T. E. Savage — Stratigrajihy of Southwestern Illinois. 441 



Sys- 

 tem 





Correla- 

 tions 



Location 



of 

 sections 



>j 



c 

 pi 

 o 



O 



7flr. 



Descriptions of horizons 



Thin-bedded, hard, gray limestone, layers 2-10 

 inches thick. Fossils rare ; Chonetes konick- 

 ianus var. present in the upper part and C. 

 pusillus and Stropheodonta concava in the 



15 ft. 









CO 



7/. 



Hard, gray, impure limestone with few fossils. . 



21 ft. 









c3 



1-5 



7e. 



Dark gray, impure limestone with thin chert 













bands near the top. Fossils numerous, Nucle- 











a? 



s 

 o 





ocrinus verneuili, Rhynchonella gainesi, Meris- 

 tella barrisi, Spirifer acuminatus, Stropheo- 







a 



cc 





donta pater soni, etc 8 



l/3ft. 







0) 



o 



7d. 



Dark gray, impure, fine-grained limestone. Cho- 







> 



CO 







netes mucronatus abundant in a zone near the 







ft 



C4 



1 







middle. Other fossils are Rhipidomella vanux- 







IB 



CD 

 1© 



>> 





emi, Spirifer grieri, Stropheodonta patersoni, 







T3 



T 1 



3 





S. per plana, and Phacops cristata 



11 ft. 





s 



bo 



cS 



o 



o 



7c. 



Heavy layers of light gray, subcrystalline 







>> 



rH 





limestone. Fossils abundant. Coscinium 







S 



o 



CO 





cribriformis, Centronella glansfagea, Spirifer 







w 



O 



CS 



s 



76. 



duodenarius, S. macrothyris and Odontoce- 

 phalus cegeria present throughout- 



Alternating layers of light gray, arenaceous, 



38 ft. 









o 





subcrystalline limestone and coarse-grained 





'3 







CD 





sandstone, containing Centronella glansfagea, 





O 

 > 







cS 





Meristella near lentiformis, Rhipidomella mus- 





ft 







pq 





culosa, Spirifer duodenarius and £. macro- 













thyris 15 l/2ft. 













« t> <D E> >s 



7a. 



Bed of more or less iron-stained sandstone, in 











S <N .\p t » 3 





places soft and friable, at other points cement- 











^M^ r 8 





ed by a deposit of iron or silica, containing 













Michelinia stylopora, Aulacophyllum sp., Cen- 











. . 00 ^-|— ' 





tronella glansfagea, Spirifer duodenarius, S. 













macrothyris and Odontocephalus arenarius 



18 ft. 









l2n E -1 15 OJ 

















6e. 



Bed of light gray chert in layers 3-9 inches thick. 











32 ^ • ^' 





Amphigenia curta, Chonostrophia reversa, Eo- 









S-l 



^££ 





devonaria melonica, Schuchertella pandora and 









,2 Pi 







Spirifer worthenanus abundant 5 



1/2 ft. 







9^ 











cS 



ll 



2 o« o 



6c? 



Reddish-brown, friable sandstone with Miche- 







"3 



>i eg 





linia stylopora, Zaphrentis sp., Amphigenia 







cS 



m 



rH 



o 



r Oriska 

 : Chert, < 

 ;, 237 fee 



2 rQ T_l O 



C3 33 



31 15 s ■§ 



6c. 



curta and Spirifer duodenarius 2 



Layers of light chert, 4-8 inches thick. Anoplia 



5/6 ft. 







CD =+-< ,5 tD 



cS +3 co 





nucleata, Chonostrophia reversa, Eodevonaria 













melonica, Schuchertella pandora and Spirifer 









Poo 



j CO _u 



02PH 



66. 



worthenanus 1 



Reddish-brown, friable sandstone 



1/2 ft. 

 2 ft. 



