EARLIER TERTIARY (EOCENE AND OLIGOCENE). 749 



Miocene and Pliocene formations in northern part of Atlantic Coastal Plain. 



The Eocene deposits are found in three distinct and separate regions, so that the relations 

 of the strata in these areas to one another can not be satisfactorily determined. 



,The Shark River marl of New Jersey apparently overlies the Manasquan formation of 

 the Upper Cretaceous conformably. The two formations constitute a continuous series of rela- 

 tively deep water deposits, no evidence of erosional or other unconformity being found. These 

 stratigraphic features, together with a somewhat undiagnostic Eocene fauna, have led to the 

 reference of the beds to an earlier horizon than that of the Aquia formation of Maryland, which 

 overlies the Cretaceous strata with a marked unconformity. The Shark River marl has been 

 referred to the Midway horizon of the Gulf. 



The Aquia and Nanjemoy formations contain a distinctively Wilcox fauna, the Aquia 

 being clearly lower Wilcox and the Nanjemoy probably upper Wilcox, although a few Claiborne 

 forms appear in the upper beds of .the Nanjemoy and it may in part belong to that horizon. 



The Trent and Castle Hayne formations occupy a small area south of the Hatteras axis in 

 North Carolina. The faunas have not yet been fully studied, but the forms found are of late 

 Eocene age, which would suggest their reference to the Jackson, although they may also repre- 

 sent a part of the Claiborne as well. The bryozoans in the Castle Hayne have led Bassler to 

 refer this formation to the Vicksburg. 



The Chesapeake group and equivalent Miocene deposits from the New England coast to the 

 Hatteras axis m North Carolina belong to a single geologic province, the strata and the fossils 

 presenting a marked similarity throughout, though showing indications of increasingly colder 

 waters toward the north. The Duplin formation south of the Hatteras axis is a part of the 

 southern province and contains a fauna characteristic of much warmer water than that of the 

 Yorktown, the synchronous formation to the north. 



The Waccamaw formation is limited to the belt near the coastal border of North and South 

 Carolina and contains a subtropical fauna. 



The Lafayette formation has been traced along the western margin of the Coastal Plain, 

 o<;curring as outliers on the adjacent Piedmont Plateau, from Pennsylvania, where the last 

 remnants are found, to North Carolina. Berry ^^ has shown that the deposits at Lafayette, 

 Miss., the locality from which the name is derived, are of Eocene age, so that the term Lafayette 

 is really a misnomer. Much question still exists as to whether the Lafayette of the Atlantic 

 Coastal Plain is late Phocene or early Pleistocene. 



