XCll 



GEOLOGICAL AND PALEONTOLOGICAL RELATIONS 



Pleistocene. 



Miocene. 



Section at Drum Cliff near Jones Whai-f. 



Feet. Inches 



Reddisli yellow loam, sand and gravel 42 



Greenish clay containing poorly preserved fos- 

 sils carrying the following species: Balanus 

 concavns. Panopea anicricana. Phacoides con- 

 tractus. Carclium laqneatum, Pectcn madison- 

 ius, Ostrea carolinensis, etc. (Zone 19, in 



part ) : 6 6 



Greenish unfossiliferous clay (Zone IS) 8 



Brownish and greenish fossiliferous sand par- 

 tially indurated above, solidified to solid rock 

 at base, carrying the following species: Bal- 

 anus concarus, EcpJwra quadrioostata var. 

 umhiUcata. Turritella plebeia, Corbula idonea, 

 MacrocalUsta marylandica. Dosinia acetabu- 

 lum, Cardium laqueatum, Crassatellites turgi- 

 dulus. Astarte thisphila, Pecten madisonius. 

 Melina maxiUata. Area staminea, ScuteUa 

 aberti, etc. (Zone 17, in part) 30 



Total 86 6 



Section at Boston Cliffs, Choptank River, 1.5 miles beloiv Dover Bridge. 



Feet. 



Yellowish sand and gravel 10 



Reddish and yellowish fossiliferous sand containing 

 the following species: Pleurotoma albida, Ptyclio- 

 salpinx multirugata, Ecphora quadricostata var. umbi- 

 licata. Ecphora tampaiinsis, Scala marylandica. Seila 

 adamsii, Ccccum patuxentium. Turritella plebeia. 

 Crucibulum multiUneatum, Gadulus tJiallus. Saxi- 

 cava artica. Corbula idonea, Corbula ina^quali-s. 

 Asaphis centenaria. Metis biplicata, Melina maxil- 

 lata. etc. ( Zone 19, in part) 12 



Total 22 



Origin of Materials. 



The materials which compose the Miocene deposits of IMaryland may 

 be divided in regard to their origin into two chisses, viz., the silicions 

 and arenaceous materials which are land-derived and the calcareous 

 materials which are of organic origin. The nitimate soiirce of the for- 

 mer 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 

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

 derived from the latter is reworked in the former and occasionallv 



