THE GEOLOGY OF PRINCE GEORGE'S 



COUNTY 



BY 



BENJAMIN L. MILLER 



Introductory, 



The geologic formations represented in Prince George's County 

 range in age from Arcliean to Recent. Deposition, however, has not 

 been continuous and many gaps occur, that between the Archean and 

 Cretaceous covering a very long interval of time. ITone of the larger 

 geologic divisions since Jurassic time are entirely unrepresented. 

 Periods when there was deposition over part or the whole of the 

 region were separated by other periods of greater or less duration in 

 which the entire region was above water and erosion was active. The 

 deposits of all the periods except the Archean and Pleistocene are 

 similar in many respects. With a general northeast-southwest strike 

 and southeast dip, each formation disappears by passing under the 

 next later one. In general also the shore line during each successive 

 submergence evidently lay a short distance southeast of the position 



System. 



Series. 



Group. 



Formation. 



Quaternary 



Tertiary 



Pleistocene 



Columbia 



Cretaceous 



Archean 



f Pliocene(?) 



^ Miocene Chesapeake . . . 



[^ Eocene 



flipper Cretaceous. 



1^ Lower Cretaceous. . . . 



Pamunkey 



Potomac 



f Talbot. 

 ^ Wicomico. 

 1^ Sunderland. 



Lafayette. 

 j Choptank. 

 I Calvert. 

 < Nanjemoy. 

 ) Aquia. 

 f Monmouth. 

 J Matawan. 

 ] Magothy. 

 [ Raritan. 

 I' Patapsco. 

 .' Arundel. 

 [ Patuxent. 



Granite gneiss. 



