46 THE DEVONIAN OF MISSOURI. 



fauna to any one Upper Devonian fauna of Eastern United 

 States is not close. 



The Snyder Creek fauna is, largely, a development from 

 the Callaway fauna which preceeded it and which lacked most 

 of the Eastern Hamilton species. There is not an immigrant 

 from the eastern seas in the fauna. The formation should 

 probably be correlated with the Tully or Genessee of New York 

 but the evidence of the fossils does not indicate one of these 

 more than the other. 



Geologic Column South of Fulton in Callaway County* 



Pennsylvania!! Cherokee shales 100' 



Mississippian f Burlington limestone 100' 



\Sylamore sandstone 1' 



Devonian f Snyder Creek shale 40' 



\Callaway limestone 40' 



Jefferson City dolomite 380' 



Not exposed below the middle of the Jefferson 

 City. 



Roubidoux sandstone 150' 



Gasconade dolomite , 225' 



Proctor dolomite. . 75' 



Potosi dolomite 150' 



Ordovician • 



fElvins 75' 



Cambrian i Bonneterre 150' 



|Lamotte 150' 



Pre-Cambrian granite and prophyry. 



Geologic Column in Northwestern Ralls County, Missouri' 



Pennsylvanian Cherokee shales 100' 



Salem limestone ; 20' 



Burlington limestone 120' 



Mississippian i Chouteau limestone 30' 



Hannibal shale 90' 



Louisiana limestone 50' 



Grassy Creek shale 20' 



r^ . /■»«■. j j, n /Callaway limestone 20' 



Devonian (Middle) \ M ineola limestone 40' 



(Not exposed below the middle of the Kimmswick. 

 Kimmswick limestone! 

 Plattin limestone /' ' 



200' 



(Middle) (Joachim dolomite 150' 



1st. Peter sandstone 130' 



♦Thicknesses below Jefferson City generalized from well data and from exposures south 

 of the Missouri River. 



•Below the Kimmswick the data are generalized from St. Louis well logs. The total 

 thickness to the top of the Lamotte is known at St. Louis, but the formation boundaries 

 are arbitrarily placed. 



