SMALLER FORAMINIFERA FROM ILLINOIS 



345 



The formation containing the fossils de- 

 scribed was named the 'Torters Creek 

 group" for exposures on Porters Creek, 

 Hardemann County, Tennessee, by Staf- 

 ford (1864, p. 368) where it has a thickness 

 of 200 to 300 feet. There it overlies the Clay- 

 ton formation, which together with the Por- 

 ters Creek, comprises the Midway group of 

 the central and northern embayment areas 

 and underlies the Ackerman formation of 

 Wilcox age. Harris (1896) first correlated the 

 formation with the Midway. 



The Cretaceous and Tertiary sediments 

 in the northern part of the embayment in 

 Illinois and Missouri are almost completely 

 devoid of calcareous material and fossil re- 

 mains, except for an occasional fossil cast. 

 Lamar and Sutton (1930, p. 848) believe the 



original calcareous material, while once 

 present in the sediments, has been removed 

 by leaching. 



The microfauna described was obtained 

 from the cuttings of a water well drilled in 

 1938 at Cache, Illinois, in SE^ SEi SWi 

 sec. 19, T. 16 S., R. 1 W., Alexander Coun- 

 ty. The well was drilled for O. R. Bourland 

 by E. M. Gould, who furnished a driller's 

 log and 5-foot samples of the drill cuttings 

 to the Subsurface Division of the Illinois 

 State Geological Survey, where they were 

 studied and described by Earl C. Cochrum. 

 It was Mr. Cochrum who called my atten- 

 tion to the occurrence of the numerous 

 Foraminifera found in the samples from a 

 depth of 115 to 135 feet. All but four of the 

 species described came from the two sam- 



CORRELATION OF PoST-PaLEOZOIC SeDIMENTS IN THE UpPER MISSISSIPPI EmBAYMENT ArEA 



AGE 



ARKANSAS 



TENNESSEE^ 



KENTUCKY2 



ILLINOIS 



MISSOURI^ 



RECENT 



and/or 



PLEISTOCENE 



Alluvium 



and 



Loess 



Alluvium 

 and 



Loess 



Alluvium 



and 



Loess 



Alluvium 



and 



Loess 



Alluvium 



and 



Loess 



PLIOCENE 



Gravel 



Gravel 



Lafayette 



"Lafayette" 



Gravel 





Jackson 



Jackson 



Jackson 







EOCENE 



Claiborne 











Wilcox 



§ 



Grenada 

 Holly Springs 



Ackerman 



Grenada 

 Holly Springs 



Wilcox 



Wilcox 











PALEOCENE 



Midway 



< 



Porters Creek 

 Clayton 



Porters Creek 



Porters Creek 



Porters Creek 





Clayton 



Clayton 





Nacatoch 



s 



Owl Creek 

 McNairy 



Coon Creek 



McNairy 





McNairy 





Owl Creek 

 McNairy 

 Coon 

 Creek? 









Selma 



Selma 





Selma (?) 





Eutaw 



Eutaw 





Eutaw (?) 





Tuscaloosa 



Tuscaloosa 







1 Whitiatch (1940); 

 sMcFarlan (1943); 

 » Kansas Geol. Soc. (1939) and Stewart, McManamy, and McQueen (1943). 



