80 



THE GEOLOGY OF ST. MART S COUXTT 



II. Section at Chancellor Point. 



Feet. 

 Sandy loam 10 



'Bluish sandy clay carrying the following fossils : 

 Actaeon oroides. Return manjiandica, Terebra eur- 

 rilirata. Conns diliivianus, Siircula engonata, FtUgur 

 fiisifortiie, Tiirritella variahiUa, Panopea goldfussi, 

 Callocardia {Agripoma) sayana, Venus campechi- 

 cnsis vur. mortoni, Isocardia fraterna, Phacoides 

 (Pseudomiltha) anodonta, Pecten madisonius, P. 

 jcffcrsonius, etc. (Zone 24, in part) 25 



Total 



35 



III. Section at Cuckold Creek. 



Pleistocene. ^ S -! Section ob-scuivd 



Feet. Inches. 



B 'C I Darl; sandy clay carrying characteristic fossils of Zone 

 17. (Zone 17, in part) 



Total 



10 6 



ORIGIN OF MATERIALS. 



The materials which compose the Miocene deposits of St. Mary's 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 j\Iiocene most conspicuously being the 

 Eocene. Near the contact of the Miocene and Eocene, a rolled fauna 

 derived from the latter is reworked in the former and occasionally 

 grains of glauconite, which were in all probability formed in the Eocene 

 occur in the lower portions of the Miocene. 



The organic remains, which consist, for the most part, of shells of 

 mollusks and bones of vertebrates, are usually in a very good state of 



