92 



THE GEOLOGY OF CALVERT COUNTY 



Pleistocene. 



Miocene. 



c 9 

 cc .2 



a, 5 



-o a 



p o 





XV. Section at Little Cove Point. 



Reddisli and yellow loam, sand and gravel. 



Feet. 

 . 62 



Bluish sandy clay containing 8 feet from base a 6-incli layer 

 of fossils consisting mostly of Turritella pleheia (Zone 23) 30 



Bluish sandy clay containing numerous layers of fossils among 

 which are the following species : Balanus concavus, Terebra 

 inornata, Mangilia parva, Nassa peralta, Columbella com- 

 munis, Ecphora quadricostata, Turritella pleheia, T. varia- 

 bilis, Polynices heros, Gorbula inegualis, Pecten jeffersonius. 

 Area idonea, etc. (Zone 22) 17 



Total 109 



None of the other drainage lines exhibit as complete sections of the 

 Miocene as are found along the Calvert Cliffs, but occasionally good ex- 

 posures are luet with, one of the more important of which is given 

 below. 



Section .25 mile below mouth of St. Leonard Creek. 



Pleistocene. 



Miocene. 



a 



*J o 

 o 3 



ed a 



Yellowish gravel and sand . 



Feet. Inches. 

 18 6 





2 '■■ 



r Greenish sand partially indurated above, solidified to 

 solid rock at base of section carrying the follow- 

 ing species : Balanus concavus, Panopea americana, 

 Corbula idonea, Cardium laqueatum, Astarte this- 

 phila, Pecten madlsonius, Melina m,axillata, etc. 

 (Zone 17, in part) 18 



Total 37 



ORIGIN OF MATERIALS. 



The materials which compose the Miocene deposits of Calvert County 

 may be divided as regards their origin into two classes, viz., the silicious 

 and arenaceous materials, which are land-derived, and the calcareous 

 materials, which are of organic origin. The ultimate source of the 

 former was doubtless the rocks of the Piedmont Plateau and regions 

 beyond in Western Maryland and neighboring territory, but more im- 

 mediately they have been derived from older coastal plain deposits; 

 the one which enters into the Miocene most conspicuously being the 



