DESCRIPTION OF GEOLOGIC SECTIONS 



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92 



6 



102 



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TRIVOLI CYCLOTHEM 

 MACERATION 1128 



Diamond drill core No. 6, Mount Olive and 

 Staunton Coal Company (1300 ft N, 200 ft E of 

 SW cor. of SE NW, 8-8N-7W, Macoupin Co., 111.) . 

 Illinois Geological Survey core described by K. E. 

 Clegg and D. H. Reinertsen, 1958. 



Depth 

 Thickness to top 

 (ft in) (ft in) 



Pennsylvanian System 



Modesto Formation 



Siltstone, gray to light gray, thinly 

 and irregularly laminated, argilla- 

 ceous, micaceous; light gray portion 

 becomes harder and coarser toward 

 bottom 7 



Shale, gray, silty, argillaceous, mica- 

 ceous, well laminated, weak, very 

 uniform; grades into shale below.. 10 



Shale, gray, carbonaceous, rather well 

 laminated, fissile; becomes darker 



in bottom 6" 1 



Shale, as above but contains shells 

 and occasional sideritic nodule up 

 to Vi" in diameter 



Shale, dark gray, carbonaceous, well 

 laminated, weak. (Maceration 1128-L: 

 104' 10" to 104' lOVi".) 



Limestone, dark gray to black; con- 

 tains abundant brachiopod and pele- 

 cypod shells; intermixed with black, 

 silty, very carbonaceous shale; 

 grades into siltstone. (Maceration 

 1128-K: 105' 1/2" to 105' WV'.)... 



Siltstone, gray, argillaceous, very 

 micaceous, interlaminated with light 

 gray to white coarser siltstone; light 

 siltstone becomes coarser downward; 

 grades into sandstone 4 



Sandstone, light gray, medium grained, 

 argillaceous, micaceous, massive . . 3 



Shale, medium gray, silty, micaceous, 

 well laminated, uniform; some part- 

 ing surfaces are very micaceous and 

 very carbonaceous with abundant 

 coalified plant fragments, especially 

 in bottom 1'. (Maceration 1128-J: 

 112' 8" to 112' 8%"; maceration 

 1128-1: 115' AW to 115' 5".) 2 



Shale, light gray, silty, micaceous, 

 rather well laminated, uniform; be- 

 comes darker and smoother down- 

 ward; grades into shale below.... 2 



Shale, gray, carbonaceous, well lami- 

 nated, weak. (Maceration 1128-H: 

 120' li/ 2 " to 120' 2".) 2 



Chapel (No. 8) Coal, bright banded. 

 (Maceration 1128-G: 120' 2" to 

 120' 7".) 



Underclay, dark gray to greenish gray, 

 carbonaceous, smooth, slip-frac- 

 tured; Stigmaria; grades into clay- 

 stone. (Maceration 1128-F: 120' 7" 

 to 120' 71/2".) 



Claystone, dark gray to dark greenish 

 gray, weak, slip-fractured and slick- 

 ensided; a 2" zone 6" above base 

 contains abundant brown limestone 

 nodules up to Vi" in diameter. 

 (Maceration 1128-E: 122' 2 1/2" to 

 122' 3"; maceration 1128-D: nodules 

 122' 6" to 122' 8"; maceration 

 1128-C: 123' IV2" to 123' 2".) 2 



Core marker 



104 5 



104 9 



105 



105 2 

 109 6 



112 6 



115 5 



117 10 



120 2 



120 7 



120 11 



124 



Siltstone, greenish gray, argillaceous, 

 micaceous, poorly laminated in up- 

 per 4", better laminated downward; 

 grades into sandstone. (Maceration 

 1128-B: 124' to 124' Vz", macera- 

 tion 1128-A: 125' 11" to 125' 

 IIV2".) 2 124 



Sandstone, gray, fine grained, silty 

 and argillaceous in lower part; 

 grades into siltstone 6 126 



Siltstone, greenish gray, coarse, argil- 

 laceous, micaceous, rather well lami- 

 nated, irregularly interlaminated with 

 dark gray silty shale; occasional 

 zones up to 1' thick consist almost 

 entirely of dark gray shale 15 9 126 



TRIVOLI CYCLOTHEM — 



MACERATION 1175 



Diamond drill core No. 42, Old Ben Coal Corpo- 

 ration (700' S and 30' E of NW cor. of 25-7S-3E, 

 Franklin Co., 111.) . Illinois Geological Survey core 

 described by G. H. Cady, 1944. 



Depth 

 Thickness to top 

 (ft in) (ft in) 



Pennsylvanian System 



Modesto Formation 



Shale, gray, smooth, rather well lami- 

 nated, uniform 4 3% 252 1 



Shale, gray, well laminated, non- 

 calcareous 3 5Vi 256 4 3 A 



Shale, dark gray, noncalcareous, 

 smoother than above; occasional 

 ironstone layer or concretion up 

 to 1" thick 4 259 10V4 



Core marker 264 



Shale, as above, calcareous toward 

 base; contains pelecypods and 

 ostracodes; occasional sideritic layer. 

 (Maceration 1175-P: 265' AW to 

 265' 51/2".) 1 7/2 264 



Shale, gray; at least one ironstone 

 layer; shell fossils toward base ..0 IW2 265 IV2 



Limestone, gray, carbonaceous, very 

 fossiliferous; small brachiopod and 

 pelecypod shells; intermixed with 

 dark gray shale. (Maceration 

 1175-0: 266' 1W to 266' 8".) 21/2 266 7 



Shale, gray, dense, calcareous; con- 

 tains small shells like those above. 8V2 266 W2 



Limestone, gray, very argillaceous; 

 contains abundant brachiopods and 

 pelecypods; grades into shale 4V4 267 6 



Shale, dark gray to black, carbona- 

 ceous; abundant brachiopods and 

 pelecypods; grades into shale below. 

 (Maceration 1175-N: 267' lOVs" to 

 267' 1114"; maceration 1175-M: 269' 

 51/2" to 269' 6%".) 1 9 267 10^ 



Shale, black, carbonaceous; a few 

 pyritized pelecypods near top; coaly 

 streaks at bottom 8% 269 7V4 



Shale, dark gray, calcareous, carbona- 

 ceous, fossiliferous; contains pelecy- 

 pods and gastropods that increase in 

 abundance downward; grades into 

 shale below. (Maceration 1175-L: 

 270' 91/4" to 270' 10V4".) 91/2 270 4 



Shale, gray, very calcareous and 



fossiliferous; grades into siltstone.. W-x 111 IVi 



Siltstone, gray, micaceous; small shell 

 fossils; plant compression fossils in 

 lower 1/2" to W; calcareous in 

 upper 2". (Maceration 1175-K: 271' 

 8%" to 271' 91/2".) 6V4 271 3V4 



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