30 



GEOLOGICAL FORMATIONS. 



The general sequence of geological formations is perhaps 

 best shown in the subjoined table: 



Table of Geological Formations of Missouri. 



Age. 



Series. 



Stage. 



Formation . 



H 

 a- 



CD 







Pleistocene 



AUnvium 



25 







LoesB 



30 





Tin 



45 



Tertiary . 





Eocene . 



Bloomfleld sands 



85 





CoalMbasubes.. 



Missouri 



Upper coal measures 



1000 





Bes Moines .... 



Lower coal measures 



600 





MiSSISSIPIAN .... 

 (lower CAEBON- 

 IFEBOUS) 



Kaskaskia 



"Chester" shales 



120 





Kaskaskia limestone 



100 





Aux Vases sandstone 



50 



Carboniferons . . 



St. Louis 



Ste Genevieve limestone 



150 





St. Louis limestone 



210 





Warsaw (in part) . . 



50 





Augusta 



Warsaw (typical) 



35 





Geode Bed 



40 





Keokuk limestone . 



50 





Upper Barlington 1 



60 





Lower Barlington 1 



45 





Kinderhook 



Chouteau limestone 



75 





Hannibal shale 



75 





Louisiana limestone. . 



60 



Devonian 



Uppee 



Hamilton 



( Western) 



Callaway limestone 



70 







Grand Tower limestone . 



100 





Uppbe 



"Niagara" 



( Western) . . . 



Clear Creek limestone. . . 



150 



Silurian . . 





"Niagara" limestone... 

 Girardeau limestone. 



40 





"Hudson River' ' . . 



45 





Hudson shale 



80 







Trenton 



Trenton limestone . 



200 





Calciferous 



First Magnesian 1 



Roubidoux sandstone 



80 

 75 



Cambrian 



OZAEK. . 





Magnesian limestone . . . 



500 



Algonkian 







Pilot Kn. conglomerate. . 



40 









Iron Mtn . Porphyry 



300 











ARCHAEAN ROCKS. 



Near the eastern limit of the Ozark region, in Iron, Madi- 

 son and eight or ten of the neighboring counties, there rises, 

 abruptly, a group of bold, rugged hills, the best known of 

 which are Pilot Knob and Iron Mountain. The altitude of 

 these elevations is from 200 to 700 feet above the surrounding 

 country. The hills are composed, chiefly, of massive crystal- 

 line rocks, consisting, principally, of granites and quartz-por- 

 phyries, cut in places by dykes of more basic material. They 



