':•''•• m Bhhmh II ■■■■-.■•'=.. fl UHstttlmf If' I M Hm H 1 « ' ; {§.«• MfiHKH |Ui|m|j ' [I ■ > < ,n ■ '' v,,,, i ; '■ I ' ;. ' ■•■■• ; :■ ■■ ■' ■■ ■ H8 ■■■■ ■ " .. ' .'■■■■;V' 1 ' ■-.'■ 8Hh HM » ■' .■ . '''•'.''..''' ruiHnfUniiiUlliniiitliiitHKHl'Ui \tSSnXBi8l ^? L0GICA1 - survey 3 3051 00004 306 ) State of Illinois Henry Horner, Governor Department of Registration & Education John J. Hallihan, Director Division of the SKATE GEOLOGICAL SURVEY M. M. Leigh ton, Cliief Urbana, Illinois No. ^2 CIRCULAR May 1, 1939 STRUCTURE OF H2RRIN (NO. 6) COAL BSD IN HAMILTON, WHITE, SALIN3, AND GALLATIN COUNTIES, ILLINOIS, NORTH OF SHAWN33T0WM FAULT By Gilbert H. Cady Assisted by Earle F. Taylor, Charles C. Boley and ethers With notes on the OIL ALT) ''IAS POSSIBILITIES By Alfred H. Bell Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/structureofherri42cady LEGEND COAL MEASURES BOUNDARY BOUNDARY OF DEEP PART OF BASIN AREA COVERED BY STRUCTURE MAP ON TOP OF HERRIN (NO-6) COAL ACCOMPANYING CIRCULAR 42 AREA COVERED BY STRUCTURE MAP IN CIRCULAR 24 Page 3. STRUCTURE OF THE AREA By Gilbert H. Cady This circular presents a brief discussion of some of the outstanding structural features of the Herrin (No. 6) coal bed in Hamilton, White, Saline, and Gallatin counties north of the Shawn eet own fault. The structure and other geological fea- tures of Saline and Gallatin counties south of this fault, inclu- ding the structural basin known as Eagle Valley, are described in detail with a geological map, in Bulletin H-J, "Geology and Mineral Resources of the Equal ity-ShawneetOwn Area," by Charles Butts. The area herein described lies to the east of and immediately adjacent to the area represented by the structure map discussed in Circular 2^-. The two areas include but are not exactly coextensive with that part of the State often referred to as the Southern Illinois Coal Field. COAL MINING The coal production in- this area is mainly from the Harrisburg (No. 5) coal bed, which lies 100 to 125 feet below the Herrin (No. 6) coal bed. Only two shipping mines in the area produce coal from the uoper bed - that of the Norris City Coal Company, located at Norris City, White County, and that of the Bankston Creek Colliery Comoany, an open-cut or "strip" mine lo- cated near Carrier's Fills in western Saline County. There are eleven other shipping mines in the area, all producing coal from the Harrisburg (No. 5) coal bed in Saline County. Numerous local or truck mines operate in various beds in both Gallatin and Saline counties, located mainly along the outcrop of the coal beds There are no mines in Hamilton County. STRUCTURE MAP Because the Herrin (No. 6) coal bed in this area is practically undeveloped by mining operations, the delineation of its structure is determined almost entirely by data supolied by the logs of drill holes and by some mine shafts. The distribution of these datum points is very uneven, but in general increases in frequency toward the outcrop of the coal bed. In several locali- ties near the outcrop of the Herrin and Harrisburg coal beds Page k. closely spaced rod-drill holes have determined the details of thickness of bed and depth of cover in anticipation of the re- covery of the coal by open-cut methods. Exploration with the drill and underground mining in the region in general began near the outcrop of the Harrisburg (No. 5) coal bed and worked grad- ually toward the north, except that the mines near Eldorado have long been in operation. The necessity for deep drilling, which can be relied upon only when done with the more expensively operated diamond drill, has resulted in a scattering of drill holes at fairly wide intervals in southern Hamilton County and in northern Saline County and in but very few holes in northern Hamilton, in White, and in northern Gallatin counties. Exolor- ation for oil. and gas has provided some- information about the position of Herrin (No. 6) and Harrisburg (No. 5) coal beds, but in most cases the drilling records of such holes are not substan- tiated by a study of the cuttings and much reliance cannot be placed upon them, particularly with respect to the identity and thickness of individua.1 thin beds characteristic of the Pennsyl- vanian system. Tr ; •ul-'tion' of Surface Data A large proportion of the drill holes and shafts shown on the structure map have been located and leveled in the field by alidade and plane table or in the course of systematic geological mapping. The quality of the surface data, the nature of the drilling, and other information pertaining to the depth and thickness of the coal beds No. 5 and No. 6 are given in the tabulation of these data which may be purchased with the map. Faults and Dikes Faults . - In the delineation of faults, and likewise of dikes, it has been necessary to rely on information obtainable in mines working the Harrisburg (No. 5) coal bed, as well. as uoon outcrops and drilling data. In general all faults shown in the area except those shown in T. 9 S., R. 5 3., the Cottage Grove, and the Shawneetown faults are based upon underground observa- tions or data shown on mine maps. Actual surface evidence of dislocations has been observed' in a few places in T. 9 s «, R. 5 2. Along Brushy Creek in the NW l/*+, sec. 3 and in the NW 1/2, SW 1/4-, sec. 2, the trace of the 25-foot fault encoun- tered in the Harco Mine of Peabody Coal Company (map No. 552) has been observed; at several places in the S l/2, sec. 10, the trace of the faults that can be seen in the Illinois Central R.R. cut. in sec. 1, T. 9 3., R. k E., Williamson County, may be found. No such traces have bwen found in sees. 8 or 9> T.-9 S., R. 5 3., but the possibility of faulting in the southern part of these two sections is suggested by the sharp differences in the altitude of of Page 5. the coal as revealed by drilling and by the traces of faulting or sharp folding in the 37 l/h, sec. 10 exposed in recent road cuts and formerly in a stream bank now covered by road fills. Exposures are not good or are lacking along the indicated line faulting through the SE l/M-, sec, 10 and in sec. 11. It is suspected that this line of dislocation is con- tinuous with the fault of l60-foot throw running through sees. 1, 2, and 3 between mines No. 12 and No. 1 of the Sahara Goal Com- pany (map Nos. 575 an & 57^" respectively), and probably sees, k and 5 of T. 9 S., R. 6 E., but no trace can be discovered in outcrop in sec. 1, T. 9 S., R. 5 E., or sec 6, T. 9. S., R. 6 E. The strata in the SW l/U- SE l/k- sec. 1 and adjacent in sec. 12, T. 9 S., R. 5 E., are undisturbed with but moderate north dip. However, failure to find surface indication of faulting is not unusual, for such lack of outcrop at a critical position is general along the position of the faults in sees. 2 and 3; T. 9 S., R. 6 S., and generally in the immediate vicinity of Harrisburg. The Cottage G-rove fault, which is a continuation of the same line of faulting described in the two preceding paragraphs, is mapped entirely on the basis of drilling data and the knowledge that "there is a repetition in the outcrop of Herrin (No. 6) coal bed, as shown on the map. The writer has not seen any surface evidence of dislocation along the fault, but its presence cannot very well be doubted in view of the evidence supplied by the drill. Dikes . - The dikes- shown on the map have never been found in surface outcroo, in fact no positive evidence exists that any of them penetrate the Herrin (No. 6) coal bed. The material of which they are composed being readily susceptible to surface weathering and most of the area in which they are found never having been covered by the -ice sheets, it is very unlikely that they would persist to the surface in a form such that they would be readily recognizable. At any rate, for the present the position of the dikes that have been encountered in the various mines is shown as accurately as the scale of the map will permit in order that their possible position in the No. 6 coal bed, should they continue upward that far, can be forecast. The dikes apparently pinch out and spread, being discontinuous and irregular within the area of single mines. In some instances, at least, it is apparent that the dikes extend upward to varying stratigraphic levels, in some places rising through the Harrisburg (No. 5) coal bed to an unknown distance, elsewhere along the same line evidently not rising even to No. 5 bed. It is not improbable that the dikes shown in sees. 9, 22 and jk, T. g S., R. 7 S. , (see map No. 560) would be found continuous at depth although its continuity may be interrupted in the No. 5 coal bed. The alignment of the dike at Harco and one of those in sec. 16, T. 9 S., R. 6 E., near Harris- burg is suggestive of possible continuity at depth, if not at the level of the coal bed. Page 6. It is remarkable that the dikes uniformly strike in a northwest direction definitely transverse to the direction of the Cottage Grove-Brushy Creek line of deformation, in spite of the fact that the faulting along this latter belt is more persistent and apparently involves larger displacements. The .contempora- neity of the two systems of faulting may be questioned for this reason. STRUCTURAL FEATURES OF SPECIAL INTEREST • WITH RESPECT TO COAL OCCURRENCE AND RECOVERY . The Cottage Grov e-Brushy Creek Fau l t Zone . - This is in reality a broken anticlinal structure with the south limb commonly down faulted. Along the structure northwest directed short faults are relatively common. These are usually short, extending not more than a mile or so northwest of the main fault zone. A fault of this lateral system passing west of Harco has unusual length. This fault zone can be followed westward into Jackson County where it becomes the Campbell Hill anticline. The Rid geway-Cmaha Monocline or Fault Zone. - The map shows a prominently developed monoclinal flexure in the coal bed extending north and south a short distance west of Ridgeway and Omaha in western Gallatin County. In an earlier map (Cooperative Mining Series, Bull. 19, Pi. I, 1919) , this zone of' deformation was delineated as a fault zone. Strong probability still exists that faulting may account for the differences in the altitude of the coal beds discovered by drilling.- This probability has not been substantiated by observations at outcrops along North Fork of Saline River, so that if faulting occurs- it apparently must take place between the river and Ridgeway.. The main objection to such a position for a fault is the outcroo along the river in the SW X/U- NW. l/k sec. 23, T.. g S., R. g S. (map No.. 102) of a lime- stone believed to be the Shoal Creek. The position of this lime- stone is about 5°0'feet above Herrin (No. 6} coal in this region, so that the top of the coal bed at this place, if this correlation is correct, lies l60 feet below sea level or about 190 feet below the position of the bed as discovered in the drill hole in the NW l/ 1 !- sec. 2S of the same township (map No. 11 ) . Unfortunately the log of an oil test in sec 2g, T. g S., R. g S. , about one- eighth mile south of the outcrop of limestone is unreliable and confusing, with a four-foot . coal reported underlying a group of limestones at about 25 feet. A -five-foot coal is reported at a depth of 7^0 feet, or 660 feet below the upper limestone, a rather excessively large interval for the distance separating the Shoal Creek limestone and Herrin (No. .6) coal. The well continued to 1,200 feet without entering Chester limestone formations . it is quite possible, of course, that there may b c a fault somewhere in the belt of closely spaced contours between Ridgeway and Elba in T. g S., R. g E. (North Fork), but surface evidence of such faulting has not been found. The closely spaced contours in sec. 1, Page 7* T. 9 S., R. S 3. (Equality) are necessary in view of the differ- ence in altitude of the coal in hole No. 95 and holes 23, 2^, and 193* No outcrops have "been discovered in the critical belt in the east half of sec. 1. Longbranc h Mon ocline . - In the development of the coal resources of this area, doubtless consideration will be given to the inclination of the bed. The Eldorado and Harco mining regions lie on a relatively gently northward sloping bench which extends across a belt about k miles wide in the north-central part of Saline County. North of G-alatia extending across Tate, Longbranch, and Plainview townships, Saline County (S 1/2, T. 7 S., Rs. 5 - 7 2.), the rate of dip is about twice that in the townships to the south, amounting to about 100 feet per mile. Probably the dip will not greatly enhance the difficulties of mining, but such a rate of inclination calls for careful planning of mine operations and is at least a minor hazard. Flannigan Terrace . - The Flannigan terrace is an area of moderate dip amounting to 100 feet or less in 6 miles, occupy- ing Flannigan and Twigg townships in southern Hamilton County (Tds. 6-7 S., Rs. 5-6 2.}. Absence of drilling data for the S l/2 T. 6 S.,. " R. 7 S., and N 1/2, T. 7 3., R. 7 S., (Mayberry) makes certain the continuity of the terrace into this township. There is an unfortunate lack of drilling records of a number of drill holes in the vicinity of Waloole which, if available, would undoubtedly supply structural details of possible importance in T. 7 S., Rs . 6-72. It is hoped that the publication of the circu- lar and map will effect the release of these data. Although the coal lies at a considerable depth ( 700 to 500 feet) beneath the lower prairies, the Flannigan terrace un- doubtedly possesses structural conditions unusually favorable to mining. Reference to the tabulations will show that the No. 6 coal bed is not only relatively flat lying but of unusual thick- ness. The writer is of the opinion that the 75 to 100 square miles of this terrace represent an undeveloped coal resource of great importance, if drilling records available permit a correct interpretation of conditions. North of the Flannigan terrace is a second strip of more steeply dipping strata marked by _ some irregularities, while the others farther south are described by Dr. Bell in the discussion of oil and gas possibilities of this area. It will be noted that the information in most of White County is too scattered to justify the continuation of structure mapping over most of that county. A considerable part of Gallatin County is left blank because of a similar lack of information. Page 8. REVISION OF PRESENT MAP AND PREPARATION OF MAPS OF OTHER AREAS The present map, like that of the area to the West, is a progress map of such form that additions and corrections can be readily made from time to time. Because of the large amount of new drilling that is being done in the State and the vigorous search for records of earlier drilling, it is expected that additional information will constantly be made available for Survey use. It is anticipated that a revision of the present map will not be available for several months from the date of its issue. Until revised, except for minor corrections and additions, it will bear its Original date. Subsequent revisions will be designated as such carrying a new date of issue* The map is one of a series of seven showing the struc- ture of Herrin "(No. 6) coal in southern Illinois. The next to appear will show the structure of No. 6 coal in Randolph and adjacent parts of Perry, St. Clair, and Washington counties. REFERENCES Previously published data on the structure and on occurrence of No. 6 or No. 5 coals of parts of the area follow: Cady, G-. H., Coal resources of District V: Illinois Mining Investigations Bull. 19; 135 pages, price 75 cents. , Structure of parts of northeastern Williamson and western Saline counties: Illinois . • State Geol. Survey, Report of Invest. No. 2; 20 paged, price 25 cents. Henbest, Lloyd G-., Coal stripping possibilities in Saline and Gallatin counties near Equality: Illinois Mining Investigations Bull, 32; 2& pages, price 25 cents. Butts, Charles, Geology and mineral resources of the , Equality- Snawnee town area: Illinois State Geol. Survey Bull. 4-7; 76 pages, price 5C cents. DeWolf, F. W., Coal fields of Illinois and Arkansas - Coal investigations in the Saline-Gallatin field, Illinois, and adjoining area: U. S. Geol. Survey Bull- 316b, pages lla-136, 1907. Reprinted in Illinois State G-eol. Survey Bull, g (pages 211-227), 190S. (Both publications out of print). DeWolf, F. W., Con.l investigation in Saline- and Williamson counties, Illinois: Illinois State Geol. Survey Bull, g: pages 230-24-5, 1908. (Out of print). Page 9 NOTES ON OIL AND GAS POSSIBILITIES (In the Area Contoured on Coal No. 6 in Saline, Hamilton, Gallatin, and White Counties, Illinois) By Alfred H. Bell In using the accompanying structure map as an aid in the exploration for oil it should be borne in mind that the structural features in the pre-Pennsylvanian systems, which include most of the possible oil producing strata, are not all parallel to those of coal No. 6. Experience elsewhere in the region indicates that some structural features of the coal con- tinue downward and are accentuated with depth, whereas others do not. As yet there has been insufficient deep drilling to reveal the details of the pre-Pennsylvanian structure in the vicinity of the structural features described below. Hamilton County m The most promising structure shown on the accompanying ...ap for Hamilton County, from the point of view of oil possi- bilities, is a dome centering 2 1/2 miles northwest of Dale, herein called the Dale dome. This dome has a closure of about 75 feet and appears to occupy an area of 10 or 12 square miles. To the south of the Dale dome is a broad anticlinal nose, herein called the Walpole anticline. These two structures trend slightly east of north, similar to some of the structural trends revealed by drilling in the area to the north in Clay, Wayne, and Richland counties. A closed syncline about k miles west of the Dale -dome is shown by the contours. Regional dip to the north and northeast is indicated by the contours in much of Hamilton County. This is interrupted by the features mentioned above and by a northwest dip in an area covering about 1 1/2 townships in the southeastern corner of the county (N 1/2, T. 7 S., R. 7 E. , and nearly all of T. 6 S., R. 7 E.). Page 10. White County Structural data permit drawing contours in only about a third of the area of White County. The northern portion of a large anticline is shown south of Norris City (discussed herein under Gallatin County), ea3t of which lies a syncline, trending northeast through Herald. Gallatin County The most promising structure in Gallatin County for the oil prospector revealed by the contours on the coal is a dome near the northwest corner of the county, herein called the Omaha dome. It has a closure of about ICO feet. From the crest in the SW 1/4 sec. 32, T. J S., R. g E. , an anticlinal axis trends a little east of north to Norris City, and along this axis the coal dios approximately 375 feet in 7 1/2 miles, or at an average rate of 5° feet per mile. A pronounced syncline lies to the east of the Omaha dome. The axis of this syncline has a general trend a little east of north, passing near Cottonwood and Ridgeway. The two churn drill holes on the Omaha dome were not drilled deep enough to test the most promising possible oil- bearing strata. The one located nearest the crest of the dome, the W. D. Forester No. 1, NW 1/4 N3 1/4 sec. 32, T. 7 3., R. 5 E., Gallatin County, drilled in 1917* had a total depth of 1,507 feet, base of the Pennsylvanian system and the top of the Chester series was penetrated at depth 1,630. The well was drilled into the Kinkaid formation, in the upper part of the Chester 177 feet. The well in SW 1/4 SE 1/4 NE l/4, sec. 29 (Klevalla Oil and Gas Co. - W. E. Davis No. l), about 1/2 mile north of the last mentioned well, drilled in 1921, had a total depth of 732 feet. It did not reach the base of the Pennsylvanian. Saline County In the part of Saline County included in the accompany- ing structure map on coal-No. 6, the large number of data avail- able permit the contouring of the coal in considerable detail. This is particularly true of the area within 8> or 10 miles of the outcrop line of the coal. In the southern half of T. 7 S., and adjacent part of T. g 5., the contours indicate a rather steady northward dip of the coal at an average rate of about 60 Page 11. feet per mile, to approximately the Hamilton County line. Of the numerous minor irregularities none appear to be particularly favorable to the occurrence of oil. However, two anticlinal noses are worthy of mention, (l) in sees. 2 and 11, T. g S., R. 6 S., and (2) mainly in sees. 7, g, 17 and lg, T. g S., R. 7 E. An east-west zone contoured area mostly in T the faults trend northwest in the northern part of T. 9 s< > R s. 6-7 east-west . of faulting extends across most of the g S., and T. 9 S. The majority of but some, like the Cottage G-rove fault trend more nearly Although it is possible that some of these faults have contributed to the formation of a structural trap favorable to the accumulation of oil, there is at least an equal possibility that the faults have provided channels of escape for any oil that may have formerly accumulated. One anticline in the faulted belt has a possible closure of 50 feet or more. It is located in sees, g, 9 and 10, T. 9 s «> R. 5 3. , and is herein called the Brushy anticline after Brushy Township in which it occurs. Estimated Depth s to Subsurface Formation s Dale dome. - NW cor. sec. 11, T. 6 S., R. 6 E., Hamilton County; assumed elevation 460 feet A.T. . Depth Horizon (top) (Feet) Pennsylvanian (base) Tar Springs sandstone Cypress sandstone Bethel sandstone Ste. G-enevieve formation Devonian-Silurian ( "Niagaran" ) limestone Kimmswick-Plattin ("Trenton") limestone St. Peter sandstone lgg5 2^4-50 2750 2900 3100 5000 6600 7500 Omaha dome. - SW 1/k sec. 32, T. 7 S., R. g S. , Gallatin County; assumed elevation 360 feet A.T. Horizon (top) Pennsylvanian (base) Tar Springs sandstone Cypress sandstone Bethel sandstone Ste. G-enevieve formation Depth ( Feet) 15^5 2120 2^50 2600 2g00 Page 12. Omaha dome (Continued) . . '. Horizon (top) / McClosky horizon Devonian-Silurian ( "Niagaran" ) limestone. Kimmswick-PIattin ("Trenton")' limestone . St. Peter- sandstone Brushy anticline . - SW.-l/kNE l/k sec. '&., T."9 S., R. 5 DeDth (Feet) 2^50 ksoo 6^00 7^oo Saline County; A.T. assumed elevation 4 '40 feet Horizon ("top) Pennsylvanian (base) Tar Springs sandstone Cypress sandstone Bethel sandstone.- ..Ste. G-enevieve" formation M c Cl 6 sky ' ho r i zon Devonian-Silurian ( "Niagaran" ) limestone K immswick-Plat tin ( "Trenton" ) limestone . ' St. Peter sandstone Summary log of : Mid-Egypt G-as a Oil - I~urf NE NW NW. Arab Petroleum Corp. - Roy E. Pearce 1. Spd. and SD. 7S, SE, Indian Creek Two. 4, SE SE NE. Pyramid Petroleum CorD. - Gilbert Wade 1. D & A, 1-31-39. TD 30S0" , Ste. Genevieve Is., too 2280'. WASCHER'S" ->MDEtiS 507 S. Goodwin Urbana, I1L \M ;»■■ i«i ; ■ ■■ ■ ; : & mli ,;;.'•■■ llilr ^3 ilti U^ It liff^aillH 1! ! ' ' '• ' lUuli ' .■ •' :::i: -' H p™ ' ||g| ' ,,,..•.'' i '*.' - ; JeumJIJI' IjilflWp'iB'