THE GEOLOGY OF CALVERT COUNTY 



BY 

 GEORGE BURBANK SHATTUCK 



IXTRODUCTOKY. 



Special attention is oivcn in the following pages to the stratigraphy, 

 structure, and areal distribution of the various deposits which are 

 found within the borders of Calvert County. These deposits 

 are all unconsolidated except where the local conditions have pro- 

 duced unimportant indurations. The deposits of Calvert County are 

 among the youngest deposits in Maryland. They do not date back 

 further than the Eocene and extend with occasional breaks down to 

 the present. The geologic history of Calvtn-t County is complex, how- 

 ever, and w^as frequently interrupted by erosive intervals, so that por- 

 tions of the geologic history have been destroyed and lost. Tliesc Ijreaks 

 are made manifest by the existing unconformities between the beds 

 of different materials. 



The various formations of Calvert County in their regular sequence of 

 superposition are as follows : 



Age. Formation. Group. 



rTalbot ^ 



Pleistocene J Wicomico t Columljla. 



I Sunderland J 



rSt. Mary's T 



Miocene -| Choptaiik L Chesapeake. 



[Calvert J 



Eocene Nanjemoy Pamunkey. 



The oldest rocks of Calvert County are those of the Eocene, which be- 

 long to the Nanjemoy formation. They do not occupy an extensive area, as 

 they are present only in the extreme northwestern portion of the county. 

 Their base is nowhere exposed in this region, but they are believed to 



