South Dakota School of Mines 23 



Table of Geologic Divisions for the Black Hills Region. 



Cenozoic 



Mesozoic 



Paleozoic 



Proterozoic 

 Archeozoic 



Quaternary 



Tertiary 



Cretaceous 



Jurassic 

 Triassic 



f Caboniferous 

 Permian 

 Pennsylvanian- 

 Mississippian 



Mississippian 



< 



j Devonian 



I Silurian 



I Ordovician 

 I Cambrian 

 I (Acadian) 



Algonkian 



Recent alluvial (flood plain) de- 

 posits. 



Older high-level gravels, sands, 

 and clays. 



Pliocene. Not subdivided. 



Miocene i Nebraska Beds, etc. 

 | Arikaree. 



Oligocene \ J*£ _ _f 

 Eocene 



Chadron. 

 [Not represented.] 



f Laramie. 



Fox Hills. 



Pierre. 



Niobrara. 



Carlile. 



Greenhorn. 



Graneros. 



Dakota. 



Fuson. 



Minnewasta. 



Lakota. 



? [Morrison. 



? j Unkpapa. 

 \ Sundance, 



? Spearfish. , 



j Minnehaha. 

 I Opeche. 

 ? Minnelusa. 



j Pahasapa. 

 j Englewood. 



[Not represented.] 



[Not represented.] 



Whitewood. 



Deadwood. 



Not yet differentiated. 

 [Not represented.] 



