CLAYS IN TERTIARY FORMATIONS. 147 



THE EOCENE MARL. 



This formation includes the upper portion of the Upper marl 

 "bed, which was designated as Blue marl by Prof. Cook. It is 

 found in a limited area in Monmouth county along the valleys 

 of the Shark and Manasquan rivers, where it is seen chiefly on 

 the valley sides. It lies directly beneath the Asbury clay, being 

 often separated from . it by an indurated stony layer. It con- 

 sists of very fine, dark-green sands, which have a slight bluish 

 tinge, and it is quite fossiliferous. These fossils represent a 

 fauna, which is generally regarded as Eocene in age. There is a 

 slight unconformity between these marls and the overlying 

 Miocene beds, indicated by the general overlapping of the 

 Miocene beds upon the subjacent layers, so that towards the 

 southwest the higher beds of Miocene rest directly upon beds 

 lower than the Shark River marl. Since this formation contains 

 no clay beds, it will be dismissed with these few words. 



