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Digitized by the Internet Archive 
 
 in 2012 with funding from 
 
 University of Illinois Urbana-Champaign 
 
 http://archive.org/details/earthhistory49illi 
 
Earth History Field Trip 
 for High School Science Teachers 
 Vienna, Illinois,, November 5, 1949 
 
 Sponsored by State Geological Survey 
 M. M. Leighton, Chief 
 Gilbert 0, Raasch, Conference Director 
 Principal B» W, Hunsakcr, Conference Host 
 
 MINERAL RESOURCE 
 RECORDS DIVISION 
 
 ILLINOIS STATE 
 GEOLOGICAL SURVEY 
 
 General Instructions : 
 
 1. Please be prepared to leave promptly at 9:00 A.M». 
 
 2, Cars will assemble at Vienna Township High School, 
 
 3. Participants will provide themselves with lunches before starting. 
 
 4, At scheduled stops, please assemble promptly near leader to hear his 
 discussion before scattering for individual examination of points of 
 interest; also please be prompt to leave upon signal. This is espe- 
 cially desirable if the group is large. 
 
 Instructions for Car Drivers: 
 
 To expedite the trip and for safety, please 
 
 1. 
 2. 
 3. 
 
 4. 
 
 5. 
 
 6. 
 
 7. 
 
 9. 
 
 10. 
 
 Identify your car by attaching one of the tags provided. 
 Have your car in line before the trip starts. 
 
 Follow carefully and keep fairly close to the car ahead, with due 
 regard to safety. 
 
 Keep all gaps in the caravan closed, especially while traveling 
 through the city, in order to prevent other cars from inserting 
 themselves in the caravsn or crossing the caravan at intersections. 
 Watch the cars ahead and behind for signals. 
 
 Keep your place in the caravan as far as possible; do not attempt 
 to pass ahead of any in the caraven unless they drop out of line, 
 nor to gain an advanced position at stops. 
 
 If for accident or other reason you drop out of line, let those fol- 
 lowing you proceed, except for such help as may bo needed; in case of 
 accident to the rear car of the caravan , signal those ahead. 
 Any car dropping out of line shall take up the rear when rejoining 
 the caravan. 
 
 When parking in line at stops, draw close to the car ahead; when park- 
 ing parallel, do not leave unnecessary space between cars. 
 One passenger in each car, preferably sitting beside the driver, should 
 read the itinerary and keep the driver adequately informed with regard 
 to stops, turns, etc. 
 
Part II 
 
 ITINERARY 
 
 Vienna and Paducah Quadrangles 
 
 0.0 0,0 Caravan assembles on west side of Vienna Township High School. 
 
 0.2 0.2 CAUTION, Route 45. Turn right (S) on 45. 
 
 0.4 0.6 CAUTION. Junction with Route 146. Turn left (E) on 146, 
 
 0.3 0.9 CAUTION. Railroad crossing. 
 
 0.8 1.7 Turn right (S) on gravel road. 
 
 0.9 2.6 Road forks; go left (SE). 
 
 2,1 4,7 STOP No, 1. Mississippian, Hardinsburg Sandstone along creek. The 
 thin, even sandstone layers can be seen sloping (dipping) northerly 
 at an angle steeper than the fall of the creek. All of the bedrock 
 strata in the Vienna Area show this northerly dip. They were, of 
 course, deposited in a horizontal position. Then movements of the 
 earth's crust after Pennsylvanian Time, that formed the Illinois 
 Basin to the north, caused an upward tilting of the formations, so 
 that the layers slope downward to the north. 
 
 Erosion then planed across this uplift and exposed the edges 
 of the series of formations. 
 
 The Mississippian Formations of the Vienna Area were formed 
 in late Mississippian time and are referred to as the Chester Group. 
 This is a series of sandstone, limestone, and shale formations. The 
 sandstone formations are the hardest and act as caprock of the ridges. 
 The shales are weakest, erode rapidly, and are generally concealed 
 in the valley bottoms. 
 
 Ycu will note as we progress southward that the north slopes of 
 the ridges are gentle, conforming closely to the inclination of the 
 bed rock; but the south slopes are steep. This is because here ero- 
 sion has broken through the hard caprock and cut down rapidly through 
 the weaker formations below. (See sketch in Appendix.) Such ridges 
 are called cuestas , and their steep sides are called escarpments. 
 The most prominent escarpment in southern Illinois runs along the 
 north edge of the Vienna r uadrangle and is formed by the thick sand- 
 stone mass (Caseyville Sandstone) that lies at the base of the 
 Pennsylvanian. 
 
 This present outcrop illustrates very well the horizontal bed- 
 ding of water-deposited rock strata. The rock is also closely di- 
 vided by vertical fractures, known as joints. A hard layer of sand- 
 stone, when it is deeply buried in the earth, is like a sheet of 
 glass. If a sheet of glass is twisted, it will shatter in a pattern 
 of quadrangular fragments. The twisting that the Hardinsburg Sand- 
 stone layers have suffered has similarly caused a breaking into 
 quadrangular slabs. 
 
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The breaking of rock by the jointing process throws it open for 
 attack by erosion. N te how the waters of the creek follow and widen 
 the joint crevices. In places where pebbles accumulate, the eddying 
 motion of the water enables them to wear "pot-holes" in the sandstone, 
 
 4.7 Continue ahead (S) toward New Columbia. 
 
 5,5 10,2 Checkpoint - New Hope School. 
 
 1.0 11,2 Turn right (S) where blacktop begins, 
 
 0.5 11,7 Outcrop of Cypress Sandstone, (Descend Cypress escarpment,) 
 
 1.2 12,9 Road junction, turn left (S), 
 
 1.3 14,2 Turn left (E) in Cache Bottom. 
 
 0,6 14,8 Turn left (N) and ascend bluff of Mississipian Tar Springs Sandstone. 
 
 1.1 15,9 STOP No* 2, Walk east on old road and southeast across field, We 
 
 are looking south across the valley of the Ohio River to the low< 
 rolling hills of the Gulf Coastal Plain beyond. 
 
 Today the Ohio River does not flow through the valley it had 
 cut across southern Illinois, Instead it has borrowed the valley 
 of the Tennessee River in its course from Paducah to the Mississippi. 
 
 How this came to pass is a fairly complicated story. Before 
 the Ice Age, the Ohio River above Cincinnati flowed northwestward 
 across Indiana and central Illinois to the Mississippi. When the 
 glaciers moved down they blocked this northward flowing drainage and 
 caused the Ohio to cut a new valley westward south of the ice 
 masses. 
 
 This valley, which lies in the foreground, runs past Homberg 
 and Brownfield, and westward past Belknap, Karnak, Ullin, and Olive 
 Branch, The eastern part of this valley is now occupied by Big Bay 
 Creek and the western part by Cache Creek. The portion of the valley 
 in the foreground has no stream today. 
 
 The last of the ice sheets to come down from the north, the 
 Wisconsin Glaciation, did not reach southern Illinois, But, when it 
 melted away it released great quantities of water and of sediment. 
 This load of sediment continued to build up on the valley floor, 
 until the stream flowed several hundred feet above its original 
 level. The old Ohio valley was also filled by sediment, partly by 
 material washed down the Wabash, and partly by silt and clay deposited 
 in the backwaters from the swollen Mississippi. 
 
 At a later stage in Wisconsin Time a torrent pouring down the 
 Wabash broke through the low divide between the Ohio and the Cum- 
 berland and from thence onward the Ohio flowed down the valley of the 
 Tennessee, Finally the river abandoned its older, northern channel, 
 except in times of very high water such as the flood of 1937. 
 
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15.9 Resume route* 
 
 1.9 17.8 Junction with main gravel road at east end of New Columbia, Turn 
 right (E), 
 
 0.4 18.2 CAUTION. Begin descent of hill. 
 
 0.1 18.3 STOP No. 3, Cliff of Mississippian, Tar Springs Sandstone that once 
 was the Ohio River bluff at time when that river flowed through 
 Cache-Big Bay Valley. 
 
 The folding in the thinner layers near the top of the cliff is 
 probably not the result of earth movement since it is not reflected 
 in the massive sandstone below. The same thin bedded sandstone 
 above the falls on the west side of the road shows no folding. 
 
 A clay zone of irregular thickness between the two sandstone 
 zones probably caused the folding as this clay was irregularly 
 compacted by the weight of strata above it. 
 
 18.3 Resume route and cross Cache Valley, Note absence of any natural 
 stream in this abandoned river valley. 
 
 2,0 20,3 Ascend low ridge that marks SE side of valley. This may be a na- 
 tural levee, 
 
 3,2 23,5 Road corner in Round Knob Village; turn right (S), 
 
 0.2 23,7 STOP No, 4, Roadcut on Round Knob-Metropolis Road. 
 
 Since crossing the Big Bay Creek-Cache Creek Valley, we have 
 been traveling over the rolling topography of the upper Gulf Coastal 
 Plain, This belt of country can be traced southeastward across the 
 Kentucky "Panhandle," Tennessee, eastern Mississippi and Alabama, 
 and thence round the south end of the Appalachians to become the At- 
 lantic Coastal Plaino Geologically we are in the "Deep South," and 
 this southern flavor is reinforced here by glimpses of cypress and of 
 cotton. 
 
 The hills north of the Cache-Big Bay Valley are carved in bed- 
 rock at Paleozoic Age, The country to the south is underlain by 
 much younger and largely unconsolidated sands, clays, and gravels 
 of Cretaceous and Tertiary age. 
 
 The unconsolidated deposits of the Coastal Plain Province in 
 Illinois fall into three groups. The first and oldest group- 
 was deposited here as the result of the Gulf of Mexico Embayment 
 which in earlier times extended as far north as the southern tip of 
 Illinois. The sediments laid down in Illinois at this time came to 
 rest largely in lowlands bordering the sea of Cretaceous and Eocene 
 time. 
 
 There followed a period of moderate uplift during which the 
 Eocene and part of the Cretaceous sediments were removed. This 
 interval of non-deposition in southern Illinois extended through 
 Oligocene and Miocene time. 
 
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 In Pliocene time that followed there was deposited, for reasons 
 not thoroughly understood, a blanket of gravel over the eroded land 
 surface of what is now Illinois • These gravels, to which the term 
 LaFayette is loosely applied, occur widely over the Mississippi 
 Valley and Atlantic Coastal Plain, They are peculiar for their high- 
 ly polished surfaces and for the fact that they consist of only the 
 most resistant types of rocks such as chert, quartz, and quartzite. 
 
 Upon these gravels, or separated from them by a limited thickness 
 of colluvial sand or silt wash are several layers of loess, and ashy, 
 pulverent material deposited over the uplands by the winds of the 
 Ice Age (Pleistocene.) Since there was not one, but four glacial 
 stages during the Pleistocene, there are zones of loess corresponding 
 to several of these glaciations. Between the glacial stages there 
 were long mild periods during which soils formed and the upper part 
 of the respective underlying loess was leached by the downward 
 moving rain waters. This alteration of the loess zones of different 
 age permits their recognition and discrimination. 
 
 At the present outcrop about 10 feet of ashy Cretaceous clay 
 is present overlain by about ten feet of loess except at the north 
 end of the exposure. Here a layer of Pliocene, LaFayette gravel 
 intervenes between the clay and the loess. Elsewhere along the loess- 
 clay contact may be seen a zone with masses of limonite and pebbles 
 from the LaFayette gravel. Evidently the LaFayette deposit once 
 extended continuously above the clay but was removed before the 
 deposition of the loess. The loess itself consists of zones of dif- 
 ferent age but their discrimination is difficult here becuase of 
 modern weathering, 
 
 23,7 Continue ahead (S), 
 
 0,6 24.3 STOP No, 5, Cretaceous red sand is seen here above the Cretaceous 
 
 silty and micaceous clay* Above this lies from 1 to 5 feet of LaFay- 
 ette gravel overlain in turn by Pleistocene loess. At the preceding 
 stop (No. 4), the Cretaceous sand had been removed by erosion before 
 the deposition of the LaFayette gravel there, 
 
 24,3 Continue ahead (S). 
 
 0,4 24,7 STOP No. 6 Outcrop of about 10 feet of Cretaceous red sand and 
 sandy clay overlain by 12 feet of loess and loessal soil. The 
 LaFayette gravel is missing here, but its former presence is indi» 
 cated by a zone of residual pebbles between the Cretaceous sand and 
 the Pleistocene loess. 
 
 Note that in this area, generally, the LaFayette gravel, when 
 present, may lie on different zones of the Cretaceous, Such an ir- 
 regular relationship between two formations is termed an unconformity 
 usually involving some uplift and erosion, between the period of 
 origen of the lower formation and that of the upper. 
 
Similarly the loess base is unconf ormable, resting in places 
 on the LaFayette gravel, in others on different zones of the older 
 Cretaceous strata* 
 
 24.7 Continue ahead (S), 
 
 0.7 25,4 Round Knob hill on left. South of here to Metropolis, route is over 
 low, flat river terraces of Pleistocene age, 
 
 4.6 30.0 Junction with Route 45 at Sinclair filling station in Metropolis. 
 Go half left (SE) on Route 45. 
 
 1.6 31,6 Enter Fort Massac State Park and follow part road past George 
 Rogers Clark monument » 
 
 0.4 32.0 Go right on gravel road to Tourist Camp* 
 
 0.2 32,2 LUNCH STOP. 
 
 32.2 Continue ahead (W) to Route 45, 
 
 0.1 32.3 Turn left (s) and follow Route 45 through Metropolis. 
 
 2.6 34.9 Leave Metropolis on Route 45, going NW over Pleistocene river terrace, 
 
 4,9 39.8 Choatc We are now among rolling hills of Cretaceous and Pliocene 
 formations. Pit on hill to right is in LaFayette Gravel. 
 
 2,4 42.6 ^nter Cache-Big Bay Valley, here separated by a low ridge, probably 
 
 a natural levee, from a backwater area immediately south. This back- 
 water still exists as a swamp today. 
 
 2.6 44.8 Mermet. 
 
 1,1 45,9 STOP No 4, 7. Walk west into Mermet Stone Company Quarry, Quarry is 
 in an "island'' of Mississippian bed rock lying south of the Cache- 
 Big Bay Valley* Pockets of red sand and clay which cut down into 
 the top of the quarry limestone arc of Cretaceous age- They serve 
 to tie this spot to the Gulf Coastal Plain Province rather than to 
 the Shawnee Hills Province to which the hills of Mississippian 
 strata belong, 
 
 The old bedrock surface profile, which here lies well above the 
 level of Cache bottom, slopes steeply to the South at the rate of 
 40 to 50 feet per mile, so that at the Ohio it lies hundreds of feet: 
 below the present surface. From the Mermet Q.uarry southward- the 
 rock disappear? beneath the cover of Cretaceous and Tertiary sediments. 
 
 The location of this limestone quarry well to the south in a re- 
 gion where otherwise only unconsolidated sediments outcrop is an 
 economic advantage.-, The rock is sold for agstone and road stone. 
 
The limestone in this quarry, the Ste-, Genevieve, is the highest 
 formation of the Lower i'ississippian (Iowa) Series and the oldest rock 
 to be seen on the trip. 
 
 - 45.9 Continue ahead (NW) and cross Cache bottom. 
 
 4.7 50.6 Junction with Belknap Road. Turn left (W). 
 
 1.8 52.4 CAUTION. Railroad crossing, 
 
 1.1 53.5 Cross Cache River at a point where it leaves its own valley (lying 
 
 among the hills to the north) and enters the oversized valley 
 abandoned by the Ohio v From this point it flows west and south 
 in the abandoned Ohio Valley to join the present Ohio just above 
 Cairo. 
 
 0.5 54.0 STOP No. 8„ Belknap Quarry* Limestones and shales of the Renault 
 and Paint Creek formations of the Chester Group exposed in the 
 quarry, with a very thin remnant of Cypress Sandstone remaining at 
 top. Fossils are very abundant in some of the shaly limestones. 
 Most numerous types are fenestellid bryozoa, brachiopods, and the 
 blastoid Pent remi tes„ Some of the limestone layers are oolitic, 
 that is, full cf tiny spherical concretions,, resembling fish eggs. 
 
 54 „0 Continue ahead (SW). 
 
 0.6 54,6 Intersection in Belknap* Make U-turn and reverse route to Highway 45. 
 
 4.0 58.6 Junction with Route 45. Turn left (lJ) on No, 45. 
 
 1.2 59.8 Outcrop of Golconda Limestone on righto A better exposure lies 1 l/2 
 
 miles northeast, in the SW | of NE \ t Sec 22, T. 13 3„, R. 3 E. 
 
 2 # 4 62.2 STOP No. 9, Quarries west of Highway c . Exposure consists primarily 
 cf wo quarries,; one lying relatively to the south f the other to the 
 westo 
 
 Mississippian, Glen Dean Formation, vjith 30 feet of white to 
 light gray solid limestone at base., made up largely of ground-up 
 fossil remains., Above this is about 25 feet of dark gray $ fissile 
 shaie with interbedded ferrugious limestone layers near top which 
 show current ripple-marks, pebbles, and other indications of the 
 shallow /rater origin of the rocke This is also indicated by cross- 
 bedding in the lower massive limestone,. 
 
 In the south quarry p. mass of Tai Springs Sandstone cuts down 
 into the shale to within 5 feet of the lower massive limestone, The 
 sandstone evidently fills an old channel cut into the top of the 
 Glen Dean Formation, 
 
 Many of bhe joint crevices in the Glen Dean Limestone have been 
 widened through solution by underground waters,- Here the fossils, 
 especially erinoidal remains have been etched into relief by erosion. 
 
Masses of dull brown travertine arc scattered about the floor of the 
 quarry, but their immediate source is not evident. 
 
 End of Conference. Bon Voyage I 
 
 Vienna 1,5 miles north. 
 
ERAS 
 
 PERIODS 
 
 EPOCHS 
 
 REMARKS 
 
 
 w 
 
 r-l 
 
 g 
 
 a) 
 
 S 
 
 o 
 
 © 
 
 < 
 
 Quaternary 
 
 Pleistocene 
 
 Unglaciated; glacial stages 
 represented by loess zones 
 and alluvial terraces* 
 
 e 
 V 
 
 Tertiary- 
 
 Pliocene 
 
 LaFayette Gravel, 
 
 Cw 
 
 O -H 
 •H J 
 O 
 
 Miocene 
 
 Not present in Illinois, 
 
 « -P 
 
 2 c 
 G © 
 CD o 
 o © 
 
 Oligocene 
 
 Not present in Illinois* 
 
 rt 
 
 Eocene 
 
 Not present in field area. 
 
 
 Paleocene 
 
 Not present in field area* 
 
 
 Age of 
 
 Reptiles 
 
 Cretaceous 
 
 
 McNairy Sands and Clays. 
 
 ozoic 
 iddle 
 ife" 
 
 Jurassic 
 
 
 Not present in Illinois* 
 
 W 3 J 
 © S 
 
 Triassic 
 
 
 Not present in Illinois* 
 
 
 Age of Amphibians and Early- 
 Plants 
 
 Permian 
 
 
 Not present in Illinois 
 
 
 Pennsylvanian 
 
 
 Caseyville sandstone along 
 north edge of Vienna Quad- 
 rangle. 
 
 ~© 
 
 Cm 
 
 O -H 
 
 Mississippian 
 
 Chester 
 
 A thick series of rather %) 
 thin sandstone, limestone 
 and shale units. 
 
 Paleozoi 
 Ancient L 
 
 Iowa 
 
 Chiefly thick limestone for- 
 mations. 
 
 ■ 
 
 Agecf 
 
 f 
 Devonian 
 
 
 No data in field area. 
 
 
 1 
 Age of 
 [rare rtebr ate s 
 
 Silurian 
 
 
 No data in field area» 
 
 
 Ordovician 
 
 
 No data in field area. 
 
 
 Cambrian 
 
 
 No data in field area. 
 
 Proterozoic 
 
 •H 
 © 
 
 
 
 No data in southern Illinois 
 
 fcrcheozoic 
 
 
Part IV 
 Geologic History 
 
 If borings for deep wells went thousands of feet deeper than they do in the 
 Vienna Area, they would doubtless reach a foundation of hard crystalline rocks 
 such as granite and basalt, fife know this is the case elsewhere in Illinois and 
 adjoining states. This foundation is made up of most ancient rocks of Pre-Cam- 
 brian Age, Some of them originated as sediments in seas, some from molten magma 
 injected deep in the crust or expelled as lava, but all now broken and twisted 
 by ancient mountain-making stresses, The mountains themselves are long gone, 
 having been planed away to their roots by erosion before the ancient Paleozoic 
 seas swept over the ^orth American Continent. 
 
 This "reign of the ancient seas" began some 500,000,000 years ago and en- 
 dured for over 250,000,000 years. The lands surrounding these inland invasions 
 of the sea were low and could not supply much sediment, so that for the most 
 part, limestones were deposited in the clear and shallow waters. This continued 
 to be the case until late in Ilississippian time, when the lands began to rise 
 intermittently, erosion set to work, and sands and muds began to fill the interior 
 sea. By Pennsylvanian time, with the rise of the mountains along the East Coast 
 and in the Midcontinent, prodigious quantities of sediment were brought into the 
 interior sea blotting it out much of the time, to turn the region into a swampy 
 coastal plain. It was under these conditions that Illinois' rich coal deposits 
 were formed. 
 
 Following Pennsylvanian time, all of Illinois rose above the sea, most of 
 it never to be submerged again. Erosion set to work to cut away the rock layers 
 and "t;o carry the detritus thus formed off into distant oceans. By Cretaceous 
 Time the sea again approached Illinois and the Gulf of Mexico extended over the 
 southern tip of the State, Here it remained through the early part of the 
 Tertiary Period that followed. Then, by Oligocene Time, the rise of the lands 
 to the north brought all of the state above the waters where it has remained 
 since that time. 
 
 Late in Tertiary <Iime when the YJestern Cordillera were rising to great 
 heights vast quantities of sand and gravel were washed down across the western 
 half of the Mississippi Basin to form deposits of great thickness, A charac- 
 teristic of these gravels is their highly polished surfaces. 
 
 In Illinois at this time a similar deposit of highly polished pebbles 
 (Pliocene, LaFayette Gravel) accumulated in a thin but fairly continuous blanket 
 over much of the state* The pebbles, however, did not come from the western 
 mountains but are largely of local origin, with additions from probably the 
 Ozarks and from the states to the north. 
 
 The immediately following period, the Quaternary, witnessed the successive 
 advance and retreat of great continental ice sheets that had their centers of 
 accumulation in various parts of Canada, None of them reached the Vienna Area, 
 but one, the Illinoian, stopped only ten miles north of the city. 
 
Nevertheless, the area has been profoundly effected by the glaciation. The 
 ice movements displaced major rivers and caused them to cut new valleys >; the 
 great quantities of sediment washed from the melting ice filled existing valleys 
 for hundreds of feet above their bedrock floors, and a blanket of fine dust, or 
 loess, was blown from these sediment-choked flood plains, to accumulate over the 
 uplands. 
 
 There is of course, no evidence that the Ice Age is ended. It has been 
 only some 25,000 years since the last of the continental glaciers melted away 
 In as much as some interglacial intervals lasted for several hundred thousand 
 years, the present period may be merely another such an interval, to be termi- 
 nated in a hundred thousand years or more, by a fifth readvance of the ice. 
 
". 
 
 • ' 
 
,TILL PLAINS SECTION GREAT LAKE 
 
 SECTION 
 
 CENTRAL 
 LOWLAND 
 PROVINCE 
 
 CENTRAL 
 
 LOWLAND 
 
 PROVINCE 
 
 INTERIOR 
 LOW 
 
 PLATEAUS 
 PROVINCE 
 
 COASTAL PLAIN 
 PROVINCE 
 
 ILLINOIS STATE GEOLOGICAL SURVEY 
 
 PHYSIOGRAPHIC DIVISIONS OF ILLINOIS 
 
 (Reprinted from Report of Investigations No. 129, Physiographic Divisions of Illinois, 
 by M. M. Leighton, George E. Ekblaw, and Leland Horberg) 
 
 M (S3093) 
 

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