30 The Upper Cretaceous Deposits of Maryland 



The organic remains consist chiefly of fossil plants in the Earitan 

 and Magothy formations, and of fossil invertebrates in the Matawan, 

 Monmouth and Eancocas formations. The flora consists largely of dico- 

 tyledonous types, those forms found in the Karitan formation being dis- 

 tinctly Cenomanian in character, while those of the Magothy are appa- 

 rently Turonian in age, which is apparently also the age of the Matawan 

 invertebrates. The Monmouth fauna, corersponding to the Ripley fauna 

 of the Gulf, is universally regarded as of Senonian age, while the over- 

 lying Eancocas fauna has been referred to the Danian. 



The total average thickness of the Upper Cretaceous formations of 

 Maryland is about 400 feet. They show a dip of from 25 feet to 35 feet 

 in the mile to the southeast. 



TERTIARY 



Eocene 



The Eocene is represented by the Pamunkey Group, which consists of 

 the Aquia and Nanjemoy formations. The deposits are of marine origin 

 and comprise part of a geologic province embracing Virginia, Maryland, 

 and Delaware. 



The two formations constitute an apparently conformable series which 

 overlies the Upper Cretaceous deposits in Maryland unconformably while 

 in Virginia it has transgressed the latter and is found overlying the 

 Lower Cretaceous strata unconformably. The deposits consist chiefly 

 of greensands which are often calcareous in the Aquia formation and 

 generally argillaceous in the Nanjemoy formations. 



The fossils consist mainly of animal remains and comprise an extensive 

 fauna, embracing particularly the molluscs and corals, which show a 

 faunal relationship with the Wilcox and probably with the lower Claiborne 

 beds of the Gulf. 



The total thickness of the Eocene deposits in Maryland is about 225 

 feet, and they show an average dip of 12^ feet in the mile to the southeast. 



