Cooper Lake and Kenai Lake is believed to have been caused by the earthquake (Fred O. Jones, oral commun., 1967). The collars of some drilled wells were displaced by vibration or by consolidation of adjacent soils, and a few water wells and one aban- doned exploratory oil well near Yakataga were sheared off. There are, however, no reports of dam- age to any wells that were more than a few hundred feet deep, such as the many oil and gas wells in and along Cook Inlet. In and near the landslide areas in Anchorage, most sewers and other under- ground utility lines were exten- 28 Slvely fractured or displaced (Bur- ton, in Logan, 1967 ; Hansen, 1965; Eckel, 1967; McCulloch and B0- nilla, 1970). Ground fissures also broke many buried pipelines in Seward (Lemke, 1967) and else- where. In Valdez, Coulter and Migliaccio (1966) were able to use the horizontal separation of water lines to measure the amount of lat- eral displacement back of the majin submarine slide. Elsewhere, pipe- ALASKA EARTHQUAKE, MARCH 27, lines that traversed unfissured ground received little or no damage. ARCHEOLOGIC REMAINS Regional and local subsidence of Kodiak Island, as elsewhere, re- sulted in increased erosion of some sediments along the shore. In a few places near Ouz1nk1e, erosion ex- posed rich accumulations of stone and bone artifacts mixed with 1964 bones of sea animals. The archeo- logic remains occur at two hori- zons, separated by dark soil. Ap- parently they belong to the Aleut or Koniag cultures, but some may be older (Chaffin, 1966). Else- where in the Kodiak group of is- lands, many coastal archeological sites in subsided areas were made inaccessible or were sub- jected to accelerated erosion (Plaf- ker and Kachadoorian, 1966). EARTHQUAKE EFFECTS, GEOLOGY AND DAMAGE The earthquake took 130 lives and caused more than $300 million in damage to manmade structures. Details are not recounted here, but an attempt is made to relate the TS % T //sfi 4 /“’..il,,;é i X 2 Uimy fmfi/M I /\\ {W f/(l/NM LN > fix} Cin W // //////// // xx“ ( eer tonk ees loss of life and the structural dam- age to the earthquake and its ef- fects, especially as these effects were modified by local geology and terrain. Aside from a number of casual- ties that resulted from airplane and other accidents during the re- construction period, all casualties to living creatures resulted either directly from the earth tremors and tectonic displacements or in- directly from water waves gener- ated by them. Ground motion caused structural damage primar- ily by (1) direct shaking of some structures, (2) triggering land- slides and subaqueous slides, (3) cracking underlying unconsoli- dated deposits, and (4) consolidat- "Subaqueous slides and waves were to- gether responsible for spreading the few major fires that had already started in petroleum storage areas." ing and subsiding loose sediments. The violent local waves that ac- companied or followed most sub- aqueous slides were major indirect effects. Subaqueous slides and waves were together responsible for spreading the few major fires that had already started in petro- leum storage areas. These fires, incidentally, taught another im- portant lesson. In earthquake prone regions, petroleum-storage tanks are especially vulnerable to earthquake vibrations; to the ex- tent possible, they should be placed away from built-up areas and should be protected by revet- ments to avoid spreading of fires (Rinne, 1967). Tectonic ground displacements, both up and down, caused long- term damage to coastal communi- ties and shoreline facilities, either directly by changing the shore relative to sea level or indirectly by the seismic sea waves generated. In addition, widespread hori- zontal tectonic movements may have generated some of the de- structive local waves. Local waves and seismic sea waves together took most of the human lives that were lost. GEOLOGIC CONTROL OF VIBRATION DAMAGE The long-known fact that the intensity and duration of earth- quake vibrations are enhanced in unconsolidated water-saturated ground was evident in the dis- tribution of vibration damage in Alaska. The varied intensity and effect of shaking were much more closely related to the local geology than to distance from the epicen- ter. In general, intensity was great- est in areas underlain by thick saturated unconsolidated deposits, least on indurated bedrock, and intermediate on coarse gravel with low water table, on morainal de- posits, or on moderately indurated sedimentary rocks of late Tertiary age. Nowhere was there significant vibration damage to structures founded on indurated bedrock or on bedrock that was only thinly veneered by unconsolidated de- posits. Where direct comparisons could be made, as at Whittier (Kachadoorian, 1965) and Cor- dova (Plafker and others, 1969), the difference in the behavior of buildings on bedrock and of those on loose material was striking. Distance from the epicenter, too, had far less influence on the intensity of vibration damage than LESSONS AND CONCLUSIONS did the local geology. Buildings on bedrock that were only 12 to 25 miles from the instrumental epi- center were undamaged except for jostled contents (Plafker and others, 1969), and the ice on some small rock-enclosed lakes in this vicinity was not even cracked (Waller, 1966b). Buildings at Anchorage, however, more than 75 miles away from the epicenter but founded on unconsolidated ma- terials, were demolished by earth- quake vibrations (Hansen, 1965). Some structural damage resulted from shaking at even greater distances. The lack of coincidence between structural damage and distance from the epicenter is partly ex- plained by the fact that the gen- erally accepted instrumental epi- center marks only one of several widely scattered points directly beneath which strong motion was centered at various moments dur- ing the history of the earthquake (Wyss and Brune, 1967). More- over, selective damage to larger and taller buildings at Anchorage is attributed by Steinbrugge (1964) to the fact that longer period large-amplitude ground motions are dominant at some dis- tance from earthquake epicentral regions, in contrast to the short- period motions that characterize close-in localities. 29 Locally, - seismic - vibrations caused minor structural damage to communities situated on late Ter- tiary sediments or on unconsoli- dated materials with low water table on the Kenai Peninsula, the west shore of Cook Inlet, in the Matanuska Valley, and elsewhere (Waller, 1966b; Plafker and others, 1969). By far the most severe vibratory damage to buildings or to highway and railroad roadbeds and bridges occurred in areas of relatively thick, noncohesive unconsolidated deposits, generally where the materials were fine grained and where the water table was close to the surface. Anchorage, the Alaska transportation systems (Kacha- doorian, 1968; McCulloch and Bonilla, 1970), the FAA station on the Copper River Delta, and Girdwood and Portage on Turn- again Arm (Plafker and others, 1969) are examples of sites of such vibratory damage. At most of these places, and many others, more damage resulted from foundation failure than from di- rect vibration of - buildings. Ground cracks, differential com- paction, and liquefaction of satu- rated materials accompanied by landspreading toward topograph- ic depressions all were contribu- tory factors. "Buildings at Anchorage, however, more than 75 miles away from the epicenter but founded on unconsolidated materials, were dumflfil/WW .. 55'le /// lly |........ lemunnuh. demolished by earthquake vibrations." e, 12 // // A/G, ////// / GGFan U “WW "HI! * // / ////// | ae 30 SURFACE FAULTS From the standpoint of public safety, perhaps the most impor- tant bit of knowledge that was re- emphasized by the Alaska earth- quake is that faults, with breakage and displacement of surface mate- rials, are relatively minor causes of widespread earthquake damage. In Alaska, of course, there were no fault displacements in popu- lated places. The only displace- ments on land were on uninhabited Montague Island in Prince Wil- liam Sound, though there is good reason to believe that rocks on the sea floor were broken and dis- placed for a long distance south- westward of the island (Malloy, 1964; Plafker, 1967). Aside from the destruction and death dealt by sea waves, all of the damage was done by seismic vibration or its direct consequences. The lesson is clear for all com- munities in earthquake-prone re- gions that the presence of an active fault, such as the San Andreas in California, constitutes only one of the dangers from future earth- quakes. Delineations of such faults and predictions as to where, how, and when they may move are essential, for they may very well localize areas of great destruction when an earthquake strikes. The lesson of the Alaska earthquake, however, is that no one can take comfort simply because he, his home, or his town is some distance removed from an active fault or from the possible epicenter of a future earthquake. The founda- tion on which he builds is far more significant. LANDSLIDES Translatory slides at Anchorage (Hansen, 1966) and subaqueous slides at Whittier (Kachadoorian, 1965), Valdez (Coulter and Migli- accio, 1966), Seward (Lemke, ALASKA EARTHQUAKE, MARCH 27, 1964 1967), and elsewhere were all caused indirectly by seismic vibra- tions, though horizontal tectonic displacement of the land may have been a factor in starting some of them. All of these slides were in soft, saturated unconsolidated ma- terials in which the vibration caused sufficient loss of strength to make preearthquake slopes unstable. Such materials were consolidated to some extent by vi- bration, but it is doubtful that consolidation was sufficient to make any of the materials signifi- cantly less prone to failure in the event of future earthquakes. Many of the violent local waves were generated by known subaque- ous slides, either as backfills of the space left by the downslid mate- rial or on opposite shores where the spreading slide material pushed water ahead of it (McCulloch, 1966). Subaqueous slides that oc- curred as a series of small slumps apparently did not generate waves. Many of the other local waves that developed around the shores of Prince William Sound are suspected to have been caused by subaqueous slides, though some that struck the shores of fiords and semienclosed embayments must have had other causes. >o. xt res / \ Z : fl", <2 VERTICAL TECTONIC DISPLACEMENTS AND SEISMIC SEA WAVES Tectonic uplift and subsidence of the land relative to sea level wrought much long-term damage, either by inundating shore instal- lations or by raising them above all but the highest tides. These ef- fects were independent of local ge- ologic conditions, except where the net amount of submergence or emergence was affected by vibra- tion-caused surficial subsidence of unconsolidated sediments. Homer Spit (Waller, 1966a) and several communities on the Kodiak group of islands (Kachadoorian and Plafker, 1966) provided good ex- amples of submergence resulting from both tectonic and surficial subsidence. - Seldovia - (Eckel, 1967), Hope, Girdwood, Portage, and several other towns (Plafker and others, 1969) all underwent tectonic subsidence ; remedial rais- ing or relocation of buildings. roadways, and wharves was nece« sary. In Prince William Sound, where the land was tectonically raised, dredging of harbors and lengthening of piers were neces- sary to compensate for the lower "Translatory slides at Anchorage and subaqueous slides * * * elsewhere were all caused indirectly by seismic vibrations, though horizontal tectonic displacement of the land may have been a factor in starting some." relative water levels. Cordova, Hinchinbrook Island, and Tatit- lek were the places most affected (Eckel, 1967; Plafker and others, 49069). Of far greater importance than the tectonic uplift and subsidence, so far as damage was concerned, was an indirect effect-the genera- tion of seismic sea waves (tsuna- mis) by the sudden uplift of a large expanse of the ocean floor. Besides the damage they did to Alaska, the tsunamis struck south- ward as far as California. They took 12 lives and wrecked the waterfront at Crescent City, Calif., and did appreciable dam- age to shore facilities as far away as Hawaii. Local geologic conditions had little effect on the amount of dam- age caused by seismic sea waves, LESSONS AND CONCLUSIONS though local topography, both above and below water, was of great importance in guiding and refracting the waves and con- trolling their runups. One local geologic complication of sea-wave damage was in the Kodiak harbor; here strong currents generated by the tsunami scoured all unconsoli- dated material from the bedrock floor, making pile driving difficult or impossible (Kachadoorian and Plafker, 1966). GROUND AND SURFACE WATER HYDROLOGY Local geology helped control the earthquake's effects on water. In areas underlain by unconsoli- dated deposits where ground fis- sures occurred, there was tempo- rary loss of water in the floors of some lakes and streams, or ground 31 water was emitted from beneath the surface through mudspouts and waterspouts. In some places, cjected ground water flooded val- ley floors (McCulloch and Bonilla, 1970). Vibration caused rearrange- ment of particles in aquifers, with resultant surges in wells and tem- porary or permanent changes in water levels. Regional or local sub- sidence led to intrusion of sea water in some coastal aquifers. Regional geology, too, to a large extent controlled the earthquake's effects on hydrologic systems, as shown in the conterminous United States, where McGarr and Vorhis (1968) found that seiches in wells and bodies of surface water were controlled by geologic structures of regional or continental dimen- sions. BENEFICIAL EFFECTS OF THE EARTHQUAKE soCcIOECONOMIC BENEFITS Devastating as was the Alaska earthquake of March 27, 1964, it had many long-term beneficial ef- fects. Most of these benefits were in the fields of socioeconomics and engineering and are only men- tioned briefly here. Economically, the Federal mon- ies and other funds spent for re- construction exceeded the total damage cost of the earthquake, largely because of decisions to upgrade or enlarge facilities beyond their preearthquake con- dition. Many improvements resulted from the aid poured into recon- struction. One whole town, Valdez, was razed and rebuilt on a more stable site; the area of one of the most disastrous landslides in the business heart of Anchorage was permanently stabilized by a gigan- tic earth buttress; new and better port facilities were provided in all the affected seacoast towns; the fishing fleet acquired, under very favorable financial terms, new boats and modern floating or land- based canneries. The pattern of rail-sea transport was drastically changed, partly 'because of the discovery that the port of Anchor- age could actually be used year- round, despite the ice in Knik Arm that had hitherto closed it in win- ter. (This change of pattern, of course, was hardly a benefit to Se- ward and Valdez.) Forced by pres- sures of reconstruction, builders learned that plastic tents over their buildings permitted construction work to continue during the sub- Arctic winter. These and many other direct benefits from the earthquake are summarized by George and Lyle and by Chance (in Hansen and others, 1966). One of the more important social-political-economic develop- ments was use by the Federal Gov- ernment of a new device to channel and control reconstruction and re- habilitation aid : The Federal Re- construction and Development Commission for Alaska repre- sented both the legislative and the executive arms of Government and included the heads of all Federal agencies that had a part to play in the reconstruction effort. One of the Commission's offspring, the Scientific and Engineering Task Force, brought soils and structural engineers, geologists and seismol- ogists together in an effort to apply 32 "L /,,,",, egy ALASKA EARTHQUAKE, MARCH 27, /‘ 5;be ”7 1964 mn- 2 N/K/A u\\\\\\\\\‘“\\\ I / l I "Many improvements resulted from the aid poured into reconstruction. One whole town, Valdez, was razed and rebuilt on a more their combined skills to guide decisions as to land use (Eckel and Schaem, in Hansen and others, 1966). The many opportunities that were provided by the recon- struction effort for team work and mutual understanding between en- gineers and earth scientists were themselves among the more valu- able byproduct benefits of the earthquake. In addition, scientists learned much that helps toward a better understanding of earth- quake mechanisms and effects and how to investigate them. They also learned many new basic facts about the structural and historical geology and the hydrology of a large part of south-central Alaska. Some of these scientific benefits from the earthquake and its in- vestigation are worthy of brief mention. DIRECT GEOLOGIC BENEFITS Truly beneficial direct geologic effects of the earthquake were few. Navigation conditions and harbor stable site." facilities were improved in a few places by tectonic uplift or subsid- ence, and tidewater and beach lands were improved or extended. For example, the subsidence that led to tidal flooding of Homer Spit also exposed new deposits of ma- terial to erosion, with the result that the spit began at once to heal itself and to build new storm berms (Stanley, in Waller, 1966; Stan- ley, 1968). Landslide hazards were averted, at least for some years to come, by uplift of Hinchinbrook Island; elsewhere imminent land- slides and avalanches that might well have harmed people or prop- erty later were harmlessly trig- gered by the earthquake. Though the direct physical benefits of the earthquake were few, the earth sciences benefitted greatly from the intensive investigations of it. The knowledge thus gained added not only to the general fund of human knowledge; more impor- tantly, it created an awareness of many potential hazards, pre- viously unrecognized or ignored, both in Alaska and in other earth- quake-prone areas, and of how to apply earth-science knowledge to reduce such hazards. SCIENTIFIC BENEFITS NEW AND CORROBORATIVE GEOLOGIC AND HYDROLOGIC INFORMATION One of the richest rewards of the earthquake study lay in the additions to geological and hydro- logic knowledge and in corrobo- rations of existing theory. The myriad observations essential to understanding the effects of the Alaska earthquake threw much new light on earthquake processes and earthquake effects in general. In addition, the investigations added greatly to our scientific knowledge of a large part of Alaska. Some of the knowledge so produced might never have come to light under ordinary circum- stances. Other discoveries were ad- vanced by many years under the earthquake-generated acceleration of basic investigations. The earthquake investigations led to better understanding of the regional tectonics of south-central Alaska. The regional gravity field was better defined than it had been before, and it was reevaluated in terms of its relation to the under- lying geology and to changes caused by the earthquake. Data, hitherto unavailable, were pro- vided on the seismicity of the re- gion. Knowledge of the structure and age of the rocks was greatly expanded. Thanks to the need to understand the vertical tectonic displacements caused by the earth- quake, new knowledge was ob- tained on the history of submer- gence and emergence throughout Holocene time. Field evidence was augmented by many new radio- carbon datings. Reconnaissance marine geological and geophysical studies were undertaken over much of the Continental Shelf, slope, and contiguous deep-sea floor. These studies have materially in- creased our understanding of the submarine areas. Detailed geologic maps became available for most of the affected cities and towns. Strip geologic maps along the ramifying rail and highway net provided a skeleton control of geologic knowledge of a wide area, particularly as to the distribution and nature of the un- LESSONS AND CONCLUSIONS consolidated deposits on which man does most of his building. Accurate and abundant geodetic control, on stable ground, is essen- tial for evaluating tectonic move- ments in the mobile belts of the world; the earthquake of 1964 gave impetus to establishment of such control. For a significant part of Alaska itself, better geodetic control resulted from the earth- quake-caused need for accurate tri- angulation and leveling and for establishment of tidal bench marks and tide gages. These data will be invaluable in any studies of future tectonic dislocations of the land surface. Support for the hypothesis that some great landslides and ava- lanches travel on cushions of compressed air came from the earthquake studies. Conversely, evidence was brought to light that tends to discount a widely held theory of glacial advance as a re- sult of earthquakes (Tarr and Martin, 1912). One kind of landslide that has received little attention in the past from geologists and engineers the translatory slide that was so disastrous in Anchorage-is now well understood, although extrap- olation of the knowledge gained to future earthquakes will still be extremely difficult. Extensive stud- "* * * the translatory slide that was so disastrous in Anchorage is now well under- stood, although extrapolation of the knowledge gained to future earthquakes will still be extremely difficult." 38 ies led to the beginning of an explosion of new knowledge on the behavior of sensitive clays and sands under dynamic conditions. A minor byproduct of the An- chorage landslide studies was the discovery of microfossils that shed new light on the environmental conditions under which the Boot- legger Cove Clay was laid down, hitherto a puzzling point for ge- ologists. Other byproducts of these studies were (1) production of de- tailed topographic maps of highly complex landslide areas and (2) development of the "graben rule" (Hansen, 1965) by which the depth to the sliding plane of a translatory slide can be easily and rather accurately estimated. Too little study was made of the response of shore processes to sudden changes in relative sea levels, but many bits of useful in- formation were discovered never- theless. The shape, character, and stabil- ity of fiord deltas built to deep water is now better known than before as a result of intensive ge- ologic, soils, hydrographic, and hydrologic studies both on land and under water. Such studies were essential to an understanding of ”7 //////”/” 8 g 34 the destructive subaqueous slides that had been almost unknown as important effects of great earth- quakes. Knowledge of the water re- sources of south-central Alaska was increased by earthquake- prompted studies of ground and surface waters; much new infor- mation also came to light as to the relations - between - earthquake- caused ground fissures and local water tables. The study of hydro- seisms, or seiches and surges in surface-water bodies and wells, throughout the world produced greater understanding of the rela- tion of hydrology to seismology. Seismic sea waves, or tsunamis, have been studied intensively for many years because of the dangers they hold for coastal communities. The Alaska earthquake of 1964, however, presented an unparal- leled opportunity to relate the source, generation, and propaga- tion of a sea-wave train to measur- able tectonic dislocations of the crust. NEW AND IMPROVED INVESTIGATIVE TECHNIQUES Virtually all investigative tech- niques known to earth scientists were applied in studies of the Alaska earthquake. Some, such as scuba diving, bathymetric surveys, and use of helicopters and fixed- wing aircraft were, of course, not new, but their widespread appli- cation to specific earthquake-con- nected problems was either new or little-used in the past. Many un- orthodox photogrammetric, engi- neering, biological, and geodetic techniques and data were applied in the attempts to appraise pre- earthquake conditions in areas of poor horizontal and vertical con- trol. Some of these techniques, dis- cussed briefly below, were new to Alaska or to individual investiga- ALASKA EARTHQUAKE, MARCH 27, 1964 tors assigned there. A secondary result of the earthquake investiga- tions of no mean significance, therefore, was the development of a large cadre of experienced and technologically well-equipped sci- entists who will be available for knowledgeable investigations of future great earthquakes. Of utmost importance for the {future is the fact that the knowl- edge gained from the Alaskan ex- perience can be adapted by the scientific community to underline possible hazards in other earth- quake-prone areas. Thus, it should be possible to relate ground con- ditions to urban planning, zoning regulations, and building codes in such a manner to forestall or minimize future earthquake disasters. USES OF RECORDING GAGES The records from continuously recording gages served purposes not originally intended. A water- level gage at the power station on Kenai Lake, for example, enabled McCulloch (1966) to make a pre- cise study of seiche action in a closed basin and to draw conclu- sions of far-reaching importance. Again, fluctuations in the record- ing of an automatic outside-air temperature recorder at Whittier gave a rough measure of the duration of earthquake vibra- tions there (Kachadoorian, 1965). Stream gages on Kodiak Island, designed to measure the levels of flowing streams, suddenly became excellent recorders of wave runup and even served as tide gages when the mouths of streams on which they were installed were brought within the reach of tides by local and regional subsidence (Plafker and Kachadoorian, 1966; Waller, 1966b). By far the most significant extension of knowledge of the usefulness of recording gages came from the study of hy- droseisms in wells and on sur- face waters on continent-wide or even larger bases. Investigations showed that, among other results, a network of recording water-level gages can act as a valuable adjunct to the worldwide seismograph net- work. It was also shown that any earthquake near a coast that is capable of causing as great fluctu- ations as that recorded by the Nunn-Bush well in Minnesota is also capable of generating a seis- mic sea wave (Vorhis, 1967; Mc- Garr and Vorhis, 1968). TELEVISION FOR UNDERGROUND OBSERVATIONS A novel application of television to the mapping of cracks in buried utilities-and incidentally of frac- tures or fault displacements in the surrounding soil-is described by Burton (in Logan, 1967). To avoid costly excavation of buried utility systems, a small-diameter borehole television camera was drawn through the ducts. Cracks were clearly visible and easily measured; their location and the amount and direction of offset of the ducts added materially to the general knowledge gained from other sources as to the character of ground movements in the An- chorage landslide areas. LAKES AS TILTMETERS Kenai Lake was the only long lake that happened to have bench marks at both ends; hence McCul- loch (1966) was able to use it as a unique giant tiltmeter. It gave a permanent record of landwarp- ing caused by the earthquake. Mc- Culloch's method of comparing the preearthquake height of the lake surface with preearthquake bench marks at the two ends of the lake necessarily left some ambi- guity in the measurements because of difficulty in locating the pre- earthquake bench marks accurate- ly, but it left no doubt whatever LESSONS AND CONCLUSIONS "Measurement of the displacement of intertidal sessile marine organisms emerged as one of the most useful techniques for determining vertical tectonic movements along coasts." that the Kenai Lake basin was tilted westward about 3 feet. As a direct outgrowth of the earth- quake investigations, and in order to monitor future crustal changes in south-central Alaska, a network of permanent bench marks has now been established on the shores of 17 large lakes within a 500-mile radius of Anchorage. These bench marks were referenced to the wa- ter levels of the lakes so that the direction and amount of any tilt- ing can be obtained from periodic monitoring (Hansen and Eckel, 1966). A systematic study of these lake levels was started by D. S. McCulloch and Arthur Grantz in the summer of 1966 (written com- mun., 1968). MEASUREMENT OF LAND-LEVEL CHANGES Measurement of the displace- ment of intertidal sessile marine organisms emerged as one of the most useful techniques for deter- mining vertical tectonic move- ments along coasts. The technique had been used elsewhere, by Tarr and Martin (1912), for example, who studied the effects of the Yakutat Bay earthquake of 1899. With the aid of Dr. G Dallas Hanna, a marine biologist of the California Academy of Sciences, however, the method was greatly refined and was applied by Plaf- ker and his associates after the Alaska earthquake of March 27, 1964, to a far larger area than ever before (Plafker, 1969). The deeply indented rocky coast of the area affected by the 1964 earthquake was ideal for ap- plication of the method. The com- mon acorn barnacle (Balanus balanoides (Linnaeus)), which is widely distributed and forms a prominent band with a sharply defined upper limit relative to tide level, was used in hundreds of "barnacle-line" measurements; in its absence the common olive- green rockweed (Fucus distichus) was almost equally useful. The normal - preearthquake - upper growth limit of barnacles and rockweed relative to mean lower low water was determined empiri- cally for the range of tidal condi- tions in the area at 17 localities 35 where the amount of vertical dis- placement was known from pre- and post-earthquake tide-gage readings. Departures of the post- earthquake barnacle line from its normal altitude above mean lower low water was taken as the amount of vertical displacement at any given place along the shore. By this method, absolute land-level changes could generally be meas- ured to an accuracy within 1 foot; even under unfavorable cireum- stances, the error is probably less than 2 feet. Other methods of determining land-level changes along the coasts and elsewhere were also employed. Changes in gravity, as determined before and after the earthquake with the same instrument, were used by Barnes (1966) in comput- ing elevation changes. In subsided areas, it was noted that wells be- came brackish, vegetation was killed by invasion of salt water, beach berms and stream deltas were shifted landward and built up to higher levels, and roads or other installations along the shores were inundated by the tides. In tectonically uplifted areas, in- dications of uplift include new reefs and islands, raised sea cliffs, and surf-cut platforms. Wherever feasibl. , the method used was the most accurate known-compari- son of pre- and postearthquake tide-gage readings at accurately placed tidal bench marks of the U.S. Coast and Geodetic Survey. Even where gages were destroyed, some bench marks were recover- able and new series of readings could be made to determine land- level - changes. - Unfortunately, there were only a few permanent automatic recording gages in south-central Alaska, and also many tidal bench marks were on unconsolidated deposits where ties to bedrock were difficult or impos- sible to reestablish. 36 DISTINCTION BETWEEN LOCAL AND REGIONAL SUBSIDENCE Clear distinctions between local subsidence caused by compaction of sediments and more widespread subsidence caused by tectonic downdrop of the region are not always easy to make. One tech- nique used by Plafker and Kacha- doorian (1966) on Kodiak and the nearby islands was to note the dif- ference in amount of inundation of unconsolidated shoreline fea- tures as compared with nearby rock outcrops. The lowering of the rock cliffs, as measured by barnacle lines or other means, represents tectonic subsidence, whereas the lowering of beaches and delta sur- faces represents a combination of tectonic subsidence and local com- paction. By using a similar tech- nique-measuring differences in the heights of piles whose tops were originally level-Plafker and Kachadoorian were able to distin- guish between local compaction- subsidence of beach deposits and tectonic downdrop. Casings of deep wells may also be helpful in distinguishing local and regional subsidence. Near the ALASKA EARTHQUAKE, MARCH 27, end of Homer Spit, for example, the top of a well casing that had previously been a known height above the ground stood several feet higher after the earthquake. Such protrusion could only have been caused by compaction and subsidence of the unconsolidated materials around the casing, for regional subsidence would have carried the casing down along with the land surface (Grantz and others, 1964, fig. 6). EVIDENCE OF WAVE ACTION AND RUNUP As part of their studies of wave- damaged shorelines, various in- vestigators made extensive use of natural materials that indicated the relative intensity and move- ment direction of waves (McCul- loch, 1966; Plafker and others, 1969; Plafker and Kachadoorian, 1966). Runup heights were deter- mined from strandlines of wave- deposited debris, abraded bark or broken branches in vegetation along the shore, and water stains on snow or structures. Movement directions of the waves could be inferred from the gross distribu- "As part of their studies of wave-damaged shorelines, * * * investiga- tors made * * * use of * * * materials that indicated the * * * intensity and * * * direction of waves * * *" =t tm - Git i; sd W/ \\\\ f \ o oe sue T '+ > t C3) Sese: fl 1964 tion of damage along shores, the directions in which limbs and trunks of trees and brush were scarred, bent, and broken off, and the directions in which objects such as buoys, structures, and shoreline deposits were displaced. To aid in comparative studies of wave-damaged shorelines along the coast, Plafker and Mayo de- vised a scale of relative magnitude of wave damage (Plafker and others, 1969)-a scale which was also used by McCulloch and Mayo (McCulloch, 1966) in modified form for plotting wave damage along the shore of Kenai Lake. The magnitude scale evolved is summarized below in order of increasing damage. Wave-magnitude scale [After Plafker and others, 1969, pl. 2] 1. Brush combed and scoured in di- rection of wave travel. Small limbs broken and minor scarring of trees. Runup heights only a few feet above extreme high-water level. Some wooden structures floated from foundations. 2. Trees and limbs less than 2 inches in diameter broken. Small trees uprooted. Driftwood and finer beach deposits thrown up above extreme high-water level. Piling swept from beneath some struc- ___ _ tures and wooden structures U R /N floated off their foundations. Runup reached about 25 feet on steep shores. 3. Trees and limbs as much as 8 inches in diameter broken; some large trees overturned. Rocks to cobble size eroded from intertidal zones and deposited above extreme high-water level. Soil stripped from bedrock areas. All inundated structures except those of rein- forced concrete destroyed - or floated away. Heavy machinery moved about. Maximum runup height 55 feet. 4. Trees larger than 8 inches in diam- LESSONS AND CONCLUSIONS eter 'broken, uprooted, and over- turned. Boulders thrown above extreme high-water line. Loose rocks on cliffs moved. All struc- rocks and equipment damaged or destroyed in inundated areas. Maximum runup height 70 feet. 5. Extensive areas of total destruction of vegetation. Boulders deposited 50 feet or more above normal ex- treme high-water level. Maximum runup height 170 feet. Using a wave-magnitude num- bering system modified from an early version of Plafker and Mayo, SCIENTIFIC PREPARATION FOR FUTURE EARTHQUAKES FUNDAMENTAL RESEARCH Much more research is needed on the origins and mechanisms of earthquakes, on crustal structure and makeup, and on generation and prediction of tsunamis, local waves, and seiches. Better theoreti- cal and experimental means of de- termining focal mechanisms are particularly needed, not only for scientific reasons but to aid earth scientists and structural engineers in relating focal mechanisms to ground motion and in relating the response of buildings to seismic shock. Study is needed too on all phases of rock and soil mechanics, with emphasis on the causes and nature of rock fracture in the earth's interior, on the response of different rocks to strong seismic motion, and on the behavior of soils under dynamic loading. Well-conceived research in any of these fields is certain to show results that apply to the overall earthquake problem. Existing re- search projects should be sup- ported, and new ones, designed to fill the gaps in existing knowledge, CONCLUSIONS should be sought out and encour- aged. In-depth studies by such groups as the Federal Council for Science and Technology (1968) have clearly defined the needs. The rate of accomplishment of re- search, however, is far less than it should be. It cannot be too strongly recommended that funds be pro- vided as soon as possible to support these necessary research programs. EARTHQUAKE FORECASTING AND EVALUATION OF EARTHQUAKE HAZARDS An ability to predict precisely the time, place, and magnitude of future earthquakes would repre- sent an accomplishment of the greatest importance and signifi- cance to the scientific community. Because of the sociologic, political, and economic consequences that would result from erroneous pre- dictions, and because useful results seem to be more easily attainable, it is believed that more attention should be directed, initially, to- ward forecasting in terms of the probability of earthquakes of cer- tain magnitude ranges within seis- mic regions, rather than as to the exact time when the next earth- quake may be expected at a specific 37 to allow for the additional damage caused by ice, McCulloch (1966) mapped the distribution of inten- sity and maximum runup of waves on the shores of Kenai Lake. The highest runup measured there was T2 feet, where a wave struck a steep bank. By measuring the upper limit of wave damage to trees in the direction of wave travel, Mc- Culloch also was able to show the history of the wave crests that overran several deltas. place. Every forward step will be directly applicable to the develop- ment of better and more detailed earthquake-hazard maps based on improved knowledge of regional geology, fault behavior, and earth- quake mechanisms. Hopefully, each step will also lead to better guides for land-use planning, hence to closer control of new con- struction in areas of potentlal earthquake hazards. One step toward useful forecast- ing of future earthquakes that should be taken at once is the prep- aration of - earthquake-hazard maps. Such maps should be based in part on detailed knowledge of active faults and their behavior during historic and geologic times, as well as on recent instrumental observations of earthquakes and fault movements. Although an earlier version was adopted by the International _ Conference _ of Building Officials, by military construction agencies, and by some State and local governments, the official seismic risk map of the United States (U.S. Coast and Ge- odetic Survey, 1969) is too lack- ing in detail to be of value for other than very broad planning. 38 Preparation of useful earth- quake-hazard maps, on whatever scale, will require close collabora- tion of earthquake engineers, seis- mologists, and geologists. These maps are essential to local and re- gional planning officials and to all others who are involved in formu- lation of plans for coping with earthquakes; their preparation should begin at once. They are, perhaps, especially needed by building-code officials and by de- signers of earthquake-resistant structures, for the response of foundation materials to seismic loads and the interactions between foundation and structure are just as important as antiseismic design of the structure. Such maps should be revised periodically as more geologic and seismic data become available. GEOLOGIC MAPPING OF COMMUNITIES Within the area that was tecroun- ically elevated or depressed by the Alaska earthquake, virtually all inhabited places were damaged or devastated, though the kind, amount, and causes of damage varied widely. Unfortunately, the very features that make a site de- sirable for building are often the ones that make it subject to earth- quake damage. Ports, docks, and canneries ob- viously have to be built close to the shore. But the Alaskan experi- ence indicates that the hazards are enormously compounded if such facilities are built on steep-faced deltas or other deposits of uncon- solidated materials that are mar- ginally stable under seismic con- ditions. At many places, such de- posits offer the only level surfaces near tidewater for easy or econom- ical construction. If they must be utilized, advance knowledge that they are vulnerable to future ALASKA EARTHQUAKE, MARCH 27, 1964 "* * * the hazards are enormously compounded if [port, dock, and cannery] facilities are built on steep-faced deltas * * * that are marginally stable under seismic con- ditions. * * * If [such sites] must be utilized, knowledge that they are vulnerable to future earthquakes may stimulate planning to minimize the hazards." earthquakes may stimulate plan- ning to minimize the hazards. The same reasoning applies to earthquake hazards inland. If all towns, railroads, and highways could be built on bedrock, they would be in comparatively little danger from any earthquake ef- fects except surface faults, floods, or avalanches. There would be vi- bration damage, of course, but much less of it than on materials other than solid rock. Unfortu- nately, building sites on bedrock are scarce and tend to be economi- cally infeasible, particularly in rugged terrain like Alaska's. Man must therefore often build on less stable terrain, including water- saturated - unconsolidated - sedi- ments, on potentially unstable slopes, and on or near active faults. Even though it is necessary to build in earthquake-vulnerable areas, - builders and - planners should recognize the potential haz- ard in advance and build accord- ingly. A vigorous program of geologic mapping should therefore be car- ried out in all inhabited earth- quake-prone parts of the country. As a direct result of the lessons learned from the earthquake of 1964, the U.S. Geological Survey began engineering-geologic stud- ies of all of Alaska's coastal com- munities, whether or not they received - earthquake - damage. Similarly, the geology of some western cities and metropolitan complexes in the conterminous States is already known or is un- der study. However, many other towns and cities that may well be struck by earthquakes in the fu- ture are without adequate geologic maps. All such communities, as well as places where communities are likely to spread or develop in the future, should be geologically mapped by trained personnel as rapidly as is feasible with avail- able funds. The need is increasing at a far faster rate than is the re- quired geologic information. The minimum geologic map for each community would delineate all active faults and landslides and would discriminate between areas underlain by bedrock and those underlain by unconsolidated ma- terials. The next most needed re- finement would be to distinguish areas of fine- and coarse-grained soils and to note whether the near- surface layers are normally dry or saturated. The topographic base of the geologic map would of course also show unconfined slopes bordering topographic depres- sions, even minor ones, where earth fissures or lateral spreading of loose materials are to be antici- pated. Such maps could be pre- pared quickly and at relatively low cost. They would be extremely valuable in guiding authorities to wise decisions on land use, in the location of seismic instruments that would develop a maximum of useful information, and in the preparation or - refinement of earthquake-hazard maps. Much more elaborate-and more costly-geologic maps can be pre- pared, of course. Such maps are needed for all larger communities and for smaller ones where the geologic and soils problems are "Modern geologic maps were available and geologists had warned in print tha in the event of future earthquakes. * * * Disastrous transla tory the correctness of the warnings." LESSONS AND CONCLUSIONS complex. Ideally, these maps should contain all the geologic, topographic, and hydrologic de- tail that could have any bearing on the relative reaction of parts of the community's foundations to earthquake stresses. They should depict not only the makeup of the land, but the character of contigu- ous water bodies and their bottom materials. Knowledge of the character, shape, and stability of off-shore deposits derived from surface observations, borings, bath- ymetric surveys, and bottom sampling would go far toward warning coastal residents of their danger in the event of an earth- quake. Cooperative effort by soils engineers, geologists, and ocean- ographers is needed for this work. Provision of good geologic maps alone is not enough, of course, to insure that the facts they show will be used effectively in reducing earthquake hazards. This lesson v 2 Wes Jt ' / % +4 4 A( Wffwgfl Z 39 was forcefully taught by the Alaska experience of 1964. Modern geologic maps of Anchorage were available, and geologists had warned in print that one of the map units, the Bootlegger Cove Clay, would be unstable in the event of future earthquakes. The warnings went unheeded, however, because civic authorities, builders, and others either were unaware of the existence of the geologic in- formation or ignored its implica- tions. Disastrous - translatory - land- slides initiated by the earthquake of 1964 amply proved the correct- ness of the warnings. Obviously, means must be sought to acquaint city planners, engi- neers, builders and the populace with the existence of useful geo- logic information and with its im- plications in terms of earthquake hazards and land use. t * * * the Bootlegger Cove Clay would be unstable landslides initiated by the earthquake of 1964 amply proved 40 INSTRUMENTATION AND MEASUREMENTS Suitable networks of recording seismographs should be installed in all areas where earthquakes are considered likely to occur. Where feasible, signals from the seismom- eters should be telemetered by tele- phone lines or by radio to a central recording and data-processing facility. The seismograph net- works should be supplemented by other earthquake-sensing instru- ments, such as strain meters, tilt- meters, magnetometers, and gra- vimeters. In some areas, existing networks maintained by univer- sity and Federal agencies can be used as bases for improved modern telemetry networks. In other areas, entirely new networks must be installed. In selecting the sites for such in- struments, it is essential that the local and regional geology be known in some detail and that the instruments be placed so as to ob- tain the maximum amount of in- formation on the behavior of active faults and the effects of the various kinds of rock and soils on seismic response. It is particularly impor- tant that the seismograph net- works be of such geometric form that earthquakes can be located ac- curately and immediately by means of digital computers and related to known or suspected active faults. In addition to the networks of standard seismographs and other earthquake-sensing - instruments, the existing networks of strong- motion seismographs should be strengthened and extended to all earthquake zones. Strong-motion seismograph recordings are partic- ularly useful in testing the inter- actions between buildings and dif- ferent materials on which they rest when subjected to seismic shock, and it is, therefore, important that strong-motion seismographs be ALASKA EARTHQUAKE, MARCH 27 , 1964 sited on the basis of detailed knowledge of the local geology. The instruments discussed above are now available and can be in- stalled immediately. A new gen- eration of instruments is also needed-laser strain meters, ab- solute-stress measuring devices, and devices for monitoring minute variations with changing stress of acoustic velocities in rock. These instruments can be devel- oped, and should be developed without delay. The arrays of standard and strong-motion seismographs in all earthquake-prone areas might well be supplemented by a nationwide system of test wells in confined aquifers, equipped to record long- period seismic waves and to damp out subsequent water fluctuations. Studies of well records after the Alaska earthquake demonstrated that hydroseisms can be used ef- fectively to predict and explain certain hydrologic phenomena and can also serve as supplemental seismic recorders. In addition to a system of water-level recorders in wells, improved stream gages are needed, built to withstand earth- quake shocks and to remain oper- ational in winter. Such gages pro- vide needed information on the reaction of streams and surface- water supplies to earthquake-in- duced land movements, and there is also abundant evidence that the measurements of seiches in streams and lakes can contribute greatly to the study of sites of high seismic activity. Many more bench marks, tri- angulation stations, tide gages, and tidal bench marks are needed in earthquake-prone regions to permit accurate measurements of lateral or vertical crustal strains between, as well as during, major earthquakes. To the extent possi- ble, all such stations should be es- tablished on bedrock and should be so built as to withstand earth- quake vibration, inundation by giant waves, and local land move- ments. Bench marks should also be established at the ends of long lakes - throughout - earthquake- prone regions, and their altitudes should be resurveyed periodically. With a suitable net of tidal bench marks and level lines and a suit- able number of lake tiltmeters, both long-term and sudden warp- ing of the earth's surface can be determined accurately and cheap- ly. Such data are required to test the hypothesis that premonitory vertical displacements sometimes precede major earthquakes; if they do, these displacements could be an important prediction tool. More information on the normal height of barnacles and other sessile organisms relative to tide levels along all the shores of the Pacific would permit students of future earthquakes to make quick and reasonably accurate measure- ments of tectonic changes. Effec- tive use of this information would also require improved tide tables based on tide-gage measure- ments at many localities. Detailed geomorphic studies supplemented by many more radiocarbon dates along emergent and submergent shores are needed to clarify the Holocene history of vertical land movements. These studies would provide an under- standing of the distribution and recurrence interval of earthquake- induced changes in land levels within the time range of radiocar- bon-dating methods. Such studies might lead to the development of useful earthquake-forecasting techniques in some seismically ac- tive coastal regions because they they can roughly define broad areas of susceptibility to future major earthquake-related tectonic displacements at specific localities. INVESTIGATIONS OF ACTUAL EARTHQUAKES Every large earthquake should be regarded as a full-scale labora- tory experiment whose study can give scientific and engineering in- formation unobtainable from any other source. For this reason it is essential that every earthquake strong enough to damage man- made structures or to have meas- urable effects on the natural environment should be studied thoroughly by scientists and engineers. NEED FOR ADVANCE PLANNING In total, the scientific and en- gineering investigations of the Alaska earthquake were remark- ably successful. They resulted in accumulation and interpretation of far more knowledge, in more disciplines, than has ever been amassed before for any single earthquake. These results were ob- tained through the efforts of many individuals, sponsored by many governmental and private groups. There was no overall organiza- tional plan for the investigations, and except for the work of the Committee on the Alaska Earth- quake, National Academy of Sciences, and for voluntary per- sonal interactions of individuals and groups, no _ determined attempt was made to coordinate and integrate all the studies. This approach, even though ultimately successful, left some gaps in the record and produced some waste and duplication of effort when time and available skills were critical. Such shortcomings in future disaster - investigations could be avoided by advance plan- ning and at least a skeletal perma- nent organization. Presumably the Federal Gov- ernment will be deeply involved LESSONS AND CONCLUSIONS not only in relief and reconstruc- tion after, but also in technical investigation of, any future earth- quake disaster that is at all com- parable to the Alaska earthquake of 1964. For this reason, it seems imperative that the Federal Gov- ernment should take the lead in contingency planning for future disastrous earthquakes. This is not to say that the Federal Govern- ment should act alone in planning for disaster or in activating the plans made. State and local gov- ernments, universities, and other groups all have major responsibil- ities and skills that must be brought to bear on the problems. Largely as a result of the Alaskan experience, numerous well-inte- grated local and State groups int several earthquake-prone regions are already (1969) active in mak- ing plans for the investigation of future earthquakes. A great earth- quake, however, brings with it an immediate need for massive appli- cation of resources, both human and material, from outside the stricken locality or region. More- over, and as the Alaskan experi- ence made so plain, strong and immediate logistic and other sup- port from the military is abso- lutely essential in dealing with a great earthquake disaster, either for technical investigations or for relief and reconstruction. The chief objectives of a plan- ning effort in preparation for fu- ture great earthquakes would be (1) to define the kind and scope of investigations needed for scien- tific purposes and for protection of life and property; (2) to pro- vide guidelines to assume that the primary responsibilities of various organizations or individuals, gov- ernmental or private, are brought to bear on all necessary investiga- tions; (3) to provide for coordina- tion between investigative groups; 41 and (4) to provide means for immediate funding and fielding of investigators when disaster strikes, including military logistic and photographic support. It is emphasized that this pro- posal applies only to preplanning for disaster. Once disaster has struck, actual investigations must be left to individual groups with the requisite skills, responsibilities and funds. But the better the over- all preplanning effort, the better integrated and funded will be the actual investigations and the bet- ter their chances of complete coverage. GEOLOGIC, GEOPHYSICAL, AND HYDROLOGIC INVESTIGATIONS Once a decision has been made to investigate a reported earth- quake, a small reconnaissance par- ty should be dispatched at once, as was done successfully by the U.S. Geological Survey for the Alaska earthquake. Preferably it should be composed of one or more mature geologists and geophysi- cists who have a thorough knowl- edge of the local and regional geology of the disaster area and who have had experience with earthquakes or other similar nat- ural disasters. The sounder the decisions at this stage the better will be the results. The duties of the reconnaissance party would be partly to observe and record as many ephemeral features as possi- ble but would be primarily to as- sess the situation and to formulate advice as to the size and character of the problem and of the task force needed to attack it. Many investigations would end with the reconnaissance phase; a few would be found worth full-scale study. If further studies are recom- mended, a field team of investiga- tors should be formed and a leader appointed. Team size and makeup depend on the character of the 42 problem and on the skills and aptitudes required, but every ef- fort should be made to provide coverage of all earth-science as- pects of the disaster. Some team members, especially in the early phases of the investigations, should know the local and re- gional geology. However, both lo- cal knowledge and experience in disaster studies help in making fast, accurate observations of ephemeral geologic processes and effects. Once the field team is formed, its members should continue to be responsible only to the team leader until all field work and reports are completed. Decisions should be made early as to the general scope and character of preliminary and final reports on the earthquake. These determinations, however, should be flexible enough as to per- mit pursuit of significant research problems as they unfold. Every effort must be made to co- ordinate the geologists' and geo- physicists' work with that of all other investigative groups in order to assure free interchange of in- formation, to avoid confusion and duplication of effort, and to iden- tify gaps in the investigative effort. The work required of the field team will vary between wide limits, depending, among other things, on the size and geologic character of the affected region, on the nature and effects of the earth- quake itself, and on the kind, amount, and distribution of dam- age done. In general, however, all work done should be aimed at two principal objectives: (1) collection of all geologic and geophysical information that has any bearing on reconstruction efforts or that can be used in preventing or alle- viating the damaging effects of fu- ture earthquakes, and (2) collec- ALASKA EARTHQUAKE, MARCH 27, 1964 tion of all information that can lead to better scientific understand- ing of earthquake processes and effects. More specifically, the following steps should be taken in the geo- logic investigation, with initial emphasis on ephemeral effects that may disappear or be modified within a few hours or days: 1. Initiate immediate aerial surveys to provide complete stereo-photo cov- erage, at scales of 1:20,000 or larger, of all areas in which any earthquake effects are photo- graphically recordable. The mini- mum coverage required might be specified by the reconnaissance party, to be expanded later as fol- low up investigations progress. All of the studies listed below can be made or expedited with suitable airphoto coverage. 2. Study relations between the earth- quake effects and the local and regional geology. 3. In cooperation with soils engineers, investigate any new faults or re- activations of preexisting faults. 4, Map ground fissures, sand spouts, and pressure ridges, especially where they affect the works of man. Measure subsidence or uplift of the ground surface and distinguish between tectonic displacement and that caused by consolidation of sediments. 6. Investigate mass movements of ma- terials, such as avalanches, land- slides, and underwater slides. 7. Observe changes in stream courses and regimens. 8. Map local geology and soils, paying special attention to ground-water conditions, wherever damaging movements have occurred. 9. Ascertain the effects of tsunamis and local waves and the changes in shorelines initiated by waves or tectonic movements. 10. Study any earthquake-caused changes in volcanic activity. 11. Initiate studies, by means of port- able seismographs, of aftershocks especially for the purpose of locat- ing them and relating them to active faults. 12. Initiate geodetic and aerial surveys, both for use in studying earth- quake effects and in determining or horizontal and vertical tectonic displacements. 13. In close cooperation with soils and structural engineers, examine the effects of shaking and of ground movements on structures, paying particular attention to the rela- tionship between underlying geol- ogy and structural damage. 14. Produce good map and photographic coverage of the earthquake's ef- fects for the permanent record. AVAILABILITY OF MAPS AND OTHER BASIC DATA One of the most important les- sons learned from the Alaskan earthquake was the value of pre- earthquake information in study- ing the effects of the quake. Topographic base maps, geologic, soils, and glaciologic maps, aerial photographs, tidal and other bench inarks, triangulation stations, rec- ords of building foundations-all these were invaluable to investi- gators. Current base maps-topograph- ic maps and hydrographic charts- are essential tools for scientific and engineering investigators; so are pertinent reports and maps on local geology and soils. Detailed city plans, preferably those that show utility systems as well as streets and buildings, are needed not only by technical investigators but by relief and rehabilitation workers and by the general public. All such basic materials will be needed in quantity immediately after an earthquake. The avail- ability of such materials should, of course, be made known to city offi- cials and other potential users. QUESTIONNAIRES Questionnaires, widely distrib- uted by mail to postmasters and others or published in local news- papers, are an effective means for determining the extent, distribu- tion, and character of an earth- quake's effects, as well as for identi- fying - alert and - interested eyewitnesses who should be inter- viewed by investigators for more detailed facts than can be recorded on the returned questionnaire. The questionnaire method, supple- mented by innumerable interviews, was widely and effectively used in studies of the Alaska earthquake by the U.S. Coast and Geodetic Survey, which routinely gathers such data on all earthquakes, by the U.S. Geological Survey, and by several other groups. The ques- tionnaire used by the Geological Survey in Alaska is reproduced in the report by Plafker and others (1969). LESSONS AND CONCLUSIONS SCIENTIFIC AND ENGINEERING TASK FORCE Immediately after the Alaska earthquake, the Scientific and En- gineering Task Force of the Fed- eral Reconstruction and Develop- ment Planning Commission for Alaska (Eckel and Schaem, in Hansen and others, 1966) was set up to advise the Commission, and through it, the Federal fund-sup- plying agencies, as to where it was safe to permit new construction or rebuilding of earthquake-damaged structures. The Task Force's ad- vice, based on technical studies of the earthquake's effects on geology The selected bibliography below includes primarily what the writer considers to be the more significant papers that had appeared on earth- science aspects of the Alaska earth- quake when this paper went to press. The few other papers in- cluded that do not deal directly with the earthquake of 1964 but which are referenced in this vol- ume are marked with asterisks. Many important papers on engi- neering, biology, social science, and other disciplines that touch lightly, if at all, on geology, seismology, and hydrology are not listed. Ref- erences to such papers can be found in specialized bibliographies. Vir- tually every paper on the Alaska earthquake, of course, contains references to other items in the literature that provide useful back- ground information in under- standing facets of the Alaska earthquake. Alaskan Construction Consultant Com- mittee [1964], Reconstruction and development survey of earthquake damages in Alaska, prepared for SELECTED BIBLIOGRAPHY Federal Reconstruction and Devel- opment Planning Commission for Alaska : 98 p. Alaska Department of Health and Wel- fare, 1964, Preliminary report of earthquake damage to environ- mental health facilities and services in Alaska: Juneau, Alaska Dept. Health and Welfare, Environmental Health Br., 46 p. Algermissen, S. T., 1964, Seismological investigation of the Prince William Sound earthquake and aftershocks [abs.] : Am. Geophys. Union Trans., v. 45, no. 4, p. 633. Barnes, D. F., 1966, Gravity changes during the Alaska earthquake: Jour. Geophys. Research, v. 71, no. 2, p. 451-456. Berg, G. V., and Stratta, J. L., 1964, Anchorage and the Alaska earth- quake of March 27, 1964: New York, Am. Iron and Steel Inst., 63 p. Blum, P. A., Gaulow, R., Jobert, G., and Jobert, N., 1966, On ultra-long period seismometers operating un- der vacuum: Royal Soc. [London] Proc., ser. A, v. 290, no. 1422, p. 818-322. Bolt, B. A., 1964, Seismic air waves from the great 1964 Alaska earth- quake: Nature, v. 202, no. 4987, p. 1095-1096. 43 and soils, was translated into Com- mission decisions as to availability of Federal funds for specific areas and purposes. The approach of the Scientific and Engineering Task Force was highly successful during the re- construction period after the Alas- ka earthquake. Its potential longer term benefits to the general public were somewhat lessened, however, because there were no provisions for continuing observ- ance of its recommendations after the Federal Commission was dis- solved and because there was no control over actions of local gov- ernments or use of non-Federal funds. Bredehoeft, J. D., Cooper, H. H., Jr., Papadopoulos, I. S., and Bennett, R. R., 1965, Seismic fluctuations in an open artesian water well, in Geological Survey research, 1965: U.S. Geol. Survey Prof. Paper 525-C, p. C51-C57. Bull, Colin, and Marangunic, Cedomir, 1967, The earthquake-induced slide on the Sherman Glacier, south- central Alaska, and its glaciological effects, in Physics of snow and ice: Internat. Conf. Low Temperature Sci., Sapporo, Japan, 1966, Proc., v. 1, pt. 1, p. 895-408. Burton, L. R., 1967, Television examina- tion of earthquake damage to un- derground communication and elec- trical systems in Anchorage, int Logan, M. H., Effect of the earth- quake of March 27, 1964, on the Eklutna Hydroelectric Project, An- chorage, Alaska : U.S. Geol. Survey Prof. Paper 545-A, p. A25-A80. Case, J. E., Barnes, D. F., Plafker, George, and Robbins, S. L., 1966, Gravity survey and regional geol- ogy of the Prince William Sound epicentral region, Alaska: U.S. Geol. Survey Prof. Paper 548-C, p. C1-C12. Chaffin, Yule, 1966, The earthquake created a hobby: Alaska Sports- man, Aug. 1966, p. 39-40. 44 Chance, Genie, 1966a, Chronology of physical events of the Alaskan earthquake: Prepared under a Na- tional Science Foundation Grant to the University of Alaska. Copyright by Genie Chance, 1966. 173 p. 1966b, The year of decision and action, in Hansen, W. R., and others, The Alaska earthquake March 27, 1964-Field investiga- tions and reconstruction effort: U.S. Geol. Survey Prof. Paper 541, p. 90-105. Chouhan, R. K. S., 1966, Aftershock sequence of Alaskan earthquake of 28th March 1964 : Pure and Applied Geophysics [Italy], v. 64, p. 48-48. Christensen, M. N., and Bolt, B. A., 1964, Earth movements-Alaskan earthquake, 1964: Science, v. 145, no. 3637, p. 1207-1216. Coble, R. W., 1967, Alaska earthquake effects on ground water in Iowa, in Vorhis, R. C., Hydrologic effects of the earthquake of March 27, 1964 outside Alaska: U.S. Geol. Survey Prof. Paper 544-C, p. C23-C27. *Condon, W. H., and Cass, J. T., 1958, Map of a part of the Prince William Sound area, Alaska, showing linear geologic features as shown on aerial photographs: U.S. Geol. Survey Misc. Geol. Inv. Map I-278, scale 1:125,000. Cooper, H. H., Jr., Bredehoeft, J. D., Papadopoulos, I. S., and Bennett, R. R., 1965, The response of well- aquifer systems to seismic waves: Jour. Geophys. Research, v. 70, no. 16, p. 8915-3926. Coulter, H. W., and Migliaccio, R. R., 1966, Effects of the earthquake of March 27, 1964, at Valdez, Alaska : U.S. Geol. Survey Prof. Paper 542-C, p. C1-C36. *Crandell, D. R., and Fahnestock, R. K., 1965, Rockfalls and avalanches from Little Tahoma Peak on Mount Rainier, Washington: U.S. Geol. Survey Bull. 1221-A, p. A1-A830. Davies, Kenneth, and Baker, D. M., 1965, Ionospheric effects observed around the time of the Alaskan earthquake of March 28, 1964 : Jour. Geophys. Research, v. 70, no. 9, p. 2251-2258. Dobrovolny, Ernest, and Schmoll, H. R., 1968, Geology as applied to urban planning-an example from the Greater Anchorage Area Borough, Alaska, in Engineering geology in country planning: Internat. Geol. Cong., 23d, Prague 1968, Proc., see. 12, p. 39-56. ALASKA EARTHQUAKE, MARCH 27, 1964 Donn, W. L., 1964, Alaskan earthquake of 27 March 1964-remote seiche stimulation: Science, v. 145, no. 3629, p. 261-262. Donn, W. L., and Posmentier, E. S., 1964, Ground-coupled air waves from the great Alaska earthquake : Jour. Geophys. Research, v. 69, no. 24, p. 5357-5361. Eckel, EB. B., 1967, Effects of the earth- quake of March 27, 1964, on air and water transport, communications, and utilities systems in south- central Alaska: U.S. Geol. Survey Prof. Paper 545-B, p. B1-B27. Eckel, E. B., and Schaem, W. E., 1966, The work of the Scientific and Engi- neering Task Force-Earth science applied to policy decisions in early relief and reconstruction, in Han- sen, W. R., and others, The Alaska earthquake March 27, 1964-Field investigations and reconstruction effort: U.S. Geol. Survey Prof. Paper 541, p. 46-69. Engineering Geology Evaluation Group, 1964, Geologic report-27 March 1964 earthquake in Greater An- chorage area : Prepared for Alaska Housing Authority and the City of Anchorage; Anchorage, Alaska, 34 p. Federal Council for Science and Tech- nology, 1968, Proposal for a ten- year national earthquake hazards program: Ad hoc Interagency Working Group for Earthquake Research, prepared for the Office of Science and Technology and the Federal Council for Science and Technology, Washington, D.C., 81 p. Federal Reconstruction and Develop- ment Planning Commission for Alaska, 1964, Response to disaster, Alaskan earthquake, March 27, 1964: Washington, U.S. Govt. Printing Office, 84 p. Ferrians, O. J., Jr., 1966, Effects of the earthquake of March 27, 1964, in the Copper River Basin area, Alaska: U.S. Geol. Survey Prof. Paper 543-E, p. E1-E28. Fisher, W. E., and Merkle, D. H., 1965, The great Alaska earthquake: Air Force Weapons Lab., Kirtland Air Force Base, N. Mex., Tech. Rept. AFWL-TR-65-92, 2 v., 412 p., in- cluding 296 illus. Foley, R. E., 1964, Crescent City-tidal waves: Shore and Beach (Jour. Shore and Beach Preservation Assoc.) v. 32, p. 28 (April 1964). Foster H. L., and Karlstrom, T. N. V., 1967, Ground breakage and asso- ciated effects in the Cook Inlet area, Alaska, resulting from the March 27, 1964, earthquake: U.S. Geol. Survey Prof. Paper 543-F, p. F1-F28. Furumoto, A. S., 1967, A study of the source mechanism of the Alaska earthquake and tsunami of March 27, 1964-pt. 2, Analysis of Rayleigh wave: Pacific Sci., v. 21, no. 3, p. 311-316. George, Warren, and Lyle, R. E., 1966, Reconstruction by the Corps of Engineers-methods and accom- plishments, in Hansen, W. R., and others, The Alaska earthquake March 27, 1964-Field investiga- tions and reconstruction effort: U.S. Geol. Survey Prof. Paper 541, p. 81-89. *Grant, U. S., and Higgins, D. F., 1910, Reconnaissance of the geology and mineral resources of Prince Wil- liam Sound, Alaska: U.S. Geol. Survey Bull. 443, 89 p. 1913, Coastal glaciers of Prince William Sound and Kenai Penin- sula, Alaska: U.S. Geol. Survey Bull. 526, 75 p. Grantz, Arthur, Plafker, George, and Kachadoorian, Reuben, 1964, Alas- ka's Good Friday earthquake, March 27, 1964-a preliminary geologic evaluation: U.S. Geol. Survey Cire. 491, 35 p. Gronewald, G. J., and Duncan, W. W., 1966, Study of erosion along Homer Spit and vicinity, Kachemak Bay, Alaska, in Coastal engineering; Santa Barbara Specialty Confer- ence, 1965: New York, Am. Soc. Civil Engineers, p. 673-682. Hackman, R. J., 1965, Photointerpreta- tion of post-earthquake photog- raphy, Alaska: Photogrammetric Eng., v. 31, no. 4, p. 604-610. Hanna, G D., 1964, Biological effects of an earthquake: Pacific Discov- ery, v. 17, no. 6, p. 24-26. 1967, The great Alaska earth- quake of 1964: Pacific Discovery, v. 20, no. 3, p. 25-30. Hansen, W. R., 1965, Effects of the earthquake of March 27, 1964, at Anchorage, Alaska : U.S. Geol. Sur- vey Prof. Paper 542-A, p. A1-A68. 1966, Investigations by the Geo- logical Survey, in Hansen, W. R, and others, The Alaska earthquake March 27, 1964-Field investiga- tions and reconstruction effort: U.S. Geol. Survey Prof. Paper 541, p. 38-45. # Hansen, W. R., and Eckel, E. B., 1966, A summary description of the Alaska earthquake-its setting and effects, in Hansen, W. R., and others, The Alaska earthquake March 27, 1964-Field investiga- tions and reconstruction effort: U.S. Geol. Survey Prof. Paper 541, p. 1-37. Hansen, W. R., and others, 1966, The Alaska earthquake March 27, 1964- Field investigations and recon- struction effort: U.S. Geol. Survey Prof. Paper 541, 111 p. Harding, S. T., and Algermissen, S. T., 1969, The focal mechanism of the Prince William Sound earthquake of March 28, 1964, and related earthquakes, in Leipold, 1969a, p. 185-221. Huene, Roland von, Malloy, R. J., and Shor, G. G., Jr., 1967, Geologic structures in the aftershock region of the 1964 Alaska earthquake: Jour. Geophys. Research, v. 72, no. 14, p. 3649-3660. Huene, Roland von, Shor, G. G., Jr., and Reimnitz, Erk, 1967, Geological in- terpretation of seismic profiles in Prince William Sound, Alaska: Geol. Soc. America, Bull., v. 78, no. 2, p. 259-268. *International Conference of Building Officials, 1964, Uniform building code: Los Angeles, Calif., 1964 ed., v. 1, 508 p. Kachadoorian, Reuben, 1965, Effects of the earthquake of March 27, 1964, at Whittier, Alaska: U.S. Geol. Survey Prof. Paper 542-B, p. Bl- B21. 1968, Effects of the earthquake of March 27, 1964 on the Alaska highway system : U.S. Geol. Survey Prof. Paper 545-C, p. C1-C66. Kachadoorian, Reuben, and Plafker, George, 1967, Effects of the earth- quake of March 27, 1964, on the communities of Kodiak and near- by islands: U.S. Geol. Survey Prof. Paper 542-F, p. F1-F41. Kirkby, M. J., and Kirkby, A. V., 1969, Erosion and deposition on a beach raised by the 1964 earthquake, Mon- tague Island, Alaska: U.S. Geol. Survey Prof. Paper 543-H, p. H1- H41. Leipold, L. 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H., 1967, Effect of the, earth- quake of March 27, 1964, on the Eklutua - Hydrolelectric Project, Anchorage, Alaska, with a section on Television examination of earth- quake damage to underground com- munication and electrical systems in Anchorage, by Lynn R. Burton: U.S. Geol. Survey Prof. Paper 545-A, p. A1-A80. Long, Erwin, and George, Warren, 1967a, Buttress design earthquake- induced slides: Am. Soc. Civil En- gineers Proc., v. 93, paper 5382, Jour. Soil Mechanics and Found. Div., no. SM4, p. 595-609. 1967b, Turnagain slide stabili- zation, Anchorage, Alaska: Am. Soc. Civil Engineers Proc., v. 93, paper 53883, Jour. Soil Mechanics and Found. Div., no. SM4, p. 611- 627. Lyle, R. E., and George, Warren, 1966, Activities of the Corps of Engi- neers-cleanup and early recon- struction, in Hansen, W. R., and others, The Alaska earthquake March 27, 1964-Field investiga- tions and reconstruction effort: U.S. Geol. Survey Prof. Paper 541, p. 70-80. McCulloch, D. S., 1966, Slide-induced waves, seiching, and ground frac- turing caused by the earthquake of March 27, 1964, at Kenai Lake Alaska: U.S. Geol. Survey Prof. Paper 548-A, p. Al-A41. McCulloch, D. S., and Bonilla, M. G., 1970, Effects of the Alaska earth- quake, March 27, 1964, on The Alas- ka Railroad. U.S. Geol. Survey Prof. Paper 545-D. McGarr, Arthur, 1965, Excitation of seiches in channels by seismic waves: Jour. Geophys. Research, v. 70, no. 4, p. 847-854. McGarr, Arthur, and Vorhis, R. C., 1968, Seismic seiches from the March 1964 Alaska earthquake: 45 U.S. Geol. Survey Prof. Paper 544- E, p. E1-E43. Malloy, R. J. 1964, Crustal uplift south- west of Montague Island, Alaska : Science, v. 146, no. 3647, p. 1048- 1049. 1965, Gulf of Alaska-seafloor upheaval: Geo-Marine Technology, v. 1, no. 5, p. 22-26. Mikumo, Takeshi, 1968, Atmospheric pressure waves and tectonic defor- mation associated with the Alaskan earthquake of March 28, 1964: Jour. Geophys. 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M., 1964, Earthquake damage to Anchorage area utili- ties-March 1964: Port Hueneme, Calif., U.S. Naval Civil Eng. Lab., Tech. Note N-607, 17 p. *Tarr, R. S.. and Martin, Lawrence, 1912, The earthquakes at Yakutat Bay, Alaska, in September, 1899: U.S. Geol. Survey Prof. Paper 69, 135 p. Tobin, D. G., and Sykes, L. R., 1966, Re- lationship of hypocenters of earth- quakes to the geology of Alaska : Jour. Geophys. Research, v. 71, no. 6, p. 1659-1667. Tudor, W. J., 1964, Tsunami damage at Kodiak, Alaska, and Crescent City, California, from Alaska earthquake of 27 March, 1964: Port Hueneme, Calif., U.S. Naval Civil Eng. Lab. Tech. Note N-622, 128 p. Tuthill, S. J., 1966, Earthquake origin of superglacial drift on the glaciers of the Martin River area, south- central Alaska: Jour. Glaciology, v. 6, no. 43, p. 83-88. Tuthill, S. J., and Laird, W. M., 1966, Geomorphic effects of the earth- quake of March 27, 1964, in the Martin-Bering Rivers area, Alaska : U.S. Geol. Survey Prof. Paper 548- B, p. B1-B29. LESSONS AND CONCLUSIONS U.S. Army Chief of Engineers, Director- ate of Military Contruction, En- gineering Division, 1964, Report on analysis of earthquake damage to military construction in Alaska, 27 March 1964: Washington, p.C., 16 p., app. 1-6. U.S. Coast and Geodetic Survey, 1964, Prince William Sound, Alaskan earthquakes, March-April 1964: U.S. Coast and Geod. Survey Seis- mology Div., prelim. rept., 83 p. U.S. Coast and Geodetic Survey, 1969, Seismic risk map of the United States: U.S. Coast and Geod. Sur- vey, Environmental Sci. Services Adm., Washington, D.C. *Van Dorn, W. G., 1959, Local effects of impulsively generated waves: Scripps Inst. Oceanography Rept. II, 80 p., Univ. Calif,, La Jolla, Calif. Van Dorn, W. G., 1964, Source mecha- nism of the tsunami of March 28, 1964, in Alaska : Coastal Eng. Conf., 9th, Lisbon, 1964, Proc., p. 166-190. *Varnes, D. J., 1958, Landslide types and processes, in Eckél, E. B., ed., Landslides and engineering prac- tice: Natl. Research Council, High- way Research Board Spec. Rept. 29 (NAS-NRC Pub. 544), p. 20-47. Vorhis, R. C., 1964, Earthquake-induced water level fluctuations from a well in Dawson County, Ga.: Seismol. Soc. Am. Bull., v. 54, no. 4, p. 1028- 1033. 1967. Hydrologic effects of the earthquake of March 27, 1964, out- side Alaska, with sections on Hy- droseismograms from the Nunn- Bush Shoe Co. well, Wisconsin, by E. E. Rexin and R. C. Vorhis, and Alaska - earthquake effects on ground water in Iowa, by R. W. Coble: U.S. Geol. Survey Prof. Paper 544-C, p. C1-C54. Waller, R. M., 1966a, Effects of the earthquake of March 27, 1964, in the Homer area, Alaska with a sec- tion on Beach changes on Homer Spit, by K. W. Stanley: U.S. Geol. Survey Prof. Paper 542-D, p. D1-D28. ---,1966b, Effects of the earthquake of March 27, 1964, on the hydrology of south-central Alaska: U.S. Geol. Survey Prof. Paper 544-A, p. Al- A28. 47 1966c, Effects of the earthquake of March 27, 1964, on the hydrology of the Anchorage area, Alaska : U.S. Geol. Survey Prof. Paper 544- B, p. B1-B18. Waller, R. M., Thomas, H. E., and Vor- his, R.C., 1965, Effects of the Good Friday earthquake on water sup- plies: Am. Water Works Assoc. Jour., v. 57, no. 2, p. 123-131. Whitten, C. A., 1968, Earthquake dam- age, Montague Island, Alaska, i» Manual of color aerial photog- raphy : Falls Church, Va., Am. Soc. Photogrammetry, p. 390-391. Wigen, S. O., and White, W. R. H., 1964, Tsunami of March 27-29, 1964, west coast of Canada [abs.]: Am. Geophys. Union Trans., v. 45 no. 4, p. 634. Wilson, B. W., and Tgrum, Alf, 1968, The Tsunami of the Alaskan earth- quake, 1964-engineering evalua- tion : US. Army Corps of Engineers, Coastal Eng. Research Center, Tech. Mem. 25, 448 p., 282 ills., 5 appen. Wilson, S. D., 1967, Landslides in the city of Anchorage, in Wood, F. J.; ed.-in-chief, Research studies : seis- mology and marine geology, pt. A, Engineering seismology, v. 2 of The Prince William Sound, Alaska, earthquake of 1964 and after- shocks: U.S. Coast and Geod. Sur- vey Pub. 10-3, p. 253-297. Wood, F. J., ed.-in-chief, 1966, Opera- tional phases of the Coast and Geodetic Survey program in Alaska for the period March 27 to Decem- ber 31, 1964, v. 1 of The Prince Wil- liam Sound, Alaska, earthquake of 1964 and aftershocks: U.S. Coast and Geod. Survey, Pub. 10-3, 262 p. 1967, Research studies: seis- mology and marine geology, pt. A, Engineering seismology, v. 2 of The Prince William Sound, Alaska earthquake of 1964 and after- shocks: U.S. Coast and Geod. Sur- vey Pub. 10-3, 392 p. Wyss, Max, and Brune, J. N., 1967, The Alaska earthquake of 28 March 1964: A complex multiple rupture: Seismol. Soc. America, Bull. v. 57, no. 5, p. 1017-1023. INDEX Professional Papers 542-545: The number before the dash indicates the last digit of the prof. paper, and the letter and number after the dash indicate the chapter and page of Professional Papers 541 and 546: The number before the dash indicates the last digit of the prof. paper, A Page Afognak, 1-19, 1-96, ground and surface water..______________ 3-D23 ground .c. - 8$-D12 00 3-D6 property 3-D3 Seismic sea waves..._____________. $-D38, 3-D44 CILEA COI... 2-F29 Afognak Island, landslides -.. 3-D18 Tockelide8. =.... 9.00. l. ELE 3-D20 AMognak Strmif .s llc tle lca Ice 2-F28 Africa, hydrologic effects of Alaska earth- (Unie ARE E IN accel iis 4-C15 Aftershocks, Copper River Basin...__________ 3-E6 1-5, 8-15 Kodiak Island area. 3-D12 Air transport, effects of earthquake.. .._. 1-29, 5-B2 AKhiok 2200 se UCU SLL gali ound iy 2-F3, 2-F39 Alabama, hydrologic effects of Alaska earth- (AKC. s .cc el -... 4-016, 4-039 Alaska-Aleutian province......___.___________. 1-8 Alaska Communication System building, sy 20.10... ATLL ET 2-B13 Alaska District, Corps of Engineers . 1-70, 1-80, 1-81 Alaska Field Committee....._____ c... 1-48 Alaska Highway.........____ - 1-90, 3-3 Alaska Housing Authority. 1-81 AMasks Omnibus 1-49 Wisska Peninsula............:.l......... 1-3, 2-G44 Alaska Psychiatric Institute, Anchorage, dam- pere rs een ne nel ien n wee nn o cu den an 2-A283 Alaska Range, location...... 1-7, 1-8, 3-E2, 3-F1 pH} 32 22 res se ne eels sae o ie ince 3-123 Alaska Range geosyncline, location...... .. 3-E3 Alaska Sales and Service Building, Anchor- ESSE UC Ace 2. oom Aline ance an bacs 2-A23 Alaskan Construction Consultants Commit- hep enc deps eee ae o neon dran ee nie aad 1-48 Alaskan Continental Shelf, gravity values. Alaskan earthquakes, previous.. 1-7 Alaékanselsmic sofie....._.....__.._..__..... 1-7 Alberni Aleutian Islands, geology..._.___________. 1-7, 3-145 Aleutian Islands, tectonic setting. .._________. 3-144 Aleutian Range, description.._._.____________ 1-8 Aleutian Trench, tectonic setting . 3-D28, 3-112, 3-144 Weutian Vole@hnie 1-7, 3D-28, 3-F25, 3-12, 3-144, 3-I51 Alexander Archipelago.... ._. 1-12 l ne uy sent sean coal Looe sal Pci oe Halt 1-94 ...l. 000.0. 1-29, 4-D21 AMison Creck 2-C16 Alluvial deposits, Kodiak Island area...... _. 3-D15 Alluvial fans, Seward..............__...__.__ 2-E18 MHS EY c e. a Ino oes ibi .ie. 3-04 Alsek River .. 4-D31 Anchor Block, Eklutna project. -_ 5-A18 Anchor Point, ground water..._.__.__ -__. 4A23 Anchor River valley, landslides.... 2-D7,3-F17 reference; thus, 2-A3 is page A3 in Prof. Paper 542-A. 1-19 is page 19 in Prof. Paper 541. Italic numbers indicate major references. Page Anchorage............1.. Prof. Paper 542-4 wif transport >.. _u ver.. 5-B3 cleanup and restoration ... 1-73 communications and utilities. 5-B23 gravity .eu. LLU I 3-C6 RarpOP, 1 sooo Cu Ue ela bias 5-B8 hydrologic effects.... Prof. Paper 54,-B Jondelides.. . ._.. 0.0. AGO 5-D76, 6-17 power system.. ....220. ... iiot) 5-B19 principal causes of damage. 1 1-72 restoration of 1-83 structural damage. 1-100, 5-D143 Task Force recommendations.... .._.___. 1-57 water 000. 4-A16, 5-B23 Anchorage area, subsidence....________._.____ 4-B15 Anchorage Engineering Geology Evaluation GrOup ... 22s. caa d cs 0 1-66, 1-81 Anchorage Lowland......_. 1-9, 2-A2, 2-A8, 2-A22 Anderson en.... 2-C30, 2-G13 Andreanof-Fox Island region....._.____._._. 3-149 Animal populations, effects of earthquake.... 1-84 3-BZ Antarctica, secondary damage.._.___________. 1-86 Anton Larson highway, damage...__________ 3-D42 Archeologic remains, Uzinki_____.___. __ - 6-28 Appalachian basin, seiches.....____________. 4-E14 Archimandritof Shoals....._.__._.__.___ 2-D12, 2-D20 Arctic Slope of Alaska... 2-A2 Arizona, hydrologic effects of Alaska earth- !s. os ondon o 4-C17, 4-039 Arkansas, hydrologic effects of Alaska earth- (Make .e UTE a 4-C18, 4-039 Atkoma basin, 4-E14 Army dock, lut 2-E13 Artesian wells, Anchorage. ___. {-A18, 6-22 south-central Alagka............_.._._._. 4-A18 zone of 3-140 Artificial fill, Kodiak Island area.....____._. 3-D15 calli ool eluant eave 2-E22 .s css lone o eo ea ai 2-B5 Asia, hydrologic effects of Alaska earthquake. 4-C14 Assam, India, earthquake.._...__ 2-020, 4-C7, 4-C5 Atmospheric 1-33, 3-139 Atrevida Alacier. ... 20. ul CAn 4-D39 Atterberg limits, Bootlegger Cove Clay....... 2-A15 Seward -. .. ._ LL. Jul vede elev y 2-E27 AMH Islond...1.. . colo lll doar 1-8 Augustine Island, Cook Inlet area 2-D18, 8-F24 . 3 22.0 0000 H od et oan ito 3-C4 Augustine Island volcano............_.... 1-8, 2-D19 Australia, hydrologic effects of Alaska earth- ...... . 4-014 Avalanches, Anchor River. ... §-Fi7 Copper River 3-E24 before the 1964 earthquake.........__... 4-D26 on 4-D3, 4-D36 highways .... $027 Kodiak Island............. .. 8-D18 Martin-Bering Rivers area....__._.___... 3-B14 Ragged 3-B19 rookslides. c.: A. ccr. 3-B17, 4-D6 and the number after the dash indicates the page of reference; thus, Avalanches-Continued Page rotational and debris slides....._.......__. 2-A30 Seward. ells L2 ont ous 2-E14, 2-33 Avulsion, legal implications... 3-120 B Back Bay ence n. 3-D27 Backfill waves...____.____.. 3-A8, 3-A7, 3-A12, 3-A22 Bagley Icefield 2.1 2.00000. nre 4-D1 Bainbridge Island...._..__._.. -... 8-04 Bolanis 3-112; 6-35 ss: 20 002.00 ren neenee sare oe. ole 3-112 Barnacles, indication of land-level changes.... 3-112 Barren 2.1.0 LIAT IEC. 3-D6 .... 1-3, 2-A2 Bafty Glacier. 2 200.0000. III r 4-D26 Bathymetry, Kenal Lake....._._._._.....__.. 3-A3 Lakeview delta........ l... 3-A4 Lawing delta.......... ... 8-A12 Rocky Creek 3-A4 Bay Mouth 3-H29, 3-H30 Beaches, Homer Spit...._..._.._.....l...l.. 2-D20 Montague Island...._._..... Prof. Paper 513-H Beaches. See also Shore processes; Shorelines. Beach morphology............... Prof. Paper 548-J Bear 000. soe. ud . 2-D15,3-F16 Bear c.. 2-E17 Bedrock, Copper River Basin...__._.________ 3-E3 Sew ard . | so 20 ul nea ae dea cy 2-E17 Wilf Her: 2 0000, 2s oen ee eda sigs 2-B3 Belgium, hydrologic effects of Alaska earth- (USEC Lc Hen needa l ien a 4-C15 Belle Fourche, S.D., fluctuation of well...... 1-37 Beluga 0020. 2-D5, 2-D15, 3-F28 Bench marks, height relative to sea level...... 3-119 Beneficial effects of the earthquake...._...... 6-31 Boring Glacier. 2000 1-14, }-D18 Bering Lake, ice 3-B24 ssc. Puel aed ve tal 3-B19 Bering Lake area, uplifé................._... 3-B26 Bering River area...... .. Prof. Paper 5/8-B Bernice Lake powerplant.....__.._.__._._.____. 4-A22 Berm development, Homer......._.______.__._. 2-D23 Bihar-Nepal earthquake of 1934.....__. 2-C20, 3-E8 Billings 2-B3, 2-B18 Biologic effects....___.__._. 1-34, 3-B26, 8-136, 3-J17 Black Lake, turbidity changes........._..... 3-B21 Black Rapids 4-D38 Bluff Point. 2-D6, 2-D17 Bluff Road, Anchorage, rotational slides.. ... 2-A36 Bolivina pseudopunctata.............._____._. 2-A21 Bootlegger Cove Clay, Anchorage, description and effects. ......... 1-82, 2-412, 2-A33 ground 4-A19, {-B18 measurements of pore pressures......__.. 4-B1 Bore holes, Seward. /L L... nlite 2-E27 Valdes,. IAT 2-C15 Bouguer anomaly, Prince William Sound YegiOn cresol ooo lias ch 3-C6, 3-C9 Boulder Creek. See Rocky Creek delta. 49 50 Page "Box Creek 2-B4, 2-E15 Bradley Lake, Cook Inlet area...... .. 3-F24, 4-A7 Braided ...i dite oo be 3-G21 Breving Lagoon, barrier beach................ 3-J8 Bridges, highway....._.......- 3-D39, 3-25, 5-C20 e... Prof. Paper 545-D Bristol cinc... cence eden 4-A1l British Columbia, hydrologic effects of Alaska gartihhquake........l.}....... 1-37, 4-C15 Brooks Range, oscillations on lakes_......... 4-A4 Brain Bey -.}.0.0. nlc donne 3-153 Bucceba 1.3.2. 3.00, 000000 2-A21 :Y :. ene e Pane Nec Ios aed ties 2-A21 Buckner Building, ..- 2-B13, 2-B20 Buliminella durta...... c..00l an cess 2-A21 Bureau of Indian 1-94 Buskin Lake, subsidence. .........__......-. 3-D15 C Cachar earthquake. :. d 2-C20 Caim Point, slides.2..0.. ...o recline cull e 2-A33 California, hydrologic effects of Alaska earth- ens 1-37, 4-C18, 4-040 California earthquake of 1906... 2-C20, 3-E8 Camp avalanche................... . 3-B14, 3-B17 Campbell Creek, Cook Inlet area_.......... 2-A30, 3-F23, 4-A9 Campbell Lake. 4-A7, 4-B4 Canada, hydrologic effects of Alaska earth- annual Cannort Beach, 1-37 Cape Chiniak, seismic sea waves.. ... 3-D30, 3-D35 Cape Cleare Station, horizontal control sta- MON. edes nen eae e besa ane 3-G40 Cape Hinchinbrook Light Station... Cape 1-3, 2-A2 Cape Saint ling... ... c.}; oude ns 2-G33 Cape Suckling, major zone of uplift.. .. 8-158 Capps (Glacier. .. ...on [0 o oona des 3-F23 CariboU ANIS. 2,2 0.0... inert d ce- 3-F2 Casement Glacier. celle lc ec 4-D26 istandica.. . 22. 000.7. J. iy eden annd 2-A21 Casualties, Anchorage........... .. 2-A4 Canfornig=s. 2.22) icu. (Lele ing. 1-87 Cape Saint Bliss.. ccsp 2-G33 sculls lo eh ... 2-G16 Kaguyak..s.22 2003; 0 ruen 2-F2, 3- F375 Kodiak area one 2-F2, 3- D45 from accidents and natural disasters. ..... 1-5 from earthquakes during last 1,100 years.. - 1-4 Oregon. CLV Point Nowell.... ..2 2-02 Port Nellie Juan. ... 2-026 Sawinilt Bay. . .. 0000000 rty. 5-B11 2102.01. .L. evet a 2-E13 south-central | 1-4 W nitMer: . 2200023 oon Ates su tava the 2-B6 Cattle ranches, Kodiak Island area...._..... 3-D43 Cenozoic deformation, Prince William Sound region 2. .u .u. apes lae en 3-05 Cenozoic tectonic movements......________._. 3-144 Chakatchanis 3-F23 Chakok River, Cook Inlet area........_._... 3-F17 Charleston earthquake.. 2-C20, 3-E8 Charlotte Lake... ... GGD ver 3-B19 Chemical quality of well water, Anchorage TERZL PELL ..o. hl oe en see ene 4-B12 Chena, vessel at Valdez dock................. 2-C10 Chehnege .. 4-D34 Chenegs Island.. .. dale dun 1-36 Chenega village............ 1-17, 1-94, 2-G15, 5-B11l Chester Creek, discharge. ..... __ 2-A9, 4-A10, 4-B2 nud fountaing,s.. 000000001 2-A20 glide area.. olly. utes 1-87 Chickaloon 3-F3, 3-F25 Chignit Mountains.. __ 5-A4 Childs .c 20 uten ioo colin 4-D21 INDEX Page Chilean earthquake, 1822........_._.________.. 3-143 190022 200. 2000.0 LO a oal aes acle 2-A38, 3-142 Ching Poot od 3-F24 Ching :s. . 0. 10012. cla cet eed 2-F3 Chinlak Bay. .... ld 2-F18 Chiniak highway, 3-D39 Chinitna Bay, height of tides..._....._.......- 3-123 Chirikof Island, uplift. ._.... : :s. 2.00000 . ule dV duds aa den 3-E3 Chistoching Glacier. . ~.. _. 900000. eared 4-D26 Chistochina Lodge, Glenn highway, damage. 3-E25 Chistochina River, location......_........... 3-E3 Chita. 20. s Lot oo con n e ne 3-E3 Chiting River, location-... ... 3-E3 Chitina River flood plain, ground cracks.... 3-E17 Valley 11 ces add ive. . 1-97 Chugach Mountains, avalanches.......---.. 3-B14, 3-B18, 4-B2 Cool Ifilet ...l. cll reo cereale 3-F1 crustal thickness... 00.0.0 3-C9 deformation ..... .. s -. 8-153 Eklutna Project . .2.02. 002... ce nowe 5-A4 geographic relation to earthquake area.... . 1-1, 1-3, 1-9, 2-A2, 2-B2, 2-C1, 3-B2, 3-C5, 3-E2, 5-A4 cll lll lena on 3-B19, 4-D36 gravity 3-C8 ...:. nac 4-D1 Jatse levels.... 0000 coe be 22 ul sous tee 4-D33 gHdo# so. 22 20. oon no oie r sons alone 3-E24 lls. l 3-C5, 3-D28, 3-E8 uplift s! - lsu. Lds Aa en ane a+ + 3-C5 Valdes Group.: o-- 2. ced peace 3-C4 Chugach Mountains ...... 2-E16, 3-E6 Chugach National Forest. 3-B1 . Chugach Range. See Chugach Mountains. Chugiak, ground 4-A19 ClanbCreqk. uo co deve alu anea nees 3-F18 Clam habitat, danage................ - 1-36 Clark, Charles H., eyewitness report. . 2-09 Clear. lls scl le oes caa bodes .. 2-R23 Clearview .. .clll cues lca lc 1-63 CHE mIinC:-. s. Ze - nece as eos 2-C14, 2-C30 ClimateZCopper River Basin..............2.. 3-E3 WinitMer. .cc Lili nical ia s 2-B2 Coastlines. See Shorelines. Coastal Trough province......._........... 1-8, 1-9 College Fiord, crustal .-- 3-09 gravity ... 3-C8 Colony Olacion. ».. cl. cl. duels peee 4-A4 Colorado, hydrologic effects of Alaska earth- 22. 4-C18, 4-C40 Columbia Glacier........- _4-A5, 4-D4, 4-D33 Communications, damage. ...-......-....--- 5-B18 Compression, bridges... 5-D90 Connecticut, hydrologic effects of Alaska 4-C19, 4-C40 (Connors Lake 122. Dac ll iene cedh ceed ex naal s 4-B4 Consolidation subsidence................-..-.- 6-21 Construction, areas of potential land- 5-D94 Continental shelf and slope, tectonic deform- AMons serie ie ALP ne 3-D28, 3- G4 Controller Bay area, deformation........---.- 3-150 Cook, I. P., eyewitness account of Alaska 012.0020 5-D3 Cook Prof. Paper 548-F Cook Inletlittoral drift. ...:. 2-D20 zone of subsidence........... 3-D28, 3-F8, 3-F27 Cook Inlet-Susitna Lowland.........--.------ 1-9 Cook Inlet 22000. .. lc ill egies 3-F2 Cooper Landing, general damage........---- 2-G36 spichos.. ...o D .On Un- ._. 3-A28 glides . (920000 id ao oa lun ea n 3-A24 Coos Bay, .Oreg ...... .l... .._ 1-36 Copalis zl sav. sole 1-37 Copper Center. .s. aie rene ens 3-E3 Page Copper River, glacial melt. 4-D1 160 :L AOA icone aa 3-E10, 4-A9 JOCARION «L xE EIC Heh be nA ceed 3-E3 reduction of discharge......._............ 4-D33 tilting of river drainage................... 3-135 Copper River Basin............ Prof. Paper 518-E Copper River Basin, hydrology...-...-.--. 4-A19 seismic response of permafrost. ........... 6-27 Stbeldence. s. sou neler lila etal bonn aegina 3-E8 Copper River Delta, Cordova airport...... 5-B4 Jocation: «t.. . s sive 3-B2, 4-A7 MudveRbS L. es 0.0 ler yoke seein 3-B9 subsidence 3-B13 upliffed 3-15, 3-112 Copper River flood plain, ground cracks.... 3-E17 Copper River Highway....__.___....- 1-29, 5-C4 Copper River Lowland................... 1-9, 1-10 Copper River valley. 1-8, 1-92 Copper Valley Electric Co., damage...... 3-25 Cordova, AIFDOTLL L.- 22.2. .. seu oue en 5-B4 communications and utilities. .. 5-B24 erustal -s 3-C9 general 1-97, 2- G18 ground ince 2-G18 pround water.)... -l cella 4-A20 1-80, 1-88 shipping . ..} ce ocio nii nevere 5-B10 uplift.. ssl .t.. s del ome e ege 2-G18, 4-DM4 Cordova Building, Anchorage...........-... 2-A24 Cordova Post Office, gravity values. ......-. 3-06 Cove Crook: ..... cae 2-B18, 5-B26 Crab population, effects of earthquake. . ... .- 1-36 Craters. See Earthquake-fountain craters; subsidence craters. Crescent City; Calif.. 1-1, 1-37 _ Cretaceous rocks, Kodiak Island.....-.-.---- 3-D7 Prince William Sound region.... .. 8-C4 Cretaceous to Jurassic deformation.... . 3-153 Cretaceous to Tertiary deformation . 3-152 Crosswind Lake. .. lll chalk 3-E3 Crustal changes, Cook Inlet region....---..- 3-F25 Crustal deformation, general.-_...---. 3-18, 3-142 Crustal structure, local, relation to seismic sur- face Wavesl_ onl. Poe raven anes 4-E18 D Damage, dollar VAIU@L 1 1-18 c liens red eal 1-19 Danger Bay 3-D27 Deception Creek, Montague Island...... --- 3-G13 Delaware, hydrologic effects of Alaska earth- (fUAKe.. Llc. c cu eeu es enne di tence c 4-C19, 4-040 Delta materials, Kenai Lake.-.....---------- 3-A12 Lawing delta.... 3-A12 Rocky _.. 8-A22 Ship ense danes 3-A18 M12. coid nena nce ened 3-A31 Deltas and fans, railroad embankments.... .. - 5-D66 Delia River. ...... 1-10 Denali fault 3-154 Denali Highway. 1-41 Denmark, hydrologic effects of Alaska earth- (UOKG. 1.2 ice /n c ue nee se one's oe oan cd 4-C15 Densities, rocks from Prince William Sound... 3-C5 BD-. ne sei nake cae 2-A21 Dé Pos Bay, nece. 1-37 Depth soundings, comparisons.......------ --- 3-120 Diamond Creeks. ... cns enn clad 2-D1 Disenchantment Bay.. --------------------- 4-D38 Dislocation theory, representation.... .-- --- 3-167 Drainage, glacially fed rivers........--------- 4-D33 Martin-Bering Rivers area.......-..----- 3-B26 Valdbn: A nl. Lol lon inden aan o 2-06 Drift River, Cook Inlet area.........-------- 3-F23 Drill holes F.A. 1 and F.A. 2.....--...------ 2-38 Drilling, onshore, Seward......-.-.---------- 2-E31 Drilling and soil testing, Anchorage area.... . 2-A11 Seward lei fic 2-E26 Dust coat, Chugach Mountains.......---.--- 3-B19 E Page Kagle Harbor Creek.................. -... 8-D27 Kagle 2-A2, 2-A12 Fagle River valley. ...............l.....l2.. 3-F23 Rarthflows, 2-D7 Kodiak group of islands 3-D21 south-central 4-A9 Earthquake-fountain craters, Martin-Bering Rivers llc) .l lA A IIL 3-B11 Economic pattern, 5-B7 Economic planning, long range 1-50 Edgerton Highway, damage.....____.__._.___ 3-E27 1oc@Mon: 002 .. 0. Apu 3-E3 Eiby, G. A., on ground waves......_______.__ 3-E7 Eklutna Dam, earthquake effects...... _. 5-6, 6-21 u 5-A1 Eklutna Hydroelectric Project... Prof. Paper 545-A, 6-21 3-F20, 4-A5, 5-A1 Eluta .. 0. 5-A4 EKlutns 5-A8 EKTubna valley 1.2 ll... oon 3-F19 Elasticrebound theory...-....._.....}........ 6-13 .r N0 5-B11 Ellamar Peninsula, gravity values....______. 3-C11 Elmendorf Air Force Base.... __. 1-73, 2-A2, 2-42, 4-B4, 5-B4 Elmendorf Moraine. ... 2-A12, 2-A33, 5-B3 Elphidiella groenlamdica......_..______.____._. 2-A21 2-A21 Elphidium clavatum... w. R-ARM rides eee ge. 22 l ede read 2-A21 t UC.. A eric 2-A21 cli AC atin. o 2-A21 Elrington Island, gravity values..._____.___. 3-C11 Emergence. See Uplift. Emmons Glacier, rockfall avalanche...______ 4-D26 Engineering factors influencing damage inten- SPF etn oat oo l 5-047 Engineering Geology Evaluation Group...... 1-57, 2-A2, 2-A10, 2-A25, 2-A43 Enelish Bay.. tD ... 00 00 .c. 1-96, 2-GS6 Eocene to Oligocene deformation. . ....._____. 3-I51 1-1, 2-A2, 2-E4, 8-A2, 3D73F13J14E15FD66—8 Epicentral region, Prince William Sound...... 3-C1 _...... 2-D24, 8-J12 Lakeview .}... 3-A7 Lawing 3-A12 Montague Island...... Prof. Paper 5/8-H AC 3-A22 Europe, hydrologic effects of Alaska earth- @uARe: .L. c. cts 4-C15 Evans 1-17, 1-36, 3-C4, 5-B11 wan anl 3-E3 yak Lakes .D.. rel.. ci oti 4-A20 Eyak River:... 09.0... 5-029 Eyewitness account, coastal area... _._ 3-131 iffomers uae cise aco ln Ee 2-D3 Kenai 3-A17, 3-498 F Fairbanks....c......:.... 1-7, 2-B1, 2-02, 2-64 Fairbanks Committee for Alaska Earthquake BRetovery.-2..cl cl.... 1.0... 2-C3 Fairweather 3-153 Fairweather 4-D26 Fairweather Range, deformation....._.______ 3-153 physiceraphy............ .._. . 1-8, 1-14, 3-13 Fan deltas, railroad damage. 5-D93 Seward. cll. u nior 2-E18 Far-shore waves......._._.._____ 3-A8, 3-A11, 3-A22 INDEX Page Fathometer profiles, Ship Creek delta..._.._. 3-A18 Fault Cove, Montague Island......__________ 3-G27 Faults, amount of damage.. 6-30 Kodiak Island areas.. lull. .... 3-D27 MAIOL . Asl. ., o nene 1.1 oul de 3-153 Martin-Bering Rivers area - 3-B26 Montague Island . ...:... 3-D28, Prof. Paper 548-G, 3-125, 6-12, 6-30 Port Valdes.. :o... !. NCAS Ia .. 2-C16 Prince William Sound Region 3-C5, 3-C9, 6-12, 6-30 relation to vertical displacements.__._____ 3-130 Fauna of Alaska, drainage...____.______ 1-34, 2-B6 See also Seafood industry. Federal aid to Alaska, summary...________.__ 1-103 Federal Aviation Agency facilities..__________ 5-B4 Federal Disaster lull. 2-D9 Federal Field Committee. 1-51 Federal financial assistance 1-50 Federal Reconstruction and Development Planning Commission for Alaska.. 1-46, 1-103 Glacier.. .. acc ege. 4-D21 Fifth Avenue Chrysler Center, Anchorage.. 2-A24 ¥ill fatlures. .... . .oo... n cede 5-D60 Finger Lakes:... :...... {Al a ey. 3-F12, 4-A8 Fire, Seward. - 1-23, 1-78, 2-B4, 2-E5 te vacant 1-28, 2-083 Whittier. ..... - 1-23, 2-B6, 2-B20 Fire Ieland-....0..0l co econ 4-A19, A-B12 First Avenue slide area, Anchorage.. 1-57, 1-59, 1-82 First Federal Savings and Loan Building, /l csc. 22. 2-A24 Ple Creek... ...20.2...00. sul 2-A20, 2-A61, 4-B6 Fishing industry. See Seafood industry. Fissures. See Ground fractures. IME p 2s 200 200 00 0000 ACTV Nr cl 2-A21 Flood plains, active.. ...... inactive. railroad embankments. ...._____..__.___. 5-D63 Flooding, Valdes:.. .. 2... ... alain 2d 2-C6 Flora of Alaska. Floretice, Oreg.. 23000200 0a b ea Haie l Florida, hydrologic effects of Alaska earth- quake. -{. .. ui tina 4-C19, 4-040 Fluvial sediments, Copper River Basin...__- 3-E6 Focal mechnism studies of earthquake.. 8-17, 6-13 Forb-grass, food of the Canda goose..._...... 3-J18 Forest Acres, Seward...._.__..__...___ 1-63, 2-E34 Fort Randell: 2. 00. 0. [.. route nere 2-A2 Fort Richatdson......-..\....u.222. 22; 2-A2, 5-B3 Fossils, Bootlegger Cove Clay...__._______._. 2-A21 Valdes Group..... :.... in bison. 3-04 Four Seasons Apartment Building, Anchor- AOL Ieee io mii diena daly 2- A24 Fourth Avenue slide area, Anchorage.... _. 1-57, 1-59, 1-78, 1-82, 2-A4, 2-A18, 2-A22, 2-A27, 2-A38, 2-A41 Fourth of Tuly fan-delta ..... . 2-E2L Fourth of July 2-E13, 2-E16 Fox Island-Andreanof region ... _._.__________ 3-149 Fox River, Cook Inlet 3-F17 Fractures. See Ground fractures. Frite Crook 2.2 cloth 2-D1, 2-D7 Frost, relation to ground cracks. 3-E6, 3-E13, 3-E24 Pocus. ix ce neni oen cough ol 1-34 21. .e UNII ISE 3-112, 6-35 Fukui, Japan, earthquake -... 2-A8, 2-020 Fur-bearing animals, Martin-Bering Rivers loco [e e praca e 3-B27 Fufrow. } 0.2.2. d., 3-E11 G Gages, recording, mises. 6-34 Gaging stations, instruments and records.... . 4-E10 es loo. . 10. 9 3-E3 Galiano Olacier. _... i 4-D38 51 Page Geodetic measurements, horizontal displace- Mets». . clo nodal 3-G40 Geographic setting, Afognak .. .. 2-F28 soo... ileus Homer Spit. Raguyak acl orcad 20 2d oun eee 2-F37 Kodiak.... .l. 2-F3, 2-F17 Kodiak Island area 2-F3, $-D8 Montague Island 3- G4, 3-H2 Old ceci Ac 2-F34 Geographic setting, Uzinki 2-F33 . . 020102 lete GLE us .. 2-B2 Geologic setting, Afognak....._..___________ 2-F28 Aleutian 0. cee 0+. 3-145 Anchorage. ...;. cl (dv resto tus 2-A11 Cook Inlet aren. . . 2 o.. 2... celeriac enne 3-F2 Copper River Basin 3-E3 Eklutna Hydroelectric Project.....__.._.. 5-A4 highway system.... c scene dees. 5-C2 Raguyalk s. ... 00.0 ue. omnes o 2-F37 Rodink .s. . ..o 009 io rue ai dent at 2-F17 Kodiak Island 3-D6 Montague Island... 3-G4, 3-H4 Old Harbor. 22.. 0220002. eel iin dl. 2-F34 Prince William Sound area. .............. 3-C5 relstion to 5-D95 collonies ... 2-E16 Wanslatory 2-A38 Uzinki. 2-F33 Valdez. ». 22 000. 22000. ACII 2-B3 Geometry and mode of failure of slides, Anchor- ers eee deedee ek eras acne 2-A40 Geometry of deformation.........._._.._..... 3-124 Geomorphic effects, Martin-Bering Rivers ATERSAA LO O rents -B3 Georgia, hydrologic effects of Alaska earth- quske.. nn: a tees 4-019, 4-C42 Gibbons, Frank, eyewitness account of, . 2.2 sL deere ei 8-A17 ..... 09. iret ls 1-34, 1-100, 2-G36 Glacial deposits, Copper River Basin......._. 3-E6 Kodiak group of Islands.._...... . 3-D7 nll cleo .... 2-B18 Glacial outwash terraces, relation to rail dam- ECL eo, Soe dob aes eel pide 5-D92 Glacial till, .... Ae 3-D21 Glaciation, Martin-Bering Rivers area...... 3-B19 Glaciers. :. 0.0 ecco Prof. Paper 544-D, 6-21 Glacier Island, gravity values...._..________ 3-C11 Glenn Highway - 22 0070000, LCL EA Len en t 1-29, 3-E3, 3-E25, 5A-1, 5-C4 (Hennallen, damages... 0.22000 3-E25 effectson 3-E8, 4420 ground: motion...». 22.0 , do adv et line 3-E7 PODHIAHON : . 2. 510009 css el secede 3-E3 Glennallen Road Camp, damage............ '8-R25 Globigerina bulloides......._........ 221 S0. .'. umes de cale 2-A21 Goot Monnifain . : : .... .l 299 es cont BV e A liane 5-A1 - 2-E18, 2-BE21 Godwin Glacier...... Gold Coast, Oreg. .-..... vis Gold Creek .. 2-C16~ Government Hill slide, Anchorage............ 1-57, 1-59, 1-78, 1-82, 2-A2, 2-A 27, 2-58 Graben, use of term in 2-A40 Graben rile. 202.2000. cea a een is 2-A2, 2-411 Grain size of sediments, damage to highways. 5-C43 Granitic rocks, Prince William Sound region.. 3-C% Gravel-coated snow cones................_._... 3-B22 Graveyard coche. 2-F28 Gravity, changes caused by vertical displace- TENNIS. » coc AL ce cein cece. 3-142 Gravity survey...... .. paper 548-C Gravity - -L del a 2-020 Grays Harbor County, Wash................. 1-37 Great Cutch earthquake, India. ............. 3-143 52 Page Great Indian Earthquake of 1897. See Assam, India, earthquake. Greenstone, description.. ........-.---------- 3-04 Greenstone belt, Prince William Sound...... . 3-C9 Grewingk 2-D5 Ground cracks. See Ground fractures. Ground fissures. See Ground fractures. Ground fractures, Anchorage.....----------- 2-A27 caused by landspreading and embank- menifs.. cll. ne e 5-D90 Chitina River flood plain.............~.-- 3-E17 Cook Inlet.. Prof. Paper 584-F Copper River Basin....................- 3-E1l Homer. so caa LL ice- erat 2-D7, 3-F12 Jap Creek fan...... 2-E34, 4-A114, 5-D55, 5-D98 Kachemak 3-F3, 3-F24 Kenai Lake deltas.. Kodiak: rn, 9.00 2.200. i ORU ce ser ue s 2-F7 Kodiak group of islands.... .- - $-D13 Martin-Bering River area. .--. Matanuska flats..........- .._ 2-B21 Mineral Creek flood plain................ 5-D99 OVIgih --. SCENIC I-- ec ache nus rears 3-E23 Portage Luc ler coule evar 2-B21, 3-F19 relation to frost.. 3-E6, 3-E13, 3-E24 Robe River flats: U0 Ai. 29 2-B21 Rocky Creek delta. _...... 3-A33, 3-A37, 5-D76 Sew itd lie neer pelos naar eae dele 2-E4, 2-88 south-central Alaska 3-B3, 4-A9, 5-D53, 6-19 Padina Glacier, 3-B24 theory of formation . . Tustumena Lake area.. 3-F16 Valdes. 2-C1, 2-C18, 2-020, 2-C30 Victory Creek. ... B-AB7 Whither. 22 dere 2-B15 With 2-A27 Womens Bay . .L leu dad 2-F7 Ground motion, Copper River Basin. ...--... 3-E7 generals Acco L Le oren cereal . 2-0C20,6-26 Kodiak Island area......--.-. - 8-D7, 3-D12 Kodiak Naval Station.........._....l..... 2-F6 SowarQ- rus .o s ou ae et ode a Lda 2-E4 Valdeza 1 ni- 1200.6 .E one ien aeon 2-C30 Ground water, affected by earthquake.. ..... 6-22 ATOENAR ALS ORL soll dle ee seco 3-D23 Amchor Point.. L. ules 4-A23 Anchorage Brea.... cdg 4-B4 Bootlegger Cove Clay........._......... 4-B13 CHUBIAKL LOON Noreen a o 4-A19 Copper River Basin......._....... 3-E8, 4-A19 Cordova.. .-.... Yi.. GCL cu ened d 4-A20 fiictuation. ... "1. 20.0. ICO Ace esu e i e. 3-E8 Homer: lien dade 2-D16, 4-A21 Kodiak Island 3-D23 Seward:::.....}...... 2-E27, 4-A24 south-central Alaska. . ......__...__....- 4-A13 Ground-water table, relation to ground 2... anv nn 3-E13 Growth limit, sessile intertidal organisms.... 3-112 Gulf of Alaska. .... ie ds. 1-7, 1-14, 2-E2, 2-E41, 2-F3, 2-F18, 3-E3 Gulf of Mexico.. 1-37 sen ue) oy cerca clears der be eames 3-E3 Gulkana Airfield, damage..... ... 3-B25 Gulkana River. cleus lue 3-E3 Guilkana Upland}. lee. 1-10 H Halibut Cove. .... l. cl i arie 2-D4 Hanning Bay fault. . _ 3-G6, 8-27, 3-125, 3-144, 6-12 Harbors and 1-30, 5-B6 Harding Icefield................. 2-B2, 2-E17, 4-D1 Harriman Fiord, gravity values...........--- 3-C8 INDEX Page Harriman 4-D36 Harvard Olacler..... 2: need ee ancl s 4-D4 Hawaii, hydrologic effects of Alaska earth- quake. cL Alley celles 4-C23, 4-C43 secondary damage................_....... 1-36 Hebgen Lake, Mont., earthquake.. lumen Helden Canyon.................. 1-17, 2-C1, 2-C18 Hidden 4-D38 High-risk areas, Anchorage......-- 1-63, 2-E26, 2-E32 Valdez..) .. co. e eau e cin en ene old 1-79 Highways, Copper River Basin area...... ..- 3-25 Kodiak Island...... ces 3-D39 overall damage.....---- 1-27, Prof. Paper 545-C See also names of highways. Hill Building, Anchorage...-.-...---.-------- 2-A25 Hillside Apartments, Anchorage....-..------ 2-A25 Hinchinbrook Island, basaltic lavas... . submarine Scarpg......_..._._._....- Hodge Building, Whittier.........-.-- 2-B6, 2-B20 Holocene deposits, Montague Island...... .. 3-G26 Hiolocene faults.. .._... - 8-153 Holocene vertical shoreline movements....... 3-155 Homer:... loll ec. ur Prof. Paper 548-D Sirport_...!.-._.... cleanup and restoration.... .... 1-80, 1-88, 1-90 ground 3-F12 ground SHDSIGENCO:L L. ...l -do hire ece r + 1-82, 1-90, 2-D4, 2-D13, 2-D22, 3-713 Task Force recommendations... Homer area, landslides.. ...-- --- Homer SDH. .._. Prof. Paper 542-D beach 3-]1 .. 1-63, 3-F14 lle edocs 5-B5 Hood cess 2-A61 Hood Lake, landing Strip......--------------- 2-A9 MUG 4-B4 Hope, general damage.... 2-G36 subsidence.... Horgan, Lake Zurich, Switzerland, turbidity Current l cll ll oo Loana eee e 3-A1l Horizontal bridge accelerations . 5-D91 Horizontal compaction. ...-... .------------- 3-E23 Horizontal displacements...........----- 3-126, 6-11 Horizontal movements of mobilized soil. ..... 6-16 Hot Springs Cove, B.C. _._......-.----- 1-37 Howe Sound ............- Hunter Flats, alluvial fan... flood plain............ Hurricane, Alaska......_...........- 1-26 Hydrodynamic factors, ...... ... 4-E12 Hydrodynamic WaVes......_......_.....---- 3-D12 Hydrologic effects...... Prof. Paper series 51}, See also Ground water; individual feature or locality. Hydrology, definition of terms-........--.-.- 4-E2 Hydroseism, definition.........----...------ 4-C2 from aftershocks...............- ._ 4-034 largest recorded outside Alaska. . . .. . 4-032 surface-water bodies. .. .._......-..------- 4-C5 apelie 2. . LL LOUTH LT s Lent aoe 4-C4, 4-06 worldwide occurrence. _.. 6-23 See also Seiches. Hydroseismogram, definition... 4-C2 Nunn-Bush Shoe Co. well, Wisconsin. .. 4-C10 3-D7, 3-E6, 3-14 I Ice J-D5, 4-036 Ice cover, effects on lakes.... ._.... 4-A4 effects on streams. . .............--------- 4-A9 Page Tce fractures, Bering Lake. ...._..........--- 3-B24 Copper River.... sed 3-E10, 4-A9 general. ewe 6-22 Nelchina River............l.li0cll . 3-E10 Sanford River. - 3-E10 PId@68L ...!. one ne rene eo oe + 4-A5 Icebergs, College FiOrd .... 4-D36 Tty Point, AIASK@L .. 1-14 Idaho, hydrologic effects of Alaksa earth- roan 4-C23, 4-C43 Tliamna Bay, height of tides............------ 3-123 Tllinois, hydrologic effects of Alaksa earth- Guake -.: ALLTEL Ll 4-023, 4-044 'Indian Creek, Cook Inlet area..............-- 3-F16 Indiana, hydrologic effects of Alaska earth- quake... 4-C23, 4-C44 Ingram, John, eyewitness account, seiching. 3-A28 TnOCETOMUSE 2. 22 020000000 uC Lhe nu nlra hice aon 3-C4 Instrumentation and measurements.......... 6-40 Towa, Alaska earthquake effects on ground Weber:. rien ech sou 4-C23, 4-045 Tron 2.20 llc 2-E17, 2-£28 Israel, hydrologic effects of Alaska earth- cris at Pains. 4-C14 3 Jackson Point.. }. . O eres cea d 2-C30 Jap Creek...._.... _._. 2-E15, 2-E17, 5-B25 'Jap Creek canyon.... .. 2-F4, 2-E14, 2-E20, 2-E33 Jap Creek fan, grand fractures..............- 2-E34, 4-A114, 5-D55, 5-D98 Jandslideg. . ..... cadens 2-E15 12 (iced ce dl crees 2-©20 Japan, secondary damage..... 1-36 Japanese earthquakes.......... 3-E8, 3-143 Jeanie Creek, Patton Bay fault.. ... $-G16 Juneau.... Jurassic rocks, Kodiak Island..........-.----- 3-D6 Prince William Sound region.. . :. 3-04 Jurassic to Cretaceous deformation . . K Kachemak Bay, beach erosion........---..-.- 3-14 ground fractures..........._...._..-- 3-F3, 3-F24 location ... .. ele eee b dees 2-D1 SEICHO8.. .: lu... ico dene een air 2-D14 cl 00.0. inset doma ne 5-B12 Kadiak Fisheries cannery damage...-..---- 3-D43 slc . lire ce cece ne 3-D11 subsidence.......------ ___. $-D13, 3-D18 Kaguyak, damage....-------- ___ 1-19, 1-94, 2-F87 DODUIAEIORNL . . ... 3-D6 PrOperty 1088@8. . .. 22 3-D3 SUbsidencé.. ...... sed 2-F38 Kaguyak Bay....._.__....-..-- __ 2-F38 Kalgin Island, Cook Inlet area...... 3-F24 Kalsin Bay, damage to bridges. ...-... --- 3-D39 seismic sea WAVeS...._...-.-------- .. Kalsin River, damage to bridges..........--- 3-D39 Kansas, hydrologic effects of Alaska earth- 4-C27, 4-045 Karluk, 2-F3, . . . .. 3-D6 Kagliof River...»). 3-F3, 3-135, 4-A10 Kasiteria regen 2-D4 Katall®, 1-41 Katmai Volcano, deposits. . ..... 3-D7 Kayak Island, uplift....... --- 2... I-17 Kenai area, general damage.........--------- 3-G37 2 cece -->> 4-A21 Kenai-Chugach Mountains........------ 1-12, 3-D6 Kenai 2-D6 Kensl Prof. Paper 518-4 fan 5-D105 horizontal displacement. . _.. 1-40, 3-134, 6-34 Kenai 3-126 Kenai Lowland, Cook Inlet area.... . 1-9, 1-44, 8-F8 GTOUNG WALL ~~ >>> 4-A21 Page Kenai Mountains, Eklutna 5-A4 geography and geolOgy..-.--------------- 1-9, 2-A11, 2-B2, 2-D1, 2-E16, 3-C5, 3-D6, 3-F1. 4-D36 4-D1 1@Ke I6¥@l8. ...... 4-D33 regional subsidence. 3-D28, 3-160 Kenai Peninsula, airstrips. .... 5-B5 . . 00 >--- ---> 2-G85 10CBNION. . . .. ...or ecu cn olan nies beri 3-A2 ofl and F481... ls 1-100 power .-- .. 5-B19 rate of bluff reces8ION... .... 3-J19 subsidence.....---- £s ... 8-158 WAVES. L..... __.. 3-123 Kentucky, hydrologic effects of - Alaska earthquake.. ..----------- 4-C27, 4-045 KIJANA .. n 3-E21 Kiana Creek delta, subsidence.--..---------- 3-E21 Kiliuda Bay, subsidence.. 3-D13 Kilinda Creeks. 3-D27 King Salmon, community. - ___.. 2-G44 Kiniklik, gravity VAM... --. 3-C8 icons doce ee dewar 46 1-98 Kluane ---> 4-D39 Klutina Lake.......-.--- 3-E3, 3-E10, 3-E13, 3-E2l Klutina River, diversion.....--------- 3-E13, 4-A9 10CBLION_. L... 3-E3 Knight Island, geology.... ------------- 3-C4,3-06 gravity values...... 3-C8,3-C10, 3-C11 SHEAF ZON. . ..... enn 3-C6 Knik and Matanuska River flood plains.... . 5-D153 Knik Arm, 4-A18 as geographic boundary.... ..------------ 1-18, 1-73, 1-102, 2-A2, 2-A28, 2-A30, 3-E3 GiSChATg® ZON@S.. .. .c ooo -- 4-B12 EKIutmA PrOjJ@Qb. . .cc --- b-A4 slides on West Side. ...--... 2-A34 Knik Arms Apartment Building, Anchorage.. 2-A26 Prof. Paper 543-F Qlty AIFBETIpL .._ 5-B5 communications and utilities. 5-B24 Kodiak and nearby islands.... -- Prof. Paper 548-D Kodiak Island, coastal lakes......---- ___. 4-A8 Kodiak Island area, subsidence....--. - 3-D13, 5-B8 Kodiak Naval Station, damage.. 2-F5,3-D3, 5-B15 SUbSIGeNG@.. L. .... cn -n- 2-F10 L L Street Apartment Building, Anchorage... - 2-A26 L Street slide, Anchorage. ..-... 2-A43 L-K Street slide area, Anchorage...---.------ 1-57, 1-59, 1-82, 1-100; 2-A4, 2-A22, 2-A27 La Coste and Romberg geodetic meter G-17.... 3-06 Lacustrine deposits, Copper River Basin. ..... 3-E6 Kodiak Island area- 3-D15 LaGrange's 3-D37 Lake basins, tilting....---------------- 8-184, 3-F26 Lake Charlotte, landslides.......------------ 3-B19 Lake Clark-Castle Mountains fault.... 3-F2, 3-F23 Lake 3-F2 Lake-ice fracture, Copper River Basin.... .- 3-E10 Martin-Bering Rivers area.. ---.. 3-B24 Lake Louise, location... ..-... .... $-E3 Lake Louise ..-. ------------------- 10 Lake nad 4-B4 Lake Rose Tead, bridge.......-------------- 3-D42 stibgidence. ._.... 3-D15 Lake 4-B4 Lakes, Anchorage 4-B4 as tiltmeters. 6-34, - 3-F2 effecis. . JL ins 20s sewa bee be no 4-A4 fluctuations in level.. .-- --- 3-D24, 3-141, 4-A7 ice fractures......-..- 3-B24, 3-D 24, 3-E10, /-A4 Lakeview delta, bathymetry. ........-------- 3-A4 3-A3, 5-D106 WAVES... U. dusan 3-A7 INDEX Page Land area affected by earthquake......------ 3-]1 Land ownership, legalities......--- - __ 3-718 Land snails, effects of earthquake......------ 3-B27 Landslides, Anchorage area.. 2-A9, 2-A21, 2-430, 5 D-76, 6-17 Sce also Turnagain Heights. Anchor River 2-D7 Bering 3-B19 Cape Saint Elias. .... 2-G33 CARES. 3-D22 Copper River _. $-E11 damage to highways.. __ 5-026 damage to railroad . . ...----.------------ 5-D72 effects on lakes... sane 2-D3, 2-D6, 2-D10 Jap Cr6GK faR . ne- 2-E15 Kenal . 3-A3 Klutina Lake.. ...-.-.---------- 3-E13, 3-E21 Kodiak Island 3-D18 Lake Charlotte..........------ - 3-B19 Little Martin Lake.....----- ... 3-B19 Meadow Creek delta. ....------- _... 3-AM prior to the March 27 earthquake.... --- 2-A66 Prince William Sound..----.------------- 6-16 Quartz Creek delta.... ___ 3-A2M Richardson Highway . . .--------------- 3-E24 Rocky Creek delta.. 3-A3, 3-A12, 3-A22, 5-D76 Seward 2-E22, 2-E14, 2-E28 Ship Creek.......----.----- 3-A12, 3-418, 5-B3 south-central Alaska..------------ J-A?, 6-30 Tokun Creek delta. Ponsinga Lake. 3-E21 ... 60> 2-A88,6-30 Turnggain Arm.....--------- 2A-30, 5-D73 Turnagain Heights 1-18, 1-57, 1-59, 1-73, 1-82 2-A2, 2-A13, 2-A28, 2-A38, 2-459, 5-B4, 6-18 Victory Creek. .. 3-A3 Valdez.. 2-C1, 2-C7, 2-C10, #-C14, 2-030, 2-035 2-B15, 2-B21 Landsliding and lurching. - --- 5-D56 Landspreading, bridge damage-..--- 3-A31, 5-D89 construction in potential areas..--..----- 5-D94 cee ns 6-16 new term prOpOS@d. ...... 5-D57 Lakeview delta, ground fracture....--------- 3-A33 lateral spreading . - -.- ------------- 3-A 4, 8-A1l §HObs: : 2. ool cera eee neuen $3-A8,8-A12 Laramide 3-152 Larsen Bay, damage.....-------------- 2-F3, 2-F40 erosion by Storm WAVs... ...... -------~--~ 3-J15 DODUIGAHION. ...... 3-D6 Latouche Island, earthquake effects . . 2-G22 gravity 3-C11 Lawing alrstrip. 5-B5 Lawing delta, bathymetry.....-------------- 3-A12 3-A28 slides.... cul: _. 3-A12,8-A2 3-A20 WAVOR. _.. .po vali e nabe ber 3-A12 Learnard 2-B3 Lee's - Guide - Service, - Glenn Highway, GaMAgeL os 3-E25 Legal problems, littoral rights... --- -- 3-719 Legislation, special Federal.... .-----------~-- 1-49 Leveling, comparison of preearthquake and postearthqtake.. ..... .------------ 3-120 first order, at Seward -. ---.------------- 2-E16 Libya, hydrologic effects of Alaska earth- @UBK®.. 2020 22.9 4-C14 Limnogram, SeIChING ...-- 3-A25 Liquid Himit, S0ll8. . 2-A15 IAquidity 2-A16 Lisbon earthquake, seiches. ... --- ----------- 3-A20 Little Martin Lake, landslides. ...--. ------- 3-B19 Little Susitna __ 4-Al Little Tonsina River bridge, damage..------ 3-E26 Little Tonsina River landslide, Copper River 3-E13 53 Page Lituya Bay, 1958 earthquake.....--..-.------- 1-14 rockslide @V@IANCh@... ...--... ----------> 4-D26 Logging industry, Kodiak Island area._..---- 3-D44 LONG ISIANGL .... .... 8-04 Long Island 2-F18 Longshore material movement.......--.------ 3-]15 Louisiana, hydrologic effects of Alaska earth- L 4-C27, 4-045 LOYVG ---> .... 5-D27 Low-angle thrust theory.... -.--------------- 6-13 Low-water features.... 3-16 LoWe RIv@r......._._.....llll.. 2-02, 2-C7, 2-C14 Lowe River valley.. . 2-C1 Lowell Creek at Seward..----- __ 2-E16, 4A2 Lowell Creek canyon.... - 2-E4, 2-E14, 2-E18, 2-33 LOWell CreeK fM. . ...... ~~~ 4-A15 Lowell Point..........---------- 1-63, 2-E13, 2-E16 Lowell Point fan delta. . --.---------------~- 2-E21 Lower Tonsing Hill. ...-..------------- _.. 5-027 Lower Tonsina River bridge, damage.. ..-. -- 3-E27 Lucia 4-D39 M Maclaren River, 1OC&tION. ..... -- ------------~- 3-E3 MacLeod Harbor, effects on raised beach. .... 8-H2 Hanning Bay fault.... ...... ------------- 3-G27 Magnetic effects of earthquake.... 1-33 3-D 7, 6-26 Main Sand Bay...------------- 3-H27, 3-H29, 3-H30 Maine, hydrologic effects of Alaska earth- 4-C28, 4-046 Malaspina piedmont glacier..~.~.------------- 1-14 Manitoba, hydrologic effects of Alaska earth- ell kail et h> 4-C16 Marathon Creek.... -- . 5-B25 Marathon . .- 2-E17 Margerie Glacier.. -.. .... 4-D26 Marka li 3-D27 Maps and other basic data, availability . - -- 6-3, 6-42 Marmot ._. 2-F28 Marmot Island, landslides. .... ----------=--~ 3-D18 .. L. .c. lool cele nere note- 3-D25 Martin-Bering Rivers area-. Prof. Paper 543-B Martin Lake, landslides... .. -.-----------~--- 3-B19 SHOW dee nr 3-B22 Martin River Glacier, rockslidéavalanthes. - . 4-D13 turbidity changes in lakes....----------- 3-B21 Martin River valley . ..- --------------- 3-B2, 3-B19 Maryland, hydrologic effects of Alaska earth- 4-028, 4-046 MASS MOYVOMNERL 00999 6-14 Massachusetts, hydrologic effects of Alaska earthquake.. 4-C28, 4-046 Matanuska, railroad damage... -- -- --- _. 5-D156 Matanuska flats, ground fracturing ___ 2-B21 Matanuska geosyncline. ..... -------------~--- 3-E3 Matanuska Glacier 3-£25 Matanuska River, location....---------- 3-E3, 4-D1 Matanuska Valley, general damage. - - - - --- --- 2-G45 geologic and hydrologic environment... .- 4-A23 DOWF 5-B19 Mayflower Creek, damage to bridges. .------- 3-D39 Meadow Creek delta, Slide. . .. .------------~~ 3-A24 Meares Qlagler. ._ nnn 4-D4 Mercalli intensity, ground shaking.........-« 3-D12 Hoth@r .ll Ceed inden eas 2-D3, 2-D18 deer nanos 2-F40 Kodiak group of islands. . .- --- --- 2-F29, 3-D12 O14 HarBbof... .. 2-F35 Merian ..... 3-A25 Metrill Field.... " 5-B3 Mesozoic rocks, Prince William Sound region.. 3-C5 Michigan, hydrologic effects of Alaska earth- 4-028, 4-C46 Michigan basin, . . ...-- 4-E14 Middle Bay, damage to bridges.... --- -------- 3-D39 54 Middleton Island, crustal thickness general damage..cl....}.0..0...200.; horizontal displacement. ....__.___________ 3-130 upliffo.2ss clo... st ., 3-D28, 3-121, 3-I60 Miles [Oc 4-A4 Millers Landing area, wave erosion...._.______ 3-712 Million Dollar Bridge..............;_.. 1-29, 5-C35 Minpral ._ ...: 2-C35 Mineral Creek ..; 5-D40 Mineral Oreek delta............___...._.__., 2-C16 Mincral Creek fan...:...._._...} 2-C1, 2-C3, 2-034 Mineral Creek flood plain, ground cracks. .... 5-D99 Mineralogy, Bootlegger Cove 2-A19 Miners Lake.. -.. ...... tat t cu 4-A7 Mines, effects of earthquake. .__..__.__.____.___ 6-27 Minnesota, hydrologic effects of Alaska earth- :c cdg .ll. 4-C28, 4-C47 Mission lca coca n a | 2-F18 Mississippi, hydrologic effects of Alaska earth- (Hakes 1200. ts 4-C28, 4-047 Mississippi . 1-33 Missouri, hydrologic effects of Alaska earth- @HAkOL.: s: re Lu 20s 4-C28, 4-C48 Modified Mercalli scale.. ._... ___ 2-D3, 2-D18, 3-D12 See also Mercalli intensity. Mollusk 00.0... 2-A21 Montague Island, beach erosion and deposition Prof. Paper 548-H faults...... Prof. Paper 548-G, 3-C6, 3-125, 6-12 gtavity valfies.-.........l2 nll tcl 3-C8 horizontal displacements... .. 3-130 subsidence. .... .in 0.02 tn O0 3-160 2s Sse ais oid t ---- 3-D28, Prof. Papers 643-0, H, 3-118, 3-143, 3-J12 Montague Strait, gravity values......_._.____, 3-C9 Montana, hydrologic effects of Alaska earth- ct 222 a 4-C29, 4-C48 Moorcroft, J. W., eyewitness account of sliding.3-A 28 Moose Creek, Cook Inlet area.. ._.__.________ 3-F16 Moose - 1-40, 3-A28 Mount l}.) 0C. 1-11 Mount Fairweather............._...ll 1-8 Mount Foraker 0}. ___ 1-9 Mount Gerdine.:..!....._.. $) <- 158 Mount 000.0} -_ 1-9 Mount Hubbard... ..._.._. ._.... . 0 1-14 Mount IMamns..... 0 1010000) 1-8 Mount Logan........_._..:..._... -.. 1-14 Mount MceKinley....._..___ ;.... ...... 1-8, 2-A11 Mount McKinley Building, Anchorage....._. 2-A26 Mount Marathon......._.¢...l;. [.._ [._ 0. 1-90 Mount Pelee eruption................_.. __... 1-5 Mount Saint Eligs......;_.__..._._.__ _._ 1-8 Mount Sanford.... 1-11 Mount Spurr. l Cc |" 3-145 Mount {200 00. 0C 3-F23 Mount :.. __. [___ 1-14 Mount .. ( 0.0} 1-11 0 2-A20, 4-B4 Mud volcanoes. See Mudvents. 2 i 000000000 3-B13 Mudvents, Copper River delta...__._________. 3-B9 Martin-Bering Rivers area. ---. 3$-B8 Muldrow ...:...) __ [__. 4-D38 Munson Point: !...... l Oil. 2-D3 Myrtle Creek, seismic seawaves....... 3-D34,3-D35 N Nankaido earthquake. ___ 3-143 Narrow Cape, fluctuations in well levels.... 3-D23 landslides . 200 ta 9} 3-D21 seismic seawaves....._____________ 3-D30, 3-D35 HPHE - .s sA Lote oon og 3-D25 Narrow Cape spur road, damage. .._...____ 3-D42 Namow _... __ 2-F33 Native Hospital slide, Anchorage. __. 2-A41, 2-449, 2-A66 Native villages 1-94 See also particular wuagéf AAAAAAAAAAAAAAAAA INDEX Page Navigation gide.::.....0._ .}. 0.0000. 5-B7 Near Islands.... 2m 22 Ac. 2-F18 Nebraska, hydrologic effects of Alaska earth- -.... 4-C29, 4-C48 Necanioum .. 0 go. 1-37 Neek ...can t 3-G7 Nelching -...... 2 ovi tle o_ 3-E24 Nelchina River, ice fracture..___...__._______ 3-E10 Nelchina River delta, ground cracks.. 8-E17 Nellie Juan River.... 002 clin (20. to 4-D34 Nellie Martin River...... oue 3-G20 Netiand Glacier.... ... .c. nlanr cnn anu e 4-D31 Nevada, hydrologic effects of Alaska earth- (Hike .i Caney 4-C29, 4-C49 New, Lester, eyewitness account..... 3-B27 New Hampshire, hydrologic effects of Alaska earthquake.: 4-C29, 4-C49 New Jersey, hydrologic effects of Alaska earth- 4. utr 4-C29, 4-C49 New Madrid, Mo., earthquakes of 1811 . 2-A38; 2-C20 New Mexico, hydrologic effects of Alaska earth- toons. 4-C29, 4-C49 New York, hydrologic effects of Alaska earth- } it 3 4-C30, 4-C50 New Zealand earthquakes....._______________ 3-143 News coverage, Task Force decisions. --.. 1-65 Niigata, Japan earthquakes.._________________ 3-143 Ninlichik..-.2. s' -. 4-A23 Ninlichik runway. ..s.. egt 5-B5 North American Standardization Pendulum Staton. . ..is! oot oils 3-C6 North Carolina, hydrologic effects of Alaska 4-C30, 4-C50 North Dakota, hydrologic effects of Alaska earthquake. .............. 4-C30, 4-C50 North Sandy Bay...... .._. 3-H29, 3-H33, 3-H38 Northwest Territories, Canada, hydrologic effects of Alaska earthquake.._._. 4-C16 Nunn-Bush Shoe Co. well, Wisconsin, hydro- .c; 4-C10 Nyman l}. 2-F6, 2-F12 0 Occanographiceffcets:.. 6-23 Office of Emergency Planning...... 0.1; 1-46, 1-94 Ohio, hydrologic effects of Alaska earth- coal cain ot 4-C30, 4-C50 Oklahoma, hydrologic effects of Alaska earth- anl ll cu 4-C30, 4-C51 Old Harbor, fluctuations in well levels . . __.. 3-D23 --. 3-06, 2-F3 property losses.___________ -_ 3-D3, 2-F24 seismic sea waves...__ 1-19, 1-94, 2-F36, 3-D32, 3-D33, 3-D35, 4-A11 200... ut... .. 3-D15, 2-F34 Olds River, erosion of bottom . _ .} -. 8-D27 Olympic Mountaing..........._.. ...... .l. .l 1-8 Ontario, hydrologic effects of Alaska earth- quakes. sls rel c .. 4-C16 Orea Group-. 0000}: 3-C4, 3-06, 3-G4 Ofes Inleb. :. -. . ons dee TOE 1-32 Oregon, hydrologic effects of Alaska earth- quake.» 1-37, 4-C31, 4-C51 Orogenies, south-central Alaska ..___________ 3-150 Oshetns River, location.......__. _.......__ 3-E3 coun- 2-A21 Ouzinkie. See Uzinki. e P phases on seismograms...__._______________ 5-D8 Pacific Border Ranges province. ....____ 1-12,3-D6 Pacific Coastal forest, Prince William Sound ATORk sence eon ad veal ee eet eaves 3-B2 Pacific Mountain System 1-8 Pacific Ocean ...l... }.. 1-7 Palmer, damage..... - 8-F20, 2-G45, 4-A23 electric - 5-A1 Palmer Creek 2-D6 Page Palmer cfl. 1-36 Passage /- 2-B2,2-B5, 3-C6, 5-B6 Pateoris .._ ..... 2-A21 Patton Bay .ll. ci E cic Coa 3-H7 Patton Bay fault.. 3- G7, 3-125, 3-I31, 3-144, 6-12 Patton 222202. 10:90." 3-G7, 3-G16 Patton River Valley, Patton Bay fault._____ 3-G21 lus pne" 3-E3 Paxson Lakes.... -. 3-E3 (100000000 5-D92 Penny's Department Store Building, An- . 2-A26 Penstock, Eklutna project..._.______________ 5-A13 Pennsylvania, hydrologic effects of Alaska .. 4-C31, 4-C51 Pert .l 2-D4 Permafrost, Copper River Basin...__________ 3-6, 3-E13, 4-A19, 6-27 Petry il <.. 2- G28 Petroleum and natural gas facilities..________ 5-B21 Philippines, Republic of, hydrologic effects of Alaska earthquake..._________ 4-C14 Physical environment, effects....______________ 6-14 Physiographic divisions . .___________ 10 1-7 Physiography, Copper River Basin . ___ - 3-E2 Fairweather Range. .____________ 1-8, 1-14, 3-J3 Kenai oll. conc o 3-A2 Martin-Bering Rivers area._..____________ 3-B2 relation to damage. 5-D95 south-central Alaska. ._.__.._..______ 1-7, 3-134 4-B8, 4-B13 Pinnacle 2-633 Placer River flood plain. ..........._..___ ._. 5-D118 Placer River Valley.....:.!. /...} ...;..." 4-A15 Plasticity index, 2-A15 Pleasant Valley, Nev., earthquake of 1915. . __ 3-E8 Pleistocene deposits, Anchorage area... 2-A11, 2-A12 Copper River c.. 3-E6 Point 0.000: 2-A30 Point cu 1-3, 2-A2 Point 0000.0 00000 be 2-G24 Point Woronzof, Bootlegger Cone Clay. -_ 2-A12 landsliding. ...s so se ulan oo 2-A33 Polymorptna lus ao 2-A21 Pony Point>Ofeg.:.... 10000... 000." 1-37 Porcupine Creek, 3-A 24 Porcupine Island...... ___ 3-A 3, 2-A25, 3-A 30 Port Alberni, BJC... 0.010 . 1-37 Port Bailey, fluctuations in streamflow . _. .._ 3-D24 Port Bailey cannery, fluctuations in well levels. cu. .io ol ules dt 3-D23 Pork. GrahaniL. ..o. aes sonce n o 2-G37 Port Gravina, gravity values.. -. 3-C8,8-C9 Port Gravina pluton, density......_.._...._. 3-C10 Pott Mons . ...s. one oen eet 1-96, 2-F28 See also Afognak. Port Nellie 5-B11, 2-G24 Port lulu, ." 5-B11, 2-G25 Port of Anchorage area...... ... -. 2-19, 3-487 Port Royal, Jamica, 1692 slide. ....._________. 3~A3 Port Valdes :...... 2... ISOs LAI 1-36, 2-C1, 2-C10, 2-C14, 4-A26, 5-B15 Port Valdez i000... 2-C18 Port Valdez fjord . .. - 1-17, 1-40, 2-C3 Port Wells.. 2090s. 0010 acy 1-36 Portage, general damage...................._ 2-G40 ground fractures.........}::..0l}. 2-B21, 3-F19 tallroad damage........ 5-D139 regional subsidente...........______._.._. 5-D80 Portage Creek flood plain.... 5-D118 Portage Glacier.._._____ - 2-B2, 4-A4 Portage Lake...... .. ction n vea e. 2-B2, 4-A5 Portage 020. ld rea Lole 2-B2 Ports and ADI. 1-30, 5-B6 Potatopateh Lake.... 003 2-F19, 4-A8 PObbeN: 2. .t puce us ean eon uo -.. 1-25, 2-A8 Potter Hill landsliding, Anchorage.... 2-A 31, 5-D72 Power Ureak .. o. 022.00. Joan cen cane 4-A10 Power spectral density function, defined.. ... 3-A25 Page Power systems. ...-- Prof. Paper 545-A, 5-B19 Powerplant, Eklutna 5-A15 Precipitation, Copper River Basin Av. 8-R3 Martin-Bering Rivers area... -- . 3-B2 President's Disaster Relief Fund.:----------- 1-47 Prince William Sound, biologic effects. . ..- --- 1-34 communities.... g-G11, 5-B1l gravity cire 3-C10 number of . . 4-D41 sStrUCtUFG Of OCKSL --no no" 3-C5 cls lcci c iets 3-D28, 5-B8 Valdez GIOUp.. --- ------------~~> .._ 8-04 water depths.. .---------- ... 8-C9 WAVORL. ...:. un manera ene ner 3-A1 Property values, affected by earthquake.... .- 3-J19 Protelphidium Orbicul@re. .. 2-A21 Ptarmigan 3-A12 Puerto Rico, hydrologit effects of Alaska earth- LO .cc or 4-C31, 4-052 Puget «nos 2-FA1, $-G41 Purple Bluff. 3-07, 3-G22 Q @uartk cobol noo. 3-A30 Quartz Creek delta, landslide...------------- 3-A24 Quaternary deposits, Kodiak Island...... 3-D11 Questionnaires, determining earthquakes' ef- ccc kane earn tends Pen 6-42 Quinquelocultina . ...- -------------- 2-A21 R Rabbit Creek: conor engin on 2-A32 Radioactive contamination, Kodiak Naval 20. once au s noe non 2-F17 Radiocarbon d&tINEL . ..- 3-159 Ragged Mountain Wan ine 3-153 Ragged Mountains, avalanches.. ------------ 3-B19 location ... 22 cla cele no nene dn r on 3-B2 Railbelt Reporter, damage from earthquake L. ceci dlc cca aber cnc eft noon 5-D3 Railroads. See The Alaska Railroad. Raspberry I8lafid...210 2-F3 Raspberry Straits, effects of tectonic deforma- AION. eel ncn edi reran neice een nore 3-D44 Rat Island @@rthGUAK@L 3-149 Rayleigh Waves.. ..- l.... 1-88, 5-D25 Recent 3-E6 Recent tectonit RIStOTY.L .. 3-150 Reconstruction.. ...-- -- . Prof. Paper 541 Recording gages, USeS._...- -- ------- Ma 6-34 Redoubt Bay, Cook Inlet area... --- . $-F23 Reid mechanism of earthquake generation.... - 3-164 Research, origins of earthquakes..------------ 6-37 Resurrection Bay... .- ------- 1-73, 2-E17, 5-B6, 5-D4 Resurrection 2-E15, 2-£29 Resurrection River flood plain, distribution of 1.0. inin Bete de nana rea irr nt 5-D98 Resurrection River valley. ---. - 2-E17, 2-E37, 4-A24 Resurrection River-Mineral Creek bridges.... 5-D35 Rhode Island, hydrologic effects.. .. -- - 4-C31, 4-052 Richardson Highway, damage..... ----- 3-E26, 5-C4 local 5-020 location.... 3-E3 landslides.. ... .... .-.. Arcee 3-E24 ._.... e> 5-020 Uplift. . 2-C18, 3-123 Richter magnitude, earthquake. 2-A2, 2-F4, 2-F2, 3-D7, 3-E6 first P 5-D8 River drainages, tilting... 3-135 River ice, Copper River Basin........------- 3-E10 Roads. See Highways. Robe ine 2-02, 2-C21 Robe River flats, ground fractures.......---- 2-B21 Roberts, Mrs. Hadley, eyewitness account of 3-A17, 3-A28 Rock avalanches, defined... .-- 3-B13 See also Rockslides. E INDEX Page Rock densities, Prince William Sound..------ 3-C5 Rockslides, Copper River Basin. ._ Kodiak group of islands... --- - 3-D20 Martin-Bering Rivers @I@A-------------- 3-B17 on glaciers. }-D6, 4-D26, 6-15 Rocky nev nn 2-G42 Rocky Creek delta, bathymetry...----------- 3-A4 ground fracture. ..--------- $-A83, 3-A37, 5-D76 landslides. ----------- 3-A3, 3-A12, 3-A22, 5-D76 railroad-bridge damage.. ..- --- --------~- . 3-A31 Rocky Mountains, atmospheric effects. . 1-33 o aio e v _._ 4-R14 Rogtie RIveL.. lance bcn ans 1-36 Romig Hill slide area, Anchorage.... 1-57, 1-60, 1-82 SD. Al-O: 001 cos n me bref 2-A21 Russian Jack 4-B2 S @ .L... ators 5-D27 Saddlébag 4-D21 Saint, Flias-Chugach fault...... 3-B2, 3-B19 Saint Elias Mountains, deformation....------ 3-153 physo@graphy. - .-- 1-8, 1-14, 3-13 Saint Paul Harbor, Kodiak. 1... 2-F18 Salmon Creek. l... 2-B22 Salmon fishing. See Seafood industry; Biologi- cal effects. Salmon River flood plain, distribution of dam- ABB. elles acetone ett rona n" 5-D98 Saltery Cove 3-D27 Saltery Cove spur road, damage..----------- Saltery Lake, subsidence. .------ San Andreag 6-30 San Diego, Calif.... -- 1-37 San Francisco Bay, Calf... --------~~--~~~~~ 1-37 San Francisco earthquake.... 2-A8, 5-D23 San Juan dock, Seward....---- 2-E13, 2-E23, 2-E28 gan Rafael, Calif. nnn" 1-37 Sand 3-B8 Sand boils, Anchorage. . --------------~~~~~~~ 2-A29 Seward...._.....-.- op dust 2-E38 Sand ejecta DIANKGtS. . 5-C27 Sand flows, effects on ground water..... ----- 4-A14 Sand ancer 3-B8 Sand boneca rc 2-F40 Sand vents, Cook Inlet Area.. ------------~-~ 2-F4 Kodiak group of islands. ..- -- ---> ___ 8-D15 theory of 2-C20 Sanford River, ito 3-E10 location. . cols access 3-E3 Santa Crug, Calif.... .... 1-37 Sargent Icefield...-- .- -~------~~~ 2-B2, 4-D1, 4-D34 Saskatchewan, hydrologic effects of Alaska CATERGUAKG.. 1 4-C16 1-17, 2-C14, 5-B11, 2-628 Sawmill Creek delta.... ....~~------==~=-~~~~ 2-C16 Schwan Glacier. .. 4-D13 Scientific and Engineering Task Force and its Field Team. . . . 1-46, 1-51, 2-E26, 2-B41, Sawmill Bay..------ 6-48 Scientific benefits of earthquake... ----------- 6-82 Scientific preparation for future earthquakes... 6-37 Scott Olatief:...... . 4-D31 21. nice sean een r 2-B8 Seafood industry, economic pattern. .... §-B7 effects of tectonism ...-- -- -- P s 3-133 Kodiak Island area. .. .- ------------~~~~~ 3-D42 Martin-Bering Rivers TOA... --------~~~ 3-B26 south-central Alaska.... - --- 1-25, 3-317, 5-B6 Seagide, lea coco inna n on" 1-37 . ...l... lo den airs nfo on" 2-B8 Sediment, relation to highway damage. --- - 5-043 Sediment compaction, Kodiak......-..._..-- 2-F18 Kodiak Naval Station.. . - 2-F7 __ 21-1 12 1. aden san frit tor 2-B15 Sediment displacements, models. ...-- ------- 5-D90 Sediment load, effects on streams...--------- 4-A13 55 Page Sediment thickness, relation to seiches.... - - - - 4-E13 Prof. Papers E (ANCROTARO AI@QL L222 nn -c nnn 4-B4 Cooper 3-A28 defNItION.... . 2-F2, 4-02, 4-E2 sl 2-D3, 2-D14 Kachemak 2-D14 Kenai Lake. ....---------- 3-A25, 4-A7 Kodiak Naval Station. ... .- ------------- 2-F17 Lakes in south-central 4-A5 Paggage Canal.. 2-B18 Snow River delta.. cocci nn worldwide OCCUITeNCE... . --- --~----~~ Seismic alt WaVeS...------~-----~~~~ Seismic data, Copper River 3-E6 Seismic effects, direct, Afognak......-------- 2-F28 e> 2-A21 2-F38 Old Harbor... __ 2-F34 .: en 2-F33 Whittier. 2-B11 Seismic history, Homer 2-D18 X gldbr.. .. .. Toa eH keren s ae eres 2-C7 Seismic sea waves, Afognak...------- 3-D33, 3-D44 Cape Chink. 3-D30, 3-D35 Cape Saint Elias... 9000 2-(G33 CHEACEA.. ._ cel 1-94, 2-G15 Cofdova.l.. l... caesar ece men" 2-G18 crest heights.... --- _.. 8-D33 damage to bridges. 11. 5-032 damage to port facilities. .. - -----------~- 5-D89 effects on stream mouths. ...-- ------- .. 8-711 gen@rabion... ._.. dicey. tenns 3-138 .._ 2-D4, 2-D18 Kadiak Fisheries cannery Kagliyak. Kalsin Bay Kodiak.. 22.10.20 Septet 2-F19 Kodiak and nearby islands. 4-A11, 3-D30 Kodiak Naval Station. ..--------- g-11F, 5-B15 magnitude seale. . ... 6-36 Montague Island.... .. 3-026 Myrtle 3-D24, 3-D25 Narrow Cape. .---------- . 3-D30, 3-D35 id 2. ne ce co cents 1-19, 1-94, 2-F36, 3-D23, 3-D33, 3-D35, 4-A1l relation to vertical displacements... 3-G48, 6-30 1-73, 1-91, 2-E4, 2-£13, 2-B41 Sitkalidak Island.. .--. .... 8-D35 south-central AlASk@... _ 6-25 Rivet: chide bba or 3-D34 Three Saints BAy.----------- _. 3-D30 Uganik 3-D34 LLL... cp ces renee 3-D33 AVhitHMer Line ellen cc duce ua ee onces 1-99 Womens Bay. 2-F2, 3-D33 Seismic Sea Wave Warning System. -. ------- 3-D45 Seismic seiches. See Seiches. Seismic shaking, 2-A22 damage to bridge approaches.... -------- 5-032 _______ 2-F6 SeWaLd.... r 2-E4 Seismic surface waves, amplitude distribution . 6-23 effect on lake 4-A4 relation to seiches. . . ...- -~-----~~~~ 1-33, 4-E15 dri doen eno" 3-14, 3-145 Seismographs, suitable networks.... 6-40 Seismology, definition of terMS. . . --- --=----~~ 4-R2 Seldovia, airstrip. ...... 5-B5 cleanup and 1-80 L 3-E3, 3-153 general d@MAg@--.--------------- .... 2042 shippiig...- . -------~~~~~ .. 5-B13 hon dr onn 2-D13 Serpentine 4-D36 Sessile intertidal organisms, growth limit... -- 3-112 56 Page null cta tt Prof. Paper 5}g-E Sir .l scn nle: nle. .l. .[; 5-B6 cleanup and restoration...... ___ _ 1-73, 1-85, 1-91 communications and utilities.....______. 5-B25 damage to city wells.......__..__________ 4-A16 port destruction......_.. 1-17, 1-31, 5-B7, 5-B12 lll cl aie to ; 5-D96 Shipping...: nuo l nt 5-B12 cl ell. O01. 2-E16 Task Force recommendations......_______ 1-63 Seward Peninsula, strong oscillations on lakes. 2:0... n. sial inny 4-A4 2-F18 Shakespeare (Hlacier............_.________.___ 2-B3 Shearwater Bay.......__________ 1-32, 3-D13, 5-B15 Shearwater 00 Antolin 5-B15 Sheep Creek. ie..... 1.0002) 3-F18 Sheep Mountain, Copper River Basin....._. 3-E25 Sheep Mountain Inn, Glenn Highway, dam- ere een on onl onn elo peal 3-25 Shelby-tube --- 2-B27 Shelikof Strait.... __ 2-F3, 3-D6, 3-D33, 3-D35, 3-12 Shellfish..............___ - 1-36, 3-133, 3-137, 3-J17 Sherman glacier...._._....._._.___ 1-14, 4-D6, 4-D31 Ship Creek, geographic relation to Anchorage. 1-100, 1-102, 2-A9, 2-A30, 2-436, 4-A9 -- 3-A12, 3-A18, 5-B3 snowelide..c inc cll ci... L 12. LT 4-B2 Waves. nece ele cl nc ull Ship Creek Bridge... elt. 5-D45 Shipping.: ct.. (100... Prof. Paper 545-B Shore processes.........__________ Prof. Paper 543-J Shorelines, Cook Inlet 3-F12, 3-F25 Mil etate alt Kodiak Island area......._________ Shoup Bay............ ... Shoup Glacier stream delta Shoup Spif...:...;...__;. ._ Shuyak Island, lake levels....__.____________ 3-D24 . -- $-D20 ppp oren tional 3-D25 Bilt .. 0000.00.00. 3-B8 Silver Lake, gravity values... -. 3-0 Sinkholes, filling of ice-walled....___.____..__ 3-B21 Sioux Glacier. See Slide Glacier. Sitka port, damages: . .l; 5-B7 Sitkalidak Island, cattle ranches...__________ 3-D44 __.. - 8$-D20 seismic sea waves......._________________ 3-D35 ll; 2.0 3-D15 Uplift .c LIES. .Q 000.0. 3-D25, 3-D28 Sitkalidak :o. --. 2-F34 Sitkalidzk Strait, geography....._.__ --. 2-F3M4 tectonic deformation. .._________________ 3-D44 Sitkinak Island, _._... 3-D20 uplift.... ._. 3-D25, 3-I21 Meias unl alt 3-F17 Skilak Lake.... .__ 3-A2, 3-F2, 3-F14, 8-F17, 4-A7 Skilak River Valley.....__________________ 4-A15 Sinna, ground waves." ...; _.. Cl 3-E7 Slide Creek, Montague Island. ...___________ 3-G13 Slide Glacier, avalanches.... 3-B14, 3-B17, 4-D13 (N.B. Since publication of the earlier vol- umes of this series, the feature formerly referred to as "Sioux Glacier" has been officially named "Slide Glacier.") Slides. See Landslides, Rockslides, Snow avalanches. Small Business Administration's 502 program. 1-99 Snails, Martin-Bering Rivers ills 2; 3-B27 Snow avalanches, defined........_.__________ 3-B13 Island............__..... [}. 3-D18 Martin-Bering Rivers BeBe selec eri ll 3-B14 onglaciers........__ __.. cnl. ..i. 2-E14, 2-E33 Tigkel River......___.__ |_ 3-E10, 3-E27, 4-449 Loulsiona River...... ...: 11/2 7 (C 3E-10 Snow cones, gravel gc} 3-B22 INDEX Page fnow River............ {IN. [iball o. 4-All Snow River bridge........:.............1. 5-D44 Snow River Crossing, severe damage to road- Maps.. eol lc cen or be ceva eau d do ul o 5-C10 Snow River delta, seiches......._____________ 3-A28 finow River Ol.) 2-E40 Socioeconomic benefits of earthquake. --- 6-31 Soils; 0 Dus OI 6-16 plastic ...l. . luc l -_ 2-A15 Seward... ..... clon Warp oil 2-E27 Yaldez. :. css select o hall 2-C15 Soldatna, ground water. .._____________ . 4-422 c + rere Pee i ad nece ol bo alos ee nae dis 5-B5 Soldatna-Sterling area.... ...________________ 4-A 22 Sound 3-D13, 3-E7, 6-26 South Africa, Republic of, hydrologic effects of Alaska earthquake. .........._____________ 4-C14 South Carolina, hydrologic effects of Alaska 00m. un 4-C32, 4-052 South Dakota, hydrologic effects of Alaska parthquinke. L...... 0.101 4-032, 4-C52 South Fork Campbell Creek...._.____________ '4-B2 South-West Africa, hydrologic effects of Alaska earthquake... s... luli .sit t 4-C14 Specific gravity, Bootlegger Cove Clay...__ 2-A18 Spruce Creek.... ... gull iud (oll 2-E17 Spruce Creek ELR ATO cares 2-B21 Spruce 0 [!. 2-F3,2-F33 Squarehead Cove, Cook Inlet area...... ._.; 3-F24 Stair Station, horizontal control station... ._. 3-G40 Standard Oil dock at Seward... 2-E13, 2-E23, 2-28 Afarigki Creek..........l.........0 ...l 0000. 3-F17 Stellor 4-D13 Sterling, groundwater......._..______________ 4-A22 Sterling _._ 3-F12, 5-04 Stewart, M.D., master of Chena, report.. .._. 2-C10 Storm beaches, differences in 3-117 Stratigraphy, Copper River Basin......_______ 3-E3 Prince William Sound.. .._....._________ 3-C1 Stream crossings, failures of embankments.. 5-D62 Streams, Anchorage area. ._____________ --.. 4B2 Homer atea.../....._.0._}:_ ..i} 2-D15 south-central Alaska...._.___________ --- 4-49 Stream erosion, Montague Island. ___.... ___.. 3-H7 Stream-mouth changes. ...__._.______________ 3-J10 Streamflow, changes. ....__. ._. 3-D24, 4-410, 8-I41 Strike Creek, Montague Island .....___.____. 3-G14 Submarine cable, Valdez to Sitka. ---. 2-C16 Subsidence, Afognak..........!.....__|_|_|_ 2-F29 axis of Kodiak-Kenai-C hugach Mountains. 3-120 beaches and shorelines......_____..______ Prof. Paper 548-J, 3-141, 3-155 Pliskin Lake...:......100 .:.. 3-D15 by consolidation... 6-21 Chugach Mountains... 3-E8 Cook Inlet region......_....._._.__ 3-E8, $-Far distinction between local and regional... 6-36 effects on marine 3-136 2: CLO .O O2; 2-G36 c te . Lal}. 5-029 Holocene.... clon cei toi. LIL C 3-155 Homer... 1-32, 1-90, 2-D4, 2-D13, 2-D22, 3-113 investigative techniques....... ---- 6-36 Kachemak Bay.... lp , 5-B12 Kadiak Fisheries cannery....__.__ 3-D13, 3-D18 Kenai Mountains......____________ 3-D28, 3-160 Kensal .[... }.. 3-I58 Kiana Creek delta_..__._______ .CA 3-D13 0. ul nc. 2-F19 Marmot Island ..... --.. 3-D25 Montague Island . ____________ Old -- 2-F35 Olds (all O 3-D27 Portage.... inu uct en rH 5-D80 ---- 3-E8, 3-18, 5-D80 Seldovia. . - 2-D13 «hort term. pelt. lol eae LY 3-160 Shugak [[[ 3-D25 h. Subsidence-Continued Page Talkeetna Mountains......._..___________ 3-E8 Carling Lake....:nl..ll.}.0}._____ [[[. 3-E21 Terror 1. [l 3-D15 Turnsgain Arm...}}._;._._;._ _ 5-C29, 5-D80 U.S. Coast Guard Loran Facility:. .._. 3-D15 Hess ale bev ea n le 2-C18 Whither. 2-B9, 2B-15 Subsidence craters. - 3-B11 Subsidence _-. ___ [L... 3-120 Surface-water changes, Copper River Basin.. 3-E8 general: css. te linc Ore tot 6-23, 6-31 Kodiak Island area. 3-D23 Surfacewaves amplitude.....________________. 3-14 Kodiak Island area....._________________ 3-D12 ccs recede once eal diia dll 6-26 Surprise Qlacler.....:......_.__....__ 4-D 26, 4-D36 Surveyor, gravity measurements. 3-C6, 3-C9, 3-C10 Susitna Giscler:.........._..}._ _: [. 4-D38 Susitna Dowland......._.._..__.__.._. 2-A1l, 3-3 Susitna River, location. .........______.______ 3-E3 2: Ure ee nays bere on 2-G46 Sutton branch line drainage. __.. ---. 5-D157 cl.. 000.000 0001, 5-D79 Swanson River oil field, Cook Inlet area. . __ 3-F12, 3-F24, 3-140 T. Tailrace, Eklutna project.........._._.____.__ 5-A20 Talkeetna geanticline..............__ ___ 3-E3, 3-153 Talkeetna Mountains, description......._.._. 1-9, 1-10, 8-F2, 5b-A4 0.0 3-153 cine nil s - 3-R2 subsidence. =:. usc. ila (EC 3-E8 Tanana River. c.. enlil ol.. s 4-A1l Tanya Lake, Cook Inlet area. ....___________. 3-F16 00000022; 1-17, 1-94, 5-B11, 2-G30 Tazlina Glacier, ground grafks.s. 20002020000. 3-E24 Tazlina Glacier Lodge, damage......________ 3-E25 Tazlina Lake, fluctuation.... .. -- 3-E10 location- re r at ou £ -. 3-E3 cla l.. - 3$-E21 Tazlina River, location........______________. 3-E3 --- Prof. Paper 548-1. see also Subsidence; Uplift. Television, examination of earthquake dam- MEB foo eries ne ce rede bul 5-25, 6-34 Tennessee, hydrologic effects of Alaska earth- 3. only lutte eld - 4-032, 4-052 Terraces, surf-cut Holocene.......___.________ 3-162 Terror Lake, subsidence.............________ 3-D15 Terror River, seismic sea waves...._____.____ 3-D34 Terror River delta, subsidence... ...._______ 3-D15 Terror River gage, seismic sea waves. . ______ 3-D35 Tertiary aquifer, south-central Alaska ______ 4-A19 Tertiary foothills, 3-B19 Martin-Bering Rivers area.._.____________ 3-B2 Tertiary rocks, Kodiak Islands... sC B-D7 predominance of landslides. _._. -- 8-D22 Prince William Sound region .. .._____.____ 3-04 Tertiary to Cretaceous deformation . _ _._. -- 8-162 Texas, hydrologic effects of Alaska earth- 4-C32, 4-C53 The Alaska Railroad . _ ___.. 1-25, Prof Paper 545-D Anchorage.... ulin. se 2-A8, 2-488 Lakeview " 3-A31 land-level changes........_....___..___._._. 3-123 Seward....:...._.. 2-E13, 2-£30 ---. 2-B6 Thels, C..V., 4-C29 Thompson Pass, south-central Alaska. . .._ 4-A9 Thrall, Mr., eyewitness account of seiching.. 3-A28 Three Saints Bay, seismic sea waves. . ______ 3-D30 Thrust faults, 3-164 relation to seiches..............._.__._..__ 4-E13 Thutub ng tates, 2-E17 Thurston Canyon: 0a} 2-D7 Tidal bench marks, height relative to sea level. 3-119 Page Tidal glaciers, direct effects of the 1964 earth- ione bees 4-D36 Tidal inlets, HOMOPL ..... ---------~--------~ 2-D27 Tidal waves. See Seismic sea waves. Tide-gage readings, pre- and postearthquake.. 3-110 Tides, KOGiAK 1 . nnn c 2-F18 Kodiak group of islands. ..-... 3-D6 'Tiekel River, snow avalanche... 3-E10, 3-E27, 4-A9 WPikke Glacier. 4-D39 Tilley, Jerry, eyewitness report.. ..... 2-F22, 3-D30 Tilting, lake basins...-..---- . 3-A29, 3-134, 6-34 Tilting, river drainages. . ..-... .-------------- 3-135 'Time of G@AItRGUAK@L 1 . 1-1, 2-A2, 2-B5, 2-C1, 2-D3, 2-E4, 2-F2, 8-14, 3-J1, 6-2 "POK JUNCHORL L.. 6690 3-E3 'Tokun Creek delta, landslide.......--------- 3-B19 Pokun Lake. 3-B2, 3-B19 Tonsina Lake, effects of earthquake.........- 3-E10 landslides. 3-E21 10CSQION. . ...... ns 3-E3 'Tonsina Lodge, 3-£25 Tonsing River, ice jam......--------- 3-E27, 4-A1l 10CAHION. L L clk cll oul L ene 3-E3 SNOW AVAIAMCh@L L L 1 3-E10 Topographic strike, relation to fractures. . . - - - 3-B5 upper Martin River valley.. 3-B5 Tortuous Creek, Montague Island.... ---... - 3-G13 Patton Bay fAUlt. .... 3-G16 ... 1+103 Trading Bay, Cook Inlet area.... 3-F23 FAI Lake, L...... delles ue nn 4-AT Proil River......... .-.. 3-A12 Trail River valley, IOWer......------------- 5-D108 'Translatory landslides, Anchorage... .-- 6-17, 2-A38 Transmission lines, Eklutna project.... .--. - 5-A23 Transportation.. .-- -- ------- 1-25, Prof. Paper 545-B Trenches TP-1 and TP-2.....--------------- 2-E38 Triassic rocks, Kodiak Island . - .. 8-D6 'Prinity 1-5 Troublesome Creek delta....-..-..---------- 3-F20 "Tsing Lodge, Richardson Highway damage.. 3-625 Tsunami, d@ADIHONL . ...-- 2-F2 See also Seismic Sea Waves. Tugidak Island......-..-.-----.-------- 2-F3, 3-D6 Tunnels, effects of earthquake......---------- 6-27 Turbidity changes, lakes on Martin River coos 3-B21 Turbidity current, Horgan, Lake Zurich, Switzerland 3-All Turnagain Arm, biologic effects.. ...--... --- 1-34 fractures in roAdway...... ---... 5-C14 geographic boundary feature...... ------- 1-100, 2-A2, 2-B2, 2-E16, 3-F3, 4-A 18, 4-B12 2-480, 5-D73 5-C29, 5-D80 Turnagain Heights, landslide.....------------ 1-18, 1-57, 1-59, 1-78, 1-82, 2-A2, 2-A 18, 2-A28, 2-A38, 2-459, 5-B4, 6-18 Tustumena Lake, Cook Inlet area...... 3-F2, 3-F14, 4-A6, 4-A16 Ailting of basin.. 3-134 Tuxedni Bay, height of tides. ..-----...------ 3-123 Tuxedni Channel, Cook Inlet area.~.....---. 3-F23 Twentymile River bridge. ...........-----.- 5-D45 Twentymile River flood plain.....-....---. 5-D118 Twin Creek, damage to bridges.........----- 3-D39 .iso lille 3-F2, 2-G4} U Ugak Bay........}..... (UOganik 2-F3 Uganik River, seismic sea 3-D34 UMIAEE AL. A2 se re ads nous dh o awan on 1-3, 2-A2 Unakwik Inlet, epicenter...--- 2-E4, 3-R6, 3-71 Uniform Building Code for Seismic Zone 3... 1-63 Island.... 0000000 1-3 United Arab Republic, hydrologic effects of Alaska earthquake.........---... 4-C14 INDEX Page United Kingdom, hydrologic effects of Alaska earthquake. ......._........--.--- 4-C15 United States, hydrologic effects of Alaska earthquake. ......._....~...-.--- 4-C16 U.S. Army Corps of Engineers, reconstruction. 1-70 1-81, 2-E24 U.9. Coast and Geodetic Survey, .- 3-E8 revision of nautical charts. .........------ 5-B8 U.S. Coast Guard Loran facility, subsidence 3-D15, Uplift, beaches and shorelines. ___Prof. Paper 548-J Chugach Mountains.. -..-----.----------- 3-C5 Copper River Basin.......-.....--------- 3-E8 Cordovs-..:.....: . 2-G18, 4-D34 distribution:. ..... 6-11 effects ON L.. 3-136 Ellamar cannery... ._ 5-B1 oute 3-155 Kayak 3-117 Geno bene or 3-121 Martin-Bering Rivers area_.....--------- 3-B26 Middleton Island........---- 3-D 28, 3-121, 3-160 Montague Island.... ..-...-------------- 3-D28, Prof. Papers 548-G, H, 3-118, 3-143, 3-112 NBIrOW 3-D25 Prince William Sound...... -- 3-D28, 5-B8 relation to seismic sea Waves.... ---. 6-3 Sitkalidak Island... . 3-D25, 3-D28 Sitkinak Island...... .-- 3-D25, 3-121 Valdez. ol.: lU needa - anser 2-C18 Upper Trail Lake. 5-D11l1 Utah, hydrologic effects of Alaska earthquake 4-C33, 4-053 anes ee 2-A 4, 5-B18 See also Eklutna Hydroelectric Project. Uyak ank es 2-F40 Uzinki, archeologic remains. damage. .c... cc... enn 2-F2, 2-F33 @TOUNG 3-D12 3-D6 prOPeTtY o-- --> 3-D3 seismic SGA WAVeS........----------- ... 3-D38 subsidence...........- 2-F34 Uzinki cannery, damage.....---------------- 3-D43 y Vaiont Dam, over-tOpping. ..... 3-A11 sellin ie aes __ Prof. Paper 518%-C cleanup and restoration.... . 1-40, 1-79, 1-85, 1-98 communications and utilities.......... --- 5-B25 3-C6 ground fracturing... .-------------------- 2-B21 port and harbor......-.---------- _. 1-31, 5-B7 recommendations of Task Force....--.--- 1-66 §hIpPH@g.. .c... 5-B15 water Wells.............._...------ 4-A17, 4- A96 Valdez ArM.........l...vsvernlidee 1-98, 3-C4, 3-C6 Valdez Development Corp.......------------- 1-99 Valdez Glacier._........... 202, 2-06, 2-C14, 2-033 Valdez Glacier valley...... --- 2-C1 Valdez Group, description. .....-------- 2-C3, Valdez Narrows............._.-- 2-C1, 2-C10, 2-C30 Valdez outwash delta...-.------------ 2-C16, 2-035 Valley alluvium, Seward... -... ------------ 2-B21 Variegated Glacier. 4-D39 Vegetation, indication of subsidence. ...-- -- - 3-D27 Vermont, hydrologic effects of Alaska earth- 4-C33, 4-053 .... c. .... L curio eeu be dva + 3-112 Vibration damage, Anchorage. . 2-A22 CordoV@ AIFDOrb. .. ...- 2-G18 Cape Saint Elias. ...... 2-G33 geologic control... ---. 6-28 . : ..... leva lure bane non 6-9 Vibration tests, Bootlegger Cove Clay ...... - 2-A17 Viedry 3-A3 See Victory Creek. ViGLOF 3-A3 See Victory Creek. 57 Page Victory Creek, diversion.......-.-.----------- 3-A33 grOUNG . co 3-A37 Victory Creek delta, landslide __ 8-A8 ViekOd@ Bay. ... 3-D15 Virgin Islands, hydrologic effects of Alaska earthquake........-.------ 4-C33, 4-053 Virginia, hydrologic effects of Alaska earth- 4-C33, 4-053 Volcanic ash, earthflOW8. .-.. 3-D21 Volcanic eruption, Homer. 2-D18 Volcanic rocks, Kodiak group of islands.....-- 3-D7 OCB ccc enn -n =- -->> 3-C4 w Wakefield 3-J19 Washington, damage from sea Waves... -- ------ 1-37 hydrologic effects of Alaska earthquake 4-C33, 4-054 Wagiflq.. .._. cca centa es ase 4-A23 Water levels, causes of residual changes .. 4-B10 expanded-scale records.... ---. --- _.. 4-010 recorders and charts......~ _. 4-05 wells at Homer.......----- cee RDH Water quality, Homer. 2-D15, $-D18 Water storage, CBANG@S.. ..... 4-A8 Water-system structures, damage....--------- 4-A9 Water table, 5-C44 T@SDOMS@L. .. 60990609 4-B6 Water transport, affected by earthquake.... - 5-B6 Waves, backfill.........--------- 3-A7, 3-A12, 3-A22 ground. See Ground motion. local...... 2-B6, 2-B18, 2-C14, 2-030, 2-G24, 3-A7, 3-A12, 6-24 3-D13, 3-E7, 6-26 AYDOS- S.. de 2-FA41 SOUFC@ MeCR&AMISML. ...- -------~--~-~---- 3-138 See also Seiches; seismic sea Waves. Waxell Ridge.... 4-D13 Wells, Anchorage area . 4-B6, 4-A13, 6-22 nc 4-A16 fluctuations in level... 3-D23, 4-039, 4-A13, 6-27 3-E8, 4-A20 . ics dral doe 2-D17 2-E16 Well-aquifer SYSt@MS- ..- 4-B6 West Anchorage High School........--------- 2-A27 West Virginia, hydrologic effects of Alaska earthquake.....-.--------- 4-C33, 4-054 Whidbey Bay.. 2-FA41, $-G42 Whittier. Prof. Paper 548-B BP 2200000026 >>-- nn 99 >> 5-B6 cleanup and restoration...... --- 1-17, 1-99, 1-80 communications and utilities.......----- 5-B26 railroad facilities......------- 5-D2, 5-D4, 5-D88 Whittier to Portage rail line ...... 5-D138 Wildfowl. ...... acd nne 3-717 Williston basin, seiches. ...- ----------- ._ 4-E14 Windy Point, Cook Inlet Area... .----------- 3-F16 Wisconsin, hydrologic effects of Alaska earth- (UAKe. 2 4-C33, 4-C54 Wolcot Mountain alluvial fan. ..-..--.------ 5-D103 Womens Bay, damage to bridges............. 8-D89 ground fractures.. ...-- 120 2-F7 SCADIANG AMDS. ..... 5-B4 seismic SeA WAYS. .. ..-. ---------~ 2-F3, 3-D33 Woods Canyon. ...... -- __. 1-10, 4-49 Woody 2-F18 Worldwide geodetic Meter. . ..... ------------- 3-C6 Worthington 3-26 Wrangell Mountains...... --- -- 1-8, 1-10, 3-E2, 3-145 Wyoming, hydrologic effects of Alaska earth- Fo ee 4-C33, 4-054 ¥ Yakutat, earthquake of 1899.....- 1-12, 2-C6, 4-D37 general damage... 2-G35 Yakataga._...----- ___. 2-034, 8-71 Yale 4-D4 Yanert Glacier.....------------ U.S. GOVERNMENT PRINTING OFFICE: 1970 O 359-625 7 DAY C¥etaceous Ammonites From the Lower Part of The Matanuska Formation Southern Alaska rrr GEOLOGICAL SURVEY PROFESSIONAL PAPER 547 Cretaceous Ammonites From the Lower Part of The Matanuska Formation Southern Alaska By DAVID L. JONES With a STRATIGRAPHIC SUMMARY By ARTHUR GRANTZ GEOLOGIC AL SUR V E Y PROFESSION A L PAPER 547 UNITED STATES GOVERNMENT PRINTING OFFICE, wWASHINGTON : 1967 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Congress catalog-card No. GS 66-286 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20407 - Price $1.25 (paper cover) CONTENTS Page conn agt" o" 1 | Stratigraphic summary of the lower part of the Matanuska c 1 Formation—Continued Mid-Cretaceous faunal sequence in southern Alaska----- 2 Unit B, sandstone of Cenomanian Ag@------------- NiDian...... l . 8 Unit C, strata of Cenomanian to Santonian(?) age--- Cenomanian. .- nce ro" 4 Unit C-1, lutite of Cenomanian to Coniacian or Stratigraphic summary of the lower part of the Matanuska Santoman a Tormation, by Arthur 4 Unit C-2, composite sequence of Coniacian and Unit A, strata of AIDIAN 6 Santoman(?) dge. Limestone Hills area 7 | Regional correlation of the lower part of the Matanuska North front of the Chugach Mountains.------- 7 cloacae Matanuska Valley . __-_-------------=--~-~ 7 | Geographic distribution of ammoniteS.__--------------- Nelchina area and southwest Copper River Systematic a | - soo at oot ao Correlation within the Matanuska - Valley- tse as- oe MNEIching 9 PruaATE s o o Figur®E 1. g 9 P guapo pp sb F ILLUSTRATIONS [Plates 1-9 follow index; plate 10 is in pocket] Gaudryceras, Anagaudryceras, Lytoceras, and Parajaubertella. Tetragonites and Sciponoceras. Calycoceras and Eogunnarites. Puzosia, Desmoceras (Pseudouhligella), Scaphites, Otoscaphites, Hulenites, Moffitites, Aucellina and M esopuzosia. Grantziceras. ‘ Grantziceras, Brewericeras, and Subprionocyclus. Freboldiceras and Arcthoplites. Arcthoplites. Arcthoplites. Map of Matanuska Valley-Nelchina area, Alaska, showing fossil localities. from mip th ... clic ia aran eae ct a aa Schematic diagram showing relationship of informal Stratigraphic unite. teac a Generalized columnar section of the Matanuska Formation, Limestone Hills grea. . -he reala Generalized columnar section of the Matanuska Formation and correlation with rocks in the upper Chitina M er Pelle olden onn isc rane drt r a ren of ip. on. .ll. on pean onar enter ot Oa aaa Suture lines of Gabbioceras, J auberticeras, Parajaubertella, and ao} Cross sections of Gabbioceras and Pirajauberislld. . noche onan ac o D aaa denne of . ...so. cloe. saree cae dl Gare oin toll Se SBA eee ot de po.. suc oat nll 1 lt Seca Upa dine of BBL. L0. .c ulin. cie tn n acct orr oe o t loa re dine Bf Drowotseerns Lc) 0. sg oona seni scene rnt o n orer 4 o a Scatter diagram showing whorl relationship of Granmiziceras affhe cll. o eate aaa o Scatter diagram showing relation of umbilical width to whorl shape in Grantziceras fine. Bar graph showing frequency distribution in Graniziceras a PMA. ...... sate tena a an Suture lines of Graniziceras a fine...... ain diate eet c a o l a a ae y oye e api oa r i L . Derivation of Graniziceras, Freboldiceras, and oce. a a iis line of Prebafdiectns Uingnlares. ...s. ccc conch tonos C e Alie ife ine of Arsh effing ...... eqn nicl ct toons r( a s ire Tine bf .. (..o cocn e ee cdo naren entree en error ol an Close of Pigeons de 8p. ... cull c. sl clean lobes bo the cnc sont s cle la Suture line of Subprionocyclus i ormalis.. .. .cc. tse daal tena teat lool oe gr: Aine ML mea np caeca ee cores nient eine denen te m oa a Page 10 11 12 15 21 44 47 Page IV TaBu® 1. Checklist of fossils CONTENTS TABLES CRETACEOUS AMMONITES FROM THE LOWER PART OF THE MATANUSKA FORMATION soUTHERN ALASKA By Davin L. Jox®s ABSTRACT The lower part of the Matanuska Formation comprises a thick and complexly intertongued assemblage of siltstone, shale, sand- stone, and conglomerate that ranges in age from Early Creta- ceous (Albian) to Late Cretaceous (Coniacian or Santonian). These rocks were deposited mainly on eroded Jurassic sedi- mentary and volcanic rocks in a tectonically narrow trough lying between an emergent area to the north in the area of the Talkeetna Mountains and the northern Copper River Lowland and a sporadically emergent area to the south, which is now part of the northern Chugach Mountains. The rocks are overlain by claystone and - siltstone of Santonian and Campanian age at the base of the upper part of the Matanuska Formation. Deformation, uplift, and erosion during deposition of the Matanuska Formation pro- duced intraformational unconformities which now bound many of the cartographic units into which the formation has been divided. Statigraphic and structural studies by Arthur Grantz have shown that after (and perhaps also during) deposition of the Matanuska Formation, the Nelchina area was broken into three major blocks by lateral movement on two splay faults of the Castle Mountain fault system, and that these major blocks display different rock sequences, informally termed the northern, central, and southern sequences. The stratigraphic record of each sequence differs significantly from the others, and de- tailed reconstruction of the history of sedimentation and defor- mation of the Matanuska Formation rests heavily on paleonto- logic correlations between these sequences. The oldest beds of the Matanuska Formation in the Matanuska Valley-Nelchina area, near Limestone Gap in the northern se- quence, consist of sandstone-bearing abundant specimens of Aucellina sp. and rare specimens of Moffitites robustus. These rocks are assigned to the early early Albian zone of Moffitites robustus. Upper lower Albian rocks assigned to the zone of Brewericeras hulenense occur in both the northern and southern sequences but have not been positively identified in the central sequence. Middle Albian rocks are unknown throughout the area, but upper Albian rocks may be present in the southern sequence. Cenomanian rocks, characterized by Desmoceras (Pseudouhli- gella) japonicum, rare specimens of Calycoceras sp., and a new species of Inoceramus, are widespread in the central and south- ern sequences but absent in the northern sequence. - These rocks are overlain by Turonian rocks that contain fairly abundant but fragmentary specimens of Inoceramus cf. I. cuvierii, several other species of Inoceramus, and rare ammonites, including Otoscaphites teshioensis and Mesopuzsosia aff. M. indopacifica. The overlying rocks contain abundant specimens of Inoceramus uwajimensis and scarce specimens of I. yokoyamai, together with a few poorly preserved ammonites indicative of a Coniacian and possible Santonian age. In this report, 20 species of ammonites are discussed and il- lustrated. Scrappy material and poor preservation of many specimens preclude specific identification of some forms and necessitates showing only the affinities of others. Although some of the forms discussed are apparently new, the scarce and poorly preserved material now at hand does not warrant assignment of new names at this time. INTRODUCTION The main purpose of this report is to provide paleontologic data to substantiate the correlation of complex sequences of upper Lower Cretaceous and lower Upper Cretaceous rocks in the Matanuska For- mation of south-central Alaska (fig. 1). Ammonites from the upper part of the formation have been dis- cussed by Jones (1964). An account of the changing concepts concerning the ago of the Matanuska Formation and a brief description of the entire formation were given by Grantz (1964) and Jones (1964) in earlier reports and will not be treated fully here. The lower part of the formation was considered by Imlay and Reeside (1954, p. 232) to be of Coniacian age on the basis of its stratigraphic position below beds bearing the Santonian species Inoceramus undulatoplicatus, the supposed presence of Parapuzsosia and Prohauericeras, and the presence of Inoceramus close to I. umafimensis. Imlay later changed the identification of Prohauericeras to Son- ninia of Bajocian age (written commun., 1954) and that of Inoceramus undulatoplicatus to I. schmidti of Cam- panian age (written commun, 1955). Later studies by Jones showed that the Paorapuzosia belongs to Can- adoceras and that some of the specimens referred to as I. uwajimensis belong to a new species of Cenomanian age. 'These changes, together with the identification by Imlay (1959) of Albian ammonites obtained from near the base of the formation, showed that previous inter- pretations as to the lower age limit of the formation re- quired revision, although when first discovered, the stratigraphic significance of the Albian ammonites was equivocal, and Imlay (1960, p. 88) suggested that they might have been reworked into much younger beds. In order to ascertain the stratigraphic position of the Albian fossils discussed by Imlay, and also to gather additional fossils from the lower part of the Matanuska Formation, Grantz and Jones visited the Matanuska Valley-Nelchina area in 1959. Field data showing that 1 24 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION, SOUTHERN ALASKA Barro CHI/[fog] eol. 162+ Sm, 24 $m A eff/78W / 2 Nelchina area * (y J" Nunwa k $ s af § Thcs r/bI/o %s/ % > ""ds / I/ f f ~ f / / fag MRC y / § x* ky" 158° l §§) day Tess. 4d FIGURE 1.-Location of the Matanuska Valley- the Albian fossils were indeed in place, and that rocks of Cenomanian and probable Turonian ages were also present, were published in a preliminary note (Grantz and Jones, 1960). In that report, as well as in a later report on the ammonites from the upper part of the Matanuska Formation (Jones, 1964), it was suggested that strata of Coniacian and Santonian ages were missing and that Campanian beds rested directly on probable Turonian beds. This interpretation was based on a lack of identifiable fossils of known Coniacian and Santonian ages. In 1963 Grantz revisited the Nelchina area and collected well-preserved specimens of Znocer- amus wwajimensis Yehara and other Inoceramii and ammonites indicative of Coniacian and possibly San- tonian ages. These collections, augmented by addi- tional fossils collected by Jones and Grantz in 1964, indicate that the total age span of the Matanuska For- mation in the Nelchina area is from at least early Albian to early Maestrichtian, although deposition was not con- 6 | Matanuska Valley. Ney are2 _;7j¥ <> Upper Chitin Va & 138° Cus Queen" \ o 100 200 MILES charlotte Op" Nelchina area and the upper Chitina Valley area. tinuous and no single sequence contains a complete sedi- mentary record. In the present report Grantz is responsible for discus- sion of the stratigraphy and for lithologic correlations within the Matanuska Valley-Nelchina area; Jones is responsible for local and regional paleontologic correla- tions and for systematic descriptions. MID-CRETACEOUS FAUNAL SEQUENCE IN SOUTHERN ALASKA In order to establish the age of the fossils from the structurally complex and lithologically heterogeneous rocks of the Matanuska Formation in the Matanuska Valley-Nelchina area, these fossils must be compared with those in a local standard of reference, preferably one with a structurally simple sequence of rocks con- taining abundant fossils that have been studied in some detail. In southern Alaska the most richly fossilifer- ous sequence of Albian and Cenomanian rocks occurs in MID-CRETACEOUS FAUNAL SEQUENCE 3 the upper Chitina Valley, an arta currently being studied by Jones. No detailed description of the Cretaceous rocks of the entire region is yet available, although a general account was given by Moffit and Capps (1911) and Moffit (1918, 1938), and the Creta- ceous rocks of the McCarthy A-4 quadrangle have been mapped by Miller and MacColl (1964) and described by Jones and Berg (1964). Recently, Imlay (1959, 1960) and Matsumoto (19592) have figured Cretaceous fossils from the upper Chitina Valley, but the stratigraphic relationships reported in these papers are either obscure or in need of partial revision. The following summary of the mid-Cretaceous faunal sequence in the upper Chitina Valley is presented here to provide a back- ground to assist in understanding the age and facies relationships of the Matanuska Formation in the Matanuska Valley-Nelchina area, where the rock sequence is stratigraphically less complete, generally less fossiliferous, and structurally more complex. ALBIAN On the basis of studies of the ammonite faunas of the upper Chitina Valley, Imlay (1960) established several faunal zones of Albian age. The lowest zone, contain- ing the "Leconteites modestus and Puzsosigelle fau- nules," was said to be characterized by L. modestus (Anderson), Puzsosigella cf. P. rogersi (Hall and Am- brose) , P. cf. P. perrinsmithi (Anderson), P. cf. P. taff (Anderson), Anagaudryceras aurarium (Anderson), and Aucellina sp. - Rocks bearing this faunule were cor- related with the Leconteites lecontei zone of California and assigned an early or early middle Albian age (Im- lay, 1960, p. 89). From rocks overlying the Leconteites modestus and Puzsosigella zone, Imlay recognized the "Moffitites ro- bustus and Leconteites deansi faunule," characterized by Moffitites robustus Imlay, Kennicottia bifurcata Imlay, Leconteites deansi (Whiteaves), L. crassicostatus Imlay (nomen nudum), Anagaudryceras - aurarium (Anderson), PhyUopachyceras - cf. P. shastalense (Anderson), Calliphyloceras cf. C. aldersoni (Ander- son), Ptychoceras cf. P. laeve (Gabhb), Callizoniceras (Wollemanmiceras) alaskaonum Imlay, C. (W.) fohli- nense Imlay, and other species. The correlation of this zone with the zonal sequence of California established by Anderson (1938) and Murphy (1956) was uncertain, and Imlay (1960, p. 91) suggested that it occupied a position intermediate between the zones of Leconteites lecontei and Brewericeras hulenense. The Moffitites robustus zone is overlain, according to Imlay, by rocks containing the "Brewericeras breweri and B. cf. B. hulenense faunule" characterized by many species, the most important of which are Brew- ericesras brewer (Gabb), B. cf, B. hulenense (Ander- son), Pusosia alaskana Imlay, Porasilesites bullatus Imlay, Hulenites cf. H . reesidei (Anderson), and Lemu- roceras (Subarcthoplites) aff. L. bellé, McLearn. This zone was considered to be approximately equivalent to the zone of B. Aulenense of northern California and was assigned a late early Albian age in the sense of Breis- troffer (1947) and Wright (1957) or an early middle Albian age in the sense of Spath (1923, 1942). A fourth faunule, the "Freboldiceras singulare fau- nule" known only from the Matanuska Formation in the Talkeetna Mountains, was also recognized by Imlay (1960, p. 92). This faunule included Tetragonites sp., Beudanticeras [= Grantziceras of the present report] glabrum, Grantziceras multiconstrictum, and Lemuro- ceras [= Arcthoplites of the present report] talkeetna- num and was of particular interest "because its com- ponent species show close affinities with Albian species | in the western interior of Canada and in India, and because its genera and species have no known affinities with the Albian ammonites of California or Oregon, although they occur in the same marine basin as the Albian ammonites of the Chitina Valley that are closely related to ammonites in California and Qregon" (Im- lay, 1960, p. 92). 'This fauna was suggested to be either slightly older or slightly younger than the Brewericeras zone of the upper Chitina Valley, and a younger age was favored (Imlay, 1960, p. 92). Imlay's work was based on fossils collected by various geologists engaged in reconnaissance studies of the rocks of the upper Chitina Valley, and many of the collec- tions could either not be located precisely or were de- rived from float. More detailed collecting by Jones, in conjunction with geologic studies by E. M. Mac- Kevett, Jr., and the late Don J. Miller, both of the U.S. Geological Survey, was undertaken in 1961; Jones and Imlay jointly collected Cretaceous fossils from this area in 1962, and Jones made additional collections in 1963 and 1965. - Preliminary studies of these collections necessitate a revision of Imlay's zonal scheme as sum- marized above. In brief, the major changes are as follows: The Moffitites robustus fauna characterizes the lowest part of the Albian sequence of the upper Chitina Val- ley (fig. 4), and specimens of "Leconteites modestum" and "Puzsosigella cf. P. rogers?" identical with those figured by Imlay have been found with this fauna. Aucellina is extremely abundant in this zone. The Moffitites robustus zone is probably equivalent to, Of slightly older than, the early Albian Leconteites lecontei zone of California and Oregon (Jones and others, 1965). The Brewericeras hulenense zone overlies the Mof#- tites robustus zone and can be correlated with the rocks bearing the "Freboldiceras singulare faunule" of the Talkeetna Mountains. - This correlation is based on the 4 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION y presence, in the Talkeetna Mountains, of the following representatives of the Brewericeras hulenense zone: B. Ahulenense, Parasilesites bullatus, Hulenites sp., Pugosia alaskana, T etragonites sp., and Arcthoplites spp. Also Grantziceras and Freboldiceras have been found by Jones in the Brewericeras hulenense zone of the Chitina Valley, so there is little doubt as to the equivalency of these two zones. The probable early A 'bian age for the B. Ahulenense zone in Alaska is confirmed by the dis- covery, in the upper Chitina Valley, of several spec- imens of Downvilleiceras mammillatum (Schlotheim). According to Spath (1942, p. 674), this fossil is re- stricted to the regularis, monite, and inaequinodum zones, which Breistroffer ( 1947) placed in the lower Albian. In the upper Chitina Valley, strata of probable late Albian age directly overlie the Brewericeras hulenense- bearing beds. These younger rocks are characterized by Desmoceras (Pseudouhligella) dawsoni (Whiteaves) and many other species of ammonites including Pseudhelicoceras sp., - Marshallites cumshewaensis (Whiteaves), Marshallites spp., Zelandites inflatus Matsumoto, and Proplacenticeras sp. Some of these ammonites have been described by Matsumoto ( 19592). A similar fauna is known from the Queen Charlotte Is- lands, associated with the upper Albian ammonite Mortoniceras. Strata of middle and early late Albian ages equiva- lent to the zone of Ozytropidoceras packardi and the lower part of the zone of Pervinguieria hulenana of northern California (Murphy, 1956) are missing or as yet unidentified in both the Chitina Valley and the Matanuska Valley-Nelchina area and have not been reported from any other localities in southern Alaska. Likewise, the absence in southern Alaska of the Gastroplites fauna of middle Albian age known from northern and north-central Alaska and the western interior of Canada perhaps can be explained by the absence of rocks of this age. On the Queen Charlotte Islands, B.C., beds containing Rrewericeras Aulenense and those containing D. (P.) dawson; are separated by nearly 700 meters of sandstone and silt- stone in which cleoniceratid and other ammonites are common. 'These middle Albian fossils also are un- known in southern Alaska. CENOMANIAN The beds in the Chitina Valley bearing Desmoceras (Pseudouhligella) dawson are overlain by strata con- taining D. (P.) japonicum Yabe together with many other species of ammonites, some of which were des- cribed by Matsumoto (19592). Other characteristic species of this fauna include Parajaubertella imlayi SOUTHERN ALASKA Matsumoto, Zogunmarites alaskaensis Matsumoto, and Turrilites acutus Passy. This fauna is of undoubted Cenomanian age (Matsumoto, 19592, p. 81) and char- acterizes the beds herein termed the zone of Desmoceras (Pseudouhligella) japonicum. Other forms common in, but not restricted to, this zone include Zelandites in- Ratus Matsumoto and Morshallites cumshewaensis (Whiteaves). Upper Cenomanian and Turonian rocks were re- ported to occur in the upper Chitina Valley by Mat- sumoto (1959a, p. 86). These rocks crop out in the vicinity of Nikolai Creek and yielded fossils identified as Imoceramus hobetsensis Nagao and Matsumoto, 7. cf. I. pictus Sowerby, and a new species of Marshallites close to an upper Cenomanian form from Japan. Ad- ditional collecting from this place has shown that Des- moceras (Pseudouhligella) japonicum occurs in the up- permost beds and D. (P.) cf. D. japonicum occurs lower in the section in brownish-yellow siltstone that yielded the Marshallites n. sp. Still lower in the see- tion Brewericeras hulenense was collected, so this se- quence can be correlated with the Albian and Ceno- manian zones discussed above. Poorly preserved fragments of Znoceramus similar to I. cuvierii were collected in 1965 from black shale in the McCarthy B-4 quadrangle. These fossils suggest that beds of Turonian age occur locally within the upper Chitina Valley area. The presence of Turonian beds within or near the lower Chitina Valley is suggested by a single specimen of Subprionocyelus normalis found on a mudcone in the eastern part of the Copper River Lowland. This specimen is figured in this report to demonstrate that upper Turonian strata are probably present in the subsurface of that area; possibly, these beds crop out in the lower Chitina Valley, but they have not yet been identified there. STRATIGRAPHIC SUMMARY OF THE LOWER PART OF THE MATANUSKA FORMATION By Artur Grants The Matanuska Formation was deposited in a long but probably narrow trough with a complex history (the Matanuska geosynceline of Payne, 1955). This trough extended from the Chitina Valley on the east to beyond the tip of the Alaska Peninsula on the south- west. The formation, which crops out in the Mata- nuska Valley, the Nelchina area, and the southwest Copper River Lowland, comprises several overlapping prisms of clastic sedimentary rocks which are separated by unconformities (Grantz, 19602, b; 1961a, b; 1965). These unconformities record important episodes of up- lift and erosion, and thus the prisms they bound are lithogenetic units. Some of the prisms consist of a STRATIGRAPHIC SUMMARY 5 single dominant rock type; others consist of assem- blages of rock types in characteristic arrangement. Silty claystone and siltstone are the common rocks in these prisms, but sandstone and conglomerate are abundant and in some prisms are complexly interbedded and intertongued with the claystone and siltstone. Be- cause of these complexities, the character of the forma- tion is best elucidated by delineating and mapping some of its unconformity-bounded prisms, as well as its strictly lithologic units. The prisms which constitute the lower part of the Matanuska Formation range in age from Albian to Coniacian or Santonian. They rest unconformably on Jurassic and Lower Cretaceous rocks and are overlain by Santonian( ?), Campanian, and Maestrichtian rocks in the upper part of the Matanuska Formation. The relationship of the main units in the lower part of the Matanuska Formation is summarized in figure 2, and SERIES} STAGE NORTHERN SEQUENCE ef u_ NL i_ 1. .° Maestrichtian Upper part of Matanuska Formation Upper part of Matanuska Formation Campanian # 3 $ 0 Santonian y 0 A o 5 Coniacian a a m Turonian Cenomanian Albian Aptian w 3 C o fo 0 . # o Barremian m 8 E o b o A c 5 Hauterivian i B Ap eral Lf al ien sees Prive Sr mass Paws " < £ id: * Valanginian 5 & Lee 22. Bec. © © ; : a Berriasian S B Upper a © o tra -m -E AL L_L pr raat ary ars. yf it F the position of the major faults and fossil localities are shown on plate 10. The Albian units crop out in the Matanuska Valley, the Nelchina area, and the southwest part of the Copper River Lowland ; the units of Ceno- manian to Coniacian or Santonian age have so far been definitely identified only in the Nelchina area and the southwest part of the Copper River Lowland. Rocks in the Matanuska Valley-Nelchina area have undergone moderately severe deformation, and the re- sulting structural complexities have made it difficult or impossible to study complete and undisturbed see- tions of the thicker units of the Matanuska Formation. In addition, important differences exist in the char- acter of the Matanuska Formation across two major strike-slip faults which strike eastward across the Nel- china area, the Caribou fault, which strikes across its center, and a poorly exposed fault (probably an ex- tension of the Castle Mountain fault system), which strikes across its southern part near the Matanuska CENTRAL SEQUENCE SOUTHERN SEQUENCE LLE AA Upper part of Matanuska Formation ] ® 1 tain fault system Probable southern branch of Castle Moun pol- -- me ope Pop i ref e ge Pag 2 FrourE® 2.-Relationship of informal stratigraphic units of the lower part of the Matanuska Formation (stippled) in three structurally bounded sequences. Vertical ruled areas represent missing or as yet unidentified parts of the sequence. Unstippled units belong to the upper part of the Matanuska Formation or to other formations. 6. CRETACEOUS AMMONITES FROM MATANUSKA FORMATION , SOUTHERN ALASKA Uov eo c C l R 2C 0:0 0 D oo onglomerate Tertiary o -as ies sC Fegit Upper part of Matanuska Formation Mgsicigic _®'__ ain. G).— Olive-gray siltstone co_ntaining fossilifer- (Pachydiscus kamishakensis zone) locality -- k <-- l i_ -- ous limestone concretions MSbs 1] t (CGI.LZ_ mome) mone e Geng -_ _o =-- -__ ___ _ Light-olive-gray silty claystone M554 ir ATL containing fossiliferous limestone Unit M555 _-_ i222 i_ concretions A-2 -- Lower part M556 “E + -CD -O of Carter t- Matanuska | :6i__ Formation frye s ses tT Siltstone (dark yellowish brown in (Albian) Trex _ _ weathered chips) containing large Ge CDfi‘t limestone lentils and fossil wood Yos Lest Variegated medium-grained sandstone MS§57 --|- _> meth. .~" containing large sandy limestone _ 11* ' CID concretions -+ V Interbedded sandstone and siltstone Unit som Carbonaceous siltstone and claystone A-1 m interbedded with thin coal beds Unexposed ..... Olive-gray and yellowish-brown- weathering medium-grained sandstone 3 T tnt 2" Olive-gray siltstone Lower Cretaceous (Neocomian) tto tis. L Olive-black calcareous sandstone 200' 100' o' VERTICAL SCALE FIGURE 3.-Generalized columnar section of the Matanuska Formation in the Limestone Hills area. River. These faults bound three stratigraphic se- quences designated on figure 2 as the northern, central, and southern sequences. Because of these structural complexities, some of the stratigraphic sequences de- scribed below are incomplete, and a number of sections must be discussed to illustrate regional variations in the formation across its relatively narrow outcrop belt. Subdivisions of the formation will be designated in- formally by letters which are compatible with, but represent a revision of, the informal symbols for units of the Matanuska Formation used by Grantz and Jones (1960). For brevity, units consisting of mixtures of claystone, silty claystone, and siltstone, with or with- out shaliness, will in places be called lutite in the fol- lowing discussion. UNIT A, STRATA OF ALBIAN AGE Albian strata lie at the base of the Matanuska For- mation in the vicinity of Limestone Hills in the north- ern part of the Nelchina area and along the north front of the Chugach Mountains in the southern part of the Nelchina area. Between these Albian occurrences lie the important Caribou and Castle Mountain fault sys- tems, which bound an area in which Cenomanian beds form the base of the formation. The Albian rocks in the Limestone Hills are relatively thin, are character- UNIT A, STRATA OF ALBIAN AGE 7. ized by soft claystone and siltstone bearing a rich am- monite fauna, and contain sandstone and coal-bearing beds at their base (fig. 3). They rest with disconform- ity upon Hauterivian or younger calcareous sandstone. The Albian rocks of the Chugach front are grossly similar but they are entirely marine, contain fewer ammonites, and some outcrops contain beds of algal nodules. In the lower Matanuska Valley the Albian rocks rest unconformably on Upper J urassic siltstone. In the Nelchina area and southwest Copper River Low- land, they rest on Lower Jurassic volcanic and as- sociated sedimentary rocks. In addition to sandstone and shale, the Albian sequence of the Chugach front is characterized by hard siliceous claystone and siltstone bearing many poorly preserved Znoceramus valves in some beds. 'The two rather different Albian facies of the Mat- anuska Valley-Nelchina area, that of the Limestone Hills to the north and that of the Chugach front to the south, are separated by two major faults and an area in which Albian rocks were either not deposited or were removed by uplift and erosion in the late Al- bian or early Cenomanian. The abrupt change from one sequence to another may be due to juxtaposition along the major fault systems. On the other hand, transitional beds may have existed in the intervening eroded area between the faults. LIMESTONE HILLS AREA Coal-bearing beds lie at the base of the Matanuska Formation in and near the Limestone Hills (fig. 3). These beds, informally designated unit A-1, rest dis- conformably on calcareous marine sandstone of Hau- terivian or younger age and grade upward into marine beds containing Albian mollusks. All known expo- sures are small erosional remnants and lie within 8 to 9 miles of Limestone Gap, at the center of the Lime- stone Hills. - These basal coaly beds are sharply lenticu- lar and variable in lithology, and their character is known only in a general way. At their base at Lime- stone Gulch (fig. 3) is about 50 feet of current-bedded medium- and fine-grained nonmarine sandstone. This is overlain by more than 30 feet, and locally by 100 feet or more, of brownish-dark-gray carbonaceous siltstone and claystone containing beds of bone and coal ranging from a few inches to at least 3 feet thick and a few beds of sandstone. - In some sections the carbonaceous silt- stone and claystone is overlain by 60 to 100 feet of medium-grained sandstone with current bedding and large sandy calcareous concretions. In its lower part this sandstone contains thin layers of siltstone and coaly shale and is thought to be nonmarine. At Lime- stone Gulch its middle and upper parts are littoral or inner sublittoral marine deposits and contain the pele- cypod Aucellina (see pl. 4, figs. 27, 28) and rare speci- mens of the ammonite Moffitites robustus Imlay (USGS Mesozoic loc. M5357) of early early Albian age (Moffé- tites robustus zone). The middle and upper (marine) parts of this sandstone are apparently represented by only a few thin sandstone beds or a pebbly silt- stone near Flume Creek, less than 3 miles east of Lime- stone Gulch. Sandstone with coaly lenses, possibly correlative with the lower and middle (nonmarine) parts of the Limestone Gulch section, crops out on Mazuma Creek, on Caribou Creek near Chitna Creek, and perhaps elsewhere in the adjacent region; in each of these areas, it is overlain disconformably by beds of Campanian or Maestrichtian age. In the Limestone Hills the basal sandy and coaly beds are overlain conformably by about 240 feet of marine silty claystone and siltstone, informally desig- nated unit A-2, which is characterized in its lower beds by brownish-gray-weathering slopes and numerous limestone concretions containing well-preserved am- monites. The beds that form brownish-gray-weather- ing slopes are roughly 100 to 125 feet thick, light olive gray, and contain abundant limestone concretions and lentils throughout. Fossil wood occurs in about the basal two-fifths, and numerous ammonite-bearing con- cretions occur in about the upper three-fifths of these beds. -About 110 to 185 feet or more of olive-gray silty claystone and siltstone containing fewer limestone con- cretions and ammonities forms the top of the claystone and siltstone unit and is overlain disconformably by silt- stone of late Campanian or Maestrichtian age. The abundant ammonites in these claystones and siltstones (USGS Mesozoic locs. 24877, 25320, M553-M556, M3539) show that all these beds belong to the Brewericeras hulenense zone of late early Albian age; identified forms include Brewericeras hulenense (Anderson) Anagaudryceras sacya (Forbes) Arcthoplites talkeetnanus (Imlay) Freboldiceras singulare Imlay Grantziceras affine (Whiteaves) G. glabrum (Whiteaves) Lytoceras n. sp. Hulenites sp. Parasilesites bullatus Imlay Puzosia alaskana Imlay NORTH FRONT OF THE CHUGACKH MOUNTAINS MATANUSKA VALLEY Lithic (epiclastic volcanic) marine sandstone, from 0 to about 25 feet thick, forms the base of the Matanuska Formation in the lower Matanuska Valley, where it is exposed at the north front of the Chugach Mountains near Wolverine Creek. The sandstones, informal unit A-I, rests uncomformably upon siltstone of the Naknek 8 CRETACEOUS AMMONITES Formation (Upper J urassic), and its basal contact shows rough erosional microtopography. - Itis gray and brown weathering, grades from coarse and pebbly in its lower beds to very fine grained at the top, and contains limestone concretions and wood fragments. A few pele- cypods and small ammonites belonging to Anagaudry- ceras of Albian age were collected from USGS Meso- zoic locality M1168 (pl. 10) in the upper part of this sandstone. USGS Mesozoic locality M583 from the same outcrop may date the sandstone more precisely, for this locality contains Rrewericeras Ahulenense of late early Albian age. However, the precise stratigraphic position of this locality is unknown ; it might be from the sandstone itself, or from the overlying beds. The basal sandstone is conformably overlain, but also overlapped, by fairly hard dark-green and medium- dark-gray silty claystone 250 to 300 feet or more thick. These beds are informal unit A-II. Abundant lime- stone nodules that in places are concentrated into lenses of limestone conglomerate 2 to 4 feet thick occur in the lowest 40 feet of this unit. Among the nodules are banded or layered masses produced by calcareous algae and some fragments of unidentifiable ammonite and pelecypod shells. At or near the top of the exposed part of the unit is fine- and medium-grained dark-greenish- gray graywacke sandstone 40 or more feet thick that contains some plant scraps. Because they are grada- tional, it is assumed that the sandstone and the silty claystone are of the same age; and because they rest conformably on beds with Albian fossils (unit A-I) and most closely resemble Albian lutite in the Mata- nuska Formation, they are tentatively assigned to the Albian. Mesozoic locality M583, which contains late early Albian fossils, is either from these beds or from the conformably underlying sandstone (unit A-I). A large covered interval separates the Albian beds near Wolverine Creek from Tertiary conglomerate which ap- pears, from its structural position and attitude, to over- lie them unconformably. At a few localities in the upper Matanuska Valley, rather hard silty claystone overlies beds similar to unit A-I and may be correlative with unit A-IIL At USGS Mesozoic locality M572 (pl. 10) these beds yielded poorly preserved ammonites similar to Arc- thoplites of early to middle Albian age, a hamitid am- monite of uncertain age, and /mnoceramus with ribbing similar to that of Znoceramus aff. 7. cuvierii of Turonian age. Thus the age of this collection and the correlation of these rocks are equivocal. NELCHINA AREA AND SOUTHWEST COPPER RIVER LOWLAND The basal beds of the Matanuska Formation along the Chugach front in the upper Matanuska Valley- Nelchina area and southwest Copper River Lowland are FROM MATANUSKA FORMATION, SOUTHERN ALASKA marine epiclastic volcanic sandstones that are commonly crossbedded and probably correlate with the somewhat similar but much thinner and lenticular basal beds near Wolverine Creek. They therefore are assigned to the same informal unit (A-I). Unit A-I rests with angu- lar unconformity and sharp erosional microtopography upon Lower Jurassic lavas and volcaniclastic rocks wherever studied. - In a typical section on the East Fork of Matanuska River these beds consist of lithic (epiclastic volcanic) sandstone, the lower half being coarse and conglomeratic and containing some rhyn- chonellid brachiopods and the upper half being fine and medium grained. The character of these beds, however, varies considerably from place to place. For example, 3 miles southwest of the beds at the East F. ork, the basal unit is tripartite, consisting of a basal pebbly sandstone with abundant fossil wood, a medial siltstone and fine-grained sandstone with limestone nodules and concretions, and an upper sandstone unit with large sandy limestone concretions. - The thickness of unit A-I in the Nelchina and adjacent areas is also rather variable, ranging from 100 or less to almost 400 feet. About 300 feet of pebbly epiclastic volcanic sandstone beds in a small area on the southeast side of Sheep Mountain may also belong to unit A-I, although their ago has not been definitely established, and they possibly belong with the overlying beds of Cenomanian age (unit B). These beds contain small brachiopods, and, near the base, a conglomerate with zones of irregular limestone and calcareous (algal?) nodules. - Snails (USGS Mesozoic loc. M1962) and several am- monites (USGS Mesozoic locs. M2409, M2413), as well as brachiopods and wood, have been found in unit A-IL. The ammonites, which include Rrewericeras cf. B. Ahulenense, Grantziceras sp., Anagaudryceras cappsi. Arcthoplites belli, Parasilesites bullatus, and Phyl- lopachyceras sp., establish the late early Albian age (Brewericeras hulenense zone of unit A-I in this area. Unit A-I is thus equivalent to the claystone and siltstone of unit A-2 and is younger than the Moffitites- bearing beds of unit A-1 of the Limestone Hills area. Conformably overlying the basal Albian sandstone (A-I) are greenish-gray, medium-dark-gray, and some olive-gray and brown siltstone and silty claystone with locally abundant interbeds of sandstone and coarse silt- stone. This sequence, informal unit A-III, is character- ized by numerous irregularly distributed beds and thick zones of hard (siliceous) claystone and siltstone ce- mented by diagenetic calcite and silica, by accumulations of generally fragmented ZInoceramus valves in some beds, and locally by zones containing numerous irregu- larly shaped limestone and calcareous algal nodules. Limestone concretions and lentils are locally common, UNIT B, SANDSTONE OF CENOMANIAN AGE 9 and calcareous intervals, thin layers of volcanic ash (?), and a few beds of glauconitic calcarenite are present. In the southern part of the Nelchina area some sections of this sequence are at least 700 or 800 feet thick, and south of Twin Lakes, in the southwest Copper River Lowland, similar rocks are at least 300 or 400 feet thick. Thicker sections may be present, but they are obscured by the extensive faulting which characterizes the Chu- gach front. In the southern part of the Nelchina area, unit A-III is overlain by softer lutite of Turonian age, and the similar rocks south of Twin Lakes are overlain by sandstone of Cenomanian age. Beds and zones of hard (siliceous) lutite constitute the bulk of unit A-III and contain small ammonites and an unnamed species of Inoceramus which, although poorly preserved, suggest a late Albian or early Ceno- manian age. The unnamed Znoceramus is a form with very fine concentric riblets that is similar to a species which occurs in the upper Albian rocks of the upper Chitina Valley; the ammonites include Desmoceras (Pseudouhligella) ef. D. (P.) dawson and a scrap that may be Marshallites. They were collected at USGS Mesozoic localities M5390, MI1Ti4, M2410, M2411, M2412 ( ?), M2414, M2415, and M2416. South of Twin Lakes the hard (siliceous) beds of unit A-III rest on 200 feet or more of relatively soft greenish-gray lutite which contains an ammonite scrap that may belong to @rantziceras of late early Albian age (USGS Mesozoic loc. M2386). These softer beds may represent Unit A-II of Wolverine Creek. In the Nel- china area the hard (siliceous) beds of unit A-III ap- pear to rest directly on unit A-I, the basal sandstone of late early Albian age, and soft beds that may repre- sent unit A-II have not been recognized. In neither area have fossils of middle Albian age (the zone of Oxytropidoceras packardi of California) been found. These relationships suggest that the base of unit A-III may mark either a disconformity or a hiatus south of Twin Lakes and a disconformity in the southern part of the Nelchina area. CORRELATION WITHIN THE MATANUSKA VALLEY-NELCHINA AREA The Albian siltstone and silty claystone sequence of the Limestone Hills area (unit A-2) contains ammonites belonging to the Brewericeras hulenense faunizone throughout. It is thus correlative with (1) sandstone (unit A-I) at the base of the Matanuska Formation in the Chugach front in the Nelchina area, which also con- tains ammonites characteristic of this faunal zone and (2) at least some part of the Albian section near Wol- verine Creek from which B. Aulemense of late early Albian age was also collected. Unit A-1 at the base of the Matanuska Formation in the Limestone Hills area contains Awcelline and M offitites robustus of early Albian age. It is therefore slightly older than unit A-I of the Chugach front in the Nelchina area and either correlates with unit A-I of the Wolverine Creek area or is slightly older. The latter view is supported by the apparent absence from the shallow marine sand- stone that constitutes unit A-I near Wolverine Creek, of Aucellina, a common fossil in shallow marine rocks of early early Albian age in southern Alaska. Unit A-II near Wolverine Creek and units A-I and A-II(?) in the upper Matanuska Valley and south of Twin Lakes are all probably also correlative with unit A-2 of the Limestone Hills. UNIT B, SANDSTONE OF CENOMANIAN AGE A distinctive marine sandstone of Cenomanian age, generally with a basal siltstone member, is an important cartographic unit in the southern half of the Nelchina area. The Cenomanian beds, informal unit B, occur mainly where Albian beds either were never deposited or were removed by mid-Cretaceous erosion. - Thus in most places they lie at the base of the Matanuska Forma- tion. - They rest upon Lower J urassic voleanic and Mid- dle and Upper Jurassic sedimentary rocks with angular unconformity, and the subjacent volcanic rocks locally are conspicuously weathered. ; Unit B has not yet been definitely recognized in the Matanuska Valley or along the north front of the Chugach Mountains except south of Twin Lakes, in the southwestern part of the Copper River Lowland, where it rests upon the hard siltstone (unit A-III) of late Albian age. Along the Chugach front west of the Twin Lakes area, unit B is either absent or is represented by beds which could not be differentiated in the field from the upper part of unit A-III. At most places sandstone of unit B is overlain with apparent conformity by siltstone of Cenomanian or Turonian age (unit C-1), but south of Horn Moun- tains in the central part of the Nelchina area unit B is locally overlain by Campanian beds of the upper part of the Matanuska Formation. Cenomanian beds are absent from the Nelchina area north of Horn Mountains and the Caribou fault system, where Campanian or younger beds rest directly upon Albian rocks. The basal siltstone member of the Cenomanian sand- stone unit rests upon a weathered erosion surface with locally sharp microrelief. The weathered zone is several feet thick where the surface was cut in Lower Jurassic volcanic rocks. - Residual clay deposits as much as 2 feet thick and siltstone and sandstone as much as 6 feet thick containing angular granules to cobbles of volcanic rock occur locally at the base of the unit. In one area at the west end of Sheep Mountain, sandstone and coarse siltstone at the base of the basal siltstone 10 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION, SOUTHERN ALASKA member are a few tens of feet thick. Above these vari- able, lenticular, and commonly very thin basal beds is a thicker and more widespread siltstone that is promi- nent in unit B around Sheep Mountain. This siltstone was not found in the northernmost outcrops of unit B in the Nelchina area, but in places its position may be occupied by about 60 feet of silty olive-black sandstone. At Sheep Mountain the siltstone member is typically 50 to 200 feet thick, and in places it may rest directly on pre-Matanuska rocks. Typically an olive-, greenish-, or medium-dark-gray siltstone, it ranges from silty shale to coarse siltstone and very fine sandstone. At some localities the siltstone weathers reddish gray or is mot- tled reddish and greenish gray. It contains some lime- stone concretions, and coaly layers, coal fragments, and fragmentary plant remains were found in a number of outcrops. The siltstone is dated as Cenomanian (zone of Desmoceras (Pseudouhligella) japonicum) by the presence of the ammonite Desmoceras gella) japonicum Yabe, in particular, and the ammo- nites Marshallites (%) sp., Zelondites (?) sp., Zogun- narites alaskaensis Matsumoto, and Parajaubertella im- layi Matsumoto at USGS Mesozoic localities 24857, M598, M2379, M2381, M2382, and M2385. The most characteristic and widespread component of unit B is a greenish-gray fine- and very fine grained shallow marine sandstone that conformably overlies the basal siltstone. It contains common and locally abundant Znoceramus sp. "A," a moderate-sized fairly stout-shelled pelecypod, and rare ammonite fragments, including Calycoceras sp. indet. (USGS Mesozoic locs. M595, M1938). In its northernmost outcrops the sand- stone is fine to medium grained and pebbly; to the south it is fine and very fine grained with coarse silt- stone. Plant fragments are widespread but not abun- dant. The sandstone is thick bedded or massive, in many places crossbedded, and silty interbeds and small intraclasts of glauconitic siltstone occur locally, espe- cially to the south. It is variously lithic or feldspathic, nowhere quartzose. Near the Caribou fault the sand- stone is about 150 to 200 feet thick; near Sheep Moun- tain it is about 100 to 250 feet thick and possibly, at one place, about 300 feet thick. Unit B is evidently the product of clastic deposition in a shallow seaway which transgressed an uneven weathered erosion surface; the main sandstone unit seems to have had a northern source, and deposition of the siltstone member is thought to have been termi- nated by the spread of partially winnowed sand from shallow, near-shore accumulation areas in the northern part of the Cenomanian basin. If this interpretation is correct, then the siltstone member is a basinward facies of the lower part of the sandstone member. UNIT C, STRATA OF CENOMANIAN To SANTONIAN(?) AGE UNIT C-1, LUTITE OF CENOMANIAN TO CONIACIAN OR SANTONIAN AGE Medium-dark-gray lutite (silty claystone and sand- stone), informally designated unit C-1, conformably overlies unit B in the central part of the Nelchina area and along the Chugach front south of Twin Lakes in the southwest part of the Copper River Lowland. Along the Chugach front in the Nelchina area, unit C-1 rests with apparent conformity upon unit A-III. Unit C-1 is absent north of the Horn Mountains and crops out north of the Caribou fault only on the southeast flank of these mountains. It has not been definitely identified in the Matanuska Valley but probably occurs in at least the upper part of the valley. - Medium-dark- gray silty claystone of Campanian (and locally San- tonian?) age in the upper part of the Matanuska For- mation disconformably(?) overlies unit C-1 north of the Matanuska River in the Nelchina area. Along the Chugach front, however, unit C-1 is overlain with an- gular unconformity by a unit of interbedded siltstone, sandstone, and conglomerate that is informally desig- nated unit C-2. Unit C-1 is rather similar in appearance to the dark lutite of the overlying Campanian beds (Inoceramus schmidti zone), and rocks of these two units have been mapped together in parts of the Nelchina area. Where rocks of the Matanuska Formation have not been strongly indurated by tectonic compression, these units can be distinguished by the greater abundance and larger size of limestone concretions with well- developed cone-in-cone structure in the Campanian beds and by the presence of large and locally abundant valves of Inoceramus schmidti. Also, the Campanian silty claystone has a bluish cast in many outcrops, in contrast to the gray color, in places with a strong greenish or purplish cast, of unit C-1. F urthermore, along the Chugach front, unit C-1 has thicker and more num- erous beds of altered volcanic ash. Unit C-1 is possibly 1,500 feet or more thick in the valley floor of the Matanuska River; it thins to about 400 feet on the northeast side of Sheep Mountain and to a feather edge in the west-central part of the Nel- china area. Late Cretaceous erosion of unit C-1 in the central Nelchina area is demonstrated by reworked limestone concretions with Coniacian fossils in a Cam- panian channel conglomerate at USGS Mesozoic local- ity M561 and by reworked Turonian or Coniacian fossils in Campanian lutite at USGS Mesozoic locality 25964. Because unit C-1 has been mapped with Campanian beds in many places, and because complete thick sections have not been found, its maximum thickness is not known. Around Sheep Mountain its basal beds are UNIT C, STRATA OF CENOMANIAN TO SANTONIAN(?) AGE 11 olive or greenish-gray siltstone, much of which is hard, sandy, or coarse. - These beds grade into predominantly medium-dark-gray silty claystone and siltstone con- taining fossiliferous limestone concretions, thin inter- beds of fine-grained detrital sandstone, some beds of glauconitic calcarenite rich in Znmoceramus prisms and shell fragments, and a few thin shelly siltstone layers. Unit C-1 weathers typically to chunky fragments. South of the Matanuska River the unit is medium dark gray or greenish gray and commonly has a purplish cast. In places there, it is pebbly and contains sand- /stone beds and lenses and some thin beds of volcanic ash. | __ Unit C-1 contains fairly common ZInoceramus frag- \_ ments and some ammonites, but identifiable collections \ have not been found at enough places to completely fifine its age in all areas. Near Camp Creek a large collection of mollusks at USGS Mesozoic locality M600 from the base of the unit is of Cenomanian age. On the north side of the Matanuska River gorge, USGS Mesozoic locality M1989 in the lower part of C-1 con- tains fragments of the ammonite Fuomphaloceras ( ?) sp. and other fossils indicative of a possible Cenoman- ian age. At all other places where datable mollusks were found near the base of unit C-1, the fossils are of probable Turonian age. This age assignment is based mainly on the presence of Zmoceramus aff. I. cuvierii, the most common mollusk in most outcrops of unit C-1 (USGS Mesozoic locs. 25960, 25968, 25971, 25985, 25987, M5369, M6O1, M1947, M1949, M1950, M1951, M1968, M1988, M2389, M2391, M2406). At some outcrops this pelecypod is associated with ammonites and other Inoceramii that are of probable Turonian age or that are known to range into the Turonian. - These associated fossils include Otoscaphites teshioensis, Mesopuzosia aff. M. indopacifica, Seaphites cf. S. planus gigas, Tetrago- nites aff. T. glabrus, Sealarites? sp. indet., and Inoceramus cf. I. concentricus nipponicus; they were found mostly in unit C-1 (USGS Mesozoic locs. 24239, 24853, M6O01, M1945), but some of these forms occur as intraclasts in Campanian beds at USGS Mesozoic locality 25964. The youngest faunule identified from unit C-1 oc- curs around Sheep Mountain and in the valley floor of the Matanuska River. It has not yet been found in the northernmost outcrops of unit C-1 near the south side of the Horn Mountains, although it occurs as reworked intraclasts in Campanian beds of the upper part of the Matanuska Formation at USGS Mesozoic locality M561. This faunule is dominated by /moceramus umajimensis Yehara of Coniacian age (USGS Mesozoic locs. 24189, 24231, 24232, 24233, 25972, 267830, M1942, M1943, M1958, M1959(?), M1986, M1987, M1992, M1994( ?), M1995 (?)). It also contains 7. of. 7. yoko- yamai, Mesopozosia sp., and Sceaphites sp. indet. (USGS Mesozoic locs. M1992, M2384(?), M2408). The latter forms may range into the Santonian, and where they occur without Zmoceramus uimajimensis, the beds may be of Santonian age. UNIT C-2, COMPOSITE SEQUENCE OF CONIACIAN AND SANTONIAN(?) AGE Unit C-2, a thick sequence of siltstone and silty clay- stone with numerous thin to very thick interbeds of sandstone and conglomerate, crops out along the Chu- gach front and in an adjacent lowland belt in the Nel- china area and south of Twin Lakes in the southwest Copper River Lowland. Lithologically similar beds crop out near the mouth of Tazlina Lake in the south- central part of the lowland, but the paleontologic evi- dence so far obtained to support the correlation of these beds with unit C-2 is equivocal. The composite unit rests with angular unconformity on beds as young as Coniacian in unit C-1 and as old as Early Jurassic in the Talkeetna Formation. It is overlain (disconform- ably?) by silty claystones of Santonian age which are the oldest beds in the upper part of the Matanuska Formation. Unit C-2 is about 2,000 to 2,500 feet thick. It con- sists of predominantly medium-dark-gray siltstone and silty claystone containing myriad very thin to very thick interbeds of coarse siltstone, sandstone, pebbly sand- stone, and conglomerate. The sandstone interbeds are composed chiefly of lithic grains and generally contain more feldspar than quartz, which is a relatively minor constituent. The interbeds occur irregularly, and the unit is constructed of successive sequences of siltstone, a few tens to a few hundreds of feet thick, containing dif- ferent proportions and (or) types of interbeds. In some sequences sandstone predominates over siltstone, and thick-bedded and massive units of sandstone and conglomerate a few tens of feet thick are fairly common. The interbeds are characterized by graded bedding, sole- markings or "flysch figures," and both intraformational and extraformational clasts. Large-scale penecontem- poraneous slump structures were noted at a number of localities. Small-scale crossbedding, some asymmetric ripple marks, scoured or channeled bases, and carbona- ceous scraps and plant fragments are common in the sandstone interbeds. Typically, the pebbly sandstone and conglomerate beds are markedly channeled into their substrates, and some of these beds are sharply len- ticular. Some thin beds are calcarenite composed of Inoceramus prisms, broken shells, and other small car- bonate fragments. - Limestone concretions occur in both sandstone and siltstone beds but are not abundant. Several collections of Znoceramus and two collections containing ammonités have been found in the inter- 12 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION , SOUTHERN ALASKA bedded unit. The Inoceramii have been assigned to Inoceramus wwajimensis of Coniacian age (USGS Mesozoic locs. M1953, M1959 (?), M2387 ( ?), M2403 ( ?)) and to a new species related to Z. wiwajimensis that may be of Coniacian or Santonian (?) age (USGS Mesozoic locs. 25979, M591, M1272, M1773, M1952, M1961, M2384 (?), M2397, M2401, M2402, M2404, M2405). The ammonites include a scaphite from Shell Oil Co. locality T1006 that is similar to forms in the Turonian and Coni- acian of Japan and a long-ranging species of Neo- phylloceras from USGS Mesozoic localities M591 and M1952. Their ages are compatible with, but do not add to, the Coniacian age suggested by the Inoceramii. The outcrops at the mouth of Tazlina Lake, which pos- sibly belong to unit C-2, contain (at USGS Mesozoic locs. M2396 and M2397) the Zmoceramus n. sp. related to I. uwajimensis, which is of Coniacian or Santonian ( ?) age and (at USGS Mesozoic loc. M1969) an ammonite serap, which perhaps belongs to Canmadoceras or Meso- puzsosia of Santonian or Campanian age. The composite unit is clearly younger than Coniacian beds in unit C-1 along the Chugach front, for it rests upon them with angular unconformity. The lutite of unit C-2, however, is similar to lutite in the upper part of unit C-1 near Sheep Mountain where unit C-2 is absent from the section. The upper part of C-1 in this area contains Znoceramus wwajimensis, as does unit C-2, and thin beds of fossiliferous-fragmental calcarenite and detrital sandstone. The similarity of these beds to unit C-2 suggests that C-2 may be a facies of the upper part of unit C-1 near Sheep Mountain and that a disconformity corresponding to the unconformity at the base of unit C-2 may be present in the upper part of C-1 north of the Chugach front; however, because the sections with and without unit C-2 are closely juxta- posed across the Matanuska River and its East Fork, transcurrent movement along a branch of the Castle Mountain fault system near these rivers was probably at least partly responsible for the absence of unit C-2 north of the Chugach front. REGIONAL CORRELATION OF THE LOWER PART OF THE MATANUSKA FORMATION The lower part of the Matanuska Formation com- prises rocks ranging in age from Albian to Coniacian or Santonian, although the sequence is not complete and several unconformities are present (figs. 2, #). 'The fossils of Albian and Cenomanian ages are similar to those from the upper Chitina Valley, and fairly close correlation between the rocks of the two areas can be achieved. The Albian faunas include species known from California as well as from the Arctic Slope of Alaska and the western interior of Canada. This joint occurrence permits a rather close tie between two faunal provinces, the Indopacific and the Western Interior, which previously could be correlated only by indirect means. Cenomanian fossils are scarce and are generally simi- lar to forms known elsewhere in the Indopacific faunal realm. This is also true for Turonian fossils, which for the most part are poorly preserved and fragmentary. The Coniacian fossils are similar to forms known from the upper Chitina Valley and are comparable, or identi- cal, with Japanese species. The basal sandstone beds of the Matanuska Forma- tion in the vicinity of Limestone Gulch (unit A-1) are equivalent to the basal beds of the Albian sequence of the upper Chitina Valley, on the basis of the presence of Moffitities robustus and Aucellina. The overlying grayish-brown siltstone (unit A-2) containing the "Freboldiceras singulare" fauna as well as the basal sandstone (unit A-I) along the northern front of the Chugach Range south of the Matanuska River are cor- relative with beds bearing the Brewericeras hulenense fauna of the upper Chitina Valley, Queen Charlotte Islands, the Methow Valley area of northern Washing- ton (Popenoe and others, 1960, p. 1535), unnamed beds near Mitchell in central Oregon, and part of the Chickabally Mudstone Member of the Budden Canyon Formation of Murphy, Peterson, and Rodda (1964) in northern California. This stratigraphic unit is equiv- alent to part of the Ono Formation of previous usage (Murphy, 1956). Brewericeras hulenense reached its known northern extent in the Matanuska Valley-Nelchina area, where it mingled with representatives of the northern Grant- siceras and Arcthoplites fauna. Elements of this northern fauna are known as far south as the Queen Charlotte Islands, British Columbia, but are unknown from Oregon and California. @rantziceras occurs at several localities in northern Alaska. Near Hughes several well-preserved specimens of G. affine, together with a probable new species of Cleomiceras, were col- lected by W. W. Patton, Jr., of the U.S. Geological Sur- vey; Imlay (1961, p. 7) has reported G@rantziceras of- fine and G. cf. G. affine from the lower part of the Torok and Fortress Mountain Formations of the Arctic Slope of Alaska. In Canada, Grantzsiceras [="Beudanti- ceras"] occurs commonly in the Moosebar and Gates Formations, the lower part of the Buckinghorse Forma- tion, and the Loon River and Clearwater Formations (Henderson, 1954, p. 2285). The basal beds of the Matanuska Formation near Sheep Mountain (unit B) are correlative with the Des- moceras (Pseudouhligella) japonicum-bearing beds of the upper Chitina Valley on the basis of the presence of D. (P.) japonicum, Eogunnarites alaskaensis, and Parajaubertella imlayi. Rocks of the upper Albian D. (P.) dawsoni zone have not yet been positively identi- fied, but they might be represented in the region south of the Matanuska River by the siliceous beds in the upper part of unit A-III. Rocks of mid-Cenomanian age are reprwefid by sandstone beds in the upper part | of unit B that bear rare specimens of Calycoceras sp. and a new species of Znoceramus characterized by a long thin overhanging umbo in the left valve. The over- lying beds in the basal part of unit C-1 may be either late Cenomanian or early Turonian, as discussed below. In California, the Bald Hills Member, and perhaps the uppermost part of the underlying Chickabally Mud- stone Member of the Budden Canyon Formation (Mur- phy and others, 1964), are correlative with the D. (P.) REGIONAL CORRELATION 13 japonicum and D. (P.) dawsoni-bearing rocks of the Chitina Valley and the Matanuska Valley-Nélchina area. Upper Albian rocks in central Oregon (Jones, 1960; Packard and Jones, 1962) may be somewhat older than the D. (P.) dawsoni zone of southern Alaska, although a precise correlation of the two is not possible. The Oregon rocks contain an abundant ammonite fauna characterized by Mortoniceras sp., Anisoceras merriami, and Desmoceras (Pseudouhligella) sp. This latter form was referred to D. (P.) dawsoni by Matsumoto (19592, p. 61) but a study of large collections have con- vinced the writer of the present report that the Oregon specimens consistently have a more inflated whorl see- tion than do the Alaskan forms and therefore are prob- ably not conspecific. COMPOSITE COLUMNAR SECTION OF MATAN- USKA FORMATION, MATANUSKA VALLEY- NELCHINA AREA STAGE FAUNAL SEQUENCE coOMmPOSITE COLUMNAR SECTION OF CRETACEOUS ROCKS IN UPPER CHITINA VALLEY, SHOWING POSI- TION OF CHARACTERISTIC ( H -L 1. 1_ |_. Upper part of Matanuska Formation Maestrichtian Pachydiscus kamishakensis zone HOTTIE Conglomerate, sandstone and $ siltstone Campanian Inoceramus schmidti zone Inoceramus schmidti Santonian C-2 Coniacian Mesopuzosia sp., Inoceramus yokoyamai Inoceramus n. sp. "A" Inoceramus umajimensis, scaphites sp. Shale, siltstone, and minor sandstone; limestone con- cretions f . Inoceramus yokoyamai Inoceramus uwajimensis Turonian Inoceramus spp. Sciponoceras sp. Inoceramus n. sp. "B Anagaudryceras sacya Calycoceras sp. B Parajaubertella imlayt Eogunnarites alaskaensis Desmoc. (P.) japonicum Zelandites inflatus Cenomanian Inoceramus aff. I cuvierii, I aft. I concentricus nipponicus, I. n. spp., Tetragonmites aff. T. glabrus Mesopuzosia aft. M. indopacifica, P Otoscaphites teshicexsis Desmoceras (P.) japonicum AAL 1 e Sandstone and shale Desmoceras (Pseudouhligella) japonicum zone Gaudryceras denseplicatum Brewericeras hulenense Grantziceras glabrum Grantziceras affine Freboldiceras singulare Arcthoplites talkeetnanus Tetragonites aff. T. timotheanus Parasilesites bullatus Puzosia alaskana Lytoceras sp. Sandstone, shale, siliceous shale A-I11 Anagaudryceras sacya " woo - Desmoc. (P) cf: Phyllopachyceras mizi Desmoc. (P.) dawson zone w 1 T T I k ‘ D. (P.) dawsoni? Arcthoplites belli ‘ { j Anagaudryceras cappsi Albian A-2 h- and £-11 % s Sandstone and shale > ane hs Brewericeras hulenense zone A-1 Moffitites robustus, Aucellina sp. Sandstonciand shale Moffitites robustus zone FIGURE 4.-Generalized columnar section of the Matanuska Formation showing faunal succession in the lower part of the formation and correlation with rocks in the upper Chitina Valley area. 14 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION, SOUTHERN ALASKA Albian or Cenomanian rocks correlative with those of the Matanuska Valley-Nelchina area may be present elsewhere in southern Alaska, although little is known of their occurrence. Parkinson (1960) reported that on the Alaska Peninsula, Lower Cretaceous rocks crop out in the Cape Douglas area and that some of these rocks are of Albian age on the basis of microfossils (L. J. Parkinson, written commun., 1961). Because field examination in 1965 by Jones and R. Detterman re- vealed only beds of probable late Neocomian age, the identification of the Albian strata could not be sub- stantiated. Poorly preserved fossils in the Shell Oil Co. collection in Seattle, obtained from locality SOC M249, Kuiukta Bay, were examined by the writer and tentatively identified as Desmoceras (Pseudowhligella) japonicum and Marshallites sp. A large specimen of Anagaudryceras sacya, similar to the specimen of A. sacya from the Queen Charlotte Islands figured by Whiteaves (1884, pl. 25), was collected from Portage Bay by Prof. F. W. True of the U.S. Fish Commission. Unfortunately, there are three "Portage Bays" on the Alaska Peninsula, and it has not been possible to ascer- tain from which one the fossil was collected. The most likely place appears to be the Portage Bay located at the head of Kuiukta Bay, although it has not yet been demonstrated that Cretaceous rocks are exposed there. Cenomanian rocks occur in northern Alaska, but with the exception of the Arctic Slope region, they have re- ceived little detailed study and have yielded a relatively meager fauna that has little or nothing in common with those from southern Alaska. The Nanushuk Group of the Arctic Slope is of probable late Albian and Ceno- manian ages (Jones and Gryc, 1960, p. 153, fig. 31) based on Imoceramus dunveganensis McLearn, a species not known to occur in Alaska south of the Brooks Range, although erroneously reported to occur in the central Kuskokwim region (Cady and others, 1955, p. 45). The Kuskokwim region probably does contain rocks of Cenomanian age, on the basis of the presence of species of Imoceramus similar to undescribed forms from the upper Chitina Valley area and a single speci- men of Turrilites acutus of Cenomanian age from the upper Anvik River region. Rocks of probable Turonian age, containing an abundant fauna of Znoceramus and rare ammonites, oc- cur in informal unit C-1 of the Matanuska Formation. The Znoceramus specimens are generally fragmentary and whole valves are rare. The most common form is referred to Inoceramus cf. I. cuvierii, which is known from Turonian deposits of northern Alaska (Jones and Gryc, 1960) and elsewhere. Another common species is related to /noceramus concentricus nipponi- cus Nagao and Matsumoto (1939), known from Ceno- manian deposits of Japan. Associated with these spe- cies are several ammonites, including well-preserved specimens of Ofoscaphites teshioensis (Yabe), Mesopu- zosia aff. M. indopacifica (Kossmat), Tetragomites aff. T. glabrus (Jimbo), NeophyHloceras sp., and Gaudry- ceras sp. This fauna overlies beds in the lower part of unit C-1 from which a fauna of probable late Cenomanian or early Turonian age was obtained. Fossils from this fauna include Aciponoceras sp., Tetragonites aff. T. glabrus, Gaudryceras aff. G. denseplicatum (Jimbo), Bostrychoceras sp., fragments of a desmoceratid am- monite resembling D. (PseudowuAligella) japonicum, and Znoceramus sp. The presumed Turonian fauna is overlain by beds yielding abundant specimens of Inoceramus wwaeji- mensis of Coniacian age. With the exception of the upper Chitina Valley, Turonian rocks have not yet been positively identified elsewhere in southern Alaska, although the presence of a small specimen of Sub- prionocyelus normalis on a mud cone in the south- eastern part of the Copper River Lowland (Grantz and others, 1962) suggests that upper Turonian de- posits may be present locally in that area. The dis- placement of this fossil rules out any understanding of its stratigraphic significance, but it seems likely that it was brought up by connate water from subsurface marine deposits of Turonian age. Further evidence for the presence of Turonian beds in the Matanuska Valley-Nelchina area is provided by Foraminifera studied by Bergquist (1961). In his lowest microfaunal unit, zone A, Bergquist (p. 2004- 2005) reported the presence of Bathysiphon alezanderi Cushman B. taurinensis Sacco "Cribrostomoides" cretacea Cushman and Goudkoff Ammodiscus cretaceus (Reuss) G@lomospira aff. G. gordialis (Jones and Parker) Robiilus miinsteri (Roemer) G@yroidina florealis White G. globulosa (Hagenow) Eponides sp. G@lobotruncana arce (Cushman) Rectoglandulina sp. Planulina spissocostate Cushman Haplophragmoides sp. Marssonelle ozycona (Reuss) Gaudryina cf. G. bentonensis (Carmen) Marginulina bullata (Reuss) "@lobigerina'" cretacea (d'Orbigny) Pelosina complanatae Eranke Cibicides stephensoni Cushman Beds yielding this fauna occur from 100 to 400 feet above the base of the Matanuska Formation in the Squaw Creek area and from depths of 4,350 to 4,818 feet in the nearby Eureka test well 1. These beds were ten- tatively correlated by Bergquist with beds of the lower Cachenian Stage of California (G-2 of Goudkoff, 1945), mainly on the basis of the presence of Oibicides stephensoni. The lower Cachenian Stage was assigned a middle to late Turonian age by Popenoe, Imlay, and Murphy (1960, p. 1517). However, some of the forms listed above, for example, @lobotruncama arca, are indic- ative of a post-Turonian age, so it seems possible that samples from low in the section were contaminated by fossils from higher in the section. Turonian beds probably occur in the central Kuskok- wim region of southwestern Alaska, where an unde- scribed fauna of Otoscaphites, Scalarites, and Inocera- mus spp. is known from the Kuskokwim Group (Cady and others, 1955). On the Arctic Slope of Alaska, Turonian beds are widespread and have yielded many fossils (Jones and Gryc, 1960; Cobban and Grye, 1961), but these show only a slight relationship to faunas of southern Alaska. Deposits of Coniacian age, represented by lutite of unit C-1, are characterized by fairly abundant speci- mens of Inoceramus uwajimensis and rare specimens of I. cf. I. yokoyamai and Mesopuzosia sp. The over- lying sandstone of unit C-2 contains locally abundant valves of a new species of Zmoceramus close to, and pre- sumably derived from, Z. uwajimensis, which may be of late Coniacian age. Unit C-1 is thus equivalent to the lower part of the dominantly siltstone and shale sequence of the upper Chitina Valley area that in the McCarthy A—14 quadrangle was designated unit K, GEOGRAPHIC DISTRIBUTION OF AMMONITES 15 (Miller and MacColl, 1964; Jones and Berg, 1964, p. 10, $1). Elsewhere in southern Alaska, positive evidence is not available for the presence of Coniacian rocks, al- though Imlay (in Imlay and Reeside, 1954, p. 228) postulated that some deformed and fragmentary spec- imens of Znoceramus obtained from slate and gray wacke near Girdwood in the Chugach Range and from Woody Island near Kodiak are of late Coniacian or early San- tonian age. - This age determination was based on com- parison of the Alaskan specimens with those from Utah and Wyoming, as similar forms have not been found in other well-dated and richly Znoceramus-bear- ing rocks of Alaska. Such a long-range correlation without benefit of local stratigraphic control leaves this precise age determination open to some question, although undoubtedly the forms are of late Mesozoic age. Until confirming evidence is obtained, it seems best to leave open the exact age of the Imoceramus- bearing part of the Chugach slate and graywacke belt and regard as unconfirmed the determination of Conia- cian fossils from this belt. GEOGRAPHIC DISTRIBUTION OF AMMONITES The collecting localities of the ammonites described in this report and of several undescribed forms and selected species of Inoceramus are shown on table 1. The general position of each locality is shown on plate 10, and detailed descriptions of the localities are given in table 2. 16 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION , SOUTHERN ALASKA 1.-Checklist of fossils from the lower part of the Matanuska Formation, Matanuska Valley-Nelchina area USGS Mesozoic Locality No. Fossil Otoscaphites teshioensis.. . ._ ____ Scouphites sp. Mesopuzosia aft. M. indopacifica G Pere ues ie cbs areolae e+ nae bo be ank o non Sciponoceras sp. indet .... Gaudryceras aff. G. denseplicatum .. Tetragonites aft. T. glabrus...__ Subprionocyclus normalis . . Neophyloceras sp. juy._. Calycoceras sp. indet . _________ Tetragonites cf. T. timotheanus ___ Desmoceras (Pseudouhligella) japon (Pseudowhligella) sp. indet. Marshallites sp..______________ Zelandites inflatus.______________ Eogunnarites aldska A Parajaubertella imlayi . . Anagaudryceras sacya..______________ Brewericeras hulenense. Arcthoplites talkeetnanus .. Freboldiceras singulare. . Grantziceras affine. ___ glabrum._______ Lytoceras n. sp.. Puzosia alaskana..___ Hulenites sp._________ Moffitites robustus . ___ Parasilesites bullatus__ Hamitid ammonite... Euomphaloceras(?) sp Auceliing sp.........._..__. uwajimensis. .. cf. I. yokoyamai. SDP ped aed ay c oen e abnd cede cf. I. concentr ponicus .. Ammonite, gen. and sp. indet.___ Anagaudryceras cappsi_.__._______ Arcthoplites belli.__ 2 Telruobhites sp.... ._.... .D EhyMopachyceras chiftnemim... _...... m Clap immements= 2 t Aon. ir" . | 24189 24858 24855 x G ES @ 24856 24857 24877 25820 25960 250961 25062 25003 25965 25087 26730 M555 to [t- Fossil 13 18 AlR M595 M596 2. . . 2 nen olo neve. eee dae eee e ce al nance. #6 Scaphites sp. indet...._.__._____ den eden on be ado e ve Mesopuzosia aft. M. crass lll ccd CAS ACI D Conmen ened che on podlswng sles aoe enn nied Sciponoceras sp. indet____ Gaudryceras aft. G. denseplicatum . Tetragonites aff. T. glabrus.___ _ Subprionocyclus normalis ._ __________________- Neophylloceras sp. juy.__ Calycoceras sp. indet..._______ Tetragonites cf. T. timotheanus.________________ Desmoceras (Pseudouhligella) japonicum.... _ (Pseudouhligella) sp. indet . ._ 8D J 2s ot INIT Zelandites inflatus . ________ Rogunnarites [IITC ParajatherieUa Anagaudryceras sacya. _ des pra UL Brewericeras hulenense_________ Arcthoplites talkeetnanus .. ___ __ Freboldiceras singulare...________ Grantziceras affine . _ pigbruim= eds cc cc.. A. cll... .co Puzosia alaskana _ . 0.0.0 OI Moffitites robustus Parasilesites ._ Hamitid ammonite..__...___________ Euomphaloceras(?) sp rss 0 _ Inoceramus cf. I. cuvierii «p» a uds i XXXXXXXX n. sp: A*.. «wajimensis. . ._ cf. I. yokoyamai. cf. I. concentricus nipponicus_____________ Ammonite, gen. and sp. indet..____..____._ __ Anagaudryceras cappsi Arcthoplites belli. . Tetragonites gp......_...__ Phyllopachyceras chitinanum...__________________ Crab fragments.. n 00100 [LOO CHICO A TaBLs 1.-Ch CEOGRAPHIC DISTRIBUTION OF AMMONITES 17 ecklist of fossils from the lower part of the Matanuska Formation, Matanuska Valley-Nelchina area-Continued USGS Mesozoic Locality No. Soc-T1006 M2390 M2391 M2410 M2411 M2412 M2402 Otoscaphites teshioensis Scaphites sp. indet.. .. Mesopuzosia aff. M. in BD.. eee ade ec ol Sciponoceras sp. indet Gaudryceras aff. G. den Tetragonites aff. T. glo Subprionocyclus nor mali Neophylloceras sp. juy Calycoceras sp. indet... Tetragonites cf. T. tim Desmoceras (Pseudowhligella) japonicu (Pseudouhligella) i Marshallites sp . -. ...- Zelandites inflatus . ._. Eogunnarites alaskaensi Parajaubertella imlayi... Anagaudryceras sacya. . Brewericeras hulenense. Arcthoplites talkeetnan Freboldiceras singulare Grantziceras affine . . . glabrum . . .... Lytoceras n. sp.. Puzosia alaskan Flulenites sp .. ._ Moffitites robustus .... Parasilesites bullatus . Hamitid ammonite... Euomphaloceras(?) sp Aucellina sp__...-_-. cf. I. concentricus Ammonite, gen. and Anagaudryceras capp Arcthoplites belli. . .._ aye Tetragonites sp.... Phyllopachyceras ci Crab fragments....... BD. IMG. ...... ccc cece ce i 1 /M Mreil Mi X TABLE 2.-4 USGS Mes ozoic Loc. 0. 22123 24188 24189 24203 24204 Collector, year of collection, description of locality, and stratigraphic position R. A. Eckhart, 1949. Anchorage D-2 quad., 3,100 ft north of Glenn Highway. Lat 61°48'50" g" long 147°31'45"" W. Unit A. Grantz, R. Hoare, R. Imlay, 1952. Anchorage D-2 quad. On south tributary of Squaw Creek, 1.95 miles N. 40° W. of southeast summit of Gunsight Mountain. Unit B. A. Grantz, R. Hoare, R. Imlay, 1952. Anchorage D-2 quad. On south tributary of Squaw Creek, 2.01 miles N. 40.5° W. of southeast summit of Gunsight Mountain. Unit C-1. A. Grantz, R. Hoare, R. Imlay, 1952. Anchorage D-2 quad., on south tributary of Squaw Creek, 2.47 miles N. 24° E. of southeast summit of Gunsight Mountain. Unit C-1. A. Grantz, R. Hoare, R. Imlay, 1952. Anchorage D-2 quad., on south tributary of Squaw Creek, 2.25 miles N. 26° E. from southeast summit of Gun- sight Mountain. Unit B. No. 24205 24206 24229 24231 24232 24233 24239 24850 Field No. 52AGz 59-___. 52AGz 68 ___. b2AHr Ai...... s2AHr.6...... b2AHr6....:-. s2AHr 7....:. 52AGz 266 -__. b3AGz GA._.___. Ammonite and selected Inoceramus-bearing localities in the lower part of the Matanuska Formation, southern Alaska USGS Mes ozoic Loc. Collector, year of collection, description of locality, and stratigraphic position A. Grants, R. Hoare, R. Imlay, 1952. From talus, same local- ity as 24204. _ Unit B. A. Grantz, R. Hoare, and R. Imlay, 1952. Anchorage D-2 uad., south tributary of Squaw %reek, 1.50 miles N. 30.5° E. of southeast summit of Gunsight Mountain. Unit B. R. Hoare, 1952. Anchorage D-1 quad., borrow pit on north side of Glenn Highway at mile 120.25. Unit C-1. R. Hoare, 1952. Anchorage D-1 quad., north side of Glenn High- way at mile 118.94. Unit C-1 R. Hoare, 1952. _ Same locality as 24231. Unit C-1. R. Hoare, 1952. Anchorage D-2 quad., south tributary of Squaw Creek, 2.02 miles N. 60.5° W. of southeast summit of Gunsight Mountain. Unit B. A. Grantz, 1952. - Anchorage D-2 quad., on south side of Alfred Creek, 1.22 miles S. 55° W. of mouth of Pass Creek. - Unit C-1. A. Grantz, 1953. - Anchorage D-2 %uad. Same locality as 22123. nit B. 18 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION , SOUTHERN ALASKA TaBu® 2.-Ammonite and selected Inoceramus-bearing localities in the lower part of the Matanuska Formation, southern Alaska-Con. USGS Mes- ozoic Loc. Collector, year of collection, description of locality, No. Field No. and stratigraphic position 24851 58AG0z 8..._.. A. Grantz, 1958. Anchorage D-2 gluad., 2,200 ft north of Glenn ighway. Lat 61° 49'17"" N., long 147°32'10"' W. Unit B. 24853 53AGz 16... A. Grantz, L. Fay, 1953. Anchorage D-2 quad. Approximately 0.25 mile N. 57° W. of BM3117, 500 ft north of Glenn Highway. Lat 61°49'27'" N., long 147°26'48"" W. Unit C-1. 24855 58AGz 26_____ A. Grants, 1953. Anchorage D-2 quad., north of Glenn Highway, approximately 0.24 mile N. 67° . of BM3305 and 0.37 mile S. 22° W. from point where Camp Creek crosses Glenn Highway. Lat 61°50'12"" N., long 147° . 25'02"" W. Unit B. 24856 31..__._. A. Grantz, L. Fay, 1953. Anchor- age D-2 quad., north of Glenn ighway, about 0.25 mile N. 67° W. of BM3305 and 0.4 mile S. 21° W. from point where Camp Creek crosses Glenn Highway. Lat 61°50'12%4'"' N., long 147° 25'08'' W. Unit B. 24857 58AGz 52..... A. Grantz, L. Fay, 1953. Anchorage D-2 quad., float from 2.75 miles north of Glenn High- way, on north branch of south tributary to Caribou Creek. Lat 61°50'22'' N., long 147°36'19"" W. Unit B. 24877 53AGz 137-____ A. Grants, L. Fay, 1953. Talkeetna Mountains. A-2 quad., southern part of Lime- stone Gulch, east of Billy Creek. Lat 62°01'40%4"' N., long 147°39'18"" W. - Unit A-2. 25320 54AGz 58-.____ A. Grantz, 1954. Talkeetna Mountains.. A-2 quad., un- named west tributary to Flume Creek. Lat 62°00'41"' N., long 147°34'46"" W. Unit A-2. 25960 55AGz 179-___ _ A. Grants, 1955. Valdez D-8 quad., 3,000 ft southeast of southern shore of Twin Lakes, on unnamed tributary, elev 3,050 ft. Lat 61°54'41"' N., long 146° 5208" W. Unit C-1 or C-2. 25961 55AGz 183a--_ A. Grantz, 1955. Valdez D-8 quad., 7,500 ft south of Twin Lakes, elev 4,350 ft. Lat 61°54'02"" N., long 146°31'47"' W. Unit B. 25962 55AGz 184b___ A. Grantz, 1955. Valdez D-8 quad., 2%, miles south of Twin Lakes, elev 4,500 ft. Lat 61°52'58"' N., long 146°53'01"" W. Unit B. 25963 55AGz 186b-._-- A. Grants, 1955. Valdez D-8 quad., 1%, miles south of southwest tip of Twin Lakes, elev 3, 900 ft. Lat 61°53'31"' g” long 146°54'01"" W. Unit 25965 55AGz 253b-... A. Grantz, 1955. Anchorage D-1 quad., about 2, 300 ft north of Pass Creek. Lat 61°58'10'' N., long 147°21'09"" W. Unit B. 25966 55AGz 257a--- A. Grantz, 1955. Anchorage D-1 quad., 1,500 ft north of Pass Creek. Lat 61°58'04'' N., long 147°21'51"" W. Unit B. USGS Mes ozoic Loc. Collector, year of collection, description of locality, No. Field No. and stratigraphic position 25967 55AGz 258a_-_-_ A. Grantz, 1955. Anchorage D-1 quad., about 8,500 ft northeast of big bend of Pass Creek. Lat 61°58'50'' N., long 147°19'23"" W. Unit B. 25968 55AGz 266a__-_ A. Grantz, 1955. Anchorage D-1 quad., 300 ft north of Pass Creek. Lat 61°57'50"' N., 16mg 147°21'12" W. Unit -1. 25971 55AGz 289b._-_ A. Grantz, 1955. Anchorage D-1 quad., Lat 61°52'12"" N., long 147°20'40'' W. Unit C-1. 25972 55AGz 300-.____ A. Grantz, 1955. Anchorage D-2 quad., north side of Glenn Highway, 1,500 ft northeast of point where Camp Creek crosses highway. Lat 61°50'30"' g., long 147°24'09"" W. Unit 1 25974 55AGz 304g.__ A. Grantz, 1955. Anchorage D-1 quad., south bank of Pass Creek. Lat 61°57'49"' N., long 147°21'31'"' W. Unit B. 25975 55AGz 306._._._ A. Grantz, 1955. Anchorage D-1 quad., north side of Pass Creek. _ Lat 61°57'47'"' N., long 147°22'23"" W. Unit B. 25978 55AGz 347-._.__ A. Grantz, 1955. Anchorage D-1 quad., south tributary to east fork of Matanuska River, about 5,000 ft above mouth. Lat 61°48'45'' N., long 147°20' 40" W. Unit C-2. 25979 55AGz 361-_._._. A. Grantz, 1955. Anchorage D-1 quad., east fork of Matanuska River. Lat 61°50" 14'' N., long 147°14'00'"' W. Unit C-2. 25985 55ACo 50a.___ H. Condon, 1955. Valdez D-8 quad. Lat 61°53'17'"' N., long 146°39'41"" W. Unit A-III. 25987 55ACo 64a.._. H. Condon, 1955. Anchorage D-2 quad. Lat 61°50'42" N., long 147°24'02"" W. - Unit C-1. 26730 57AGz 67-._.__. A. Grantz, 1957. Anchorage D-2 quad. Lat 61°48'08"' N., long 147°36'36"" W. Unit C-1. M553 59AGz Mlig_.___. A. Grantz, D. L. Jones, 1959. Talkeetna Mountains A-2 quad., Limestone Gulch. Lat. 62°1 40'' N., long 147°39'18"" W. Fossils from concretions in brown-weathering siltstone, 225 ft above base. Unit A-2. M555 59AGz Mip... A. Grantz, D. L. Jones, 1959. Same locality as M553, but from 125 to 155 ft above base. Unit A-2. M556 59AGz 1MQ.___ A. Grantz, D. L. Jones, 1959. Same locality as M553, but from 0 to 125 ft above base. Unit A-2. M557 59AGz M3____ A. Grantz, D. L. Jones, 1959. Talkeetna Mountains A-2 uad., Limestone Gulch. Lat 62°1'42"" N., long 147°39'15"" W. From sandstone at base of brown-weathering siltstone. Unit A-1. M559 59AGz M7____ A. Grantz, D. L. Jones, 1959. Talkeetna Mountains A-2 quad., west tributary to Flume Creek. Lat 62°00'45"' N., long 147°34'50'' W. - Brown-weather- ing siltstone, about 100 ft above base. Unit A-2. TABLE 2.-Ammo USGS Mes- ozoic Loc. No M56$ M569 M572 M574 M583 M590 M591 M595 M596 M597 M598 M599 M600 M6éO1 Field No. 59AGz M31._.. 59AGz M33. __ 59A Gz M44._ .._ 59AGz M60... Standard Oil Co. of California. 59AGz M143... 59AGz M150._. | B9AGz M1355. 59AG M162__ B9AGz M1623. 59Aq§z M164._ _ 59AGz M164_. 59A¢rz M166 _. 59A Gz M193. . nite and selected Inoceramus- GEOGRAPHIC DISTRIBUTION OF AMMONITES Collector, year of ccllection, description of locality, and stratigraphic position A. Grantz, D. L. Jones, 1959. Valdez D-8 quad., float along ridge south of Twin Lakes. Lat 61°53'40"'* N. to 61°53'55"" N., long 146°51"50'' W. to 146°52'15"" W. _ Unit B. A. Grantz, D. L. Jones, 1959. Valdez D-8 quad., unnamed stream flowing northwest into Twin Lakes, elev 3,250 ft. Lat 61°54'35'' N., long 146°52'00"' W. Hard siltstone. Unit C-1. A. Grantz, D. L. Jones, 1959. South unnamed tributary of Matanuska River, 1,400 ft south of mouth. - Lat 61°46'55"" N., long 148°9'30"' W. __ Hard siltstone. - Unit A-II or C-1. A. Grants, D. L. Jones, 1959. Anchorage D-2 quad., east end of Sheep Mountain. Lat 61°51'15'" N., long 147°24'20"' W. Unit B. F. W. Godsey, L. J. Parkinson, 1959. Anchorage C-6 quad., about 2,500 ft north of Wolverine Creek. Lat 61°38'58"' N., long 148°55'30" W. - Unit A-I or A-II. A. Grants, D. L. Jones, 1959. Anchorage D-1 quad., east fork of Matanuska River. Lat 61°50'02"' N., long 147°13'45"' W. Hard siltstone. - Unit A-IIL. A. Grants, D. L. Jones, 1959. Anchorage D-1 quad., east fork of Matanuska River. Lat 61°50'10'' N., long 147°14'00"' W. Interbedded siltstone and sand- stone. - Unit C-2. A. Grantz, D. L. Jones, 1959. Anchorage D-2 quad., Camp Creek, 1,500 ft upstream from where creek crosses Glenn High- way. Lat 61°50'30'"' N., long 147°24'50'' W., elev 3,490 ft. Unit B. A. Grantz, D. L. Jones, 1959. hillside 100 ft above north bank of unnamed creek south- west of Camp Creek, 2,500 ft northwest of Glenn Highway. Lat 61°30'18"' N., long 147°26'25"" W. _ Unit B. A. Grantz, D. L. Jones, 1959. Same as M596, but about 300 ft east. - Unit B. A. Grants, D. L. Jones, 1959. Same as M597. _ Unit B. A. Grantz, D. L. Jones, 1959. Anchorage D-2 quad., in un- named creek south of Camp Creek, 2,200 ft northwest of Glenn Highway. - Unit B. A. Grants, D. L. Jones, 1959. Anchorage D-2 quad., in un- named creek south of Camp Creek, about 700 ft west of Glenn Highway. Lat 61°50'10" N., long 147°24'50'' W. - Base of Unit C-1. A. Grantz, D. L. Jones, 1959. Anchorage D-1 quad., borrow pit on north side of Glenn Highway, 1,100 ft northeast of Mile 120. Lat 61°52'10'"' N., long 147°20'40"" W. Unit C-1. On USGS Mes- ozoic Loc. 0. M1168 M1270 M1272 M1773 M1774 M1795 M1939 M1942 M1943 M1945 M1947 M1949 M1950 M1951 M1952 bearing localities in the lower part of the Matanuska Formation, Field No. 60AGz Standard Oil Co. of California Standard Oil Co. of California. 62A Gz 180... 6AGz 181-.-.--- 63AGz2.5.._... 63A Gz 183----- 63A Gz 18B.-__.- 63A Gz 28A... 63AGz 30-___- 63AGz 37..... 63A Gz 40____- 63A Gz 44. 63A Gz 46C-___ 19 southern Alaska-Con. Collector, year of collection, description of locality, and stratigraphic position A. Grantz, 1960. _ Anchorage C-6 quad., north tributary of Wol- véerine Creek. Lat 61°38'55" Eullong 148°55'30"" W. Unit R. H. McMullen, 1961. - Anchor- age 1: 250,000 quad., east end of Sheep Mountain,east of Gunsight Creek. - Lat 61°51.6' N., long 147°26.5' W. Unit B. R. H. McMullin, 1961. - Anchor- age 1:250,000 quad., east fork of Matanuska River. Lat 61°49.9' N., long 147°12.9' W. Unit C-2. A. Grants, W. Patton, 1962. Anchorage D-1 quad., east fork of Matanuska River, same locality as M591. Unit C-2. A. Grants, W. Patton, 1962. Anchorage D-2 quad., south tributary of Matanuska River. Lat 61°47'05"' N., long 147°31" 40" W. - Unit A-III. Bill E. Shaw, 1960(?7). _ West Klawasi mud cone, Copper River Lowland. About 8 miles north-northeast of Copper Center. A. Grants, J. Stout, 1963. Anchorage D-2 quad., on Glenn Highway 1,500 ft northeast of where Camp Creek crosses highway. Lat 61°50.5' N., long 147°24.12' W. - Unit C-1. A. Grants, J. Stout, 1963. Anchorage D-2 quad., north of Glenn Highway. - Lat 61°48.3' lg}, long 147°35.4' W. - Unit -1. A. Grantz, J. Stout. Anchorage D-2 quad., on south bank of Matanuska River. Lat 61° 47.58" N., long 147°37.58'" W. Unit C-1. A. Grants, J. Stout, 1963. Anchorage D-2 quad., south of Matanuska River. Lat 61° 47.45" N., long 147°33.85' W. Unit C-1. A. Grants, J. Stout, 1963. Anchorage D-2 quad., south of Matanuska River. at 61°47.35' N., long 147°33.75 W. - Unit C-1. A. Grantz, J. Stout. Anchorage D-2 quad., South of Matanuska River. Lat 61°47.3' N., long 147°54.8! Ww. Unit C-1. A. Grantz, J. Stout, 1963. Anchorage D-2 quad., south of Matanuska River. Lat 61° 47.4" N., long 147°34.7' W. Unit C-1. A. Grantz, J. Stout, 1963. An- chorage D-2 quad., south of Matanuska River. Lat 61° 47.3" N., long 147°31.62' W. Unit C-1. A. Grantz, J. Stout, 1963. An- chorage D-2 quad., south of Matanuska River. Lat 61° 47.45" N., long 147°31.38' W. Unit C-2. 20 CRETACEOUS AMMONITES FROM MATANUSKA FORMATION , SOUTHERN ALASKA TaBu® 2.-Ammonite and selected Inoceramus-bearing localities in the lower part of the Matanuska Formation, southern Alaska-Con. USGS Mes ozoic Loc. No. M1953 M1958 M1959 M1961 M1968 M1986 M1987 M1988 M1989 M1992 M1994 M1995 M2379 M2381 Collector, year of collection, description of locality, Field No. and stratigraphic position 63A0z 47.__.. A. Grantz, J. Stout, 1963. An- chorage D-2 quad., south of Matanuska River, 800 ft east of M1952. Lat 41°47.48' N., long 147°51.1" W. - Unit C-2. 63A Gz _ A. Grants, J. Stout, 1963. An- chorage D-2 quad., north flank of Chugach Mountains. Lat. 61°46.78' N., long 147°29.38' W. Unit C-1. 63AGz 65.2 .._._. A. Grantz, J. Stout, 1963. An- chorage D-2 quad., 700 ft north of M1958. Lat 61°46.82' N., long 147°29.45' W. - Unit C-1 or C-2. 63AGz 121____ A. Grantz, J. Stout, 1963. An- chorage D-1 quad. Lat 61° 51.15 N., long 147°9.55 W. Unit C-2. 63AGz 158_____ A. Grantz, J. Stout, 1963. Valdez D-8 quad., southeast of Twin Lakes. Lat 61°54.7' N., long 146°52.1' W. Unit C-1. 63AGz 308A___ A. Grantz, L. Mayo, 1963. An- chorage D-2 quad., north of Matanuska River. Lat. 61° 47.7" N., long 147°32.8' W. Unit C-1. 63AGz 309A_._. A. Grantz, L. Mayo, 1963. An- chorage D-2 quad., north side of Matanuska River. Lat. 61° 47.7" N., long 147°34.15 W. Unit C-1. 63AGz 310A._. A. Grantz, L. Mayo, 1963. An- chorage D-2 quad., north side of Matanuska River. Lat. 61° 47.68" N., long 147°34.2' W. Unit C-1. 63AGz 315.___ A. Grantz, L. Mayo, 1963. An- chorage D-2 quad., north side of Matanuska River. Lat. 61° 47.7" N., long 147°35.05 W. Unit C-1. 63AGz 321____ A. Grantz, L. Mayo, 1963. An- chorage D-2 quad., north side of Glenn Highway. Lat. 61° 47.55 N., long 147°42.1' W. Unit C-1. 63AGz 325A_-.__ A. Grantz, L. Mayo, 1963. An- chorage D-2 quad., south of Glenn Highway. Lat. 61° 47.35" N., long 147°42.8' W. Unit C-1. 63AGz 325B___ A. Grantz, L. Mayo, 1963. An- chorage D-2 quad., south of Glenn Highway. Lat 61° 47.35 N., long 147°42.9' W. Unit C-1. Soc-T1006._._. Collector unknown. Anchorage D-1 quad., east Fork of Matanuska River. Same as M590. Unit C-2. 64AGz 5° A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Anchorage D-2 quad., south- west Copper River Lowland. Lat 61°50.5" N., long 147°25.1" W. Unit B. 64AGz 9______ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Anchorage D-2 quad. Lat 61°50.55' N., long 147°25.2' W. Southwest Copper River Low- land. Unit B. USGS Mes- ozoic Loc. Collector, year of collection, description of locality, No. Field No. and stratigraphic position M2382 64AGz 10-____ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Anchorage D-2 quad. Lat 61°50.25' N., long 147°26.25 W. Southwest Copper River Lowland. _ Unit B. M2383 64AGz 11. ___. A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Anchorage D-2 quad., Lat 61°50.1' N., long 147°24.85 W. Southwest Copper River Low- land. Unit C-1. M2384 _ 64AGz 12_____ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Valdez D-8 quad. Lat 61°54.75' N., long 146°52.35' W. Southwest Copp?er River Lowland. Unit -2(?). M2385 _ 64AGz 14_____ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Valdez D-8 quad. Lat 61°53.65' N., long 146°52.4' W. Southwest Copper River Low- land. Unit B. M2386 - 64AGz 151____ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Valdez D-8 quad. Lat 61°- 53.75 N., long 146°52.35 W. Southwest Copper River Low- land. Unit-III. M2387 64AGz 18_ _ ___ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Valdez D-8 quad. Lat 61°54.3' N., long 146°52.9' W. Southwest Copper River Low- land. Unit C-2. M2388 64AGz 21 __ ___ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina district, Valdez D-8 quad. Lat 61°54.65' N., long 146°52.1' W. Southwest Copper River Low- land. Unit C-1. M2389 _ 64AGz 22_____ D. L. Jones, A. Grantz, 1964. Alaska, Nelchina area, Valdez D-8 quad. Lat 61°54.7' N., long 146°52.1' W. Unit C-1. M2390 _ 64AGz 23-____ D. L. Jones, A. Grantz, 1964. Alaska, Nelchina area, Valdez D-8 quad. Lat 61°54.7' N., long 146°52.2' W. - Unit C-1. M2391 64AGz 24_ __ __ D. L. Jones, A. Grantz, 1964. Alaska, Nelchina area, Anchor- age D-1 quad. Lat 61°52.15 g., long 147°20.7' W. Unit -1. M2392 - 64AGz 250____ D. L. Jones, A. Grantz, 1964. Alaska, Nelchina area, Anchor- age D-2 quad. Lat 61°50.5/ g., long 147°24.12' W. Unit 1 M2393 64AGz 26_____ D. L. Jones, A. Grants, 1964. Alaska, Nelchina area, Anchor- age D-2 quad. Lat 61°47.7' N., long 147°35.05 W. Unit C-1. M2396 - 64AGz 30-____ D. L. Jones, A. Grantz, 1964. Alaska, Nelchina area, Gulkana A-5 quad. Lat 62°00.65 N., long 146°13.15 W. Unit C-2(?). M2397 - 64AGz 31_____ A. Grantz, D. L. Jones, 1964. Alaska, Nelchina area, Gulkana A-5 quad. Lat 62°00.65 N., long 146°13.25 W. Unit C-3(». GEOGRAPHIC DISTRIBUTION OF AMMONITES 21 TABLE 2.——Ammon 4, 14 aequalis, Scaphites. ..... ----------- - 26 affine, Beudanticeras.....---------- ___. 31, 85 Beudanticeras (Grantziceras) . .- .---------- 31 DeSTROGCETASL ._.. -n- 31, 35 glabrum, DesmOCeras. ...--. --------------~ 35 Grantziceras . 22 16,17 Grantziceras. .. ---------------- 7, 12, 81, 32, 84, 35 alaskana, Puzosia_.~~- _ 3, 4, 16, 17, 40; pL. 4 alaskaensis, Eogumnarites.....--- .- 4, 10, 12, 16, 17, 43 alaskanum, Callizoniceras (Wollemanniceras) .. 3 Albian age rocks, Chitina Valley...------ - 4 Albian faumas-..--------------- ones 12 aldersoni, CalliphyHoceras . 3 alezanderi, Bathysiphon. ..- _-_------------ conn 14 Ammodiscus ee 14 Ammonite 2 16, 17, 18, 19, 20, 21 geographic distribution.... 15 Hamitid _____.--------- 16,17 Ammonites bladenensis....------------ 26 haviculatis..-------------- onne 42 milig.... ._ - 22 L. . 28 L -o- -- 24 Ammonitina.....-------------- Moree oce 28 .._... _.. ------------ 8, 23, 25; pl. 1 CUTOTHLML 1222020000000 --== 3 . 22222222 ccc ce- 8, 16, 17 7,14, 16, 17, 28, 24, 26; pl. 1 angulatum, Gabbioceras....._--.--------------- 26, 27 Amisoceras 13 arca, __ .._... 14, 15 3, 8, 12, 37, 88, 39 beli2 2 222 8, 16, 17, 38, 39, 40 jachromensis. . 39 UMPiW@MUS-.L 22222202 --- --- 38 talkeetnamus.... .--. 7, 16, 17, 38, 89, 40; pls. 7, 8, 9 4 15 AUCEUIMQLL 0000 nce ---> 9, 12 SD 2 ccc ccc cece ece ccc eee e-- 3, 7, 16, 17, 41 aurarium, Anagaudryceras. . 3 B 28 baculoides, Hamites. . _ _________._______-------- 28 ._ 28 Bald Hills Member......-- 13 batesi, .... 22 Bathysiphon alezanderi......____....---------- 14 14 belli, .... 8, 16, 17, 38, 39, 40 Lemuroceras. ..... 38 (Subarcthoplites) .-..... ... 3, 39 bentonensis, Gaudryina.......-__.--..--------- 14 INDE X [Italic page numbers indicate major references and descriptions] Page BeudaMbiceras... __ -__- 3, 12, 30, 31, 35 . .c ccc ccc ccc cece nnn -->> 31, 35 glabrum . . 3, 31, 35 RULERERSE. _ ___ - 29 (Gramtziceras) .....------- - 30 Off... 222 ccc ccc ccc ccc ene -->> 31 ___ ___ 31 bifurcata, . . . . ___---<<<<----------- 3 bladenensis, Ammonites. ...-- -.- -------------- 26 Bostrychoceras Sp . . .. -- -- clo- 14 breweri, Ammonites. . .- 20 BrEWETIGETA8_ ___ 3, 20 BrEDETICETA8.. ___ 3, 8, 29 breweri. . . hulenense......- 3 » 4,7, 8, 9, 12, 16, 17, 22, 26, 29, 30, 35, 38, 40, 44; pl. 6 bullata, Marginulina... 14 bullatus, Parasilesites....------------- 3, 4,7, 8, 16, 17 C CalliphyMoceras aldersoni_...........------.---- 3 (Wollemannmiceras) ...-- -- 3 fOhHMeM8E__ ___ 3 Calycoceras.....__---------- 2200 42 stoliczkai_..._____------- 42 SDL cc eee 10, 13, 16, 17, 42; pl. 3 Campanian beds, lutite......----.------------- 10 CURGUOGCETA8 . . . _.. ccc cen- -->> 1,12 Cape Douglas area, Lower Cretaceous rocks.. 14 cappsi, Anagaudryceras .._. . . . . - - -------- 8, 16, 17 Caribou Mountain, fault system 6 Castle Mountain, fault system.. 6 Cenomanian age, sandstone, Unit B-.--.----- 9 fO88il8222 2 ooc --- - 12 northern Alaska... 14 ROCKS L 222222222222 ccc ccc -->> 2 SilESbOM® . L222 ce- --- ---> 9 Cenomanian sandstone unit, basal member.... 9 Cenomanian to Santonian age, Unit C. ..---- 10 Chickabally Mudstone Member of Budden Canyon FOrMation.....-------------------- 13 Chitina Valley, ammonite faunas. 3 chitinanum, PhyUopachyceras.........--------- 16, 17 Chugach Mountains, North Front. - 7 Cibicides . .._ 14,15 CIEOMiCErA® .. . 2. 2 eccen- 12 Collignoniceratidae. . ...... 42 CoLObOGET@8 .. ... ___ ccc ne- --- 39 complanata, Pelosina . . ..-...--- 14 concentricus nipponicus, Inoceramus... .- 11, 14, 16, 17 Coniacian age, 1utite...._._.__--.--------------- 15 Coniacian and Santonian age, Unit C-2..---- 11 Coniacian 2 Crab fFA@MeNtS . 1 ccc ono 16, 17 crassicostatus, 3 crenocostates, 22 cretacea, Cribrostomoide8..... ...-- 14 Globigerima 2 2 . .. --- -- 14 cretaceus, AMMOGISCUSL . . ___ 14 Cribrostomoides cretacea . ._____...-.----------- 14 Page cumshewaensis, Marshallites . .._... - ----------- 4 cuvierii, 4,8, 11, 14, 16, 17, 41 D dawsoni, DESMOCETA8L . .. 20 Desmoceras (PseudoughligeUa)... ... --- --- 4,9, 13 japonica, Desmoceras.... . 28 deansi, LECObEIG® .... c cece cnn -~~ 3 denseplicatum, 14, 16, 17, 22 IAJLOCETM®. . . 22222 ccc ccc enn 22 (Deshayesites) aburense, Pseudohaploceras.... . - 38 DeSTMOGCETM® . 222200 coc-cc cnn n= 28 WWM. c 22 ccc ccc c ccc escent 31, 35 22222 ccc ccc cece ccc ccc --- 35 LLL 222222000000 con- 29 . 2 2222 ccc ccc cece n =-- 28 @UDPWM L 2 2 2 2222 ccc cee cnn nnn =-- 31, 35 japonica . . ..- 20 J@DOMCUM . . 222222 cocco ccc ncn == 4 (Pseudowhligella) . . . ...-- 200 28 dawsoni......----------- con. 4,9, 13 J@DOMAC® L . cc cc ccc ncn =-- 20 JGDOMCUM . 22222200 coco --- ---> 4, 10, 12, 13, 14, 16, 17, 29, 43; pl. 4 BR ccc ccc cece cece 13 28 Douvilleiceras mammillabm..... .--.---------- 4 dunveganensis, IMOCETAMAS . . .._ _-------~------ 14 E EOQUNMGTIbG® L . . --- nnn nnn ono" 43 alaskaensis... -- _ 4, 10, 12, 16, 17, 48; pl. 3 Epigoniceras @U@bPUML . . ._ 24 epigonum, Tetragonites . 24 EDOMIde® SD . . . c - 14 EuomphalOCeras SD. . .- - ------------------- 11, 16, 17 €202M8€, _ _ .cc ccc cen === 22 F Faunal sequence, Albian rocks.-_------------ 8 Cenomanian rocks... 4 mid-cretaceous... ..-. ------------ 3 florealis Gyroidima....-...---------- 14 fohlimense, Callizoniceras (Wollemanniceras) . . - 3 Fossiliferous sequence, Albian rOGKS . ._------ 2 Freboldiceras...____------------------- 4, 35, 36, 37, 38 #iM@UOTG... _ 2 ccc nnn n- ~~ 8, 7, 12, 16, 17, 35, 87, 38, 39, 40; pl. 7 G Gabbi0Ceras_ .._ 24, 25, 26; pl. 1 QMUIOMUM L 2222222220000 cence -n- 26, 27 L 2 2222 cocco ccc nnn ---> 8 23 WibUMHLM L 2 2 -n- -n- -~ 22 gardneri, ___.. __ 44 GaStrODULE® . ___ cc ccc econ nn <--- ~~ 4 absent in southern Alaska_....----------- 4 Gaudryceras._....--.-------- __ 14, 16, 17, 22; pl.1 denseplicatum...._.....------ 14, 16, 17, 22; pl. 1 QTO88OUDTG...______-_------------ L122 ~ 88 14 48 Page 23 14 bentonensis . . . .. ases oo 14 gigas, Scaphites planus.____________ - 11 glabrum, Beudanticeras...____________ 3, 31, 35 Desmoceras..______________________ - 31, 35 affime 35 Epigoniceras.._.__________________________ 25 Grantziceras . ___ 7, 16, 17, 32, 85, 36, 37, 38 24 Placenticeras....__________________________ 35 glabrus, Tetragonmites...._____________ 11,14, 16, 17, 2} Globigerina cretacea . _. ________ Globotruncana ___ globulosa, Gyroidima.....__________ Glomospira...______________________ gordialis . 14 gordialis, Glomospira..._______________________ 14 Gramtziceras..____________________ 3, 4, 9, 12, 80, 31, 37 affine. . _________ -- 7,12, 81, 32, 34, 35; pls. 5, 6 glabrum { 16,17 glabrum..__________ 7, 16, 17, 32, 85, 36, 37, 38; pl. 6 multiconstrictm....___________________ 3, 31, 35 noon noon nono onne cnn nne ones 8 (Grantziceras) affine, Beudanticeras..________ __ 31 ' Beudanticeras...._________________________ 30 multiconstrictum, Beudanticeras... ._____ __ 31 Gaudryceras._.____________________ 22 Gyroidina florealis.. . _________________________ 14 .._ 14 H Hamites baculoides..__________________________ 28 Hamitid ammonite..._________________ - 16,17 Haplophragmoides sp . ________________________ 14 havicularis, Ammonites..._____________________ 42 hearni, Puzosia (Parapuszosia)..._____________ 41 hitchinensis, Prionocyclus...__________________ 42 hobetsensis, Inoceramus. _ _____________________ 4 Hoplites jachromensis.. . ______________________ 38 hulenana, Pervinguiera.....___________________ 4 hulenense, Beudanticeras..____________________ 20 Brewericeras.________________ --- 34,7, 8, 9, 12, 16, 17, 22, 26, 29, 30, 35, 38, 40, 44 Loo - ~ oo 3, 44 JMbQL 2222222222222 lino clinics 44 onona. . .. 44 3, 44 BP . conn 40 eo enne nees nan 4,7, 16,17, 44; pl. 4 I Imlay, R. W., quoted.....____________________ 3 imlayi, Gabbioceras....________________________ 23 Parajaubertella . 4,10, 13, 16, 17, 23, 24, 26, 27: pl. 1 Imaeguinodum....__________________________ 4 indopacifica, Mesopuzosia__.__________ 11, 14, 41; pl. 4 BP oon nnn nnn enne noone nnn nene nnn esos 16, 17 inflatus, Zelandites..________________________ 4,16, 17 Imoceramus l.... 1, 4,7, 8, 9, 11,12, 13, 14,15, 16, 17, 18, 19, 20, 21, 41 concentricus nipponicus...._________ 11,14, 16, 17 eupleriil c 4, 8, 11, 14, 16, 17, 41 dunveganensis. . __________________________ 14 hobetsensig. .._ 4 pictus. _. 4 222222222220 00002 1,10 undulatoplicatus. . ________________________ 1 uwajimensis. . ____________ 1,2, 11, 12, 14, 15, 16, 17 yokoyameai 11,15, 16, 17 SP2 cocoon lins 16, 17 E oo 16,17 INDEX J Page Jachromensis, Arcthoplites. . ___________________ 39 Hoplites 2 38 japonica, Desmoceras....______________________ 20 Desmoceras dawsoni....___________ - 28 (Pseudoughligella) ._ _____________ 20 japonicum, Desmoceras...__________________ - 4 Desmoceras (PseudoughligeUla) .____________ 4, 10, 12, 13, 14, 16, 17, 29, 43 Jauberticeras 28, 25 Jauberticeras subbeticum.....__________________ 26 Jimbo, Hulenites.______________________________ 44 K Kenmicottia bifurcata. .________________________ 3 kitiani, Tetragomites.._________________________ 26 kossmati, Sciponoceras.._.______________ 28 Kossmaticeratidae....______________ 43 Kuskokwin region rocks, Cenomanian age. 14 L laeve, Pytchoceras . ____________________________ 3 lecontei, Leconteites._. 3 Leconteites crassicostatus_ 3 deansil.___________ - 8 Tecombeil 3 3 modestus... _______ 3 37, 38, 30 belliL L_ conn - 38 o 3, 37, 39 (Subarcthoplites), belli .___________________ 3, 39 Limestone Hills, Albian rocks. 6 Albian sequence..________________________ 9 limpidianus, Arcthoplites....__________________ 38 Lower part of Matanuska Formation, correla- BOM 222 nnn onn nnn ninco 12 stratigraphic summary.. _________________ 4 000000222. 10 Lytoceras....__________ - 7,16, 17, 21, 22; pl. 1 Datesi2222222222222222202222220000002220002 22 cremocostates. .L L_____L____________________ 22 denseplicatum . 22 ezoénse. .. ____________ 22 glabrum. .._ __________ men 25 mahadedac 22 25 SP ooo noon nono nnn lcci lll, 21; pl. 1 21 Lytoceratina..___________________ M 21 Lytoceratinae....________________________ - 21 M mahdeva, Lytoceras..._________________________ 22 mammillatum, Dounilleiceras...._______. __ 4 Marginulina bullata-....______________________ 14 MarshaUlites . . L_ 4,9 4 ccc -- 10, 14, 16, 17 SDDeco nooo oon onn nnn noon nnn nc ncn 4 Marssonella oxycoma. .. .______________________ 14 Matanuska Formation, age...._______________ 1 Albian to Coniacian..... 12 faulting......______________ -o- 5 in Talkeetna Mountains.....______ 3 Matanuska Valley-Nelchina area, correlation.. 9 stratigraphy... 1 Turonian beds. 14 merriami, Amisoceras......_.___________________ 13 Mesopuzosia...___________________ 11, 12, 14,16, 17, 40 indopacifica . noon es 11,14, 41, 41; pl. 4 Donon nooo nnn nnn onn nnn ccc icc 16, 17 ccc 22. 40, 41 Po noon noon nono none n lines 11,15 mitis, Ammonites. .___________________________ 22 modestum, Leconteites.._______________________ 3 modestus, Leconteites.________________________ 3 Moffitites .. _________________________ robustus. ._ __________ 3,7, 9,12, 16, 17, 41, 42; pl. 4 Page 4 Mortoniceras...._____________ 4 i 13 multiconstrictum, Beudanticeras (Grantziceras) . 31 3, 31, 35 N Nanushuk Group, Albian and Cenomanian ages.. ._. 14 Neophylloceras.._____________________________ 12 Po nono ono onn nnn ncn nnn noni 14,16, 17 nipponicus, Inoceramus concentricus... .. 11,14, 16, 17 normale, Oregoniceras. ._______________________ 42 normalis, Subprionocyclus..________ 4,14, 16,17, 42,43 0 Olcostephanus unicus. .._. 43 onona, Hulenites..____________________________ 44 Oregoniceras mormale....______________________ 42 orientale, Sciponoceras. ao oe. 28 Otoscaphites...________________________ 15, 26, 28 27 teshivensis . 11,14, 16, 17, 27, 28; pl. 4 02 15 ozycona, Marssonella... 14 Ozytropidoceras packardi....__________________ 4,9 P pacifica, Mesopuzosia..______. packardi, Ozytropidoceras....._________________ 4,9 Parajaubertella...._________________________ 28, 25, 26 10, 13, 16, 17, 28, 24, 26, 27; pl. 1 (Parapuzosia) hearni, Puzosia_....____________ 41 1 Parasilesites bullatus.__________ 3, 4, 7, 8, 16, 17 Pelosina complanata..________________________ 14 perrinsmithi, Puzosigella. .____________________ 3 Pervinguiera hulenana....____________________ 4 Phyllopachyceras chitinanum..._._____________ 16, 17 3 000000000, 0000000000 8 pictus, 4 Placenticeras glabrum . .. 35 planulata, Puzosiq....._______________________ 40 Planulina spissocostata....__________ ay 14 planus gigas, Scaphites...______________ 11 Previous studies....._________________________ 3 Prionocyclus hitchinensis - 42 Prohawericeras._______________________________ 1 Proplacenticeras gp....._______________________ 4 pseudoaequalis, Scaphites...___________________ 26 Pseudohaploceras (Deshayesites) aburense. .._ _. 38 Pseudhelicoceras sp._...._________________ 4 PseudouhligeUa...._._________________________ 28 (Pseudoughligella), Desmoceras..._____________ 28 dawsoni, Desmoceras......._________.____ 4, 9, 13 sp., Desmoceras.._________________________ 13 japonica, Desmoceras.... __ 29 japonicum, Desmoceras........____________ 4, 10, 12, 13, 14, 16, 17, 29, 43 puerculus, Otoscaphites......._________________ 27 techioensis, Yezoites.._____________________ 27 Puzosia..__________ 40 3, 4, 16, 17, 40; pl. 4 T 40 44 (Parapusoria) 41 3 perrinemithiL 222 3 POGET®LL 22222222000 3 3 Pytchoceras 3 Q Queen Charlotte Islands, fauna...._.________. 4 R Page Rectogldnidiulifit 14 reesidet, Hulenites.../.............- 3, 44 Purasia 2. sedan neonl 44 48 Regularis.. - 4 ... . ONE LL O2. Wie c 14 robustus, Moffitites......-.----- 3, 7, 9, 12, 16, 17, 41, 42 rogerst, Puso§igeUq...... ..... . 3 S 2-20 ccc ule leu antes 28 sacya, ...... 7, 14, 16, 17, 23, 24, 26 Santonian 2. 2 SCBIATUESEDIL .N. V2... con leve nene 11,15 SADMIESIIIE- 1: Cele cous eaci nan nle anes ber eus s 11,26 A.. AUL lL ol on be ase cs 26 pIRRUS Wigh®. Alc. 20202000. eus eela ien 11 PSUIODGERHGNS. . .... .. aao 26 _______________________ 11, 26; pl. 4 _________________________________ 26 26 schmidti, Inoceramus....________.___._____...- 1,10 oue ie is 28 ALL IAAL Lom 28 ROSS 0000. oue a 28 ceva ones oe d Ten bue ces ane a 28 Spe cisa enone AL 14, 16, 17, 28; pl. 2 (SATDMIRS SDL RAI. llc lulu eden as 16, 17 shastalense, PhyUlopachyceras....._.______._... 3 Sheep Mountain, faunule......-------------- 11 AA LSTA an nene ne cns 12 221-689 0O-66--4 INDEX Page singulare, Freboldiceras.... ....___...___....... 8, 7, 12, 16, 17, 35, 87, 38, 39, 40 ..on adobe eon dent 1 spissocostata, Planulina. ..... .- as 14 stephensoni, Cibicides...... ..- l... 14,16 -ne 42 Strata of Albian age rocks, Unit A-____.._---- 6 Stratigraphy, Limestone Hills area. . 7 .. . ccc ell lein nes -- 37,39 belli. . ell laa ai ae 39 I 2090 ceeds outers e ant 39 (Suwbarcthoplites) belli, Lemuroceras.......---- 3,39 ..... 2.0.00 eee us aes 42, 43 -... +s 4, 14, 16, 17, 42, 43; pl. 6 T. taffl, PuIDRIOENIGL -. .-.. culos l eN cov dena denes 3 talkeetanus, Arcthoplites.. ...... .-- - 7, 16, 17, 38, 39, 40 Talkeetna Mountains, Matanuska Forma- ERE Lic 3 talkeetnanum, Lemuroceras.. Subarcthoplites....~ ... taurinensis, 14 teshioensis, ...... -- 11, 14,16, 17, 27, 28 YeRDIe® .e. 27 . Leon cs aP re HCA ove. +s 11, 14,16, 17, 25 EDIJONU LLL I-A. CALL, ordre claw ce 24 012229, lv ues 11,14, 16, 17, 25; pl. 2 MHORNL 2. Jee ivi h ae dale ae ded ae 25 --i es ec ees oes 16, 17, 26; pl. 2 _____________ 3, 4,16, 17, 24 cle, e 22,23 49 Page dmothegnitth, 0000 26 timotheanus, Ammonites. 26 TeTaUORULSL LG IL ece ADs onlie 16, 17,26 TTufonidh Age, Pooks... .l relate es 14 siltshons. . . ..o Lol Ie revo tens 9 14 12 2 upper Chiting 4 HELPMS .. .s .no 20 20 oue ut oes socio 4, 14 U undulatoplicatus, 1 HIGHS, OICOSEEDRQMI®...L ..... 21222000 43 Unit C-2, thickness and lithology...--.------ 11 Upper Cenomanian rocks, Chitina Valley.... 4 uwajimensis, Inoceramus.... .. 1,2, 11, 12, 14,15, 16, 17 w wintunium, Gabbioceras.......~.. 22 (Wollemanniceras) alaskanum, Callizoniceras.. 3 Johlinense, 3 ¥ Yezoites puerculus teshioensis _.. 27 yokoyamai, Imoceramus..........._.. .... 11,15, 16, 17 ponekural; SCaDhites. cl s 0000, 26 Z ... .... ZLL CL c- ee can oe 4,16, 17 | 10 U.S. GOVERNMENT PRINTING OFFICE: 1966 - O-221-689 p = PLATES PLATE 1 [All figures natural size} Fraur®s 1-4. Gaudryceras aff. G. denseplicatum (Jimbo) (p. 22). Both specimens from USGS Mesozoic loc. M600. 1, 2. Side and back views of USNM 132145. 3, 4. Side and ventral views of USNM 132146. 5-7, 18-15. Anagaudryceras sacya (Forbes) (p. 23). 5-7. Side, front, and back views of plesiotype USNM 132085 from USGS Mesozoic loc. M568. 13-15. Side, front, and back views of plesiotype USNM 132086 from USGS Mesozoic loc. M556. 8-9. Lytoceras sp. (p. 21). Front and side views of USNM 132083b from USGS Mesozoic loc. M556. 10-12. Parajaubertella imlayi Matsumoto (p. 22). Side, front, and back views of plesiotype USNM 132087 from USGS Mesozoic loc. 24857. GEOLOGICAL SURVEY PROFESSIONAL PAPER 547 PLATE 1 CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION PLATE 2 [Al figures natural size] FraurEs 1-12, 23-26. Tetragonites aff. T. glabrus (Jimbo) (p. 25). 1-3. Side, front, and back views of USNM 132090 from USGS Mesozoic loc. M600. 4-6. Side, front, and back views of USNM 132091 from USGS Mesozoic loc. M6O01. 7-8. Side and back views of USNM 132092 from USGS Mesozoic loc. M600. 9-10. Side and back views of USNM 132093 from USGS Mesozoic loc. M600. 11-12. Side and back views of USNM 132094 from USGS Mesozoic loc. M600. 25-24. Side and front views of USNM 132095 from USGS Mesozoic loc. M600. 25-26. Side and back views of USNM 132096 from USGS Mesozoic loc. M600. 13-18. Tetragonites aff. T. timotheanus (Pictet) (p. 26). 13-15. Side, front, and back views of USNM 132097 from USGS Mesozoic loc. M556. 16-18. Side, front, and back views of USNM 132098 from USGS Mesozoic loc. M5356. 19-22. Sciponoceras sp. (p. 28). USNM 132100 from USGS Mesozoic loc. M600. Note deep oblique constriction at adoral (lower) end. 19. Left side. 20. Dorsal side. 21. Right side. 22. Ventral side. GEOLOGICAL SURVEY PROFESSIONAL PAPER 547 PLATE 2 CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION PLATE 3 [Figures natural size except as indicated] FraurEs 1-2. Calycoceras sp. indet. (p. 42). Back and side views of USNM 132140 from USGS Mesozoic loc. M595. X}. Specimen distorted and flattened, and ribs eroded from left side of specimen in figure 1. 3. Eogunnarites alaskaensis Matsumoto (p. 43). Side view of plesiotype USNM 132142 from USGS Mesozoic loc. M598. Specimen crushed. ¢ NOLLVWHOA VMSANVILVHN YXMOT HHL WNOHJA SMLINONNY SNAOMDVILMHD AHAXNS TVDIDOTOHD £ MLVII TVNOISSHAOUd FraurEs 1-9. 10-11. 1214, 21. 15-18. 19, 20, 22, 23. 24-26. 27-29. 30-35. PLATE 4 [Figures natural size except as indicated] Puzosta alaskana Imlay (p. 40). All specimens from USGS Mesozoic loc. M556. 1-3. Side, front, and back views of USNM 132131. 4-6. Side, front, and back views of USNM 132132. % 2. 7-9. Side, front, and back views of USNM 132133. Desmoceras (Pseudouhligella) japonicum Yabe (p. 29). Side and back views of USNM 132102 from USGS Mesozoic loc. M596. Scaphites sp. (p. 26). Side, front, and back views of USNM 132084 from SOC T-1006. Otoscaphites teshioensis (Yabe) (p. 27). Side, front, and back views of USNM 132099 from USGS Mesozoic loc. 24853. Hulenites sp. (p. 44). 19, 20. Side and back views of USNM 132148a from USGS Mesozoic loc. M553. 22,23. Side and back views of USNM 132148b from USGS Mesozoic loc. M555. Moffitites robustus Imlay (p. 41). Side and back views of USNM 132139 from USGS Mesozoic loc. M557. X 2. Aucellina sp. (p. 7). Left valve and anterior views of USNM 122144 from USGS Mesozoic loc. M557. This species is extremely abundant in Moffitites zone of Chitina Valley area. Mesopuzosia aff. M. indopacifica (Kossmat) (p. 41). 30, 35. Back and side views of USNM 132134. Specimens 31-34 are slightly to moderately distorted and were obtained from USGS Mesozoic locs. M6O01 and 24229. 31. Side view of USNM 132135. 32. Side view of USNM 132136. 33. Side view of USNM 132137. 34. Side view of USNM 132138. GEOLOGICAL SURVEY \ CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION PLATE 5 [All figures natural size. All specimens from USGS Mesozoic loc. M556] FrGurEs 1-15. Grantziceras affine (Whiteaves) (p. 31). 1-3. Side, front, and back views of plesiotype USNM 132106. Only incipient constrictions developed. 4-6. Side, front, and back views of plesiotype USNM 132107. Note one distinct and two incipient constrictions. 7; 11, 12. Front, back, and side views of plesiotype USNM 132108. Constrictions poorly developed. Note bundled striae and feather structure. 8-10. Side, front, and back views of plesiotype USNM 132109. Note abundant shallow constrictions on body chamber. 13-15. Side, front, and back views of plesiotype USNM 132110. In- tensely constricted inflated form. Note width of umbilicus and promi- nence of constrictions increase with inflation of whorl section. GEOLOGICAL SURVEY PROFESSIONAL PAPER 547 PLATE 5 CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION PLATE 6 [Figures natural size except as indicated] FraurEs 1-3, 7-9. Graniziceras glabrum (Whiteaves) (p. 33). Both specimens from USGS Mesozoic loc. M556. 1-3. Side, front, and back views of plesiotype USNM 132115. 7-9. Side, front and back views of plesiotype USNM 132114. 4-6. Graniziceras affine (Whiteaves) (p. 31). Side, front, and back views of plesiotype USNM 132111 from USGS Mesozoic loc. M556. Note slightly larger umbilicus and more broadly rounded venter than on G. glabrum. 10-11, 15-19. Brewericeras hulenense (Anderson) (p. 29). 10-11. Side and back views of plesiotype USNM 132103 from USGS Mesozoic loc. M583. This specimen is figured to document presence of Albian strata along northern border of Chugach Range, south of Matanuska River. 15, 19. Front and side views of small specimen, plesiotype USNM 132104 from USGS Mesozoic loc. M556. 16-18. Side, front, and back views of large specimen, plesiotype USNM 132105 from USGS Mesozoic loc. M556. 12-14. Subprionocyclus normalis (Anderson) (p. 42). Side and back views of plesiotype USNM 132141 from USGS Mesozoic loc. M1795; found on top of mud cone in Copper River Basin. X 2. PROFESSIONAL PAPER 547 PLATE 6 CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION PLATE 7 [Figures natural size except as indicated. All specimens from USGS Mesozoic loc. M556] FraurEs 1-25. Freboldiceras singulare Imlay (p. 37). 1-2. Side, front, and back views of USNM 132116 showing smooth inner whorls and first appearance of ribs on flank. X 2. 4-6. Side, front, and back views of USNM 132117 showing early appearance of faint secondary ribs on outer flank. 7-9. Side, front, and back views of USNM 132118 showing faint secondary ribs on outer flank and venter. 10-12. Side, front, and back views of USNM 132119 showing secondary ribs on early part of whorl and normal "Freboldiceras'"' type of umbilical swellings on later part of whorl. 13-15. Side, front, and back views of USNM 132120. 16-17, 24, 25. Side, front, and back views of USNM 132121 showing early disappearance of ribbing. 18-20. Side, front, and back views of USNM 132122 showing strong ribs on lower flank and smooth outer flank and venter. 21-23. Side and back views of USNM 132123. . Coarsely ribbed variant showing tendency of primary ribs to bifurcate to produce secondary ribs of Arcthoplites-type. 26-31. Arcthoplites talkeetnanus (Imlay) (p. 39). 26-28. Side, front, and back views of USNM 132124. Coarsely ribbed variant showing Y-shaped bifurcation of ribs high on flanks. 29-31. Side and front views of USNM 132125. A more compressed form with ribs branching lower on flanks. » GEOLOGICAL SURVEY 31 CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION PLATE 8 [All figures natural size. All specimens from USGS Mesozoic loc. M556] Fiaur®Es 1-18. Arcthoplites talkeetnanus (Imlay) (p. 39). 1-3. Side and front views of USNM 132126 showing rapid disappear- ance of ribbing. 4-6. Side, front, and back views of USNM 132127. 7-9. Side, front, and back views of USNM 132128. Variant with two secondary ribs intercalated between primary ribs on outer flank. 10-12. Side, front, and back views of USNM 132129. 13-15. Side, front, and back views of USNM 132130a showing recti- linear ribs on early part of whorl and disappearance of ribs on later part. 16-17. Side and back views of USNM 132130b showing persistence of ribbing to greater diameter. 18. Back view, USNM 132130c. GEOLOGICAL SURVEY PROFESSIONAL PAPER 547 CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION PLATE 8 PLATE 9 [All figures natural size) Firaur®Es 1-2. Arcthoplites talkeetnanus (Imlay) (p. 39). Side and front views of USNM 132130c showing disappearance of ribbing at large diameter. GEOLOGICAL SURVEY PROFESSIONAL PAPER 547 PLATE 9 CRETACEOUS AMMONITES FROM THE LOWER MATANUSKA FORMATION UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSISSQE 1311213151? 547 GEOLOGICAL SURVEY ia6%00" 149°30' 30 62°30 62°30" 149°00' 310’ 148°00" 30" ; T < / © Z & 8 firfiv f N -o n (t \\ j y § [ \\ # L X f b f ¥ - / o . _ f } Q + § yhe . A a & 4 bake &+ > \ Little & & Limestone \$6 C > Hills sut} § --Limestone Gap mo $ : p -§' Limestone a / Gul N- A Suseg M5529 M555 2532? Horn Mountains .25967 25966 25295956 a a* 25075 @ -~ 25974 24239 Creek M2390, M1968, 25960 1967 M569 M2386\. 25963 @ TAZLINA LAKE 1 C l met _ mso1, M1273, M1272 § & t Vl~t camp " rasi; M590 w Mscd soc-T-1006 “(3s Ms96 S-- <7] & & -< Z1 F Mast 20055 . \ hees we" MSSS masss ‘i s \ - m5s99 , Mata'rms Rives. # w-] ~- AMA .._. --A 12408 _ M232, _- << mu ze -S- J -- ae h M1994 a I M1986 SSL m1995 n M1987 W Pe m1989 Se- M2393 M240 M1958 - C ‘ MS72 99 m1i9sd p s => m1949 MeL M2399/ m2400 \ it M1950 M2406 M1947 M1945 M1774 M2412 EXPLANATION Major faults Dashed where approximately located; queried where doubtful FOSSIL LOCALITIES wot nt ASP mas M1961 Coniacian or Santonian Cenomanian Q m M1958 e M2409 > Coniacian Albian @ 201989 ye M572 CO Turonian Age uncertain f j | | : sg 146° 00' 30° 148°00" 30' 14700: MATANUSKA VALLEY- NELCHINA AREA, ALASKA, SHOWING FOSSIL LOCALITIES 5 0 5 10 15 20 MILES rem ro- i= I F : 221-89 O - 67 (In pocket) ieee 149°00" 20 KILOMETERS k ‘ tog J DAY Geology and F uel Resources of the Green River Formation I ‘ Southeastern Uinta Basin - Utah and Colorado GEOLOGICAL SURVEY PROFESSIONAL P A P ER 5 4 8 SEF a 167 ° & & Science Law (Geology and Fuel Resources of the Green River Formation Southeastern Uinta Basin Utah and Colorado By W. B. CASHION GEOLOGICAL SURVEY PROFESSIONAL PAPER 548 A study of the Green River Formation in a 2,300-square-mile area in northeastern Urah and northwestern Colorado UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1967 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Congress catalog-card No. GS 67-162 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page | Stratigraphy-Continued .so . nt saul t on . 1 Tertiary System-Continued Page .... _.. inl. t ll onto cll _. 1 Uinta Formation.-..:... _...... 19 Locality and ”3&1"? relalions..._._.... [_._ ___ 1 Duchesne River Formation..__.. °______..__ 21 s... ll nn. [|. coool... al 22 Previous "~' ___; 3 Structurfe ““““““““““““““““ Carrs afe 22 Present investigation.. ___.} ___ g | Eeonomic ll. {02m ao Ul 24 ._ en oan clt u c.} 4 Oi shale... o enne. ye et 24 Topography -e . j. ooo | [200 ._ 4 Composition and physical characteristics. ___ ___ 24 MAecessibility= .l. nl.. ll cnn [L.. 110° [C. 4 Mevélgpment. .=... sl con {l Unc ct 24 Fopulstion and industry...... ____' 4 Polchtial reserves:: .} [00 tic Sec 24 Drainag'e and water supply.. ._ ''." 4 _n. co 0 . clad i 30 Stra 2581511111130“ """"""""""""""""""""""" g Description and geologic setting.:...._:...-_._ 30 Ugnexposed m _n t {r- 5 Mil]? cone cecte tened teen (s 24 Tertiary System .-._!_ .O.. _.", .l [_c 5 Origins cane cuse ino coe os 35 Wasateh -Formation.:.'..._.._. .-. __ _. 5 Development......" a_... _ 2 ct ostial. 36 Green River Formation __. _-_ 7. cl cll tento o tot a at 37 Douglas Creek Member_._._______________ 8 Bituminous sandstones."... :- i /__: / _ 37 Garden Gulch Member- __: : ._._._____ 12 Ooidfand ess.... noc lls ult o 40 Parachute Creek Member._______________ 13 Development 40 Evacuation Creek Member.______________ 16 nan." "rr Tuff beds in the Green River Formation___ 18 Possibilifice-__....s... aln ig 40 Tuffaceous dikes of the Green River For- ftoferences. __.... l is un 44 mation Z...... n l 00000} 1s | lames Cols ty t's 47 Prats 1. 2. ILLUSTRATIONS [Plates are in pocket] Geologic map and section of the southeastern part of Uinta Basin. Fence diagram of the Green River Formation and the upper part of the Wasatch Formation in the southeastern part of the Uinta Basin. 3. Stratigraphic sections of the Green River and adjacent formations in the southeastern part of the Uinta Basin. 4. 5. Maps showing thickness of selected oil-shale zones. Stratigraphic sections of the Mahogany ledge. Page Figur® 1. Map showing area of this report and some adjacent structural and physiographic features.__________ ___.. __ 2 2-7. Photographs of- 2. Thin beds typical of much of the Green River Formation.=..~....c ...l c l tk 3 T 3. Green River-Uinta contact near willow Oreck 00... ill llc oe tigi Of tort 9 4. Green River Formation in Hells Hole Canyon and along Hill Creek:_...._.._. . i_ __ __} /_ 11 5. Tuffaceous dikes in the Parachute Creek and Evacuation Creek __ ___| 20 6. Jointing in the Horse Bench Sandstone Bed of Evacuation Creek Member._________________..______ 22 7. A minor fold in a siltstone bed of the Parachute Creek Member-... '.. T [l}. 23 8. Map showing thickness of ol- shale beds in the Uinta Basin''. __.. 0 [00 {_o f oen, 31 9. Map showing location and width of gilsonite n. ln ll tol ovo tog [L0 32 2 of allsonite vene. 2.1... _.. 00. alie tto cotto tto of ee s y 33 11. Longitudinal sections of gllsonite veins. -.... Aull al ac ctc t t run 38 12. Map showing outcrop of zone containing Difuminous sandstone beds.... -.:. 39 III IV TABLE 1. 2, CONTENTS TABLES Estimated tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds occurring in a continuous sequence at least 15 feet thick and yielding an average of 30 gallons oll per ton --..... Estimated tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds occurring in a continuous sequence at least 15 feet thick and yielding an average of 25 gallons oll per. ton-..l. .*.... . Estimated tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds occurring in a continuous sequence at least 15 feet thick and yielding an average of 15 gallons oil per ton._--_--------- Estimated original reserves of gilsonite in the mappe area.. _ c llc.. cel cri-" Exploratory wells drilled within the area.... o..- 'list Ll erence GEOLOGY AND FUEL RESOURCES OF THE GREEN RIVER FORMATION SOUTHEASTERN UINTA BASIN, UTAH AND COLORADO By W. B. Castor ABSTRACT The area of this report is the southeastern part of the Uinta Basin and constitutes about 2,300 square miles in northeastern Utah and northwestern Colorado. The major topographic fea- - ture is a north-sloping plateau that is highly dissected by steep- walled canyons. The topography along the southern margin is dominated by the rugged south-facing Roan Cliffs. Bedrock exposed in the area is of fluvial and lacustrine origin and of Eocene and Oligocene age. The oldest rocks exposed are the massive sandstone and variegated shale of the Wasatch Formation of Eocene age. The Wasatch Formation is divided into the main body and the Renegade Tongue (new name). The Wasatch Formation interfingers with and is overlain by the Green River Formation, also of Eocene age. The Green River Formation has been divided, in ascending order, into the Douglas Creek, Garden Gulch, Parachute Creek, and Evacuation Creek Members. The Douglas Creek Member is composed chiefly of sandstone, siltstone, and algal and oolitic limestone deposited in a nearshore-lacustrine environment. -It interfingers with the underlying Wasatch Formation toward the former shore and interfingers with the overlying Garden Gulch and Parachute Creek Members toward the former basin. The Garden Gulch, Parachute Creek, and Evacuation Creek Members are composed chiefly of thin-bedded maristone, siltstone, and oil shale deposited in a lacustrine environment. The Parachute Creek Member contains the principal oil-shale beds of the Green River Formation. The richest of these beds is the Mahogany oil-shale bed, which lies within a group of rich oil-shale beds that are designated as the Mahogany ledge at the surface and as the Mahogany zone in the subsurface. The Evacuation Creek Member of the Green River Formation is overlain by and interfingers with the Uinta Formation of Eocene age. The Uinta Formation is composed of massive sandstone and arenaceous shale deposited mainly in a fluvial environment. It contains abundant vertebrate fossils. The Uinta is overlain by the red and gray fluvial sa dstones and shales of the Duchesne River Formation of Eocene or Oligocene age. Most of the mapped area is on the south flank of the Uinta Basin and is underlain by rocks that dip gently north. Steep dips are confined to the northeastern part of the area, where the beds are tilted southwest or west. Neither the density nor the displacements of faults are great. The Green River strata are cut by a prominent system of joints. One joint set trends north- west and the other northeast. Hydrocarbons, in various forms, are abundant in the mapped area. Oil shale in the Mahogany zone and adjacent beds that yields an average of 15 gallons of oil per ton from a continuous sequence 15 feet or more thick contains an estimated 53 billion barrels of oil. The original reserves of gilsonite in the area are estimated to be about 27 million tons. Oil and gas are produced from Jurassic, Cretaceous, and Tertiary rocks. In the southern part of the area, the Douglas Creek Member contains several sandstones that are impregnated with bitumen. INTRODUCTION LOCALITY AND REGIONAL RELATIONS The area described in this report is the southeastern part of the Uinta Basin of northeastern Utah and north- western Colorado (fig. 1). About 2,150 square miles of the area is in Uintah, Grand, and Carbon Counties, Utah, and about 150 square miles is in Rio Blanco County, Colo. Boundaries of the irregularly shaped area are controlled chiefly by the outcrop of the Green River Formation. The Uinta Basin, which can be classified as a struc- tural, a depositional, or a topographic basin, has an area of approximately 7,000 square miles, 95 percent of which is in Utah. The maximum dimensions of the basin are about 130 miles from east to west and about 100 miles from north to south. As considered in this report, the basin is bounded on the north by the Uinta Mountains, on the west by the Wasatch Range, on the south by the Roan Cliffs, and on the east by the Douglas Creek arch. The Piceance Creek basin, considered by some geologists to be part of the Uinta Basin, is treated herein as an individual geomorphic subdivision. Structurally the Uinta Basin is a sharply asymmetric feature that was produced by Laramide orogeny. The axis lies in the northern part of the basin near the Uinta Mountains. On the north flank of the basin, strata of Mesozoic and early Tertiary age dip steeply south and are truncated by more gently dipping strata of late Tertiary age. On the south flank of the basin Mesozoic and lower Tertiary rocks dip gently north, and no upper Tertiary rocks are present. During Eocene time large amounts of sediment from adjacent topographically high areas were deposited in various types of lacustrine and fluvial environments in the basin. These sediments, which are assigned to the Wasatch, Green River, and Uinta Formations, are perhaps more than 15,000 feet thick near the center of the basin. Although the mapped area is marginal to 1 38° GREEN RIVER FORMATION, UTAH AND COLORADO 112" 42°r——1—;—-——~-——.| <5 z | zy» z | ZW z =p z= l =4 = =O = | <=Is | < 2 l . 2 yrs 110° wYOMING Eat tres —__I—__—— z > std fj wii] Lake: | 7 d Iru ¢ ~ cify $ UINTA MOUNTAINS | > 2 a 2 / yo lu/cu L ou LL & 24° o Cay Ligs é Z = // Vernal \\\ Yampa 2 ( fne ,." #$ 1 Ez \\ guchesne \ & tah z Ouray, MDS Je X o \ W --. -~- ¢ z 40° a Fs ] UINTA J, O/ Rangely \ /// > { BASIN Zpovelas Z g ® CREEK 3 \ J ARCH z XX ”\/l//,\ > Prices - "/p [s A\ 9 All 13235 ND 7 $0 44970), < > + §» § * z -91 § yy ~ Sy & & s ef 2 # ": = an > s Zins 1 Escalant l p Escalante | Pio : trove, m|< <, 38 & Hl O P| ¥ O River ‘ & c>Durango I ( aat Ann rr _L pascal cs Eta iii ica ARIZONA NEW MEXICO o 25 so 100 MILES (Bp d | | easy FIGURE 1.-Area of this report and some adjacent structural and physiographic features. INTRODUCTION 3 the area of thickest lacustrine deposits, it displays most of the lithologies and stratigraphic relations believed to be present in the deeper part of the lake, as well as beds deposited in nearshore-lacustrine and fluvial environments. PURPOSE OF INVESTIGATION The primary purpose of this investigation was to obtain data on the stratigraphic distribution, conti- nuity, areal extent, thickness, oil content, and attitude of oil-shale beds of the area, in order to estimate the potential oil-shale resources. The occurrence and ex- tent of gilsonite and bituminous sandstones and those factors useful in evaluation of oil and gas possibilities of the area were also studied. ACKNOWLEDGMENTS The author is indebted to the many exploration com- panies that furnished oil-shale samples from cores and rotary cuttings to the U.S. Bureau of Mines for oil- yield assay, and to Mr. K. E. Stanfield, U.S. Bureau of Mines, for furnishing the results of these assays. These data greatly facilitated computation of the potential oil- shale resources of the area. Mr. Charles Neal of Ver- nal, Utah, gave information concerning the gilsonite mining operations, past and present, in the Uinta Basin. R. L. Griggs, U.S. Geological Survey, examined and described the thin sections of the tuffaceous rocks. The hospitality of the residents of the area facilitated the work of the field parties. PREVIOUS INVESTIGATIONS Geologic maps and descriptions of the Tertiary strata in the eastern Uinta Basin were first published in 1878 (Endlich, 1878, p. 78-86; Peale, 1878, p. 174-175, pl. 11; White, 1878, p. 34-39, pl. 2). Eldridge (1896, 1901) investigated the occurrences of gilsonite in the Uinta Basin and also pointed out that the Green River Formation contains "bituminous limestones" having po- tential economic value (1896, p. 923, table #: 1901, p. 334, table 4). In 1913 a reconnaissance study of the oil-shale deposits of part of Utah and Colorado was conducted by Woodruff and Day (1915). Winchester, during 1914-18, sampled and analyzed oil-shale beds of the Green River Formation in Colorado and Utah (1916, 1918). During 1922-25 W. H. Bradley (1931) made a detailed study of the lithology and paleontology of the Green River Formation in Utah and Colorado. Published studies of the Green River Formation made by Bradley (1926, 1929, 1930, 1964) in Colorado and Wyoming have also led to a better understanding of the formation in the Uinta Basin. Dane (1954, 1955) in- vestigated the stratigraphic relations of the Green River and Uinta Formations in part of the western Uinta Basin. Dane's study was made in conjunction with a photogeologic mapping project (Ray and others, 1956). Picard (1955, 1957) described the regional subsurface lithology of the Green River Formation. PRESENT INVESTIGATION Geologic investigations of the area described in this report, and shown on the accompanying geologic map (pl. 1), started in June 1951 and continued intermit- tently until June 1959. About 500 square miles in the northeastern part of the area (areas 1 and 2 of index map on pl. 2) was mapped in 1951 by J. H. Brown, Jr., _ W. B. Cashion, C. R. Lewis, and J. L. Snider and was described in the text of U.S. Geological Survey Oil and Gas Investigations Map OM-153 (Cashion and Brown, 1956). In 1952, 750 square miles in the central part of the area was mapped by Cashion, L. W. Camp, C. R. Lewis, and R. M. Finks. During 1953 an area of 450 square miles, including part of Naval Oil-Shale Re- serve No. 2, was studied by Cashion, Camp, Lewis, J. R. Donnell, H. J. Hyden, R. G. Miller, P. P. Orkild, C. T. Sumsion, and J. C. Benson. A core-drilling pro- gram in Naval Oil-Shale Reserve No. 2, supervised by Camp, Cashion, and Donnell, and the geologic mapping were completed in 1954. The report on Naval Oil-Shale Reserve No. 2 was published as U.S. Geological Survey Bulletin 1072-0 ( Cashion, 1959). In the southernmost part of the Uinta Basin a 400-square-mile area was in- vestigated by Cashion and A. D. Zapp in 1955, and in 1956 Cashion, assisted by J. M. Baldessari, studied the intertonguing relations between the Green River and Wasatch Formations along the east and southeast edges of the Uinta Basin. During 1957-59 Cashion gathered some additional stratigraphic and structural data. In addition to the geologic mapping, a major phase of the investigation was the collection and evaluation of subsurface data on potential oil yield of the oil-shale beds. Oil-shale resources of the mapped area have been described in preliminary reports (Cashion, 1957, 1961). These resources are described in detail herein and the oil-shale resources of the entire basin are preliminarily appraised. Fieldwork consisted of geologic mapping of the re- port area by use of aerial photographs (scale 1 : 31,680), measurement of detailed stratigraphic sections, esti- mation of potential oil yield, and collection of samples from the oil-shale beds for oil-yield assay. Strati- graphic sections were measured by use of hand level and a 6-foot steel tape. Parts of oil-shale and marlstone beds were chipped clean and examined critically so that the potential oil yield could be estimated. Composite channel samples were subsequently collected from 4 GREEN RIVER FORMATION, UTAH AND COLORADO kerogen-rich oil-shale beds in some of the sections and unweathered samples were obtained from the Naval Oil-Shale Reserve No. 2 by means of core drilling. Altitudes of key beds in the Green River Formation were determined, for structural control, by use of aneroid barometer or planetable and telescopic alidade. Most distances used in computation of differences in altitude were measured on acrial-photograph mosaics. More precise methods of measurement were used in Naval Oil-Shale Reserve No. 2 and in establishment of a triangulation net for the mapped area. Because considerable error may have been introduced by meas- urement of distances from aerial mosaics (even though the use of vertical angles was kept to a minimum) the structure-contour map-except for that part in the reserve-is classed as reconnaissance. The geologic map was compiled on a mosaic of parts of three Army Map Service quadrangle maps (1° %2°)- GEOGRAPHY TOPOGRAPHY Most of the mapped area is on a north-sloping highly dissected plateau, the surface of which generally con- forms to gentle dip slopes. Along the northeast side of the area the strata dip more steeply than on the plateau surface and form cuestas and hogbacks. The south edge of the plateau is delineated by the south- facing Roan Cliffs, a prominent topographic feature of eastern Utah and western Colorado formed on ex- posures of the lower part of the Green River Formation and of the upper part of the Wasatch Formation. 'The numerous stream valleys, which dissect the pla-" teau, are narrow and steep-walled and commonly have a relief of several hundred feet. The Green River, which forms much of the western boundary of the mapped area, has cut a canyon that has a maximum relief of about 4,000 feet. Interstream divides between major drainages are broad and generally have benchlike or mesalike shapes that give form to the plateau. These divides trend north and thus facilitate travel in a north-south direction. Rugged canyon walls hinder east-west travel. 'The maximum altitude, about 9,500 feet, is on the southernmost part of the plateau, and the minimum altitude, about 4,300 feet, is along the Green River approximately 18 miles northwest of the highest area. ACCESSIBILITY Principal access to the eastern part of the area is Utah State Highway 45, which intersects U.S. High- way 40 about 24 miles east of Vernal, Utah, and extends southeastward to the Colorado-Utah border. State Highway 45 is paved from U.S. Highway 40 southward to Bonanza; the rest is unpaved. _ Access to the western part of the area is afforded by a secondary road that extends south from Ouray, Utah, to the edge of the plateau. In the mapped area this road and State High- way 45 are connected by only one good secondary road. The small part of the area west of the Green River is accessible by fair to poor secondary roads that roughly parallel Minnic Maud Creek. Although the numerous secondary roads are of fair to good quality, much of the area is accessible only on horseback or on foot. POPULATION AND INDUSTRY The estimated population of the mapped area is 225- 250 persons, which indicates a density of 1 person for each 10 square miles. - About 200 people live in Bonanza, the only settlement, and the rest live on ranches in valleys drained by perennial streams. The now- abandoned mine camps of Dragon, Rainbow, and Wat- son were inhabited when gilsonite was mined nearby. Rainbow, the last to be abandoned, was intermittently inhabited until about 1952. Much of the population is employed by the American Gilsonite Co. at Bonanza. The rest of the population is occupied mainly by stockraising and farming. Stockraising is the more prevalent because of low rainfall and the very small amount of irrigable land. DRAINAGE AND WATER sUPPLY The Green River, the master drainage of the Uinta Basin, heads in west-central Wyoming and flows south- ward to its confluence with the Colorado River, about 60 miles south of the mapped area. The Green River and its tributaries drain the entire basin. The White River, which is second in size to the Green River, heads in northwestern Colorado and flows westward to its confluence with the Green River, near Ouray, Utah. During wet climatic cycles the major creeks, such as Bitter, Willow, and Hill Creeks are perennial. During dry cycles, parts of these streams become intermittent. In general, water in these streams is suitable for drinking where the streams are above an altitude of 6,500 feet. Along the lower courses, however, the water is alkaline, and much of it is not potable. No obser- vations were made of the streams that drain southward into the Colorado River. Most of the springs occur in the southern part of the area at altitudes above 6,000 feet; in the south- western part the principal aquifer is the Horse Bench Sandstone Bed of the Green River Formation or from adjacent sandstone beds. Commonly, the sandstone beds in the Douglas Creek Member of the Green River Formation and in the Renegade Tongue of the Wasatch Formation are the aquifers for springs in the southeastern part of the area. E STRATIGRAPHY 5 VEGETATION 'The most common shrubs in the area are sagebrush, rabbitbrush, greasewood, and serviceberry. The trees are cottonwood, willow, aspen, juniper, pifion, and fir. 'The area can be roughly divided into three zones, a¢- cording to the predominant vegetation as follows: 1. A zone 4,500-6,000 feet in altitude that supports mostly sagebrush, rabbitbrush, and grease- wood and has cottonwood and willow along the perennial streams. 2. A zone 6,000-7,500 feet in altitude that contains mostly juniper, pifion, and sagebrush. 3. A zone 7,500-9,500 feet in altitude that supports mostly fir, aspen, serviceberry, and sagebrush. The flora of the Uinta Basin was described in de- tail by Graham (1937). STRATIGRAPHY UNEXPOSED ROCKS Rocks of pre-Tertiary age are not exposed in the area, but rocks ranging in age from Precambrian to Cretaceous lie in the subsurface and are exposed a short distance north of the area. Kinney (1955) presented detailed stratigraphic sections and showed a general section of rocks exposed along the south flank of the Uinta Mountains near Vernal. His general section (1955, pl. 6) has been updated as follows: System Unit Thickness Dominant lithology (feet) Mesaverde Formation 1,100 | Sandstone and shale. 5, 070-5, 290 | Shale, siltstone, and Cretaceous Mancos Shale sandstone. Dakota Sandstone 95-135 Sandstone and shale. i : 830-930 Sandstone, mudstone Morrison Formation and shale. j i i 150-270 Sandstone, shale, and Jurassic Curtis Formation limestone. ___ Entrada Sandstone 105-215 Sandstone. %. Carmel Formation i 125-390 Shale and sandstone. Jurassic and Glen Canyon Sand- 720-1, 030 | Sandstone. Triassic stone i 5 230-355 Shale, sandstone, and C reeds Chinle Formation cons’glomerate. # Moenkopi Formation 820-1, 120 | Sandstone and siltstone. Permian Park City Formation 70-195 Limestone and shale. Permian and 1,015-1,275 | Sandstone. Pennsylvanian Weber Sandstone A * Pennsylvanian i Morgan Formation ‘ 1, 035-1, 450 | Limestone and sandstone. Black shale unit 0-265 Shale and sandstone. Mississippian Limestone unit 965-1, 220 | Limestone. Cambrian Lodore Formation 6-155 Sandstone. Precambrian ’ Tinta Mountain Group | 3, 000-4, 000 | Shale and sandstone. If maximum thicknesses of the units just described are totaled, the entire section is more than 19,000 feet 236-486 O-66--2 thick. The formations in the lower part of this rock sequence thin and pinch out southward toward the Uncompahgre Uplift owing to truncation and nondep- osition. Because of their great depth, these pinchouts have not been delineated by drilling. In the mapped area the Carter Oil Co. Minton-State 1 well, center of the NEY, SE} see. 32, T. 14 S., R. 20 E., penetrated about 8,100 feet of pre-Tertiary sedimentary rocks in which the Triassic beds rest on Precambrian granite (Miller, 1956). TERTIARY SYSTEM All bedrock exposed in the mapped area is of fluvial and lacustrine origin, and almost all is of Eocene age. 'The only exception is the Duchesne River Formation of Eocene or Oligocene age, which underlies less than 1 square mile in the northernmost part. During much of Eocene time a large lake was present ~ in the area now occupied by the Piceance Creek basin and the Uinta Basin in Colorado and Utah. Bradley (1930, p. 88) proposed the name Lake Uinta for this former body of water. The size and position of the lake varied greatly, and during its earliest and latest stages it was probably divided into two or more parts. Lacustrine marlstone, oil shale, limestone, siltstone, and sandstone of the Green River Formation were deposited in Lake Uinta. During the period of expansion of Lake Tinta, fluvial beds were deposited that are now beneath and peripheral to the lake deposits. These fluvial de- posits became the shale, sandstone, and conglomerate beds of the Wasatch Formation. During the waning period of the lake, fluvial beds were deposited periph- eral to it and, when the lake dried up, finally blanketed the area. These beds are assigned to the Uinta Forma- tion. The relation of Wasatch, Green River, and Uinta Formations in the mapped area is shown on plate 2, and the measured stratigraphic sections of these formations are graphically shown on plate 3. In the mapped area the Duchesne River Formation, composed of red and gray fluvial sandstone and shale, may lie unconform- ably on the Uinta and Green River Formations. The relationship is not clear, however, due to poor exposures. In the central part of the Uinta Basin, however, the Duchesne River Formation occurs in contact with only the Uinta Formation and is conformable with it. wAaASATCH FORMATION The name Wasatch was first applied by Hayden (1869, p. 191) to a sequence of variegated sand, clay, and conglomerate exposed on the east side of the Wa- satch Mountains. The Wasatch Formation (Eocene) in the mapped area is composed predominantly of red and gray shale and siltstone, and massive, irregularly bedded fine- to medium-grained gray to brown sand- h 6 GREEN RIVER FORMATION , UTAH AND COLORADO stone containing a few thin lenticular conglomerates. The sandstones are predominantly quartz but contain some feldspar and other minerals. Individually, most Wasatch strata are irregular and discontinuous, but some zones of sandstone or shale within the formation can be traced for several miles. The formation is ex- posed around the east, south, and west edges of the area and in the upper reaches of the deep canyons. The sandstones weather to buff, brown, and reddish-brown ledges, and the shales weather to steep red and gray slopes. Only the upper part of the Wasatch was studied in detail, and the thickness of the entire formation was measured at only one locality-near Florence Creek, The Wasatch Formation, in general, thickens west- ward from the Douglas Creek arch toward the Uinta Basin and eastward from the arch toward the Piceance Creek basin. According to G. H. Horn, U.S. Geolog- ical Survey (oral commun., 1961), the red beds and basal conglomerate, which are characteristic of the Wasatch Formation in much of the area near the south end of the Douglas Creek arch, are absent in the north- eastern part of T. 4 S., R. 101 W., Colo. (just east of mapped area), and in this area an oolitic limestone unit of the Green River Formation rests on massive sand- stone. The Wasatch Formation is more than 4,100 feet thick in the west-central part of the Uinta Basin (Ab- bott, 1957, enclosure 3) and is 5,500 feet thick in the eastern part of the Piceance Creek basin (Donnell, 1961, p. 846). The thickness of Wasatch ranges from about 700 feet in wells in the northeastern part of the mapped area to about 3,000 feet on the outcrop near Florence Creek in the southwestern part. In the area of this report the Wasatch Formation is divided into two major units: the main body of the Wasatch and the overlying Renegade Tongue (new name). Both units intertongue with the Douglas Creek Member of the Green River Formation. Main body of formation The upper part of the main body of the Wasatch For- mation is composed of massive, irregularly bedded fine- to medium-grained buff, gray, and brown sandstone, red and gray shale and siltstone, and some thin beds of con- glomerate. - The lower part was not studied in this in- vestigation. The upper part of the Wasatch weathers to buff and reddish-brown ledges and steep variegated slopes. The main body of the Wasatch Formation crops out along the eastern, southern, and southwestern margins of the mapped area and in a structurally high area along Rat Hole Canyon in T. 14 8. R. 95 E., Utah. In Desolation Canyon the upper part of the main body of the Wasatch intertongues with nearshore-lacus- trine beds of the Douglas Creek Member of the Green River Formation. This part of the Wasatch is desig- nated as tongues Z and Y and has the same lithology as the main body elsewhere. Tongue Z is 270 feet thick and tongue Y 110 feet thick near the junction of Wild Horse Canyon and the Green River. Throughout the mapped area the main body of the Wasatch is conform- ably overlain by tongue D of the Douglas Creek Mem- ber of the Green River Formation. Renegade Tongue The name Renegade Tongue is herein given to the sequence of massive, irregularly bedded brown and gray sandstones and red and gray shales and siltstones that constitute the upper part of the Wasatch Formation and intertongue with the Douglas Creek Member of the Green River Formation. The type section is on a ridge just north of Renegade Canyon, from which the name was derived, in T. 19 S., R. 20 E. (pl. 3, section E.) Renegade Canyon, a tributary of Thompson Canyon, is just south of the mapped area. The Renegade Tongue is 1,000 feet thick at the type locality and thins to the north and northeast owing to its intertonguing relation with the Douglas Creek Member of the Green River Formation. Northeast of a line projected approx- imately parallel to Tenmile: Canyon (T. 16 S$. -R. 21 E.), the Renegade Tongue is divided into units X and W, which are separated by the lacustrine beds of the Green River Formation. Unit X, a predominantly red and gray shale, can be traced beyond the northeast edge. of the area. The minimum measured thickness of unit X is 7 feet, at White River; north and southwest of this locality the unit thickens. Unit W, predominantly massive, poorly bedded sandstone, can be traced north- eastward to the vicinity of Park Canyon (T. 11 S.. R. 25 E.). The Renegade Tongue conformably overlies Tongue D of the Douglas Creek Member of the Green River and is conformably overlain by tongue A of the Douglas Creek Member. The contact between the Renegade Tongue and the Douglas Creek Member separates gross lithologic units-predominantly - fluvial Renegade Tongue from predominantly lacustrine Douglas Creek Member-but both units contain fluvial and lacustrine sediments. Source, environment, and age of the formation Most of the sediments which make up the upper part of the Wasatch Formation in the mapped area were de- rived from a region to the southwest and south. Wa- satch beds composed of sediments derived from the Uinta Mountain region occur mainly outside the mapped area, although some occur in the northeastern part of the area. The Wasatch Formation was deposited on flood plains and in streambeds and deltas near the edge of Lake STRATIGRAPHY T. Uinta. Little of the Wasatch sediments studied were deposited in a reducing environment, and the few coals or carbonaceous shales are very thin and extremely lenticular. No diagnostic fossils were found in the Wasatch Formation, only fragments of vertebrate bones and plants. Tongues B and C of the Douglas Creek Mem- ber of the Green River Formation, which interfinger with the Renegade Tongue of the Wasatch, contain middle Eocene fossils. Thus, part (and perhaps all) of the Renegade Tongue is of middle Eocene age. That part of the main body of the Wasatch Formation ex- posed in the mapped area is assigned to early Eocene, as it is in most other areas. The lowermost part, ex- posed east and south of the mapped area, is probably Paleocene. The Colton Formation is a fluvial sequence under- lying the Green River Formation and is equivalent to Fraur® 2.-Thin beds typical of much of the Green River Fo all or part of the Wasatch Formation. It was named for exposures near Colton, Utah, in the western Uinta Basin (Spieker, 1946). The Colton Formation has not been mapped east of its type locality ; thus, its exact relation to the Wasatch Formation of this report is not known. GREEN RIVER FORMATION The name Green River Shales (which was later changed to Green River Formation) was first used by Hayden (1869, p. 190) in describing excellent exposures along the Green River in Wyoming. The Green River Formation is composed of beds of oil shale, marlstone, shale, siltstone, sandstone, and oolitic, algal and ostra- codal limestone and tuff deposited in a lacustrine envi- ronment. - Thin, even, notably continuous beds (fig. 2) characterize the formation, particularly the marlstone, oil shale, siltstone, and tuff that were deposited in water rmation. Tge, Evacuation Creek Member; Tgp, Parachute Creek Member. View near Watson, Utah. 8 GREEN RIVER FORMATION, UTAH AND COLORADO deep enough to protect them from wave and current ac- tion. Some thin beds of sandstone and algal and oolitic limestone that were deposited in shallow water also display these characteristics; however, most of the shal- low-water beds are more massive and are not laterally persistent. The lithology of the Green River Forma- tion was first described in detail by Bradley (1931). Milton and Eugster (1959) described the mineral as- semblages of the formation. The Green River Formation is exposed in about 75 percent of the mapped area. It crops out every where except around the periphery of the mapped area and along some of the deep canyons. Thus, the Green River Formation controls the overall topography of the area- a north-sloping plateau that is highly dissected by steep- walled canyons. Rocks of the Green River Formation described in this report are marginal to the area of maximum Green River deposition in the Uinta Basin, and the forma- tion, as a whole, thickens toward a trough northwest of the mapped area. There are few localities where the entire thickness of the Green River can be measured in a small surface area, and total thicknesses obtained from composite sections are often suspect because of the abrupt lateral changes in thickness and lithology. The intertonguing of Green River and Wasatch Formations impedes the determination of cumulative thicknesses in exploratory wells, as well as impeding the selection of formation boundaries. The maximum total thickness of the Green River For- mation measured within a small surface area is about 1,900 feet at Raven Ridge (pl. 3, section O). The maximum total thickness obtained from partial sections (pl. 3, sections A, H) by extrapolation, excluding those intertonguing units of the Wasatch Formation, is at least 2,100 feet. Exploratory well data indicate that the total cumulative thickness in the northwestern part of the area is 2,500-3,000 feet. Outside the mapped area the thickness of the Green River Formation, in- cluding the Green River-Uinta transition zone, is more than 7,000 feet near Duchesne, Utah (Abbott, 1957, en- closure 4). The Green River Formation can be visualized as a jagged-edged lens of lacustrine strata enveloped in a shell of fluvial strata. The upper part of the forma- tion interfingers with fluvial beds of the Uinta Forma- tion, and the lower part interfingers with fluvial beds of the Wasatch Formation. During part of geologic time the Uinta and Wasatch Formations probably formed a continuous fluvial sequence in the area periph- eral to Lake Uinta. If such a continuous sequence existed, however, it has since been removed by erosion or hidden by younger Tertiary strata. Intertonguing of the Green River and the Wasatch Formations is complex, and in many localities the con- tacts between shallow-water lacustrine rocks of the Green River Formation and fluvial rocks of the Wa- satch are subtle and difficult to determine. Selection of contacts was therefore an attempt to delineate the rock sequences of predominantly shallow-water lacustrine origin from those of predominantly fluvial origin, but each tongue may contain both types of lithology. Intertonguing between the Green River and the Uinta Formations is less problematic, for the differences be- tween these lacustrine and fluvial rocks are more ob- vious (fig. 3). The major source area for most detrital sediments in the Green River Formation in the mapped area lay to the southwest and is denoted by the increase southwest- ward in grain size and in number of sandstone beds. Part of the basin received a large amount of sediment from the Uinta Mountain area during Green River time; that part is north and northwest of the mapped area. A slight increase in thickness of the nearshore-lacustrine deposits toward the southern part of the Douglas Creek arch indicates that this area was topographically high during early Green River time ; however, this area prob- ably did not contribute a large amount of sediment to the Green River lake. Member names applied by Bradley (1931) to the Green River Formation in the Piceance Creek basin and in the eastern Uinta Basin are used in this report, but the boundaries of some of these members have since been somewhat modified. The members of the Green River Formation are, in ascending order, the Douglas Creek, Garden Gulch, Parachute Creek, and Evacuation Creek Members. Precise correlation of the Green River Formation in the Piceance Creek basin and in the Uinta Basin has been established through the use of key beds in the Parachute Creek Member. Correlation of the Green River Formation in the Uinta Basin with the Green River Formation of the Washakie and Green River basins of southwestern Wyoming is as yet uncertain. DOUGLAS CREEK MEMBER The Douglas Creek Member, named by Bradley (1931, p. 10), is composed mainly of sandstone, siltstone, shale, and oolitic, algal, and ostracodal limestones; locally it contains a few oil-shale beds. The sandstone beds are composed mostly of fine- to medium-grained quartz and weather to gray and brown ledges. They are pre- dominantly even bedded, although some are cross- bedded, and their upper surfaces are more planar than the upper surfaces of the sandstone beds assigned to the Wasatch Formation. In part of the area the upper sandstone beds of the Douglas Creek Member contain €. ¥ STRATIGRAPHY o FrGurE 3.-Contact relation between the Green River Formation and the Uinta Formation, near Willow Creek in the north- eastern part of T. 12 S., R. 20 E. Tv, Uinta Formation; Tgt, unmapped transition zone (included with the Green River Formation on pl. 1) ; and Tgr, Green River Formation. appreciable amounts of bituminous material. These beds are described in section "Economic Geology" of this report. The siltstone is predominantly gray to tan and weathers to tan or reddish-brown ledges and steep slopes. The shale is gray, tan, and green and weathers to green or gray slopes. Oolitic, algal, and ostracodal limestones of this unit are thin bedded to massive and are commonly gray. These limestones weather to distinct orange-brown ledges on many out- crops. Oil-shale beds of the Douglas Creek Member are thin and are less widespread than those of the Parachute Creek Member and-except for the upper- most oil-shale beds in the northwestern part of the area-have little economic significance. Principal outcrops of the Douglas Creek Member occur along the walls of deep canyons and along the Roan Cliffs. This member is characterized by a rugged topography, displaying many cliffs and ledges dissected by numerous gullies. The Douglas Creek Member is probably thickest along a west-northwest-trending strip that is several miles wide and extends from the northwest corner of the area to the northeast corner of T. 13 S., R. 25 E. North- east of this strip the member grades into and inter- fingers with the Parachute Creek and Garden Gulch Members, and southwest of this strip it grades into and interfingers with the Wasatch Formation. The Doug- las Creek Member is about 1,060 feet thick at Raven Ridge, T. 2 N., R. 104 W., and about $70 feet thick at Hells Hole Canyon, T. 10 S., R. 25 E., indicating that the Raven Ridge area lay on the northern edge of the lake. The maximum measured thickness of the member, ex- clusive of intertonguing units, is 1,180 feet, along Evac- uation Creek in T'ps. 11 and 12 S., R. 25 E. The thick- 10 GREEN RIVER FORMATION, UTAH AND COLORADO ness is probably greater, however, in the northwestern part of the area, where the basal part of the member is not exposed. The Douglas Creek may be at least 2,000 feet thick in the subsurface beneath T. 11 S., R. 19 E. The member is thinnest in the southern part of the area. A cumulative thickness of 220 feet was meas- ured in Renegade Canyon (pl. 3, section E). The Douglas Creek Member grades laterally into and intertongues with the Parachute Creek and Garden Gulch Members of the Green River Formation in a basinward direction. Douglas Creek sandstone grades laterally into siltstone, which in turn grades laterally into marlstone; and Douglas Creek limestone inter- tongues with marlstone and oil shale of the Parachute Creek and Garden Gulch Members. Sandstone, silt- stone, and algal and oolitic limestone in the Douglas Creek Member occur close to the Mahogany oil-shale bed in the southern part of the area (fig. 42), but near the White River the uppermost beds of these lithologies are separated from the Mahogany oil-shale bed by 450 feet of Garden Gulch and Parachute Creek strata (fig. 44). This separation is the result of contemporaneous deposi- tion of the shallow-water lacustrine Douglas Creek sedi- ments near the edge of Lake Uinta and the deep-water lacustrine Garden Gulch and Parachute Creek sediments along the trough of the lake, which trended west near the present course of the White River. The Douglas Creek Member also grades laterally into, and intertongues with, the Wasatch Formation in a shoreward direction. Evenly bedded sandstone of the Douglas Creek Member grades laterally into irregularly bedded coarser grained sandstone of the Wasatch, and the algal and oolitic limestone and other shallow-water lacustrine strata intertongue with sandstone and shale of the Wasatch. Many thin nearshore-lacustrine units extend laterally from the main part of the Douglas Creek Member. Only six units, containing most of the nearshore- deposited beds, were considered to be tongues of the Douglas Creek Member. Other tongues are present but are too thin to be recognized consistently or mapped separately. Tongues of member In the mapped area six lacustrine tongues of the Douglas Creek Member, designated in descending order as tongues A through F, have been differentiated from the intercalated Wasatch strata. Lithologic composi- tion of these tongues is virtually the same as that of the main part of the Douglas Creek Member. Tongue B was mapped with unit W of the Renegade Tongue of the Wasatch Formation, however, and tongue D was mapped with the basal part of the Renegade Tongue. All other tongues are shown individually on plate 1. Tongues F and E of the Douglas Creek Member inter- finger with the main body of the Wasatch Formation and crop out only along the Green River. The south- - eastern and eastern limits are not known. These tongues contain many beds that are characteristic of nearshore-lacustrine deposition; also, they contain a larger proportion of beds associated with fluvial deposi- tion than the other tongues of the Douglas Creek Mem- ber. This sequence, deposited during times of lake-level fluctuation, is difficult to subdivide. The algal and oolitic limestones and the relatively even bedding in tongues F and E relate these tongues more closely to the Douglas Creek Member than to the main body of the Wasatch Formation. In Wild Horse Canyon, tongue F is $5 feet thick and tongue E is 230 feet thick; they are separated by 270 feet of the Wasatch Formation (pl. 3, section B). Tongues F and E may be shoreward equivalents of the upper part of the "black shale facies" of Picard (1955, p. 83-87). The "black shale facies" is a dominantly lacustrine unit that presumably is confined to the subsurface of the Uinta Basin. - It is characterized by dark-gray or black thinly laminated shale and has a maximum thickness of approximately 1,100 feet in an exploratory well near Duchesne, Utah (Picard, 1955, p. 84). Tongue D of the Douglas Creek Member crops out in the mapped area as a thin band around the eastern, southern, and southwestern margins of the basin. - It is composed mostly of shale and algal and oolitic limestone and crops out as a series of orange-brown ledges and gray slopes. Measured thickness of the tongue ranges from 6 feet in the Renegade Canyon section in the south- ern part of the area to 150 feet in the Evacuation Creek section in the northeastern part. - Tongue D is less than 50 feet thick throughout much of the area and was therefore mapped with the Renegade Tongue of the Wasatch Formation. - In the northeast half of the area, it was mapped with the overlying unit X of the Rene- gade Tongue, and in the southwest half, with the undivided Renegade Tongue. Tongue D probably underlies the entire mapped area. Tongue C of the Douglas Creek is composed of gray and green shale and siltstone, gray and brown algal, oolitic, and ostracodal limestone, and gray and brown sandstone, as well as a few thin beds of dark-gray and brown oil shale and marlstone. - The tongue crops out in a narrow band extending along the eastern and south- eastern margins of the area. Tongue C weathers to green, gray, and brown ledges and steep slopes. Meas- ured thickness of tongue C ranges from 200 feet at Hay Canyon to 560 feet on Evacuation Creek (pl. 3, sections F, L). Tongue C presumably pinches out to the south- west along a north line projected from the A C STRATIGRAPHY FIGURE 4.-Members of the Green Member Formation, as viewed (A) east across Hells Hole Canyon from sec. 17, T. 10 S., R. 25 E., and (B) north along Hill Creek, see. 1, T. 14 S., R. 19 E., Uintah County, Utah. Tgp, Parachute Creek Member, including the Mahogany oil-shale bed, m,; Tgg, Garden Gulch Mem- ber; and Tgd, Douglas Creek Member. 11 12 GREEN RIVER FORMATION, UTAH AND COLORADO middle of T. 17 S., R. 22 E., to the northwest corner of T. 11 S., R. 19 E ; it is underlain by unit X of the Renegade Tongue and is overlain by unit W of the Renegade Tongue. | Tongue B of the Douglas Creek is composed of gray and green siltstone and shale, gray and brown sand- stone, and gray and brown algal, oolitic, and ostracodal limestone. - This tongue crops out in the deeply incised parts of Hill Creek, Willow Creek, and Main Canyons, and along the southeastern margin of the mapped area. It forms a thin series of ledges and steep slopes and is both overlain and underlain by the massive fluvial sand- stones of unit W of the Renegade Tongue, with which it is mapped. Tongue B is 70-95 feet thick. It pinches out to the south and southwest and probably merges with the basal part of tongue A in the subsurface in the northwestern part of the mapped area. Tongue A is composed of gray and green siltstone and shale, gray and brown sandstone, and gray and brown algal, oolitic, and ostracodal limestone, as well as a few thin beds of dark-gray and brown oil shale and marl- stone. This tongue contains almost all the oil-shale beds of the Douglas Creek Member, but these beds are much less extensive than those of the Parachute Creek Member. - Most oil-shale beds of the tongue occur in its upper 50 feet in an area bounded on the northeast by a line projected parallel to Main Canyon and on the south by the Uintah County line. Tongue A crops out throughout much of the area, either in broad strips, as in the southeast, or in narrow bands, as in the west. Outcrops of this tongue commonly weather to gray, reddish-brown, and green ledges and steep slopes. Much of the limestone weathers a distinctive orange- brown. Measured thickness of tongue A ranges from 210 feet in the Renegade Canyon section to 455 feet in Evacuation Creek (pl. 3). Tongue A conformably overlies and interfingers with unit W of the Renegade Tongue of the Wasatch Formation and in much of the area is conformably overlain by, and interfingers with, the Parachute Creek Member of the Green River Forma- tion. South of White River and east of Evacuation Creek, however, tongue A is overlain by, and inter- fingers with, the Garden Gulch Member; southwest of Main Canyon it is overlain by the Mahogany oil-shale bed. Source, environment, and fossils The source area for most sediments of the Douglas Creek Member was south and southwest of the mapped area. In the northeastern part of the area, however, the member contains sediments derived from a source north or northeast of the mapped area. The presence of thick algal and oolitic limestone beds in tongue A of the Douglas Creek Member in the southeastern part of the area indicates that much of the region now occupied by the southern part of the Douglas Creek arch was topographically high during part of Douglas Creek time but was not subjected to subaerial erosion. Beds of the Douglas Creek Member were deposited near the lakeshore in shallow water that had an abun- dant supply of lime. This conclusion is substantiated by the presence of ripple marks, mudcracks, and cross- bedding, and the numerous beds of oolitic and algal limestone. - Bradley (1929, p. 223) stated that probably most of (and certainly some of) the algal reefs were formed in water less than 6 feet deep, although a few may have formed in water as much as 15 feet or more deep. The lower part of the Douglas Creek Member was deposited during a period of rapid water-level fluc- tuation in Lake Uinta. -The upper part of the member was laid down during a phase in which the lake was predominantly transgressive. Fossils found in the Douglas Creek Member include mollusks, ostracodes, turtle and fish bones, and gar-pike scales. The mollusks, identified by John B. Reeside, Jr., are Australorbis spectabilis Meek, Australorbis sp., Lymmaet sp., Physa bridgerensis Meek, Physa plero- matis White, Physa sp., and "Planorbis" sp. in tongues B and C of the Douglas Creek Member along the Roan Cliffs. An age determination more restrictive than middle Eocene cannot be given to these forms. Swain (1956) described several ostracode zones of the lower part of the Green River Formation, but he designated the age only as early Tertiary. Bones and scales found in the report area were too fragmentary to be useful in age determinations. GARDEN GULCH MEMBER The Garden Gulch Member was named by Bradley (1931, p. 10) for exposures along Garden Gulch, in the Piceance Creek basin. In the report area the mem- ber is composed chiefly of marlstone containing appreci- able amounts of organic matter, oil shale, and siltstone. The Garden Gulch Member is characterized by thin- and even-bedded gray and brown marlstone and con- tains less oil shale than the overlying Parachute Creek Member. - Most beds are less than 1 inch thick, and some outcrops contain layers which are paper thin. The member forms steep slopes that are broken by small ledges of resistant oil-shale beds. The outcrop of the Garden Gulch in the mapped area is restricted to a narrow strip of land south of the White River and east of Evacuation Creek. Northeast and southwest of the strip, the member is absent because of gradation into the Douglas Creek and Parachute Creek Members. Oil-yield assays of rotary cuttings from exploratory wells west of the Garden Gulch out- crop indicate that the oil-shale sequence below the A STRATIGRAPHY 13 Mahogany bed assigned to the Parachute Creek Mem- ber is thicker in the subsurface than on the outcrop. Thus, the upper part of the Garden Gulch Member probably grades laterally westward into the lower part of the oil-shale-bearing Parachute Creek Member. Maximum measured thickness of the Garden Gulch Member is 230 feet, in Hells Hole Canyon ; to the north- east and southwest, the member thins. The gray slope-forming beds of the Garden Gulch Member are markedly different from the underlying brown ledge-forming beds of the Douglas Creek Mem- ber. The upper part of the Garden Gulch and the lower part of the Parachute Creek members are litho- logically similar, however, and the two members can be distinguished mainly by the larger number of oil-shale beds in the Parachute Creek (Bradley, 1931, p. 11). The Parachute Creek Member is predominantly a cliff- forming unit in that part of the basin where the Garden Gulch Member is exposed. Topographic break between these two members, however, does not occur at the same horizon everywhere and is not significant enough to be used in making a precise correlation. Oil-shale beds in the lower part of the Parachute Creek are lower grade and less abundant than oil-shale beds in the middle part and the choice of a contact between the Garden Gulch and Parachute Creek members is rather arbi- trary. At some localities the two could be considered as one unit. If the reader compares the contacts of the Garden Gulch Member as shown by Cashion and Brown (1956, fig. 1) and the contacts of the Garden Gulch Member as shown in this report (pl. 3), he will find that these contacts have been changed. In reexamin- ing the White River and Hells Hole stratigraphic see- tions, the author found that the contacts shown in the earlier report did not correspond to those originally des- ignated by Bradley. The contacts have been changed to conform more closely to those of Bradley, even though the author believes that the Garden Gulch Mem- ber in the mapped area is the lateral equivalent of the lower part of the Parachute Creek Member in the Piceance Creek basin. Source, environment, and fossils The Garden Gulch Member was deposited along the trough of Lake Uinta in water that was probably less than 75 feet deep. The member contains only a small amount of coarse sediment and consists mostly of lime, clay, and organic matter. Fossils found in the Garden Gulch Member consist of fly larvae, ostracodes, fish scales, and plant fragments. No age assignment can be made on the basis of these fossils. 236-486 0O-66--3 PARACHUTE CREEK MEMBER The Parachute Creek Member, named by Bradley (1931, p. 11) for exposures near Parachute Creek in the Piceance Creek basin, is composed mainly of marl- stone, oil shale, siltstone, sandstone, and tuff. It con- tains the principal kerogen-rich beds in the Green River Formation. Lithologic units of the Parachute Creek Member are predominantly thin and even bedded and are laterally continuous. Most strata are less than 1 inch thick, and some of the oil shales are paper thin. Key tuff beds less than 5 inches thick can be traced over thousands of square miles in the Piceance Creek basin and Uinta Basin. The Parachute Creek Member in the northeastern part of the mapped area is lithologically unlike that in in the southwestern part. Line B-2' (pl. 3, index map) is the approximate boundary between these two lithologies. In the northeastern part of the area, the Parachute Creek Member is composed mostly of thin- bedded maristone, oil shale, and tuff, all deposited in a deep-water lacustrine environment. This lithology is typical of the Parachute Creek Member. In the south- western part of the area the member is composed most- ly of siltstone and sandstone deposited in a shallow- water lacustrine environment, and it contains few beds of oil shale or tuff. Oil shale has been defined in various ways (Bradley, 1931, p. 7). In this report, however, the term "oil shale" is used for marlstone that will yield 15 gallons or more of oil per ton when subjected to destructive distillation. The physical and mineralogic characteristics of the oil shale in the Green River Formation were described in detail by Bradley (1931, p. 22-32). These oil-shale beds consist of magnesian marlstone having a high con- tent of organic matter in the form of kerogen. Un- weathered oil shale ranges from brown to very dark gray owing to differences in its kerogen content. Beds that contain the most kerogen are thus the darkest in color, as well as the most resistant to erosion. The beds having a high content of organic matter weather to dis- tinctive blue-gray ledges. The bedding of weathered oil shale is thin to very thinly laminated, but it may appear massive in fresh exposures. Beds containing the most kerogen crop out in a re- sistant dark-gray unit called the Mahogany ledge. In the mapped area it is 2-60 feet thick. This unit was so named by Bradley (1931, p. 23) because polished sur- faces of the shale resemble old mahogany. Its sub- surface correlative is called the Mahogany zone. The thick oil-shale bed containing the most kerogen-the Mahogany bed-occurs near the top of the Mahogany ledge. Other groups of kerogen-rich oil-shale beds that weather to dark-gray ledges occur above and below the 14 GREEN RIVER FORMATION, UTAH AND COLORADO Mahogany ledge but are not as thick nor as rich in kerogen content as the Mahogany ledge. Near the depositional axis of the lake in the mapped area, the Mahogany zone and the adjacent groups of kerogen- rich beds just mentioned occur in a sequence about 400 feet thick that is made up predominantly of oil shale, as indicated by oil-yield assays of cores. The Mahogany oil-shale bed lies approximately in the middle of the 400-foot-thick sequence. The thickness is estimated to be at least 700 feet in an area a few miles to the west. In general, all units of this sequence are thickest near the depositional axis of the basin and thinnest away from this axis, which trends approximately east near the confluence of the White River and Evacuation Creek. Thus the axis lies north of the western part of the mapped area. Position of the axis within the mapped area was relatively stable during Garden Gulch and early Parachute Creek time but may have shifted slightly southward during late Parachute Creek time. Near the depositional axis, the Mahogany ledge is about 60 feet thick and the Mahogany oil-shale bed is about 9 feet thick. Along the southern part of the Raven Ridge and in the area southwest of line B-B' (pl. 3, index map), however, the Mahogany ledge consists mainly of the Mahogany oil-shale bed, which is 2-5 feet thick in these areas. Variations in thickness and in kerogen content of the Mahogany bed and adjacent beds are shown on plate 4. The thick oil-shale sequence grades laterally into, or interfingers with, beds of marlstone and siltstone in any shoreward direction. In turn, the marlstone and silt- stone grade into or interfinger with beds of siltstone and sandstone. Near Hells Hole Canyon the oil-shale se- quence of the Parachute Creek Member extends down- ward 250 feet from the Mahogany oil-shale bed. Along Raven Ridge and southwest of Main Canyon, however, rocks below the Mahogany oil-shale bed contain few or no oil-shale beds, and much of the 250-foot-thick in- terval immediately below the Mahogany oil-shale bed is occupied by sandstone of the Douglas Creek Member. Also, the Parachute Creek rocks above the Mahogany oil-shale bed contain fewer and thinner oil-shale beds in these two areas than at Hells Hole Canyon. The marlstone and silty marlstone beds of the Para- chute Creek Member are mostly thin bedded, although they may appear to be massive on a surface that has not been deeply weathered. Many of these marlstones con- tain organic material that imparts a brown hue to the unweathered surfaces. Units containing only small amounts of organic material are light gray or tan. Weathered marlstone and silty marlstone are gray to buff, are commonly fissile, and form ledges and steep slopes. The siltstone is calcareous and commonly contains tuffaceous material and minor amounts of organic mat- ter. - Although beds of siltstone occur northeast of line B-B' (pl. 3, index map), they are much more common in the area southwest of this line. Many tuff beds occur in the Parachute Creek Member in the area northeast of line B-2'. They occur in a stratigraphic sequence that was deposited in lake water deep enough that the sediments were undisturbed by current or wave action. - Southwest of line B-B' there are few tuff beds, and only one tuff (which is at the base of the Mahogany bed and is thin and undulating) has great areal extent. This paucity of tuff beds in the southwestern part of the area is seemingly due to wave or current action in shallow water. The ash that fell on the lake surface over shallow water was greatly diluted by other sediment while settling to the lake bot- tom and thus did not form distinctive layers. Sandstone in the Parachute Creek Member is com- posed of quartz and a lesser amount of feldspar and contains such accessory minerals as biotite, muscovite, and zircon. - The grain size is very fine to medium, and carbonate is the most common cementing material. The sandstone bedding is thin to massive, the massive beds being most prevalent in the southernmost part of the area. - The sandstone is gray to brown and weathers to gray or brown ledges and cliffs. The thickness and number of sandstone beds in the Parachute Creek Member increase from northeast to southwest. Along the Hill Creek anticline, and for about 10 miles north of it, one prominent resistant sand- stone and siltstone sequence occurs between the Ma- hogany bed and the Horse Bench Sandstone Bed. This sequence, ranging in thickness from 10 to 50 feet, forms extensive mesa tops in many areas where the Horse Bench Sandstone Bed has been removed by erosion. - It grades into siltstone to the north and northeast and in the southernmost part of the area is associated with several other ledge-forming sandstones. Lenticular sandstones locally occur near the Mahog- any oil-shale bed in the west-central part of the mapped area. These massive sandstone lenses range in width from a few tens of feet to a few hundred feet and are as much as 50 feet thick. - Oil-shale and marlstone just below the main mass of each sandstone lens are com- monly downwarped and thinned but do not seem to be eroded. Contorted bedding is evident in all of these lenses. At several localities a sequence of oil shale and marlstone 10-20 feet thick, which includes the Mahog- STRATIGRAPHY 15 any oil-shale bed, overlaps itself for a distance of a few hundred feet, and a sandstone lens occurs between the overlapping parts. Evidence of faulting is not visible in this sequence, and the overlying and underlying strata are continuous. The author believes that plas- tic flowage within the sandstone lenses was the cause of these bedding irregularities. The sandstones are very tuffaceous, as are the sedimentary dikes in the Green River Formation, and conditions that produced the dikes could also have produced plastic flowage in the lenticular sandstone bodies. No explanation can be offered for the localized accumulation of these coarser sediments that are enclosed in finer grained sediments. The general character and stratigraphic position of the sandstones do not indicate deposition in channels or bars; however, to conclusively determine their origin, a detailed study of those deposits would have to be made. Near the Colorado-Utah border the measured thick- ness of the Parachute Creek Member ranges from about 365 feet along Evacuation Creek to about 615 feet along the White River. Oil-yield assays show that the thick- ness of oil shale in the member increases westward along the depositional axis of the basin. In most of the mapped area the Parachute Creek Member overlies and . interfingers with the Douglas Creek Member. East of Hells Hole Canyon and south of the White River, however, the Parachute Creek over- lies and interfingers with the Garden Gulch, which pinches out to the northeast and southwest and is absent along Raven Ridge and southwest of Hells Hole Can- yon. The Parachute Creek-Douglas Creek contact from Evacuation Creek southwestward to Main Canyon was arbitrarily placed at the top of the uppermost sand- stone bed. However, coarse-grained beds in this se- quence become stratigraphically higher from northeast to southwest; in the area southwest of Main Canyon, sandstones occur above the Mahogany oil-shale bed. The Parachute Creek-Douglas Creek contact in this area was mapped as the base of the Mahogany oil-shale bed instead of the top of the uppermost sandstone be- cause, by definition (Bradley, 1931, p. 11), the Para- chute Creek Member contains the principal oil-shale beds of the Green River Formation. The Parachute Creek Member underlies the Evacua- tion Creek Member. The boundary between these two members was selected on the basis of its mappability throughout the entire area and differs somewhat in stratigraphic position from the boundary as originally determined by Bradley (1931, pl. 8) in the easternmost part of the Uinta Basin and more recently by Dane (1954, 1955) in an area west of the Green River. Brad- ley (1931) did not define this boundary, but he described the Parachute Creek Member as being distinguishable from other parts of the Green River Formation by its content of oil-shale beds. In a stratigraphic section measured by Bradley in Hells Hole Canyon (1931, pl. 8, section D), the boundary between the Parachute Creek and Evacuation Creek Members was placed a few feet above the Mahogany oil-shale bed. Dane (1954, p. 413 ; 1955, columnar section 4), in a section near the head of Avintaquin Canyon (west of the mapped area), placed the boundary at the top of the oil-shale facies, as measured by Bradley (1931, pl. 11). Near the Duchesne County-Uintah County line just west of the mapped area, Dane (1955, columnar section 11) placed the boundary 315 feet above the Mahogany oil-shale bed. In the area southwest of the Rainbow and Black Dragon gilsonite veins the boundary between the Parachute Creek Member and the overlying Evacuation Creek Member is placed at the base of the Horse Bench Sand- stone Bed. The top of the Horse Bench Sandstone Bed was not mapped because the unit is less than 20 feet thick in much of the area. This bed characteristically forms a prominent buff or brown ledge among gray slope- forming marlstones. South of T. 16 S., however, this sandstone occurs with other sandstones of similar ap- pearance, and the Parachute Creek-Evacuation Creek boundary is difficult to determine. In general the rocks between the Horse Bench Sandstone Bed and the Ma- hogany oil-shale bed thicken westward. These rocks are 300 feet thick on Asphalt Wash, in T. 12 S., R. 24 E.; 390 feet thick along Willow Creek in T. 12 S., R. 21 E.; 400 feet thick along Willow Creek in T. 16 S., R. 21 E.; and 490 feet thick just west of the mapped area, in T. 11 S., R. 17 E. (Dane, 1955, columnar section 11). The Horse Bench Sandstone Bed pinches out northeastward a short distance northeast of the Rainbow and Black Dragon gilstonite veins, and where it is absent, selection of the Parachute Creek-Evacuation Creek contact was made on the basis of a color change that occurs at about the same stratigraphic position as the Horse Bench Sandstone Bed. The beds above this contact are pre- dominantly brown or buff ; those below, predominantly gray. Key beds of the Parachute Creek Member The Mahogany bed is the most useful and most wide- spread key bed in the Green River Formation. -Its dark-blue-gray weathering color and ledge-forming character make it a distinctive unit throughout much of the area. It crops out either as a darker horizontal rib in the dark-gray Mahogany ledge or, where it con- stitutes the entire ledge, in a light-gray or tan sequence of marlstone and siltstone. Where the Mahogany oil- shale bed is thin and covered by considerable vegeta- tion and soil, such as south of the Uinta County-Grand 16 -. GREEN RIVER FORMATION, UTAH AND COLORADO County line, identification of it is more difficult. Iden- tification at some localities in this southern part of the area must be made after the measurement of strati- - graphic sections rather than before as can be done in the northern area. Throughout its known extent the Mahogany oil-shale bed can be regarded as a time plane owing to its strati- graphic relation to tuff beds. Because the bed repre- sents a time plane and crops out over a large area, it was used as a datum for the structure-contour map on plate 1. The Mahogany marker, the best-known tuff bed in the Green River Formation, is 9-20 feet above the Ma- hogany oil-shale bed. It is a gray fine-grained unit which weathers to orange-brown rectangular blocks. On many outcrops the marker has the physical appear- ance of a sandstone and is commonly saturated with oil. It has very planar upper and lower surfaces, but there are no bedding planes within the unit. Evidence of the postdepositional flowage that is characteristic of many tuff beds in the Green River Formation was noted in the Mahogany marker at only one locality- that in the central part of T. 10 S., R. 25 E. The Mahogany marker is present in that part of the area northeast of line C-C' (pl. 3, index map). The thickness is 0.3-0.6 foot, averaging about 0.4 foot thick. Uniformity of thickness and appearance over a very large area distinguish the marker. The Mahogany marker also occurs in a large area in the Piceance Creek basin of Colorado (Donnell, 1961, p. 856) and, though not yet recognized, may be present in parts of the Green River and Washakie basins of Wyoming. A distinctive contorted tuff bed occurs below the Ma- hogany oil-shale bed in the area northeast of line OC-C" and in a narrow strip just southwest of this line. It oc- curs 25-85 feet below the Mahogany oil-shale bed and, commonly, in a recess at or near the base of the Mahog- any ledge. The tuff is gray where unweathered and gray to brown where weathered. The most outstanding compositional feature of the bed is the large amount of megascopic analcite crystals. Outstanding physical features of this unit are extremely undulatory upper and lower surfaces and contorted bedding. The un- dulatory nature of the contacts causes great differences in thickness within short distances. Thicknesses rang- ing from 1 inch to 18 inches within a horizontal dis- tance of 20 feet have been noted. The contorted, un- dulatory character is typical of this tuff throughout its extent, which includes a large part of the Piceance Creek basin (Donnell, 1961, p. 856). Another distinctive tuff bed is present 55-85 feet above the Mahogany marker in virtually the same area as the contorted tuff bed. This bed is distinctive be- cause in most localities it contains thin intercalated stringers of marlstone that accentuate the wavy bedding surfaces formed by plastic flowage or differential com- paction. The tuff is light gray to tan and weathers to gray and orange-brown outcrops, which are commonly not well exposed because of their nonresistance to ero- sion. This tuff also occurs in the Piceance Creek basin (Donnell, 1961, p. 856). Source, environment, and fossils The Parachute Creek Member is composed predomi- nantly of fine-grained precipitate from the lake water and various amounts of organic matter. It also con- tains coarser sediment, most of which was derived from a southwestern or southern source or from ash falls. Some sediment deposited in the northern part of the mapped area was derived from the Tinta Mountain area. The Parachute Creek Member was deposited in very shallow to deep lakes. The shallow-water, or shoreward, facies is mainly in the southern part of the area. These predominantly fine-grained strata, despite their appreciable content of coarse-grained material, are even bedded and were probably laid down on a gently sloping surface in calm water. The deep-water deposits, in the northern part of the area, were laid down on a nearly flat surface, as shown by the great con- tinuity and uniform thickness of some beds, and were seldom subjected to wave or current action. Chemical or thermal stratification of the lake water greatly af- fected this environment, especially in the deposition and diagenesis of the oil shales (Bradley, 1948, p. 644). Some oil-shale beds display brecciation and muderacks, and some occur in stratigraphic proximity to beds of algal limestone. These features and this relation in- dicate that the oil-shale was deposited in water so shallow that the shale was sometimes exposed. During much of Green River time, Lake Uinta was presumably a single body of water occupying the area now included in the Piceance Creek basin and Uinta Basin. During most of Parachute Creek time, conditions varied uniformly throughout much of the lake. This uniformity can be demonstrated by the cor- relation of kerogen-rich zones and lean zones of oil shale, as well as beds within these zones, over large areas. Fossils found in the Parachute Creek Member con- sist of insects, insect larvae, plant fragments, and fish scales. These remains, which were found at many hori- zons in the fine-grained facies, were of no value for cor- relation or age designation. EVACUATION CREEK MEMBER The Evacuation Creek Member, uppermost member of the Green River Formation, was named by Bradley (1931, p. 14) for excellent exposures along Evacuation STRATIGRAPHY 17 Creek in eastern Utah. The member crops out as a nar- row band across the northern part of the area and caps the plateau in much of the western third of the area. Rounded hills and steep slopes are the topographic features common to the Evacuation Creek Member. At many localities in the western part of the area, the mem- ber is represented by only its lowermost unit-the Horse Bench Sandstone Bed-which forms the resist- ant caps on numerous mesas. The Evacuation Creek Member is composed chiefly of marlstone and siltstone but also contains some sand- stone, tuff, oil shale, and oolitic limestone. The marl- stone and siltstone are gray and brown, thin bedded, and fissile; they weather light gray and brown. These finer grained beds make up most of the Evacuation Creek rocks in the northern part of the area, but many sand- stone beds are intercalated with them in the southern part. Some marlstone beds in the northeastern part of the area contain appreciable amounts of organic mat- ter, but the member has no thick oil-shale sequences. In the northwestern part of the area, the upper 250 feet of the Evacuation Creek contains several beds of fine-grained sandstone. The rocks in this interval are transitional from Green River to Uinta lithology (fig. 3) , but they are mostly lacustrine. Eastward these rocks intertongue with and grade into predominantly fluvial rocks of the lower part of the Uinta Formation. Sandstone beds in the Evacuation Creek Member are composed chiefly of very fine to medium-grained quartz. The bedding is thin to massive, and some units are cross laminated and ripple marked. In the southern part of the area, grain size and thickness of bedding of the sand- stones increase to the southwest. The sandstone beds are gray and brown and weather to gray and brown ledges and steep slopes. The Horse Bench Sandstone Bed is a resistant ledge- forming unit that occurs at the base of the Evacuation Creek Member throughout much of the mapped area (pl. 3). In the southwestern part of the area it is a fine- to medium-grained sandstone having a maximum thickness of about 50 feet. Grain size and thickness de- crease northeastward, and northeast of Main Canyon the bed has a maximum thickness of about 5 feet and is siltstone rather than sandstone. The bed pinches out near Evacuation Creek. Northeast of line BP-2" (pl. 3; index map) the Horse Bench Sandstone Bed is under- lain and overlain by light-gray marlstone and siltstone sequences that are less resistant to erosion than the Horse Bench, which weathers to a prominent buff or brown ledge and caps many mesas and benches. South- west of line B-B' the Horse Bench Bed is associated with other resistant sandstones and is not as topographi- cally conspicuous. The Evacuation Creek Member in the northern part of the mapped area contains many tuff beds, most of which are less than 6 inches thick, are fine grained, and have planar upper and lower surfaces. All the tuff beds contain some biotite, and a few contain enough biotite to be dark gray. In general, however, the tuff beds are light gray to tan and weather to minor reddish-brown ledges. The thickest tuff bed in the mapped area occurs in the lower part of the Evacuation Creek Member. Expo- sures of this bed occur mainly within an area bounded on the north by the White River and on the west by Evacuation Creek. The bed is as much as 20 feet thick at several localities along Evacuation Creek; in general, it thins northward, eastward, and southward from this area. Westward, it is not exposed, and its thickness is, not known. The very irregular upper and lower sur- faces of this bed, as well as inclusions of marlstone, con- torted bedding, and orientation of mica flakes, are indi- cations of plastic flowage. In see. 18, T. 11 S., R. 25 E., Utah, at a locality first called to the attention of the author by H. D. Curry of the Shell Oil Co., several square feet of the underside of the tuff bed can be seen. There the surface is marked with minute ridges and grooves which were seemingly caused by the slippage of the tuff over the surface below it. Where the Evacuation Creek Member crops out near the junction of Evacuation Creek and the White River, a zone of marlstone and siltstone containing many ellip- soidal cavities occurs in the basal part of the member. These cavities are the result of the leaching of a soluble mineral. Milton and Eugster (1959) stated that the mineral was nahcolite, which occurred as nodules. In some places the nahcolite has been replaced by calcite. The cavities are about 6-24 inches long in their greatest dimension and are in a stratigraphic zone that has a maximum thickness of approximately 50 feet. The zone is informally called the "bird's-nest zone" because its outcrop commonly has the appearance of a wall supporting many swallows' nests. The measured thickness of the Evacuation Creek Member ranges from 135 feet at Evacuation Creek to 545 feet at Willow Creek. South of T. 14 S., the upper part of the Evacuation Creek Member has been removed by erosion, and a total thickness cannot be measured. The Evacuation Creek Member is overlain by and: interfingers with the Uinta Formation. In much of the area northeast of Bitter Creek, the contact between these two units, though mainly at one stratigraphic horizon, is undulatory, as a result of contortion of the sandstone beds in the basal part of the Uinta Formation. Near Bitter Creek the contorted sandstone beds and some sandstone beds above them pinch out to the west. Here, 18 GREEN RIVER FORMATION, UTAH AND COLORADO also, stratigraphically higher beds of massive sandstone: rest with normal contact on marlstone which is the lat- eral equivalent of the contorted basal sandstone north- east of Evacuation Creek. Westward from Bitter Creek there is an abrupt lateral change from a predominance of sandy beds, which make up the basal part of the Tinta Formation northeast of Bitter Creek, to a pre- dominance of marly beds, which are included in the Evacuation Creek Member. West of Willow Creek the upper part of the Evacuation Creek Member contains a transition zone (fig. 3) of interbedded marlstone, silt- stone, and sandstone, and the upper boundary of the member is 500 feet stratigraphically higher than at Bit ter Creek. The transition zone was not mapped separately. Source, environment, and fossils The Evacuation Creek Member in most of the mapped area was deposited by the precipitation of lime from lake water and by ash falls. In the southern part of the area, however, the member contains coarser grained sediment derived from a source area to the south or southwest. Most strata of the Evacuation Creek Member were deposited in quiet water that was seemingly deeper than the water in which the Douglas Creek Member was de- posited and shallower than that in which the Parachute Creek Member was deposited. During deposition of the Evacuation Creek Member, Lake Uinta was decreasing in size, and at the end of Evacuation Creek time the lake ceased to exist; the area was then blanketed by fluvial sediments. The lake retreated northwestward from the area, so that lacus- trine deposition continued much later in the north- western part of the area than in the northeastern part. Lake Uinta evidently was not characterized by long periods of extreme desiccation, as was the lake that lay north of the Uinta Mountains. The lake deposits of the Green River Basin in Wyoming contain thick beds of saline minerals intercalated with nonsaline beds, whereas lake deposits in the mapped area contain saline minerals only as nodules or small erystals. The deep- est part of Lake Uinta, however, lay outside the mapped area, and the sediments deposited there are now deeply buried and possibly contain beds of saline minerals. Numerous beds of algal and oolitic limestone were deposited near the shore of the lake during its pre- dominantly transgressive period (Douglas Creek time). During the predominantly regressive period (Evacua- tion Creek time) few beds of algal and oolitic limestone were formed. Bradley (1929, p. 223) stated that the scarcity of algal reefs may be ascribed to one or more of three possible causes: (1) increased concentration of sulfates in the lake, (2) a lessened quantity of lime in solution available for the formation of algal reefs, and (3) periodic evaporation of the lake during the normal growing season of the algae. Fossils found in the Evacuation Creek Member con- sist of insects, insect larvae, leaves, and plant frag- ments. The age of the Evacuation Creek is generally considered to be middle Eocene ; however, the upper part interfingers with beds considered to be late Eocene. TUFF BEDS IN THE GREEN RIVER FORMATION The maristone and oil-shale sequence of the Para- chute Creek and Evacuation Creek Members of the Green River Formation contains numerous beds of tuff and altered tuff. R. L. Griggs (written commun., 1961) stated, after studying thin sections of several tuff beds in the Uinta Basin, that- the rocks examined were originally quartz latite or rhyolite tuffs composed chiefly of crystals and crystal fragments and interstitial glass. The crystalline portion generally makes up 10-80 percent of the rocks and is mainly quartz, sanidine, and sodic plagioclase, but some beds in the Evacuation Creek Mem- ber contain significant amounts of biotite and hornblende. The crystals and crystal fragments are not appreciably altered, but the interstitial glass has been altered to analcite and chalcedony or calcium carbonate. The tuff beds range in thickness from a fraction of an inch to 20 feet and probably average less than 6 inches thick. Most of the tuffs are gray and weather tan to orange brown. The shades of gray range from light to dark, the intensity depending on the biotite content. The tuff beds vary greatly in resistance to erosion, and their topographic expression accordingly ranges from that of extensive benches to grooves in cliff faces. The tuff beds have two general types of physical appearance. - In one type the upper and lower surfaces of the beds are relatively smooth, and the beds show little or no internal bedding or grain orientation. In the second type, the beds have undulatory upper and lower surfaces, the undulations commonly being a few inches in amplitude; a maximum amplitude of 2 feet has been measured. - The second type shows evidence of plastic flowage, such as contorted bedding and oriented crystals, and some beds contain inclusions of marlstone or oil shale. The irregular beds are a fraction of an inch to 20 feet thick, and most of them are less than 1 foot thick. - The regularly bedded tuffs are a fraction of an inch to about 12 inches thick. Many evenly bedded tuffs have the appearance of fine-grained sand- stone and have been described in some reports as sand- stone. Tuff beds in and adjacent to the Mahogany ledge are locally saturated with a tarry substance that gives them the appearance of a bituminous sandstone. TUFFACEOUS DIKES OF THE GREEN RIVER FORMATION Sedimentary dikes containing large amounts of tuffaceous material were observed at several localities STRATIGRAPHY 19 in the northwestern part of the area but were not mapped. They are associated with tuff beds in a strati- graphic sequence that extends 200 feet above and 200 feet below the Horse Bench Sandstone Bed. R. L. Griggs examined seven thin sections from six dikes and three thin sections from two tuff beds asso- ciated with the dikes. He stated (written commun, 1961) that- all the specimens are from altered quartz latite or rhyolite tuffs that originally consisted predominantly of crystals, and crystal fragments, of quartz, sanidine, and sodic plagioclase in a matrix of fine glass. Biotite and hornblende occur in all the rocks and, in some rocks, make up as much as 15 percent of an individual sample. Apatite and zircon occur as accessory minerals in all the thin sections. The crystalline part of the sample has under- gone only minor alteration. Virtually all the glass has been altered to analcite, chalcedony, and calcite or dolomite. In some thin sections of dike material the hornblende and biotite show the effects of solid flowage. The biotite crystals are bent around other grains, and the hornblende crystals are broken. However, it. appears that some of the tuff was altered after the dikes were injected, because the analcite and chalcedony in the dike rock show no evidence of having been sheared after these minerals crystallized. Small dikes a few inches high in cross section, that extend upward or downward from thin tuff beds into enclosing marlstone or siltstone can be seen at numerous localities. At three localities dikes cut several tens of feet of stratigraphic section : (1) the northwestern part of T. 14 S., R. 21 E., (2) the southwestern part of T. 11 S., R. 19 E., and (3) the southwestern part of T. 11 S., R. 21 E. Several dikes are exposed at each locality, and the following descriptions are based on studies of these dikes. The rock in the dikes is more resistant to erosion than the wallrock and commonly projects a few inches above the surface of the less resistant marlstone that makes up most of the stratigraphic sequence into which the tuf- faceous material was injected (fig. 52). At one locality (fig. 5A) a dike projects 3 feet above the surface of the ground for a lateral distance of approximately 50 feet. Weathered dike rock is gray to dark reddish brown, and pieces of the the dark-colored contorted material can easily be identified on the light-colored marlstone slopes. The dikes studied range in length from approximately 50 to 600 feet ; most are 50-100 feet long. The 600-foot- long dike occurs near Chimney Rock, in see. 6, T. 14 S., R. 21 E. The dikes are a fraction of an inch to 20 inches wide, but most are less than 5 inches wide. Parts of individual dikes are relatively uniform in width and show little variation except for closely spaced parallel ridges and grooves formed by flowage against the bedding edges of fractured wallrock. Other parts of the dikes show extensive pinching and swelling, as well as small offshoots from the main dike. The width was apparently controlled by the amount of induration of the rock into which the dike was injected rather than by differences in the viscosity of the dike material. In no place were both the upper and lower terminations of a single dike exposed. A dike half a mile south of Chimney Rock was traced upward along a steep slope a vertical distance of 150 feet to a point where it merges with a contorted tuff bed. The lower limit could not be seen. This tuffaceous dike has the greatest vertical length of the dikes studied, and its intersection with a tuff bed is the only one clearly exposed. This intersec- tion occurs about 20 feet below the Horse Bench Sand- stone Bed on a hillside about half a mile south-south- west of Chimney Rock. The trace of each dike is not a straight line either in plan or in cross section, but it is commonly more nearly linear in plan than in cross section. The dikes have randomly oriented strikes and are completely unrelated to the prominent joint system that was formed later than the fractures into which the dike material flowed and that cuts across the dikes. Also, the walls of the joints are extremely smooth and planar ; their regularity indicates a greater degree of lithification at the time of their formation than at the time of the formation of the irregularly walled fractures which contain the dike material. The conditions that produced the flowage of the tuff beds could not be conclusively established on the basis of information obtained in this study. It seems prob- able, however, that an appreciable amount of water was entrapped in the porous tuff beds by the overlying and underlying less permeable layers and that the water was a key factor in producing proper conditions for flowage. Water-saturated ash could have moved into incipient fractures either as a result of the increasing weight of overburden caused by continuing deposition or as a result of an increase in the volume of the tuff bed. Such a volume change might have been effected by the crys- tallization of analcite from a gel that formed from the original ash. Absence of shearing or distortion of the analcite crystals in the dike rock indicates, however, that the crystals were formed after the injection of the dikes. Possibly enough pressure was generated as the analcite crystallized in the bedded tuff to force a residue of gel into incipient fractures, where additional analcite then crystallized to form the groundmass of the dike rock. UINTA FORMATION Peterson (quoted in Osborn, 1895, p. 72-74) divided the sequence overlying the Green River Formation in the eastern Uinta Basin into three "horizons" which are, in ascending order: Horizon A, 800 feet of hard brown sandstone alternating with greenish-gray claystone; 20 GREEN RIVER FORMATION, UTAH AND COLORADO FicurE 5.-Tuffaceous dikes. A, In the Parachute Creek Member near Chimney Rock, NBZ, NEY sec. 6, T. 14 S., R. 21 E., Uintah County, Utah. Note inclusions of siltstone near center of photograph. B, In the Evacuation (reek Member near Hatch Ranch, SWM%NE% sec. 31, T. 11 S., R. 21 E., Uintah County, Utah. STRATIGRAPHY 21 horizon B, 350 feet of soft coarse sandstone and clay- stone; and horizon C, 600 feet of brown and red fer- ruginous sandstones and claystone. Peterson assigned horizon A to the Bridger Formation, horizon B to the Bridger and Uinta Formations, and horizon C to the Uinta Formation. - In recent usage, however, the entire sequence has been referred to the Uinta Formation, and this usage is followed in this report. Horizon A and the lower part of horizon B of the Tinta Formation are exposed along the northern mar- gin of the area. The formation commonly crops out in cliffs and broad resistant benches between drainages. In isolated outcrops it weathers to towerlike forms. No complete stratigraphic section of the Uinta For- mation was measured, and thickness estimates are based on that part of the formation which occurs within the mapped area. - Maximum thickness of the part exposed within the mapped area is an estimated 1,000 feet in the northeastern part of the area and an estimated 400 feet in the northwestern part. The Uinta Formation conformably overlies and inter- fingers with the Green River Formation. The Green River-Uinta contact is drawn at the base of the lower- most massive resistant fluvial sandstone bed in the Uinta. Owing to the westward pinchout of sandstone beds in the lower part of the Uinta Formation, the base of the formation along the Green River is 500 feet higher stratigraphically than it is along the White River. In much of the area northeast of Bitter Creek, the contact between the Uinta and Green River Formations though undulatory lies mainly at one stratigraphic horizon. This undulatory boundary is apparently the result of differential compaction or of plastic flowage of the massive contorted tuffaceous sandstone sequence in the basal part of the Uinta Formation. The character of this contorted sandstone sequence in the Uinta Basin is very similar to that described by Culbertson (1962) and by Rapp (1962) for certain sandstone lentils and beds in the Laney Shale Member of the Green River For- mation in the Green River basin, Wyoming. The age relation of the two sequences is not known. To the east and west, the contorted sandstone pinches out, and strat- igraphically higher massive fluvial sandstone rest con- formably on marlstone of the Green River Formation. The Uinta Formation is overlain by the Duchesne River Formation. In the central part of the Uinta Basin the contact between the two formations is con- formable. Along the northern margin of the basin, however, the Duchesne River Formation rests uncon- formably on the Uinta Formation and older rocks. In the area of this report, the Duchesne River Formation may rest unconformably on the Uinta Formation and 236-486 O-66--4 the upper part of the Green River Formation. The rela- tionship is not clear, however, owing to poor exposures. Source, environment, and fossils Sources of the Uinta Formation lay to the east and to the north of the Uinta Basin. - Surface studies of facies changes in the mapped area indicate a northern or northeastern source for the basal part of the Uinta Formation. Stagner (1941, p. 284-297), who made a detailed study of stream channels in the "Tinta B member," presented several types of evidence which showed that most of the sediments in the "Uinta B member" were derived from an eastern source, and he postulated, on the basis of reconnaissance studies, that much of the sediment in the "Uinta A member" was derived from an eastern source. - Stagner (1941, p. 295) concluded that the mineralogy of pebbles and sand which he found in the stream deposits implied a source that may have been as far east as the Park Range, Colo. Most sediments in the Uinta Formation were deposit- ed in streams and on flood plains that formed during (and after) the major waning phase of the lake that lay just south of the Uinta Mountains. The lower part of the Uinta Formation in the eastern part of the mapped area contains some thin shaly units that were deposited in a lacustrine environment and the massive contorted basal sandstone may have been laid down in a delta along the margin of the lake. The Uinta Formation has yielded numerous key fos- sils, especially vertebrates. Kay (1957, p. 111-114), who termed the Uinta Formation a "classical collecting ground" for late Eocene fossil vertebrates, discussed the fauna of the formation and listed many of its fossil vertebrates. DUCHESNE RIVER FORMATION The Duchesne River Formation was named by Kay (1934, p. 358-359) for exposures in the north-central part of the Uinta Basin. The formation underlies less than 1 square mile in the northernmost part of the map- ped area. - Here the formation is composed of red and gray poorly cemented sandstone and arenaceous shale. The Duchesne River Formation weathers to a badlands topography. In the mapped area the Duchesne River Formation may rest unconformably on the Green River and Uinta Formations, but in the central part of the Uinta Basin it rests conformably on the Uinta Forma- tion. The sediments of the fluvially deposited Duchesne River were derived from the Uinta Mountain area. The Duchesne River Formation is considered to be Eocene or Oligocene in age. 22 GREEN RIVER FORMATION, UTAH AND COLORADO QUATERNARY SYSTEM Quaternary rocks in the mapped area consist chiefly of alluvial deposits along all the major stream valleys. These deposits are composed of silt- to boulder-sized pieces of marlstone, siltstone, and sandstone. Sparse patches of cemented colluvial deposits were noted in canyons near the Green River. These patches, seen at a few scattered localities, are too small to be shown on the geologic map, plate 1. The colluvium is composed of sandstone and marlstone that are well ce- mented by calcium carbonate and are also cemented to the steep canyon walls. The colluvial deposits are a few tens of feet in diameter and have a maximum thickness of about 10 feet. STRUCTURE The Uinta Basin is a structurally asymmetric de- pression having steeply inclined rocks along its north flank. Most of the mapped area lies on the south flank of the basin. Within the mapped area the basin axis is just southwest of Raven Ridge. The inclination of the beds is greatest in the northeastern part of the area and decreases to the south and southwest. Angles of dip range from about 35° at Raven Ridge to about 1° at several localities in the west half of the area. North- east of Bitter Creek the strata have moderate to steep dips, and several anticlinal noses interrupt the pre- dominant structural trend. These structural noses, which plunge westward from the Douglas Creek arch, are most conspicuous in the northern part of the area, for the magnitude of folding decreases southward. Southwest of Bitter Creek the beds have gentle dips, and the structure is mainly that of a north-dipping homocline. The only major interruption in this north- ward dip is the Hill Creek anticline, which is mainly a northwest-plunging fold that has about 75 feet of sur- face closure in a small area near the southwest corner of T. 14 S., R. 20 E. Faulting is minor in the area. Neither the density of faults nor the displacement of individual faults is of appreciable magnitude. The greatest density of faults occurs northeast of Evacuation Creek in the area having the most folds. The predominant strike of these faults is northeast. The maximum displacement along indi- vidual faults is 10-200 feet, and the fault planes are vertical, or nearly so. The density of faults is very low southwest of Evacuation Creek, where most faults trend northwest and bound small grabens. Displace- ment is 15-50 feet, and the fault planes are vertical, or nearly so. At two localities near Sand Wash Ferry, the lower ends of the faults can be seen. At each local- ity a fault terminates downward in a fold in the thin- bedded marlstone of the Parachute Creek Member. On the basis of observations at these two localities and of the relatively small displacements of the faults, no fault in the mapped area is assumed to extend to a great depth. Because some groups of grabens in the area southwest of Evacuation Creek are parallel to the Un- compahgre uplift, however, the grabens are postulated to be related to deep-seated faults or folds that resulted from movement along the flank of the uplift. A prominent system of joints is present in the Green River strata. This system consists of two sets of verti- cal joints, whose character is shown in figure 6. The strike of these northwest- and northeast-trending sets differs in various parts of the area. The most numer- ous and the most closely spaced joints occur in the thin- bedded marlstone and siltstone, although some also oc- cur in the coarser grained strata. The orientation of many small stream valleys in the area is controlled by the joint system. Gilsonite veins occur along some FraurE 6.-Jointing in the Horse Bench Sandstone Bed of the Evacuation Creek Member, sec. 9, T. 13 S., R. 20 E., Uintah County, Utah. Note ripple marks (lower left). STRUCTURE northwest-trending joints in part of the area. At sev- eral localities walls of the joints containing the gil- sonite veins are offset 2-3 feet. The joint system is evidently the result of forces that developed at some time after the deposition of the Uinta Formation and during the downwarping of the basin. The opening of the joints to allow the entry of gilsonite probably occurred during a later period of folding. Several minor folds are present in T. 13 S., Rs. 20 and 21 E., and similar folds are probably present elsewhere in the northwestern part of the area. One of the folds examined is shown in figure 7. The folding is most evident in a thin resistant tuffaceous siltstone bed that is overlain and underlain by thin-bedded nonresistant marlstone. - The siltstone bed, about 1 foot thick, forms an extensive bench about 100 feet above the Mahogany oil-shale bed. Throughout most of their length the folds have been breached, and the nature of their crests cannot be determined. Near the ends of the doubly plunging folds, where the heights and widths can be measured in inches, the apexes are visible. At some of 28 these exposures, one limb appears to have been thrust a few inches over the other. - The folds have steeply dip- ping limbs, and a cross section of a restored fold would probably have the appearance of an inverted V. The bedding of the nonresistant marlistone above the folded siltstone bed could not be seen and rocks below the bed were seen at only one locality. There, the rocks below the folded siltstone were not folded. The axes are slightly sinuous. Maximum width of a single fold is about 8 feet, and maximum length is about 200 feet. Folds similar to those just described have been attrib- uted to (1) glacial action, (2) downslope creep of surface rocks, (3) recrystallization of the rock, (4) water freezing in joints, and (5) increase in volume of the rock due to weathering. Because of the symmetry of the folds and the absence of evidence of glaciation, possible causes 1 and 2 are rejected by the author. - The folds were apparently the result of a change in the volume of the rock or of the material adjacent to the rock and thus could have been caused by either 3, 4, or 5. FreurE 7.-Minor fold in a siltstone bed of the Parachute Creek Member, NEJ, see. 7, T. 13 S., R. 21 E., Uintah County, Utah. 24 GREEN RIVER FORMATION, UTAH AND COLORADO ECONOMIC GEOLOGY OIL SHALE COMPOSITION AND PHYSICAL CHARACTERISTICS Oil shale has been defined in various ways (Bradley, 1931, p. 7-8). In this report, however, the term "oil shale" is used for marlstone that, when distilled, will yield 15 gallons or more of oil per ton. This usage is based on present oil-shale technology. The physical and mineralogic characteristics of the oil shale of the Green River Formation were described in detail by Bradley (1931, p. 22-37, 39-40). Some salient characteristics of the oil shales are as follows: 1. The oil shales are composed of magnesian marl- stone having a high content of organic matter. 2. The predominant inorganic constituents are dolomite, calcite, and clay minerals. . Clastic minerals such as quartz, sanidine, feld- spar, muscovite, zircon, and apatite occur in minor amounts and are partly of volcanic origin. . Syngenetic analcite in crystalline form and PYy- rite in disseminated form occur in many of the oil-shale beds. . The organic matter is of two types. One type is structureless, translucent, and lemon yellow to reddish brown. The other type consists of complete or fragmentary organisms such as algae, protozoa, and insects, and parts of higher plants-spores, pollen grains, and mi- nute pieces of tissue. The oil-shale beds are generally thin and regular. Many of the moderately rich oil-shale sequences are varved, consisting of alternating laminae of dark organic-rich material and light mineral-rich material. Kerogen-rich oil-shale beds weather to distinctive bluish-gray ledges. The degree of resistance to erosion and the darkness of color of the outcrop are in direct proportion to the content of organic matter. Un- weathered oil shale ranges from tan or brown in the low-grade oil shale to very dark gray in the high-grade oil shale. Kerogen-rich beds are tough and resilient, whereas beds containing only a small amount of kero- gen are brittle. A sliver of the oil shale that yields more than 35 gallons of oil per ton will burn for a short period of time when heated with a match. The specific gravity of oil shale is inversely proportional to the potential shale-oil yield. Oil shale that will yield 15 gallons of oil per ton has an average specific gravity of about 2.38, and oil shale that will yield 100 gallons of oil per ton has an average specific gravity of about 1.40 (Stanfield and others, 1957, p. 5-6). Oil shale will yield free shale oil when heated in a closed Op > Ot system. Part of the organic matter changes from a solid to a gas, most of which, upon cooling, condenses to form oil. DEVELOPMENT Shale oil has not been produced on a large com- mercial scale in this country. However, since World War I there has been fluctuating interest in oil shale as a possible source of liquid fuel. Early activities in- volved the construction of a few experimental retorts, small-scale open-pit mining, and the digging of many evaluation pits. In recent years the oil-production activity in the Uinta Basin has consisted of core-drilling operations and the leasing or buying of available oil- shale land, whereas advances made in oil-shale mining and in retorting technology have resulted mainly from activities in the Piceance Creek basin of Colorado. From 1945 through 1956 the U.S. Bureau of Mines operated an experimental oil-shale mine and retort near Rifle, Colo. In the same general area, Union Oil Co. of California conducted experimental mining and re- torting operations, and Sinclair Oil Co. investigated the feasibility of retorting oil shale in place. The Denver Research Inst., under contract to the Oil Shale Corp., has operated a pilot plant to perfect a retorting proce- dure known as the Aspeco Process. In 1960 a small chemical explosive experiment was conducted at the U.S. Bureau of Mines underground workings near Rifle. This experiment was a part of a study made by the Lawrence Radiation Laboratory of the problems asso- ciated with the recovery of petroleum products from oil shale by means of nuclear explosive energy. The results of the experiment were described by Adelman, Bacigalupi, and Momyer (1960). POTENTIAL RESERVES Because oil-shale deposits in the United States are not being commercially developed at present but per- haps will be developed in the future, they can be con- sidered as potential reserves or resources. At present, the average grade of oil shale that will eventually prove most suitable for retorting and the minimum minable thickness are not assuredly predictable. For the proc- esses used in research at the U.S. Bureau of Mines plant near Rifle, oil shale ranging in grade from 25 to 33 gallons of oil per ton seemed to be best suited for retorting, and a minimum thickness of 25 feet appeared necessary for the most effective mining. However, other types of retorts and mining equipment require different grades and thicknesses of oil shale. Advance- ments in the technology of mining and processing oil shale and changes in certain economic factors may alter these requirements; therefore, three grades of oil shale (yielding 15, 25, and 30 gallons per ton) and a mini- mum thickness of 15 feet are discussed in this report. 7? ECONOMIC Methods used in computing estimates of potential reserves Reserve computations in this report are based on oil- yield assays of cores, drill cuttings, and outcrop sam- ples, and on oil-yield estimates of outcrop samples. Most of the assayed samples were processed by the U.S. Bureau of Mines by use of the modified Fischer method, as described by Stanfield, Frost, McAuley, and Smith (1951). For each locality where samples of the oil- shale sequence were obtained, the gallons-per-ton assays and the thickness of the bed represented by the sample were used to calculate the maximum thicknesses of the continuous sequence that has an average oil yield of (1) 30 gallons of oil per ton, (2) 25 gallons per ton, and (3) 15 gallons of oil per ton. Sequence 2 includes the rocks that make up sequence 1, and sequence 3 in- cludes the rocks that make up sequence 2. These sam- ple localities (or control points) were used to construct thickness maps for the three grades of oil shale: yield- ing an average of 15, 25, or 30 gallons per ton (pl. 8Yy: Average thickness of each grade of shale was then esti- mated for each township, and the volume of oil shale of each grade was computed and converted to tons. Finally, the yield of oil, in barrels, was computed from the tonnage and the average grade of the shale. 'The basic information on potential oil yield generally consists of individual assays of a series of samples taken from a stratigraphic sequence. The samples are varied both in thickness of strata represented and in oil yield. When assay data of a series of samples were combined for determination of the average oil yield of the total thickness, values of the individual samples were weighted according to both the thickness of the strata represented and the specific gravity. Samples from 39 core holes and 20 exploratory wells in the mapped area were assayed for oil yield by the U.S. Bureau of Mines. - Eighteen of the core holes were drilled in Naval Oil-Shale Reserve No. 2, and the re- sults of the assays were discussed by Cashion (1959). Oil-yield data for all the 39 core holes and 20 explora- tory wells were presented by Stanfield, Rose, McAuley, and Tesch (1954, p. 123-126, 129; 1964). Assays and vil-yield estimates of surface samples are shown on plates 3 and 4. The oil yield of the surface rocks is decreased by weathering ; therefore, oil yield data from surface-rock samples were used only when no other data were available. In computation of the reserves of shale oil, a poten- tial oil yield of 1,157 barrels per acre foot was assumed for "15-gallon" shale, 1,791 barrels per acre foot for "25-gallon" shale, and 2,078 barrels per acre foot for «"30-gallon" shale. These figures are based on informa- tion given by Stanfield, Rose, McAuley, and Tesch (1957, p. 2-5). GEOLOGY 25 Classification of reserves The potential reserves described in this report are divided into two categories-indicated and inferred- according to the reliability of the data. - This classifi- cation is patterned after that used by Donnell (1957, 1961) when he estimated oil-shale reserves of the Piceance Creek basin. The accuracy of the estimates depends mainly on the reliability of sample data and the spacing of control points. The most reliable oil- yield data were obtained from assayed samples that were unweathered, uncontaminated, and properly cor- related with the stratigraphic section. Weathered oil- shale beds have lost part of their original organic matter; therefore, assays of samples from a weathered bed indicate a lower oil yield than do assays of samples from the same bed where it is unweathered. For ex- ample, a sample of weathered oil shale from the Ma- hogany bed assayed at 12.$ gallons of oil per ton, whereas an un weathered sample taken from close by but 2 feet beneath the surface assayed at 45.5 gallons of oil per ton (Guthrie, 1938, p. 99). Although oil-yield assays of weathered strata are known to be lower than assays of the same strata where they are not weathered, a constant upgrading factor cannot be applied because of great variation in the weathering of oil-shale beds. Oil-yield assays of contaminated samples may be higher or lower than the actual oil yield-the direction of the variation depending on the degree of contamination and on the oil yield of the contaminating rock frag- ments. - The potential oil yield of surface samples can be estimated with moderate accuracy by an experienced investigator who considers color, sheen, and specific gravity. Such estimates tend to be low, however, and were used in this report only when assay data were not available. Estimates of indicated potential reserves are based on assays of samples from core holes and of drill cuttings from exploratory wells. Because of the possibility of contamination or of human error in the collection of drill cuttings, and because drill-cutting samples rep- resent thick sample units (generally 10 ft thick), core- sample assays are more reliable. - Assays of cuttings are adequate, however, for estimation of indicated potential reserves-unless these assays are completely anomalous with those from nearby control points and with known geology. Estimates of inferred potential reserves are based on assays of outcrop samples or on interpolation between widely spaced core holes or exploratory wells. In estimating reserves, core-hole and exploratory-well localities are designated as primary control points, and surface sections, as secondary control points. Mapped areas of indicated potential reserves are delineated by an encircling boundary drawn approximately 2 miles from 26 GREEN RIVER FORMATION, UTAH AND COLORADO an isolated primary control point, or approximately 2 miles from the outermost primary control points of a group in which any two adjacent points are less than 6 miles apart. Areas of inferred potential reserves are delineated by boundaries drawn by the use of data from secondary control points and widely spaced primary control points. Summary of reserves The estimates of tonnage and of potential oil yield of oil shale in the mapped area are for total oil shale in place and for total potential oil yield; these estimates are based on the assumption that all the oil could be extracted from the deposit. The amount of recoverable oil would undoubtedly be less than the total potential oil yield, owing to losses in mining and processing, and would perhaps be further decreased by cutoff limits of grade, depth, thickness, or distance from outcrop. Estimates of tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds which is in a continuous sequence at least 15 feet thick and which yields an average of 30 gallons oil per ton are shown in table 1, and the thickness and distribution are shown on plate 5C. An area of approximately 195 square miles contains indicated reserves of about 11.76 billion tons of shale having a potential yield of about 8.4 bil- lion barrels of oil. Of this total oil reserve, 8.34 bil- lion barrels is in Utah and the rest is in Colorado. Ap- proximately 266 square miles cont tins inferred reserves of about 14.5 billion tons of shale having a potential yield of about 10.35 billion barrels of oil. Of this in- ferred reserve, 10.3 billion barrels is in Utah and the rest is in Colorado. Estimates of tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds which yield an average of 25 gallons oil per ton in a continuous sequence at least 15 feet thick are shown in table 2, and the thickness and distribution are shown on plate 52. This sequence includes the shale that yields an average of 30 gallons oil per ton (table 1). Indicated reserves of about 22.12 billion tons of shale having a potential yield of about 18.16 billion barrels of oil underlie an area of approximately 274 square miles. Of this total oil reserve, about 13.01 billion barrels is in Utah, and the rest is in Colorado. Inferred reserves of about 23.3 billion tons of shale that will yield about 13.88 billion barrels of oil underlie an area of approximately 297 square miles. Of this total, about 138.76 billion barrels is in Utah, and the rest is in Colorado. Estimates of tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds which yields an average of 15 gallons oil per ton in a continu- ous sequence at least 15 feet thick are shown in table 3, and the thickness and distribution are shown on plate 5A. This sequence includes the shale of the two grades previously discussed (tables 1, 2). An area of approxi- mately 315 square miles contains indicated reserves of about 77.2 billion tons of shale having a potential oil yield of about 27.6 billion barrels. Of this reserve, about 27.18 billion barrels is in Utah, and the rest is in Colorado. The approximately 376-square-mile area contains inferred reserves of about 72.8 billion tons of shale having a potential oil yield of about 26 billion bar- rels of oil. Of this total, 24.78 billion barrels is in Utah, and the rest is in Colorado. Oil-shale areas most favorable for future development The most favorable area for future development of an oil-shale industry seems to be near the White River in Ips. 9 and 10 S., R. 925 E. The thickest sequence of rich oil shale is exposed here, and water for industrial plant use is available nearby in the White River. The crude-oil pipeline connecting the Rangely oil field and Salt Lake City passes through the northern part of the mapped area and could possibly transport the shale oil to market. The most convenient railroad shipping point, Craig, Colo., is about 100 miles away. Much of the rich oil shale in the area near the White River is overlain by several hundred feet of overburden, which would probably necessitate underground mining or re- covery of oil from the shale in place. No strip mining of oil shale has been done on a com- mercial basis in the United States; therefore, no data on the requirements of such an operation in this country are available. Many areas, of various sizes, in the south- eastern part of the Uinta Basin, may be suitable for strip mining. The general location of a few of the larger areas are (1) along McCook Ridge, in T. 13 S., Rs. 23 and 24 E., (2) along the ridge just north of Burnt Tim- ber Canyon, in T. 13 S., Rs. 24 and 25 E., and (3) along the ridges between Agency Draw and Willow Creek, in Eps. 12 and 18 S., R. 21 E. Each area contains several hundred acres in which the overburden above the Ma- hogany zone is 100 feet thick or less. The thickness of shale in these areas where the shale yields an average of 15, 25, or 30 gallons of oil per ton is shown on plate 5. Oil-shale resources of the Uinta Basin A major part of the oil-shale resources, or potential reserves, of the Uinta Basin occurs outside the mapped area. The entire basin must consequently be considered when its oil-shale resources are evaluated. Preliminary estimates of the oil-shale resources of the entire basin are therefore included in this report. it, ECONOMIC GEOLOGY 27 TasLE 1.-Estimated tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds occurring in a continuous sequence at least 15 feet thick and yielding an average of 30 gallons oil per ton [Estimates include the total tonnage and total potential oil yield of the deposit; no allowances were made for losses in mining or processing. Totals for indicated and inferred potential reserves given at the bottom of columns 3, 7, 8] Location Average tonnage Average oil yield Tonnage of oil lPotentjal oil Acreage Average thickness per acre of oil per acre (thousands | shale (millions of yield (millions of cf oil shale (feet) | shale (tthougands of of barrels) tons) barrels) ons Township Range INDICATED POTENTIAL RESERVES Colorado 1 N 104 W. 116 26 75. T 54. 1 9 - 6 1 8 104 W. T7O 34 98. 9 70. 6 76 54 Utah 9 S. 24 E. 700 46 133. 9 95. 6 94 67 25 E. 8, 801 39 113. 5 81. 1 999 714 10 S. 24 E. 5, 466 64 186. 2 133. 0 1, 018 T2T 25 E. 11, 780 46 133. 9 95. 6 1, 577 1, 126 11 S8. 18 E. 2, 755 19 55. 8 39. 5 152 109 19 E. 3, 260 27 78. 6 56. 1 256 183 20 E. 362 28 81. 5 58. 2 30 21 24 E. 13, 050 42 122. 2 87. 3 1, 595 1, 139 25 E. 13, 862 36 104. 8 74. 9 1, 453 1, 038 12 S8. 18 E. 2, 475 18 52. 4 37. 4 130 93 19 E. 14, 288 20 58. 2 41. 6 832 594 20 E. 15, 879 28 66. 9 47. 8 1, 042 744 21 E. 2, 508 20 58. 2 41. 6 146 104 24 E. 14, 900 32 93. 1 66. 5 1, 387 991 25 E. 3, 840 30 87. 3 62. 4 335 240 13 S. 18 E. 456 A7 49. 5 35. 4 23 16 19 E. 2, 980 17. 49. 5 35. 4 147 105 20 E. 2.087 19 55. 3 39. 5 140 100 21 E. 1, 078 16 46. 6 33. 3 50 36 24 E. 3, 262 26 70.7 54. 1 247 176 25 E. 300 25 7a. T 31. 0 22 16 l ram. | ala rica rar iss 11, 760 8, 399 INFERRED POTENTIAL RESERVES Colorado 1 S. 104 W. 565 21 61. 1 43. 6 35 25 2 8. 104 W. 320 18 52. 4 37. 4 17 12 Utah 9 S. 24 E.. 11, 092 40 116. 4 83. 1 1, 291 922 25 E. 4, 495 28 81. 5 58. 2 366 262 10 8. 24 E. 3, 552 65 189. 1 185. 1 672 480 18. 18 E. 12, 035 21 61. 1 43. 6 700 525 19 E. 15, 730 29 84. 4 60. 3 1, 328 948 20 E. 18, 400 32 93. 1 66. 5 1,713 1, 224 21 E. 6, 400 31 90. 2 64. 4 577 412 24 E. 1, 970 40 116. 4 83. 1 229 164 25 E. 1, 769 21 61. 1 48. 6 108 T7. 12 8. 20 E. 6, 887 28 81. 5 58. 2 561 401 21 E. 13, 282 27 78. 6 56. 1 1, 044 745 22 E. 15, 360 30 87. 3 62. 4 1, 341 958 23 E. 17, 030 32 93. 1 66. 5 1, 585 1, 132 24 E.. 6, 740 38 96. 0 68. 6 647 462 13 S8. 21 E. 3, H7 20 58. 2 41. 6 181 130 22 E. 18, 700 22 64. 0 45. 7 1, 197 855 23 E. 9, 520 22 64. 0 45. 7 609 435 24 E. 2, 830 26 75.7 54. 1 214 153 25 E.. 650 20 58. 2 41. 6 38 27 170444 -_ im( ocr 14, 488 10, 349 28 GREEN RIVER FORMATION, UTAH AND COLORADO TaBu® 2.-Estimated tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds occurring in a continuous sequence at least 15 feet thick and yielding an average of 25 gallons oil per ton [Estimates include the total tonnage and total potential oil yield of the deposit; no allowances were made for losses in mining or processing. Estimates include the rock con- taining potential reserves shown in table 1. Totals for indicated and inferred potential reserves given at the bottom of columns 3, 7, 8] Location Average tonnage Average oil yield Tonnage of oil Potential oil Se Acreage Average thickness per acre of oil per acre (thousands | shale (millions of yield (millions of of oil shale (feet) | shale (thousands of of barrels) tons) barrels) Township Range tons) INDICATED POTENTIAL RESERVES Colorado 1 N. 104 W. 319 37 111.7 66. 5 36 21 1 S. 104 W. T70 58 175. 2 104. 3 135 80 Utah 9 8. 24 E. 700 94 283. 9 169. 0 199 118 25 E. 9, 280 67 202. 3 120. 4 1, 877 1, 117. 10 S. 24 E. 5, 466 103 311. 1 185. 2 1, 700 1, 012 25 E. 11, 780 TZ 282. 5 138. 4 2, 739 1, 630 11 S. 18 E. 3, 360 26 78. 5 46. 7 264 157 19 E. 3, 260 34 102. 7 61. 1 335 199 20 E. 362 38 114. 8 68. 3 42 25 24 E. 13, 050 64 193. 3 115. 0 2, 523 1, 501 25 E. 13, 862 57 172. 1 102. 4 2, 386 1, 419 12 S. 18 E. 7, 680 22 66. 4 39. 5 510 303 19 E. 21, 361 24 72.5 43. 1 1, 549 921 20 E. 15, 573 34 102. 7 61. 1 1, 599 951 21 E. 2, 508 30 90. 6 53. 9 227 135 24 E. 14, 900 50 151. 0 89. 9 2, 250 1, 339 25 E. 3, 840 45 135. 9 80. 9 522 311 13 S. 18 E. 12, 456 18 54. 4 32. 4 678 404 19 E. 11, 585 19 57. 4 34. 2 665 396 20 E. 14, 645 23 69. 5 41. 4 1, 018 606 21 E. 2, 972 24 72. 5 43. 1 215 128 23 E. 2, 218 26 78. 5 46. 7 174 104 24 E. 3, 260 45 135. 9 80. 9 443 264 25 E. 300 36 108. 7 64. 7 33 19 90h (| _c .s t Pair. 22, 119 13, 160 INFERRED POTENTIAL RESERVES Colorado 1 N. 103 W. 10 16 48. 3 28. 7 (@) (1) 104 W. 1, 609 20 60. 4 35. 9 97 58 1 S. 104 W. 680 34 102. 7 61. 1 70 42 2 5. 104 W. 320 27 81. 5 48. 5 26 15 3 S. 104 W. 45 20 60. 4 35. 9 3 2 Utah 8 S. 25 E. 620 18 54. 4 32. 4 34 20 0 8. 24 E. 12, 150 60 181. 2 107. 8 2, 202 1, 310 25 E. 8, 120 35 105. 7 62. 9 858 511 10 S. 24 E. 3, 552 120 362. 4 215. 7 1, 287 766 11 S. 18 E. 12, 250 30 90. 6 53. 9 1, 110 660 19 E. 15, 730 38 114. 8 68. 3 1, 806 1, 074 20 E. 18, 400 42 126. 8 75. 5 2, 333 1, 389 21 E. 6, 400 42 126. 8 75. 5 812 483 24 E. 1, 970 60 181. 2 107. 8 357 212 25 E. 2, 044 36 108. 7 64. 7 222 132 12 S. 20 E. 6, 887 37 111. 7 66. 5 769 458 21 E. 13, 282 38 114. 8 68. 3 1, 525 907 22 E. 15, 360 44 132. 9 79. 1 2, 041 1, 215 23 E. 17, 030 47 141. 9 84. 5 2, 417 1, 439 24 E. 6, 740 50 151. 0 89. 9 1, 018 606 13 S. 20 E. 3, 330 16 48. 3 28. 7 161 96 21 E. 1,027 24 12. 5 43. 1 553 329 22 E. 18, 780 32 96. 6 57. 5 1, 814 1, 080 23 E. 10, 000 39 117. 8 70. 1 1, 178 701 24 E. 2, 870 42 126. 8 7D. 5 364 217 25 E. 1, 100 30 90. 6 53. 9 100 59 14 S. 21 E. 2, 030 16 48. 3 28. T 98 58 22 E. 1, 300 17 51. 3 30. 5 67 40 Seeman lt onn | 190, 236 yes uo (oan eae ata alo nen 28, 322 13, 879 ' Number less than 1, ECONOMIC GEOLOGY 20 TaBug 3.-Estimated tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds occurring in a continuous sequence at least 15 feet thick and yielding an average of 15 gallons oil per ton [Estimates include the total tonnage and total potential oil yield of the deposit; no allowances were made for losses in mining or processing. Estimates include the rock containing potential reserves shown in tables 1 and 2. - Totals for indicated and inferred potential reserves given at the bottom of columns 3, 7, 8 Location Average tonnage Average oil yield Tonnage of oil Potential oil Acreage Average thickness per acre of oil per acre (thousands shale (millions of yield (millions of of oil shale (feet) | shale (thousands of of barrels) tons) barrels) Township Range tons) INDICATED POTENTIAL RESERVES Colorado 1 N. 104 W. 899 200 648. 0 281. 4 583 208 1 S. 104 W. T70 225 729. 0 260. 3 561 200 Utah 9 S. 24 E. 700 290 939. 6 335. 5 658 285 25 E. 9, 280 255 826. 2 295. 0 7, 667 2, 738 10 S. 24 E. 5, 466 320 1, 036. 8 370. 4 5, 667 2, 025 25 E. 11, 780 295 955. 8 341. 3 11, 259 4, O21 11 8. 18 E. 3, 360 60 194. 4 69. 4 653 238 19 E. 3, 260 87 281. 9 100. 7 919 328 20 E. 362 99 320. 8 114. 6 116 41 24 E. 13, 050 225 729. 0 260. 3 9, 513 3, 397 25 E. 13, 862 215 696. 6 248. 8 9, 656 3, 449 12 8. 18 E. 9, 870 50 162. 0 57. 8 1, 599 570 19 E. 22, 811 59 191. 2 68. 3 4, 361 1, 558 20 E. 15, 578 82 265. T 94. 9 4, 138 1, 478 21 E. 2, 508 74 239. 8 85. 6 601 215 24 E. 14, 900 157 508. 7 181. 7 7, 580 2, TO7 25 E. 3, 840 95 307. 8 109. 9 1, 182 422 13 8. 18 E. 14, 876 34 110. 2 39. 3 1, 639 585 19 E. 20, 369 40 129. 6 46. 3 2, 640 943 20 E. 14, 862 56 181. 4 64. 8 2, 696 963 21 B. 2, 972 58 187. 9 67. 1 558 199 23 E. 2, 842 70 226. 8 81. 0 645 230 24 E. 4, 263 120 388. 8 138. 8 1, 657 592 25 E. 300 85 275. 4 98. 3 83 29 14 S. 18 E. 4, 100 22 T1. 8 25. 5 2092 104 19 E. 5, 050 20 64. 8 23. 1 327 117 201,925 . T7, 250 27, 587 INFERRED POTENTIAL RESERVES Colorado 1 N. 103 W. 2, 798 40 129. 6 46. 3 363 130 104 W. 4, 132 125 405. 0 144. 6 1, 673 597 2. N. 103 W. 1, 740 28 90. 7 32. 4 158 56 104 W. 4, 959 45 145. 8 52. 1 728 258 1°B. 104 W. 680 200 648. 0 281. 4 441 157 2 8. 104 W. 320 60 194. 4 69. 4 62 22 3 B. 104 W. 45 16 51. 8 18. 5 2 1 30 GREEN RIVER FORMATION, UTAH AND COLORADO TABLE 3.-HEstimated tonnage and potential oil yield of that part of the Mahogany zone and adjacent beds occurring in a continu- ous sequence at least 15 feet thick and yielding an average of 15 gallons oil per ton-Continued Location l Average tonnage Average oil yield Tonnage of oil Potential oil Acreage Average thickness per acre of oil per acre (thousands | shale (millions of yield (millions of of oil shale (feet) | shale (thousands of of barrels) tons) barrels) Township Range k tons) INFERRED POTENTIAL RESERVES-Continued Utah 8 S. 25 E. 3, 480 130 421, 2 150. 4 1, 466 523 9 .. 8. 24 E. 12, 150 220 712. 8 254. 5 8, 661 3, 092 25 E. 8, 120 175 567. 0 202. 5 4, 604 1, 644 10 - 'S: 24 E. 3, 552 335 1, 085. 4 387. 6 3, 855 1, 877 14. :S. 15 ' E. 12, 250 70 226. 8 81. 0 2, TT8 992 10 -E. 15, 730 97 314. 3 112. 2 4, 944 1, 765 20 E. 18, 400 108 349. 9 124. 9 6, 438 2, 298 21 -B. 6, 400 100 324. 0 115. 7 2, 074 740 24 E. 1, 970 210 680. 4 243. 0 1, 340 .. 479 25 E. 2, 044 80 259. 2 92. 6 530 189 12 8. 20 E. 6, 887 93 301. 3 107. 6 2, 075 TA4l 21. B. 13, 282 85 275. 4 98. 3 3, 658 1, 306 22 E. 15, 360 91 204. 8 105. 3 4, 528 1, 617 23 E. 17, 030 120 388. 8 138. 8 6, 621 2, 364 24 E. 6, 740 168 544. 3 194. 4 3, 669 1, 310 13 S8. 17 E. T70 24 71. 8 27. 8 60 21 18 E. 4, 220 27 87.5 31. 2 369 1832 20 E. 6, 162 34 110. 2 39. 3 679 242 21 E. 7, 627 50 162. 0 57. 8 1, 236 441 22 E. 18, 780 61 197. 6 70. 6 3, TH 1, 326 23 E. 10, 500 85 275. 4 98. 3 2, 892 1, 032 24 E. 2, 102 128 398. 5 142. 3 838 299 25 E. 1, 100 37 119. 9 42. 8 132 47 14 S. 17. B. 1, 770 18 58. 3 20. 8 103 37 18 E. 6,235 18 58. 3 20. 8 363 130 19 E. 2, 400 16 51. 8 18. 5 124 44 20° E. 11, 310 22 T1. 8 25. 5 806 288 21 EB. 5, 510 26 84. 2 30. 1 464 166 22 E. 2, 450 34 110. 2 39. 3 270 96 15 S8. 21 -E. 1, 920 17 55. 1 19. 7 106 38 C40 Pan _ csc on ancl sea l ect cart t_ 72, 816 25, 997 The estimates are based on assays of approximately 150 sets of subsurface samples and approximately 25 sets of surface samples. The descriptions of the subsurface sample localities and their assay data were published by the U.S. Bureau of Mines ( Stanfield, Rose, and others, 1954; Stanfield and others, 1964). Forty of the sub- surface sample sets are from core holes, only one of which is outside the mapped area. Virtually all the estimated resources not in the report area are classed as inferred because control points are sparse in the western part of the basin, and because there are no core assay data to substantiate the cutting assays. Also, the assays of cuttings from several wells in the east-central part of the basin indicated anomalous thicknesses of oil shale. A small amount of additional indicated potential reserves lies adjacent to the northeastern part of the mapped area. Owing to inconclusive assay data, estimates were made only for shale averaging 15 gallons oil per ton. The thickness map for shale of this grade in the Uinta Basin is shown in figure 8. The Uinta Basin contains an estimated 31 billion barrels of oil as indicated po- tential reserves and about 290 billion barrels of oil as inferred potential reserves in the shale yielding an aver- age of 15 gallons of oil per ton. These reserves are in a sequence that has a minimum thickness of 15 feet and a maximum thickness of presumably more than. 700 feet. GILSONITE DESCRIPTION AND GEOLOGIC SETTING Gilsonite (classed as an asphaltite) is the residue of natural petroleum. - The mineral was first described by Blake (1885), who named it "wintahite." It is com- monly called gilsonite, however, for Samuel H. Gilson, who was first to encourage the mining of this solid hy- drocarbon. Gilsonite is a black homogeneous tarry-ap- pearing substance having a hardness of about 2. It is very brittle and commonly has a conchoidal fracture. On fresh surfaces this asphaltite has a brilliant luster, but on weathered surfaces the asphaltite is dull black or brown. The physical and chemical characteristics of gilsonite were described by Abraham (1945, p. 250-253). ECONOMIC GEOLOGY 31 $11" 110° 109° I geen ._ 1 Ver > Koy. & Vernal EMA} | y ** s | # | os 5 & s d' Aren ___ cst ‘fl E X NY)?“ t 5 UTAH X A $2 B € % a. f--- t. 67 23; U/ ~y I 8 8/ E (7 yore $18 voor Aja al ~ < ZH Lower oil- " (@} E a g shale zone Ez olf PIP A Dashed where approximately located; short dashed where oil-shale sequence is eroded Contact Dashed where approximately located; dotted where concealed 0 10 20 30 MILES L icp cpg d c_ _L__ * CARBON ~*% $ | | FrcurE 8.-Thickness, in feet, of oil-shale beds of the Green River Formation, Uinta Basin area, that will yield an average of 15 gallons of oil per ton. Thickness interval is 100 feet with 15-foot cutoff. Stippled pattern shows outcrop area of the part of the Green River Formation underlying the Mahogany bed (m). from Bradley (1931, pl. 1). For marketing purposes gilsonite is classified as selects" or as "standards," in accordance with its melt- ing point. - The select ore melts at temperatures between 250° and 300° F, and standard ore melts at temperatures between 300° and 500° F. Gilsonite occurs as long narrow vein deposits between the walls of northwest-trending nearly vertical joints. Veins in the mapped area are about 0.5-7 miles long and a few inches to about 18 feet wide. Widths measured along the veins are shown in figure 9. The maximum vertical extent is estimated to be about 1,400 feet. The veins are almost parallel, and the average strike is ap- proximately N. 60° W. Only one northeast-trending vein was seen ; it has a maximum width of 12 inches and can be traced laterally about 200 feet southwest from its intersection with the Little Bonanza vein, just out- side the mapped area. Most of the veins lie along two northwest-plunging structural noses. - The trace of each vein is remarkably straight, and even the longest veins Outcrop area west of the Green River modified in the mapped area deviate only a few hundred feet from a straight line. - Walls of the veins are smooth and show little irregularity (fig. 104); however, small faults have horizontally offset the veins. Each offset noted is less than the width of the vein displaced. In the mapped area gilsonite veins occur in the Wasatch, Green River, and Uinta Formations. North- west of the mapped area veins also occur in the Duchesne River Formation. The widest and longest veins occur mainly in the Uinta Formation. These veins are widest in the massive sandstone beds in the basal part of the Uinta Formation and thin upward in the shale and sandstone in the middle part of the Uinta Formation. They also thin downward in the marlstone in the Green River Formation and pinch out above the Mahogany bed. Veins below the Mahogany bed are thickest in sandstone beds of the Douglas Creek Member of the Green River Formation and Renegade Tongue of the Wasatch Formation and thin downward in the shale 32 GREEN RIVER FORMATION , UTAH AND COLORADO EXPLANATION lv ‘ Area underlain by Mahogany ~ oil-shale bed T.1 N Gilsonite vein Dashed where indefinit 'o shed where indefinite 2g. 24 \°§ Width of vein, in inches, H § measured by author } 19 & Width of vein, in inches, \ measured by Eldridge (1901) y & 67 > Combined widths, in inches \ of two or more veins TAS $0. - sa shes % 3 5 Q & |8 \21.'°l7 mla B: «lr SIS O 9 1.29. Tp r CBX" Park.. c: ; Creek _... si C |. l= 48 I 24 I 1:38. 60 I .'. I % 1 X 1 i | / R. 104 W. R. 103 W. R. 23 E. Rise F 25 E FreUurE 9.-Location and width of gilsonite veins. ECONOMIC GEOLOGY 33 A FrGurE 10.-Gilsonite veins. Note pole stulls that have been buckled by compression. pinches out near base of Mahogany oil-shale bed. and sandstone in the lower part of the Green River Formation and in the upper part of the Wasatch. These veins thin upward in the marlstone of the Green River Formation and pinch out below the Mahogany bed (fig. 10B). The forces that fractured and separated the sandstone beds produced only flowage or bedding-plane slippage in the Mahogany bed, and the veins therefore do not cut this bed. Where the veins cut marlstone ad- jacent to the Mahogany bed, they commonly split into several veins or veinlets that pinch out upward or down- ward toward the Mahogany bed. The width attained by a vein in the sandstone sequence generally is directly proportional to the thickness of the marlstone sequence cut by the vein. The absence of a thick sandstone se- quence in the Green River Formation below the Ma- hogany bed in the area northeast of Hells Hole Canyon is probably the reason that the Independent and Cowboy A, Mined-out vein near Rainbow, Utah, NE see. 23, T. 11 S., R. 24 E. Vein is about 7 feet wide. B, Black Dragon vein in NW! see. 4, T. 12 S., R. 25 E. Vein Tgp, Parachute Creek Member; Tgd, Douglas Creek Member. veins have no wide counterparts below the Mahogany bed. The gilsonite veins are homogeneous and contain very little foreign matter. The foreign matter present con- sists of sparse chunks of wallrock. Vugs containing water are sometimes found in mining (Charles Neal, oral commun., 1959). Plastic gilsonite has been re- ported in some of the deeper mines. Evidently this is petroleum that, because of its deep burial, has not lost all its lighter fractions. Impregnation of the wallrock by gilsonite is common where the wallrock is sandstone. (Gilsonite has permeated these beds over distances rang- ing from a fraction of an inch to several feet. No im- pregnation of the marlstone was noted. The gilsonite in some veins has a "penecillate" structure near the wall of the vein. This fine columnar structure, perpendicular to the walls of veins and extending inward from the 34 GREEN RIVER FORMATION, UTAH AND COLORADO walls for a few inches, may have been caused by com- pression due to readjustment of the walls of the joints. Other indications of compression are buckled stulls (fig. 104) and small pieces of gilsonite that burst or pop from the working face during mining. MAJOR VEINS Cowboy vein-The Cowboy vein is the widest gil- sonite vein in the Uinta Basin. The maximum width, measured by Eldridge (1901), is 171% feet. Total length of the outcrop of the Cowboy vein is about 10 miles, T miles of which is within the mapped area. Estimated maximum vertical extent of the Cowboy vein in the mapped area is 1,000 feet. In outcrop the vein trends N. 60°%-63° W. The Cowboy vein is widest in a massive sandstone in the lower part of the Uinta Formation. Outerops indicate that the vein pinches out stratigraphi- cally downward in marlstone and oil shale about 150 feet above the Mahogany bed, and pinches out upward in a predominantly thin-bedded sequence in the Uinta Formation. _ The Eureka mine, operated (1964) by the American Gilsonite Co., is mined along the widest part of the Cowboy vein (about 314 miles northeast of Bonanza) and is at least 800 feet deep (Kretchman, 1957, p. 72- 73). Gilsonite from the Eureka mine is carried by a slurry pipeline to a refinery at Gilsonite, Colo., which is about 14 miles northwest of Grand Junction. Independent-Tabor vein.-The Independent vein and the Tabor vein are actually one vein, but the parts north- west and southeast of the junction with the Little Bonanza vein are separately named. The Independent vein, also called the Bonanza vein, is northwest of the junction, and the Tabor vein is to the southeast. Total length of outcrop of the Independent-Tabor vein is about 714 miles, 7 miles of which is within the mapped area. The maximum width, measured by Eldridge (1901), is approximately 14 feet. The estimated maxi- mum vertical extent in the mapped area is 1,100 feet. In outcrop the vein trends N. 55°%-62° W. The vein is widest in a predominantly massive sandstone sequence in the lower part of the Uinta Formation. It pinches out stratigraphically downward in marlstone above the Mahogany bed in the Parachute Creek Member of the Green River Formation and pinches out upward in shale and sandstone in the Uinta Formation. Little Bonanza vein.-The outcrop of the Little Bo- nanza vein is approximately 5 miles long, virtually all of which lies within the mapped area. The maximum width, measured by Eldridge (1901), is 13 feet. Esti- mated maximum vertical extent of the vein in the mapped area is 1,200 feet. The outcrop trends N. 68° W. The Little Bonanza vein is widest in a predomi- nantly massive sandstone sequence in the Uinta Forma- tion. The vein outcrop pinches out stratigraphically upward in shale and sandstone in the Uinta Formation, and downward presumably in thin-bedded marlstone in the Parachute Creek Member of the Green River Formation and above the Mahogany oil-shale bed. The American Gilsonite Co. is mining (1964) the Little Bonanza vein southeast of Bonanza, Utah. The ore is hauled by truck to the railroad at either Rifle or Craig, Colo. Wagonhound vein.-The total length. of the outcrop of the Wagonhound vein is about 41/4 miles, all of which is within the mapped area - The maximum width measured by the author is about 314 feet. The estimated vertical extent of the Wagonhound vein is 1,300 feet. In outcrop this vein trends N. 65° W. The Wagon- hound vein is thickest in sandstone of the Uinta For- mation. The outcrop pinches out stratigraphically upward in the Uinta Formation, and downward in marlstone of the Evacuation Creek Member of the Green River Formation. Weaver-Colorado vein.-The total length of outcrop of the Weaver-Colorado vein is 614 miles, all of which lies within the mapped area. The name "Weaver" is applied to the Utah part of the vein, and "Colorado," to the Colorado part. 'The maximum width measured by the author is 2 feet, and the estimated vertical extent is 1,400 feet. The outcrop, which lies approximately on a projection of the outcrop of the Wagonhound vein, trends N. 58° W. - The Weaver-Colorado vein is widest in massive sandstone and limestone in the Douglas Creek Member of the Green River Formation. The outcrop of the vein pinches out stratigraphically up- ward in marlstone of the Parachute Creek Member of the Green River Formation and pinches out downward in shale in the Wasatch Formation. Little Emma (Uinta) vein.-The outcrop of the Little Emma (Uinta) vein is about 414 miles long, 244 miles of which lies within the mapped area. The maximum width of the vein is about 3 feet (Charles Neal, oral commun., 1959). - The estimated vertical extent is 1,000 feet. The outcrop of the vein trends N. 67° W. Maxi- mum width of the vein is in sandstone of the Uinta Formation. - The vein pinches out stratigraphically up- ward and downward in the Uinta Formation. Rainbow vein.-The Rainbow vein, whose outcrop is about 414 miles long, lies almost entirely within the mapped area. The northwestward extension of the Rainbow vein is called the Pride-of-the-West vein. The dividing line between these two parts of the vein is just west of the western boundary of the mapped area. The maximum width of the Rainbow vein, where it lies in a single fracture, is approximately 8 feet. In the rocks that are about 200 feet above and 200 feet below the —-_'_—_—7 ECONOMIC GEOLOGY 35 Tinta-Green River contact, the Rainbow system consists of from two to six veins. At one locality six veins have a combined width of approximately 11 feet, and maxi- mum width of any vein in this group is approximately 3 feet. The estimated maximum vertical extent of the Rainbow vein is 600 feet. The outcrop of the Rainbow vein trends N. 48%-58° W. The vein is widest in the massive sandstone of the lower part of the Uinta For- mation. The outcrop of the vein pinches out strati- graphically downward above the Mahogany bed in marlstone of the Parachute Creek Member of the Green River Formation and thins stratigraphically upward in the Uinta Formation. For many years, during the operation of the Uintah Railway, the Rainbow vein supplied a large percentage of all the high-grade gilsonite produced. The vein was mined to a depth of about 400 feet (Charles Neal, oral commun., 1959). Small-scale mining was conducted sporadically along the Rainbow vein during 1940-55. Black Dragon vein-The Black Dragon vein crop§ out for a distance of about 5 miles. The entire outcrop is within the mapped area. The maximum width, meas- ured by Eldridge (1901), is 5 feet, and the estimated maximum vertical extent is 1,100 feet. The Black Dragon vein trends N. 48° W. and lies a few hundred feet northeast of the projected Rainbow vein. The vein is widest in massive sandstone beds of the Douglas Creek Member of the Green River Formation and of the Renegade Tongue of the Wasatch Formation. It pinches out stratigraphically downward in shale of the Douglas Creek Member and pinches out upward just below the Mahogany bed in oil-shale beds of the Para- chute Creek Member. Outcrops of the northwest end of the Black Dragon vein and of the southeast end of the Rainbow vein are about half a mile apart; the two veins are apparently separated by approximately 150 feet of stratigraphic section. The author believes that the Black Dragon vein extends northwestward beneath the Rainbow vein (fig. 11). The northwest extent of the Black Dragon vein is probably limited by the extent of the massive sandstone in the Douglas Creek Member. The Black Dragon vein has yielded much select gilson- ite and has been mined to a depth of 700 feet (Charles Neal, oral commun., 1959). Very little mining has been done along the Black Dragon vein since 1940. ORIGIN Gilsonite is residue of a petroleum that flowed into fractures from a source not definitely known. After moving into the fractures, most of the hydrocarbon solidified. Proposed theories concerning the origin of the petroleum and an appraisal of each are as follows: 1. The petroleum came from an overlying asphalt lake or overlying reservoir beds. The geometry of the fractures containing gilsonite and the absence of any indication of a preexisting asphalt lake or overlying source beds virtually preclude this theory. 2. The petroleum came from reservoirs in pre-Tertiary rocks. - This theory is proposed chiefly because of 'the large reserves of hydrocarbons in pre-Tertiary beds in nearby fields. Stratigraphically, outcrops of gilsonite occur no lower than the upper part of the Wasatch Formation; however, gilsonite was reportedly found during exploratory drilling in Cretaceous rocks in the eastern part of the Uinta Basin. Some geologists suggest that the Weber Sandstone of Permian and Pennsylvanian age-2 prolific oil producer in the Rangely and Ashley Valley fields-is a possible source for the gilsonite. But the rocks between the base of the Green River Formation and the top of the Weber Sandstone near Bonanza are approximately 9,500 feet thick. Also, the trace-element suite in gilsonite is similar to the trace-element suites in crude oils and asphalt seeps from the Wasatch and Green River Forma- tions, but it is not similar to the trace-element suite in crude oil from the Weber Sandstone (Erickson and others, 1954, table 3; Bell, 1960, tables 2, 3). 3. The petroleum came from reservoirs in the upper part of the Wasatch Formation and the lower part of the Green River Formation. High-pour-point oil is being produced from the upper part of the Wasatch Formation and the lower part of the Green River Formation in fields in the Uinta Basin. Fractures containing gilsonite are found in out- crops of the upper part of the Wasatch and lower part of the Green River Formations; beneath the surface such fractures may penetrate reservoir beds that could have furnished a large volume of petro- leum to the void spaces. The association of the veins with structural noses also supports this theory. The position of the large veins above the unfractured Mahogany bed, however, requires cir- cuitous movement of the oil from reservoirs in the basal Green River or upper Wasatch. The petro- leum could move upward only in some marginal part of the basin where the Mahogany bed was not deposited or where there is an unconformity, and then move laterally to its present position. 4. The petroleum is a result of the metamorphosis of kerogenaceous material in the marlstones and oil shales adjacent to the veins. Most, and possibly all, of the veins are, at least in part, adjacent to beds of the Green River Formation that contain h 36 GREEN RIVER FORMATION, UTAH AND COLORADO organic matter. organic matter in the Green River Formation, metamorphosis of only a small part of it would form enough petroleum to fill the gilsonite veins. Hunt, Stewart, and Dickey (1954), in a study of hydrocarbons of the Uinta Basin, compared several chemical and physical properties of free hydrocar- bons with those of hydrocarbons extracted from adjacent beds of the Wasatch, Green River, and Uinta Formations. From these comparisons they (1954, p. 1683-1690) concluded that each type of free hydrocarbon, such as wurtzilite or ozocerite, was derived from the organic matter in a partic- ular stratigraphic unit adjacent to the free hydro- carbon occurrence, and that the probable source of gilsonite was the oil shale in the middle and upper parts of the Green River Formation from which shale oil moved directly into the veins. 5. The petroleum came from sandstone beds adjacent to the widest part of the vein. All veins of ap- preciable size are associated with thick sequences of sandstone. These veins cut across the sandstone beds, reach their maximum width in sandstone, become progressively narrower, and finally pinch out, in the finer grained sediments above and below the sandstone beds. Perhaps oil and gas derived from organic matter in the sediments migrated with connate water into the sandstone shortly after deposition, and the remaining organic matter later formed kerogen. Later, fractures formed and be- came filled with fluids from the sandstone reservoir. T wo facts are in disagreement with this interpreta- tion. The sandstone of the Uinta Formation con- tains no gilsonite or evidence of petroleum residue except for minor and erratic impregnation im- mediately adjacent to the gilsonite veins, and the veins are not apparently connected with the wide- spread impregnated sandstone beds in the Douglas Creek Member. Also, the gilsonite seems to have been highly viscous when it was emplaced, and no obvious mechanism for the nearly complete removal of viscous hydrocarbon from the main body of sandstone has been observed or proposed. Conclusions The present study did not produce sufficient data to establish details of the origin of gilsonite veins. How- ever, certain conclusions based on field evidence seem significant. The gilsonite-forming hydrocarbons were evidently viscous fluids emplaced during a relatively short period of time, this rapid accumulation suggesting that their source was a large highly permeable reservoir or reservoirs. - All major veins are widest in thick sand- stone and pinch out stratigraphically upward and down- Because of the vast amount of ward in finer grained rock; this variation indicates a greater fluid pressure in the sandstone, or less resistance to opening of fractures in the sandstone, than in the finer grained rock. Fracturing of the rocks occurred after their complete lithification and when the oil shale proba- bly had little permeability. If the indurated oil shale is assumed to be permeable enough to allow its fluids to move into veins, the shale adjacent to a vein should be depleted or enriched, de- pending on the amount of permeability, in some hydro- carbon fractions and should be leaner or richer than the same shale farther from the vein. Field examinations have not revealed diminution or increase in the potential oil yield of oil-shale beds near gilsonite veins. Any major movement of fluids out of the organic-rich sedi- ments, therefore, probably was directed toward more permeable beds and occurred prior to lithification. Sandstone best fits the description of the assumed reservoir. The sandstones cropping out adjacent to the widest parts of the veins are not considered to be likely sources, however, because most of these sandstones con- tain little or no petroleum residue. Accordingly, at- tention was focused on the sandstones in the Green River Formation that produce asphaltic oil in fields downdip from the gilsonite veins. The fields are in an area between the structural axis on the north and the depositional axis ( during Green River time) on the south. Oil production is from beds that were deposited in a near-shore environment that received abundant detrital material from the direction of the Uinta Moun- tains and lay adjacent to a lake environment that was rich in organic matter. Fluids from the organic-rich lacustrine sediments are postulated to have moved into the porous sediments a short time after deposition. The sediments were later lithified and folded, and the fluids became trapped in updip pinchouts of the coarser sedi- ments. The coarser rocks were susceptible to extensive vertical fracturing that allowed widespread vertical and horizontal movement of fluid hydrocarbons from any breached reservoir; the fracturing and circulation thus produced the gilsonite veins. The inspissation of the fluids took place as erosion progressed and is still taking © place in deeply buried veins. DEVELOPMENT Mining and marketing of gilsonite began about 1888 and have increased through the years as the mining and transportation methods have been improved and the number of uses of the mineral has been increased. The first mines were in the north-central part of the Uinta Basin, outside the mapped area. About 1900 the center of operations moved into the southeastern part of the basin because the largest veins were located ECONOMIC there. Several mines were opened along the Rainbow and Black Dragon veins and nearby veins. From 1900 to 1935 these mines produced a large percentage of the total gilsonite marketed throughout the world. Dur- ing this time the mining camps of Rainbow, Dragon, and Watson were established. - About 1935 these camps were abandoned except for sporadic inhabitance, and most of the mining operations were moved north of the White River to the area around Bonanza. Virtually all gilsonite mined in the world comes from the Uinta Basin, and the Cowboy and Little Bonanza veins pro- duce a large percentage of this ore. For many years all gilsonite was mined by use of pick and shovel, and some is still produced by this method. The narrowness of many veins prohibits mechanization, and blasting is hazardous because of the explosive nature of gilsonite dust. Several disas- trous fires have resulted from explosions set off by spark or open flame. Gilsonite dust also interferes with mechanization of mining because the dust clogs some types of equipment. Much recent research in gilsonite technology has been directed toward finding a method for mining gilsonite by means of rotary drill powered by water under high pressure. Since 1957 the American Gilsonite Co. has successfully used sev- eral new mining methods, among which are the use of a tunnel-boring machine and a large-hole rig. These new methods of mining were described by Kilborn (1964). Transportation of gilsonite from mine to market has advanced through several stages. The first gilsonite shipped out of the Uinta Basin was moved by wagon to the railroad at Price, Utah ; the wagon was the chief means of transportation until a railroad was con- structed in the Uinta Basin. In 1904 the Uintah Rail- way was completed between Dragon, Utah and Mack, Colo. (about 20 miles northwest of Grand Junction), where it joined with the Denver and Rio Grande Western Railroad. Later the railway was extended to Watson, Utah, and Rainbow, Utah. This unusual narrow-gage line featured 71/4 percent grades and 76° curves (Kretchman, 1957, p. 40, 44). The Uintah Railway was abandoned in 1987 because the truck had become the principal hauler of gilsonite. Although trucks are still used for transportation of gilsonite, another method is also used. Gilsonite is carried a distance of 72 miles by means of a 6-inch diameter slurry pipeline from the Cowboy vein to a refinery at Gilsonite, Colo. (Kretchman, 1957). Gilsonite is used in numerous ways. At present a major part of the gilsonite mined is supplied to the refinery at Gilsonite, Colo., where it is converted to metallurgical coke and gasoline. - Gilsonite is also used 37 GEOLOGY f in the manufacture of floor tile, inks, paints, electrical insulations, brake linings, caulking materials, battery boxes, some types of fiberboard, and insulation for underground steam and hot-water pipes (Kretchman, 1957, p. 61). RESERVES The original gilsonite reserves of all veins in the area were estimated by the author through the use of avail- able surface and subsurface data. The estimates given in table 4 are for total reserves in place and are not adjusted for gilsonite that has already been mined or for gilsonite that may not be mined in the future because of limitations of vein width or other factors. Little is known about the complete extent and configuration of the veins underground; hence, several assumptions based on surface observations were used in the estima- tion of reserves. - These assumptions are (1) the widths of the veins change uniformly between points of meas- urement, (2) the widths are constant downdip from points of measurement to a line directly below the northwesternmost outcrop of the vein or to the bound- ary of the area, and (3) the base of each vein occurs along the base of the lowermost bed in which the vein crops out or along the base of the lowermost bed where gilsonite has been mined, depending on which bed is lowermost in the stratigraphic sequence. Longitudinal sections were drawn for all veins in the area for aid in calculation of reserves. Four of these sections are shown in figure 11. Data on all the longitudinal sections and the information shown in figure 9, as well as other field observations were used in the estimation of the original gilsonite reserves. TaBL® 4.-Estimated original reserves of gilsonite in the mapped area Vein Mil- lions of tons g or ...... ». elio. ol ae oe eel alle -be ama we no td a nudie ae an we 5B dee Res bene th Independent-Tabor......-. Little Bonanza...-.....--- Rainbow Black Dragon.... Weaver-Colorado........-- Wagonhound.....-.------- Little Emma.......-- AM others. -.. ! 002. ou avec MBLAL. L2]. 00.20 shou oo. Ve ao oo ewe oe o e cis aren s awe » e Bata The 27.4 million tons of gilsonite estimated as the original reserve for the mapped area is a large part of the total estimated. reserve of the Uinta Basin. The original reserve of the basin is estimated to have been about 45 million tons; probably about one-tenth of this amount has been mined (Cashion, 1964, p. 65). pir Fp te so 5 aowna-o-10 27. 4 BITUMINOUS SANDSTONES Sandstones impregnated with bituminous material occur in the uppermost part of the Douglas Creek Mem- ber and in the lowermost part of the Parachute Creek Member in the southeastern and south-central parts of 38 GREEN RIVER FORMATION, UTAH AND COLORADO 6000' 5000' . pf" _- - Mahogany oil-shale bed _ 222 4000" INDEPENDENT-TABOR VEIN NW NW 6000' 5000' s etiam Amhogany oil-shale bed 4000" NW SE 6000' 5000' 2 a L _- - /4Mahogany oil-shale bed 4000" COWBOY VEIN SE 6500' Mahogany oil-shale bed 6000' ' 5000' /S>>~>~ BL HMMSHMN |--====~~~----~~ z ssuuds tto '0p Ito ts;u0ufu0;) *pouopueqe pus |~~~~~ pJOAES@pYT | 08 'f o0g+- ~ ~ o. |= IC I6G'9| CH Wo|CcS EI ST MHSHMSHHS |--==~-~~--~~~~ 1 sSupidg ItO '0p ItO *Uor}BULI0 J oproatsopy tol EIDADW O81 MOB |~=~~~~~~~~--------- op ous 's oF: '. > ("~ ACS6T'Y | CH W |CS gI |~-~~~~ FL MHSFHEMNELM N |-- t ssupidg ItO '0p IO IH-448 *Uor}8U10,J YOJGSEM TO (ox0u0 'U}T) UIDADW 098'8 MOB I8MIUL |~~~~~===~~~~----~--- op:" Fe's 1 Uo agement 4GO6's | 'C fe 1 "8 gt € MHMSMHEN z ssuuds Io 'daop owsry a. *|* "~:" oreyg soowepy | 0084- :: *>. - [""" 4D Feld | CM de |C8 BI Fo MMSHMS |-=====~~--~- 8LT-I yeu '0p sth » IO 419pus *pouopueqe pus |~~*~~ | 128 '¢ pad 0a) (Tos ay ss | "s ~~~ ~*~ IT Lt-I tO 40148 L-14I@G yojesem toJ CIDADW 008'9 MOK |~~~~~~~~~~~~~ oreyg | 165 's Ore F :; }: gyxsio| C If |S. gr it MHANHMS |-; ~~~ $FAASHMAN [-=- 1 90,7 uosq1oqoy 'v 6a). yoreseM | 02¢ ¢ 008 I+ . ~ - 4GKs's | CX If | C8 If |~~~~~~~~ S HANFLMEMME ==-- THOM '00 ITO OM4O "oc: » {*~* opdoatsopyt | 228 8 0064 1.0 .: gx | '% Of !'s Ar 6 |-- T '0; tuno101194 va- yorestM | 189 '¢ Ogg I-! | -' ID 's | CZ 61 | 's I1 |-- --- 86 HMNHMNMHAMN |--~~~ T 49910 IIH 'dop sep pus Ito xyoormeys Oc. »| s st aes op :> sso 's 0 {cf's 1p |C 95 | cs Of |~~~~~ 96 MESNTLM NFLN H 98-1 tesopoyt "our 'IIO od .a: :~." oreys soouept | pag'p | O80 "I- ___ |~~~~~~ agseog | cw as | cs or |~~~~~~~ %o ~~ > z szusuog "our 'O Cd |"" uor}euL10 ,f | 632 'F oof 4 _ " sgt" ap re | "a eo |g) On| FE FTMEITIM® 1 uos;eM '0p (t fog: : 1 tft nan op: ~~: sre 's get ..'." j" ~> 1D Leo | 'H 1C | 's Of --- "pf FHMEFEME z uos;e, '0p It tequounu0; fod. _.] gs bp :~ slg 'T 008- | & #G | Cs 6 |--" F8 HMNFEMEIMAS y uos;em uung pus uosugor 'pouopueqe pus pasSnq |~~~~~~~ Y9JeSEM | 242 'I o= =~ ~d sim Laos | cw gs | cs 6 [~~~ 6 HMNMAMNEEMAN ¢ uostem uosuyor Jy 40x 'pouoptreqs pus '1odeop pal[LIp [9M PIQ |~~~~~~~~~~~~~ werddtsstssIJN | 889 'gT OH- i) ae es 9G |S 6 |-~~~~ F8 MMNHAMNHMS |-==~=~~~~~-7-g uos;eM 'o;) urnajonog sdt[[IYJ od! ~] =~ YoJ8SEM | 080 's 00p- 0808 | CH gs | cs) 6 |~~~~~~: L0 FHMESMAMEMEANG I szueuog uosuyof 'Jy 40x 'pouopueq® pus posSnIq |~~~=~~~~~~~~- oreyg soouspt | ¢1g 'L ori+ "cs; Adore l 'I e | 4g "6. |-~~-~*~*~ F6 HAMNMMNO ~I eaweuog "out 'sterourpy un 'pouopusqe pus |--~~~~~--~~~~ oreyg soouspyt | 290 'p ost :~. gawro |M sof 's g 08 MHASHEANMEN |-~~~~~~~~~~ 5 uogurpy 1401 IQ [ejuouf3u0;) ,J UostL10 JY vos; 'W-44) CIDADW $19 MOB ISMTUT |-~~~~~~~ eperqug | 016 '0 Ogo 't- . :-. | o ~~ quo;spusy spenqug | £16 '; Old: .:.: . . 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Abraham, Herbert, 1945, Asphalts and allied substances, their occurrence, modes of production, uses in the arts and meth- ods of testing: 5th ed., New York, D. Van Nostrand Co., v. 1, 887 p. Adelman, F. I., Bacigalupi, C. M., and Momyer, F. F., 1960, Final report on the Pinot experiment: California Univ. Lawrence Radiation Lab. Rept. UCRL-6274, 21 p. Bell, K. G., 1960, Uranium and other trace elements in petro- leums and rock asphalts: U.S. Geol. Survey Prof. Paper 356-B, 21 p. [1961]. Blake, W. P., 1885, Uintahite, a new variety of asphaltum from the Uinta Mountains, Utah : Eng. Mining J our., v. 40, p. 481. Bradley, W. H., 1926, Shore phases of the Green River forma- tion in northern Sweetwater County, Wyoming: U.S. Geol. Survey Prof. Paper 140-D, 11 p. 1929, Algae reefs and oolites of the Green River Forma- tion: U.S. Geol. Survey Prof. Paper 154-G, 21 p. [1930]. 1930, The varves and climate of the Green River epoch : U.S. Geol. Survey Prof. Paper 158-B, 24 p. 1931, Origin and microfossils of the oil shale of the Green River formation of Colorado and Utah : U.S. Geol. Survey Prof. Paper 168, 58 p. 1948, Limnology and the Eocene lakes of the Rocky Mountain region : Geol. Soc. America Bull., v. 59, no. 7, p. 635-648. 1964, Geology of Green River Formation and associated Eocene rocks in southwestern Wyoming and adjacent parts of Colorado and Utah : U.S. Geol. Survey Prof. Paper 496-A, 86 p. [1965]. Cashion, W. B., 1957, Stratigraphic relations and oil shale of the Green River Formation in the eastern Uinta Basin [Utah], in» Intermountain Assoc. Petroleum Geologists Guidebook 8th Ann. Field Conf., Uinta Basin: p. 181-135. 1959, Geology and oil-shale resources of Naval Oil-Shale Reserve No. 2, Uintah and Carbon Counties, Utah: U.S. Geol. Survey Bull. 1072-0, 41 p. [1960]. 1961, Potential oil-shale reserves of the Green River Formation in the southeastern Uinta Basin, Utah and Colo- rado, in Short papers in the geologic and hydrologic sciences: U.S. Geol. Survey Prof. Paper 424-C, p. C©22-C24, 1964, Other bituminous substances, in Mineral and water resources of Utah: Utah Geol. and Mineralog. Survey Bull. 73, p. 63-70. Cashion, W. B., and Brown, J. H., Jr., 1956, Geology of the Bonanza-Dragon oil-shale area, Uintah County, Utah, and Rio Blanco County, Colorado: U.S. Geol. Survey Oil and Gas Inv. Map OM-153. Culbertson, W. C., 1962, Laney Shale Member and Tower Sand- stone Lentil of the Green River Formation, Green River area, Wyoming, in Short papers in geology and hydrology : U.S. Geol. Survey Prof. Paper 450-C, p. C54-C37. Dane, C. H., 1954, Stratigraphic and facies relationships of upper part of Green River formation and lower part of Uinta formation in Duchesne, Uintah, and Wasatch Coun- ties, Utah: Am. Assoc. Petroleum Geologists Bull., v. 38, no. 3, p. 405-425. 1955, Stratigraphic and facies relationships of the upper part of the Green River formation and the lower part of the Uinta formation in Duchesne, Uintah, and Wasatch Coun- ties, Utah : U.S. Geol. Survey Oil and Gas Inv. Chart 00-52. Donnell, J. R., 1957, Preliminary report on oil-shale resources of Piceance Creek basin, northwestern Colorado: U.S. Geol. Survey Bull. 1042-H, p. 255-271. C 1961, Tertiary geology and oil-shale resources of the Piceance Creek basin between the Colorado and White Rivers, northwestern Colorado : U.S. Geol. Survey Bull. 1082-L, 57 p. Eldridge, G. H., 1896, The uintaite (gilsonite) deposits of Utah, in Walcott, C. D., U.S. Geol. Survey 17th Ann. Rept., pt. 1: p. 909-949. 1901, The asphalt and bituminous rock deposits of the United States, in Walcott, C. D., U.S. Geol. Survey 22d Ann. Rept., pt. 1 : p. 209-452. Endlich, F. M., 1878, Report on the geology of the White River district, in Hayden, F. V., U.S. Geol. and Geog. Survey Terr. 10th Ann. Rept. : p. 61-131. Erickson, R. L., Myers, A. T., and Horr, C. A., 1954, Association of uranium and other metals with crude oil, asphalt, and petroliferous rock: Am. Assoc. Petroleum Geologists Bull., v. 38, no. 10, p. 2200-2218. Graham, E. H., 1937, Botanical studies in the Uinta Basin of Utah and Colorado : Pittsburgh, Carnegie Mus. Annals, v. 26, 482 p. E Guthrie, Boyd, 1938, Studies of certain properties of oil shale and shale oil : U.S. Bur. Mines Bull. 415, 159 p. Hansen, G. H., 1957, History of drilling operations in Utah's Uinta Basin, in Intermountain Assoc. Petroleum Geologists Guidebook 8th Ann. Field Conf., Uinta Basin: p. 165-167. Hayden, F. V., 1869, Review of leading groups, in U.S. Geol. Survey Terr. 3d Ann. Rept. : p. 189-192. Hunt, J. M., Stewart, Francis, and Dickey, P. A., 1954, Origin of hydrocarbons of Uinta Basin, Utah: Am. Assoc. Petro- leum Geologists Bull., v. 38, no. 8, p. 1671-1698. Kay, J. L., 1934, The Tertiary formations of the Uinta Basin, Utah: Pittsburgh, Carnegie Mus. Annals, v. 23, p. 357-372. - 1957, The Eocene vertebrates of the Uinta Basin, Utah, in Intermountain Assoc. Petroleum Geologists Guidebook 8th Ann. Field Conf., Uinta Basin : p. 110-114. Kilborn, G. R., 1964, New methods of mining and refining gil- sonite, in Intermountain Assoc. Petroleum Geologists Guide- book 13th Ann. Field Conf., Guidebook to the geology and mineral resources of the Uinta Basin, Utah's hydrocarbon storehouse : p. 247-252. Kinney, D. M., 1955, Geology of the Uinta River-Brush Creek area, Duchesne and Uintah Counties, Utah: U.S. Geol. Survey Bull. 1007, 185 p. + Kretchman, H. F., 1957, The story of gilsonite: Am. Gilsonite Co., 96 p. Miller, D. F., 1956, The Hill Creek area [Utah], in Intermoun- tain Assoc. Petroleum Geologists Guidebook 7th Ann. Field Conf., Geology and economic deposits of east-central Utah : p. 199-201. Milton, Charles, and Eugster, H. P., 1959, Mineral assemblages of the Green River formation [Colo.-Utah-Wyo.], in Abel- son, P. H., ed., Researches in geochemistry: New York, John Wiley & Sons, Inc., p. 118-150. Osborn, H. F., 1895, Fossil mammals of the Uinta beds [Utah] : Am. Mus. Nat. History Bull., v. 7, p. 71-105. Peale, A. C., 1878, Geological report on the Grand River district, in Hayden, F. V., U.S. Geol. and Geog. Survey Terr. Ann. Rept., 1876 : p. 161-185. Picard, M. D., 1955, Subsurface stratigraphy and lithology of Green River formation in Uinta Basin, Utah: Am. Assoc. Petroleum Geologists Bull., v. 89, no. 1, p. 75-102. REFERENCES 45 Picard, M. D., 1957, Green River and lower Tinta formations- subsurface stratigraphic changes in central and eastern Uinta Basin, Utah, in Intermountain Assoc. Petroleum Geologists Guidebook 8th Ann. Field Conf., Uinta Basin : p. 116-1830. Rapp, J. R., 1962, Roll in a sandstone lentil of the Green River Formation, in Short papers in geology and hydrology : U.S. Geol. Survey Prof. Paper 450-C, p. ©85-C8T. Ray, R. G., Kent, B. H., and Dane, C. H., 1956, Stratigraphy and photogeology of the southwestern part of Uinta Basin, Duchesne and Uintah Counties, Utah : U.S. Geol. Survey Oil and Gas Inv. Map OM-171. Spieker, E. M., 1946, Late Mesozoic and early Cenozoic history of central Utah : U.S. Geol. Survey Prof. Paper 205-D, 45 p. Stagner, W. L., 1941, The paleogeography of the eastern part of the Uinta Basin during Uinta B (Eocene) time: Pittsburgh, Carnegie Mus. Annals, v. 28, p. 273-308. Stanfield, K. E., Frost, I. C., McAuley, W. S., and Smith, H. N., 1951, Properties of Colorado oil shale : U.S. Bur. Mines Rept. Inv. 4825, 27 p. Stanfield, K. E., Rose, C. K., McAuley, w. S., and Tesch, W. J;, Jr., 1954, Oil yields of sections of Green River oil shale in Colorado, Utah, and Wyoming, 1945-52: U.S. Bur. Mines Rpt. Inv. 5081, 153 p. 1957, Oil yields of sections of Green River oil shale in Colorado, 1952-54: U.S. Bur. Mines Rept. Inv. 5321, 132 p. Stanfield, K. E., Smith, J. W., and Trudell, T. G., 1964, Oil yields of sections of Green River oil shale in Utah, 1952-62: U.S. Bur. Mines Rept. Inv. 6420, 217 p. Swain, F. M., 1956, Early Tertiary ostracode zones of Uinta Basin [Colo.-Utah], in Intermountain Assoc. Petroleum Ge- ologists Guidebook 7th Ann. Field Conf., Geology and eco- nomic deposits of east-central Utah: p. 125-139. White, C. A., 1878, Report on the geology of a portion of north- western Colorado, in Hayden, F. V., U.S. Geol. and Geog. Survey Terr. Ann. Rept., 1876: p. 1-60. Whittier, W. H., and Becker, R. C., 1962, Geologic map and sec- tions of the bituminous sandstone deposits in the P. R. Springs area, Grand and Uintah Counties, Utah : U.S. Geol. Survey open-file report, 1 p. Winchester, D. E., 1916, Oil shale in northwestern Colorado and adjacent areas: U.S. Geol. Survey Bull. 641-F, 60 p. [1917]. 1918, Oil shale of the Uinta Basin, northeastern Utah: U.S. Geol. Survey Bull. 691-B, 24 p. [1919]. Woodruff, E. G., and Day, D. T., 1915, Oil shale of northwestern Colorado and northeastern Utah: U.S. Geol. Survey Bull. 581-A, 21 p. A Page L0 ATORL:: c .L UL 4 3 Algal reefs... o -- 1218 Alluvial deposits, Quaternary .._.......- 22 American Gilsonite Co., mining methods...... 37 2... oo. era re ecco asa 16, 19, 24 B Badlands, Duchesne River Formation....... 21 Bilumin, 30 Bituminous sandstones, Douglas Creek 9 Black Dragon vein, gilsonite..............--.. 35, 37 Black shale facies, Douglas Creek Member... 10 Bonanza vein. - See Independent-Tabor vein. Burnt Timber Canyon, oil shale suitable for strip mining near._......_......-- 26 C Chimney Rock, tuffaceous dikes near...... 19 Classification of oil-shale reserves.._........-- 25 Colluvial deposits, Quaternary.........------ 22 Colorado, exploration wells..................- 41 indicated oil-shale reserves, estimated at I6 galperton.:.:..............«.. 29 estimated at 25 gal per ton 28 estimated at 30 gal per ton....._...... 27 inferred oil-shale reserves, estimated at 15 @ulperton.......<-........... 3 29 estimated at 25 gal per ton... 3 28 estimated at 30 gal per ton... nem :d Colton Formation......................._._..« 7 Cowboy vein, gilsonite......._..._........... 34, 87 Craig, Colo., shipping point.................. 26 D Dakota Sandstone, oil and gas..._...........- 40 Depositional environment, Douglas Creek Member:: 22002. cous 10,12 Evacuation Creek Member.. 18 Garden Gulch Member...._......-------- 13 Green River Formation......_......--.--- 8 Parachute Creek Member........-..----- 16 Cinta 21 Wasatch Formation......_._._..........-- 6 Development of oil #4 Dikes, tuffaceous, Green River Formation... 18 Douglas Creek arch, Wasatch Formation near. 6 Douglas Creek Member, 4 bituminous sandstones.. . 287 black-shale facies.........~- a 10 characteristic topography...._...........~ 9 SAL 2.2L cin 8,9 .A cocks 7,14 gilsonite veINS......__.___...__.....-.---- 31 o 912 stratigraphic relations.......... 10 Drainage, study area.......-.-.---- Duchesne River Formation. INDEX [Italic page numbers indicate major references] E Page ECONOMIC 24 Entrada Sandstone, oil and gas..........----- 40 Eureka gilsonite ming..........-_......------ 34 Evacuation Creek Member, discussion...... 16 Exploration wells, listed and described....--- 41 F $8 28 Fossils, Douglas Creek Member. . 7,12 Evacuation Creek Member. .. 18 Garden Gulch Member....-.- 13 in oll shale.... 24 Parachute Creek Member........-------- 16 Tinta Formation...._......_......---..-- 21 Wasatch Formation................------- d a Garden Gulch Member.......---------------- 18 Gas. See Oil and gas. Gilsonite, age relative to folding........----~- 23 characteristits..................---.-.-.----- 80 31 TMAJOT --- 84 mining and 86 mining methods..----- Mp 37 occurrence........~-- 81 85 81 SOG. cL N2: ec st O7 GHilsonite veins, characteristics... - _ 8 in Joints.... - 22,23 relation to structure....-~.-- Te Bt Green River Formation.....__.....--.-.------ 8 bituminous sandstones.........-..------- 30 Douglas Creek Member........ h 8 Evacuation Creek Member.....--- sos +16 Garden Gulch Member.......----- fess! gilsonite veins.... .s ABL joint system.....~ uc ge kerogen-rich bed8..._.......---...-------- 13 denes 7 modifications of member boundaries.. ..... 8 oll and 40 Parachute Creek Member........-.------ 18 Suff el ens bees 18 tuffaceous dikes....._......_._____....... 18 See also individual members. Green River Shales, name change........---- 7 Griggs, R. L., quoted..._____.._..___.......~-- 18, 19 H Hill Creek anticline....._.___....-.__.-------- 22 Horse Bench Sandstone Bed............-.---- 14 BQUIfOTL . c 222 coco cece ne- --- 4 17 I Independent-Tabor vein, gilsonite.. ..... 34 Industry in area....__._..__..._.. 4 Investigations, present and past.....-....---- 8 J, K Page Joints. ...... 0. lud ly ades iene 22 Kerogen-rich beds, Green River Formation.... _ 13 lithologic characteristics.. z 14 weathering characteristics...._.....------ 24 L Lake 5,6, 16 Little Bonanza vein, gilsonite........_....--.-- 34, 87 Little Emma vein, gilsonite...........------- 34 M McCook Ridge, oil shale suitable for strip . vc esen 26 Marker beds, Parachute Creek Member.... 15 Marketing, gilsonite...........---....-------- 86 Mahogany ledge.......~~- 18 Mahogany marker, tuff bed..........-.------- 16 Mahogany oil-shale bed.......__.....---.----- 18 bedding-plane slippage.....-..----------- 33 {ime plafipl..L cule niente 16 Mahogany ZOMG...__________._._._____.______~.-- 18, 26 Marlstone. See Oil shale. Mesaverde Formation, oil and gas...._...---- 40 Mining, 86 requirements, oil shale........_..--.------ 24 Morrison Formation, oil and gas._..._.._..---- 40 0 Oil and gag... 40 Oil shale, assay procedures.... 25 24 color, relation to kerogen content...... 13 defined.... .. 18, 24 development..............-- * #4 Douglas Creek Member.... ... _._. 9,12 fossils In.... c.. 100 2M Garden Gulch Member.. x 12 mining requirements.....___.-.....-.---- 24 Parachute Creek Member........_....~.-- 18 potential reserves....._.______------ 24, 27, 28, 29 relation of specific gravity to oil content:. 24 weathering characteristics. ...__.~- 13 resources, Uinta Basin......_._._...-.---- 26 Oil traps, stratigraphic and structural features. 40 Origin of gilsonite-forming petroleum, theories. _ $5 Pr Q P.R. Springs area, bituminous sandstones... . 39 Parachute Creek Member, bituminous sand- SFONBS. ... Gose cein engine nut 87 discussion.... .._. ce eli os 18 _____________ 16 _____ 8,15 oll 2a 48 tuff /o. 18 Petroleum, gilsonite-forming, theories on ori- gin... eve duane ece nases 85 Phosphoria Formation, oil and gas........... 40 Piceance Creek basin..._._.......--- + 1 Plastic flowage, sandstone beds... ah 15 Suff beds. . . :... . CLD esi tne 17 47 48 Population of area... collin 4 Potential oil-shale reserves, estimated from sample-assay data 25 Pride-of-the-West vein..._.___________________ 34 Quaternary Systemi....>.. - l. 22 R Rainbow vein, gilsonite....._________________ 34, 37 Red beds, Wasatch Formation.. .... 2000000000 iii s 44 Renegade Tongue, Wasatch Formation. ._____ 4,6 Wasatch Formation, gilsonite veins.._____ 31 Reserves, gilsonite, estimated.....____________ 87 oil-shale, classification. .__________________ 25 methods of computing..._____________ 25 24, 27, 28, 29 000.2000 G2 :. 26 8 Sandstones, bituminous....____._____________ 87 Source of sediments, Douglas Creek Member. 12 Duchesne Formation.._..________________ 21 Evacuation Creek Member.._.___________ 18 Garden Gulch Member..._.___._______.___ 13 Green River Formation.. 8 Parachute Creek Member...._.______.___ 16 Uints 21 Wasatch Formation......._.__.___________ 6 INDEX Specific gravity of oil shale, relation to oil Springs Stratigraphic section, south flank of Uinta Mountains...... ci .s relation to bitumin accumulations....____ Uinta Basin.....1.s..00000..00.. {ROE} Sweetwater Canyon, bituminous sandstones MOST .o. cs 20202. acolo naan oa T Tertiary System, oil and gas... Time plane, Mahogany oil-shale bed. Tonnage estimates, Mahogany zone, 15 gallons ofl per Mahogany zone, 25 gallons oil per ton.... 30 gallons oil per ton....__..__________ Topography of area....________________ Tuff beds, Evacuation Creek Member flowage Parachute Creek Member..______________ U,. V Uinta Basin, description . gilsonite mining.. .. Page Uinta Formation, discussion...__.____.______ fogsls.... 200. .ll geen AL Oe n.. . Uncompahgre uplift, oil and gas Unexposed rocks, stratigraphy... Utah, exploration wells...__________ indicated oil-shale reserves, estimated at legal per estimated at 25 gal per ton estimated at 30 gal per ton. inferred oil shale reserves, estimated at 15 gal-per ton............_. estimated at 25 gal per ton. estimated at 30 gal per ton_.__________ Vegetation....._.____ fish ie ari ls at Wagonhound vein, gilsonite....._.__._________ Wasatch Formation, basal conglomerate. .____ discussion. .. cis 0.0. Water supply, study area. ._. Weathering, effect on oil shales... Weaver-Colorado vein, gilsonite.. Weber Sandstone, oil and gas. ._. Wells, exploration, mapped area. White River, rich oil shale near....___________ U.S. GOVERNMENT PRINTING OFFICE: 1967 - O-236-486 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY WP. by €, ~ £0 4491, 14,77 &, \\/ (* \ew @R M. sxe" x_col D Co EMER RAN \_’/-\—’/_\\-/G \ *% Al ye #7 Bonanza 0 R white X / Bonanza o UINTAH_ CO 4 CARBON -CO 55 A aA . U* pC mas ho Co co 2 CARBOpy UINTAH co | EMERY =o." GRAND CO \fi\ Ex 0 5 10 MILES I I METERS FEET o- 0 m+ 100 - hve. 500 Marble Spring 200- Ao" 300+ 1000 400- -1500 500-7 69971-2000 FENCE DIAGRAM OF THE GREEN RIVER FORMATION AND THE UPPER PART OF THE WASATCH FORMATION IN THE SOUTHEASTERN PART OF THE UINTA BASIN, UTAH AND COLORADO Explanation of geologic symbols shown on plate 1 PROFESSIONAL PAPER 548 COLORADO ves \§UINTéH Co GRAND Co 0 5 10 KILOMETERS 236-486 O - 67 (In pocket) No. #1 A BIG CANYON Sec. 14, T. 13 S., R: 17 t. Sec. 7, 1.13 S., R. 18°C. (Unsurveyed) Estimated oil yield (gallons per ton) 60 30 0 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Horse Bench Sandstone Bed Note: Lower halves of sections A, B, and C are generalized intervals measured with aneroid barometer B WILD HORSE CANYON Secs. 15 and 16, T. 14 S., R. 17 E. (Unsurveyed) Estimated oil yield (gallons per ton) 60 30 0 C FLORENCE CANYON Secs. 25 and 36, T. 16 S., R. 17 E. (Unsurveyed) Estimated oil yield (gallons per ton) eo so o ._ D NEAR HEAD OF POST CANYON Secs. 7 and 8, T. 17 S., R. 19 E. Estimated oil yield (gallons per ton) 60 30 0 o o o o 0 o 9, I I Tongue Y of the Wasatch Formation Tohgue E of the Douglas Creek Member Tongue Z of the Wasatch Formation Tongue F of the Douglas Creek Member 1 Ie \ o o o ATT: _T T3 pest Tongue A Renegade Tongue of the Wasatch Formation sees Main body of the Wasatch Formation STRATIGRAPHIC SECTIONS OF THE GREEN RIVER AND ADJACENT Douglas G GREEN CANYON Secs. 7, 8, 9, and 10, T. 13 S., R. 20 E. Estimated oil yield (gallons per ton) 60 30 0 -~ E RENEGADE CANYON Secs. 33 and 34, T. 18 S., R. 20 E. Secs. 18 and 19, T. 19 S., R. 20 E. Estimated oil yield (gallons per ton) 60 30 0 1Anafyzed oil yield (gallons per ton) 60 30 0 F HAY CANYON Secs. 20, 28, and 29, T. 16 S., R. 23 E. Estimated oil yield (gallons per ton) *Analyzed oil yield (gallons per ton) 60 30 0 Member f 4 53 on £35. 4+4 o* C EFE i gis A Fak TC EF HFE 44 H F 4344 edd cf odd fdsaf 4294 pd def e 49 Lad d - I4 H WILLOW CREEK Secs. 20 and 29, T. 12 S., R. 21 E. Estimated oil yield (gallons per ton) 60 30 0 CJT .T 2Analyzed oil yield (gallons per ton) 6030 0 = Parachute 35555 Creek £23; Member Z: Unit W of the Renegade Tongue Uinta Formation Parachute Creek Member Mahogany. marker ---_-____2c 2002000000 00 Mahogany oil-shale bed I HORSE CANYON Secs. 7 and 18, T. 16 S., R. 24 E. Estimated oil yield (gallons per ton) 60 30 0 narnia Evacuation Creek Member K BITTER CREEK Secs. 21 and 28, T. 12 S., R. 23 E. Sec. 4, 1/13 8.. R. 23 C. Secs. 15, 21, 34, and 35, T. 13 S., R. 24 E. Secs. 2 and 12, T. 14 S., R. 24 E. Sec. 21, T. 14 S., R. 25 E. Estimated oil yield (gallons per ton) 60 30. 0 r; r T 4 w 4.4 14 <4 s 4 424 bobo bs EBs bs bek. [[ bebe pe bobs bsb uk -= Faz? 3 y o " Analyzed oil yield J a a is (gallons per ton) Ir 60 30 0 Tongue B of the Douglas Creek Member Unit W of the Renegade Tongue Tongue C of the Douglas Creek Member Unit X of the Renegade Tongue - 1 [ & lo &; 1A C 313 0 T; *t Hlo ~ L‘f’o Di - \<£\ i> '.~O/ IO T. 1 ym -~ =-- T :T‘157/z s T, Aa R: 26 E R ZE R 2iE a 2It n #s ¢ EXPLANATION / ' H Location of measured stratigraphic section G:: B' Approximate southwestern limits of pre- dominantly marly facies of the Para- chute Creek Member -- --- €: Approximate southwestern limits of the Mahogany marker 5 10 MILES LOCATIONS OF MEASURED SECTIONS AND APPROXIMATE LIMITS: OF - SELECTED LITHOLOGIC UNITS Tongue D WEST BITTER CREEK Secs. 3 and 4, T. 16 S., R. 25 E. Estimated oil yield (gallons per ton) -100 -200 PROFESSIONAL PAPER 548 PLATE 3 O RAVEN RIDGE Secs. 11 and 12, T. 2 N., R. 104 W. N Estimated oil yield (gallons per ton) WHITE RIVER cd 30 0 Secs. 9, 10, and 11, T. 1 N., R. 103 W. ; f Estimated oil yield ~ (gallons per ton) pool 60 30 0 sr TAT Malt TLT.iT TaTLT M ne actin 1. Tiris Tutt HELLS HOLE CANYON FLCIT Ta *iTet wass Fig/EPA??? TCiEgKR pg g. _ Secs. 18, 20, 21, 22, and 25, e os ecs. 7, 21, 34, an 4. wR. F adh. 414+ T. 10 S., R25 E. i£TiT Tu Tat Secs. 1 and 25, T. 12 S., R. 25 E. (oh Timir as Estimated oii yield =[<]" Estimated oil yield (gallons per ton) T bit ¥ ie ge (gallons per ton) 60 30 0 zLiL: gh, soso o . % ¥ Kae, ...... Titgy fiT«* aTe Tivtir aTa«* siz TT T TIT t PWT" Titit TCT aT. Tu* .s tit? River ose Formation F Tayrkr Ti.rir Ten m= Tiryr Pail alt mur utr TaTaT Tarr ‘h-vrffi‘“ TaTaT Fifat iy se Pipit #> +. (es? Tit i+ Tirg- est i Taita«* {f+ Tir«~ mots Tima" Ziz*L iri+- TaT at TLT.LT Tur co TLT ar Pat at te on jar Tirir Tiryr *I+I4 Ti+{= Tatra" T*" 3 --- tur. + Trg Taa wi +i rl + _ TaLTLT 7 of the Green Ter, River Formation C s ss Tyre Tivrir Tut." " buti at th a T:*:* analcitized tuff {ii—afi Manel ILIJ—I o z gl. __ Be if -- ~~ (I Ting. a+. Te, «T TJ_*4?:' Analyzed oil yield molp 2 Analyzed oil yield Ti'4 T ITfT: ; se I firgr a ao to (gallons per ton) *I" Ll (gallons per ton) A# * 60 30 0 arte 60 30 0 4 TTA Contorted tuff beg "Tan WTT A is iP u turn 3.1.4.1-4 t+ ors Tara Member | 47 IC a/+ # §/. N x *, / < < x - % 3 P9 "al 3 N 5 G x~ G > / ye & cx > / / Ceo ss mem Douglas Creek Member of the Green River Formation o go 6a +48 [P & A Member EXPLANATION Gray and green shale i_ __ Red shale Shale Gray grading laterally to red Silty marlstone Sandstone Bitumi Conglomerate FORMATIONS IN THE SOUTHEASTERN PART OF THE UINTA BASIN, UTAH AND COLORADO Limestone Bed containing evaporite crystal cavities >- >- >- mal mel ae Tuff, or altered tuff, less than 0.5 ft thick Tuff, or altered tuff, more than 0.5 ft thick Oil shale Marlstone that yields approxi- mately 15 or more gallons of oil per ton when retorted by U.S. Bureau of Mines 2Analyzed by U.S. Geological Survey es Algal limestone 0000000 00 00 000 0 00 0 $0 Oolitic limestone Ostracodal limestone n L Geographic location of stratigraphic sections shown on plate 1 INTERIOR-GEOLOGICAL SURVE Y, WASHINGTON, D. C -1966-Gés112 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY 1 COTTONWOOD CREEK Sec. 31, T. 1 N., R. 103 W. Estimated oil yield (gallons per ton) 2 -~ 60 30-0 Analyzed oil yield) | (gallons per ton) § 60 50 0 7 AGENCY DRAW Sec. 19, T. 13 8.. R. 21 E. Estimated oil yield (gallons per ton) 60 30 0 13 FIREWATER CANYON Sec. 8, T. 14 8., R. 18 E. (Unsurveyed) Estimated oil yield (gallons per ton) 60 30 0 ! Analyzed oil yield (gallons per ton) 60 30 0 21 CHANDLER CANYON Sec. 9; T. 15 S., R. 18 £. Estimated oil yield (gallons per ton) 60 ! Analyzed oil yield (gallons per ton) 60 30 0 27 DESERT SPRING Sec. 12, T. 16 S., R. 18 C. Estimated oil yield (gallons per ton) 60 30 0 . 1 Analyzed oil yield (gallons per ton) 60 30 0 33 SPRING CREEK Sec. 1, 1.17 S., R. 19 E. Estimated oil yield (gallons per ton) 60 30 0 Analyzed oil yield (gallons per ton) 60 30 0 STRATIGRAPHIC 2 cowBOY CANYON Sec. 28, T. 9 S., R. 25 L. Estimated oil yield (gallons per ton) 2 . 60.30 0 Analyzed oil yield T es, (gallons per ton) yee 60 30 O- arie 8 THREEMILE CANYON Sec. 8. T. 13 S., R. 25 £. Estimated oil yield (gallons per ton) 2 Analyzed oil yield (gallons per ton)60 30 9 , ... . , 60 30 0 £ 14 S PARK CANYON Sec. 25, T. I1 8., R. 25 C. Estimated oil yield (gallons per ton) 30 0 2 Analyzed oil yield <*> allons per ton ts 60.30 O‘l D 9 ZANE CANYON Sec. 9, T. 13 S., R. 24 E. +Estimated oil yield (gallons per ton) 60 30 0 2 Analyzed oil yield (gallons per ton) 60 30 O- MOUTH OF HORSECORN CANYON Sec. I. T.: 14 S.. R. 19 £. Estimated oil yield (gallons per ton) 60 30 O _ 1 Analyzed oil yield (gallons per ton) 60 30 0 22 WAGON CANYON Seo. 17, T. 15 S., R. 20 E. Estimated oil yield (gallons per ton) 60 30 0 | | | | | | | 1 Analyzed oil yield! (gallons per ton) 60 30 0 28 LITTLE MOUNTAIN $66. 31, T. 16 S., R. 19 C. Estimated oil yield (gallons per ton) 60 30 0 1 Analyzed oil yield (gallons per ton) 60 30 0 34 COAL CREEK Sec. 31, 1. 17 S.. R. 19 C. Estimated oil yield (gallons per ton) 6030 0 Top of Mahogany 15 TABYAGO CANYON Sec. 6, T. 14 S., R. 19 C. Estimated oil yield (gallons per ton) 60 30 0 238 HIDDEN SPRING Sec. 33, 1. 15 5., R. 20 t. Estimated oil yield (gallons per ton) 60 30 0 ! Analyzed oil yield (gallons per ton) 60 30 0 29 BLACK KNOLLS Sec. 5, 1T. 16 S.. R. 20 C. Estimated oil yield (gallons per ton) 60 30 0 ' Analyzed oil yield (gallons per ton) 60 30 0 35 PIOCHE CREEK Sec. 20, T. 17 $.,. R. 20 E. Estimated oil yield (gallons per ton) 60 30 0 oil-shale bed 6 SUNDAY SCHOOL CANYON Sec.: 16, T. 13 S., R. 22 C. Estimated oil yield (gallons per ton) 60 30 0 4 o LONG DRAW LOWER THREEMILE CANYON Sec. 36, T. 12 S., R. 24 E. SecB, I. 12 S.. R. 25 C. Estimated oil yield Estimated oil yield (gallons per ton) (gallons per ton) 60 30 0 6030 0 2 Analyzed oil yield | allons per ton) C 60 go 0 Mahogany marker Top of Mahogany oil-shale bed 12 NEAR WILD HORSE CANYON Sec. 26, T. 14 S.. R. 17 C. (Unsurveyed) Estimated oil yield (gallons per ton) 11 60 30 0 KLONDIKE CANYON Sec. 17, T. 13 S., R. 23 E. Estimated oil yield (gallons per ton) 10 SWEETWATER CANYON Sec. 27, T. 13 8., R. 23 C. Estimated oil yield (gallons per ton) 'Analyzed oil yield (gallons per ton) 60 30 0 60 30 0 ares 2 Analyzed oil yield Mahogany marker pce allons per ton) ess oil-shale bed S9 20, P Top of Mahogan 16 HORSECORN CANYON 17 Sec. 22, T. 14 S., R. 19 E. 18 FLAT ROCK UTE CANYON Estimated oil yield (gallons per ton) 60 30 O, Sec. 36, T. 14 S., R. 20 E. Estimated oil yield (gallons per ton) $0 30 O Sec. 18, T. 14 S., R. 21 E. Estimated oil yield (gallons per ton) 60 30 0 2 Analyzed oil yield (gallons péer ton) 60 0 1 Analyzed oil yield o (gallons per ton) § 1 Analyzed oil yield (gallons per ton) 60 30 0 atic 26 BLUEBELL CANYON Sec. 1, 1. 16 S.. R. 17 E. Estimated oil yield (gallons per ton) 60 30 0 25 MEADOW CREEK Sec..21; 1. 15 S.,. .R. 21 E: Estimated oil yield (gallons per ton) 6030 0 I\ FFELEL 24 DRY CANYON Sec. 19, 1. 15 S., R. 21 E. Estimated oil yield (gallons per ton) 60 30 0 1 Analyzed oil yield (gallons per ton) 60 30 0 Top of Mahogany oil-shale bed 32 MOON RIDGE Sec. 19, 1.16 S.. R. 22 C. Estimated oil yield (gallons per ton) 60 30 0 30 UPPER WILLOW CREEK Sec.:31, T. 16 8., R. 21 L. Estimated oil yield (gallons per ton) 60 30 0_ 3 31 WINTER RIDGE Seo. 1, T. 16 S.. R. 22 E. Estimated oil yield (gallons per ton) 60 30 0 oil-shale bed Top of Mahogany -- 36 ROAN CLIFFS Sec. 20, 1. 17. S., R. 22 E. (Unsurveyed) Estimated oil yield (gallons per,ton) 60 30 0 + 38 DIAMOND RIDGE Sec. 2, T. 18 S., R.21 C. Estimated oil yield (gallons per ton) 60.30 0 / _ 37 UPPER HILL CREEK Sec. 1, T. 18 S., R. 19 E. Estimated oil yield (gallons per ton) 60 30 0 404 4 414, + Gon * Analyzed oil yield (gallons per ton) 60 30 O Top of Mahogany Av z weal PROFESSIONAL PAPER 548 PLATE 4 EXPLANATION Sandstone Conglomerate Crossbedded sandstone Bituminous sandstone Siltstone Maristone « -+ f Oil shale MarIstone that will yield 15 or more gallons of oil per ton 1 Analyzed by U.S. Bureau of Mines 2 Analyzed by U.S. Geological Survey Silty limestone == Algal limestone 0000 0000 0 Oolitic limestone Tuff, or altered tuff, less than 0.5 ft thick -- Tuff, or altered tuff, more than 0.5 ft thick Geographic location of measured sections shown on plate 1 19 RIGHT FORK OF UPPER BOTTOM Sec. 35, T. 14 S., R. 21 E. Estimated oil yield (gallons per ton) 60 30 0 39 SALERATUS CANYON Sec. 1, T. 19 S.; R. 19 L. (Unsurveyed) Estimated oil yield (gallons per ton) 60 30 0 oil-shale bed INTERIOR-GEOLOGICAL SURVEY, WASHINGTON, D. C.-1966-G66112 FORMATION, SOUTHEASTERN UINTA BASIN, UTAH AND COLORADO FEET 25 50 20 CROW ROOST CANYON Sec. 10, T. 14 S., R. 22 E. Estimated oil yield (gallons per ton) 60 30 O _ w 40 EAST WILLOW CREEK Sec. 6, T. 19 S.,. R. 21 E. Estimated oil yield (gallons per ton) 60 30 0 ! Analyzed oil yield (gallons per ton) 60 30 0 SECTIONS OF THE MAHOGANY LEDGE AND ADJACENT BEDS IN THE GREEN RIVER UNITED STATES DEPARTMENT OF THE INTERIOR PROFESSIONAL PAPER 548 GEOLOGICAL SURVEY PLATE 5 on“) yg poon" T.11 5. $29 f s & $Ars, ‘ ers. UINTAK_ CO ' I ~HEZ- UINTAH__CO 3 | ’ UINTAH_ CO CARBON CO 232 1.35. CARBON. CO0 _ f az". R sat tizs /\ Z " 1% 74285. : : a t ist a." issourt Greek (nam cree A - T. 36: b S f 4 +4 ] UTAH _L __ COLORADO - [zd & COLORADO ___ ~ RESERVE No. 2 a COLORADO $ *. ...-_-* Liofues dee VU"\\)\)\I\J o a =! a Granp CO EMERY "CO R.24 E. EXPLANATION e t s) 5 naan aler oie al Line showing thickness, in feet, of la _ a sequence of oil-shale beds Area of indicated potential Dashed where Mahogany oil-shale bed is eroded. Thickness interval reserves 10 feet Reserve No. 2 Short dashed where unsurveyed Area of inferred potential & 70 E Location of core hole; oil content of cores assayed Outcrop of Mahogany oil-shale bed g A. OIL-SHALE BEDS THAT YIELD AN AVERAGE B. OIL-SHALE BEDS THAT:YIELD AN AVERAGE EXPIO’aCtOgW‘f“? oil figment“ C. OI-SHALE BEDS THAT YIELD AN AVERAGE OF 15 GALLONS OF OIL_PER TON OF 25 CALLEONS OF oll. PER TON nil{hee assays OF so -GALLONS OF OIL PER LON R. 20 C MAPS SHOWING THICKNESS OF SELECTED OIL-SHA IN THE SOUTHEASTERN PART OF THE UINTA BASIN, UTAH AND COLORADO LE ZONES OF THE GREEN RIVER F ORMATION 20 30 35 MILES ks I ad 20 35 KILOMETERS " wa o _ ] 236-486 O - 67 (In pocket) No. #2