360 



r: 



Nason — Geological Relations and the Age of 



m 03 

 O £ 



o Kesiduary Potosi Clay with Drusy 

 S Quartz. 



ft 1 



Cherty Limestone. 



- 02 & g 



Ph 





Pi 



Jh SB 



Drusy Quartz, 



Shaly Limestone. 



Fossilif erous beds Conglomerates. 

 o of Slates and Trilobites. 

 " rH Lingulella. Brachiopods. 



Pteropods. 

 h» Dividing line. Potosi. 



St. Joseph.. 



Upper Lead Zone. 



Lower Lead Zone. Lingulella. 



Sandstone. Lingulella. 





Granite and Porphyry. 



Geological Column near Flat river, St. Francois county, Missouri. 



