SECTIONS IN THE MATTAPONI RIVER VALLEY. 



Ill 



A fairly good exposure of the Calvert-Nanjemoy contact was seen at 

 one place, where it was sharp and decidedly undulating. 



About iy2 miles below the preceding, the greensand appears 

 at the base of a 15-foot terrace. The exposure is a few rods back from 

 the river bank. This locality is about one-half mile below the mouth of 

 Pole Cat Creek. 



TIT. Section left hanh of Mattaponi River about one-half mile below the 

 preceding, one-half mile above Burhe's Bridge. 



Feet 



Pleistocene ( ?) Concealed 14 



Eocene. Nanjemoy Compact greensand with impressions of Veneri- 



cardia potapacoensis 12 



Total 26 



At Burke's Bridge and for several miles below. Eocene greensand is 

 occasionally seen at the base of a 15 or 20-foot terrace. 



TV. Section left bank of Mattaponi River three or four miles below 



Burke's Bridge. 



Feet 

 Pleistocene Concealed 8 or 10 



Eocene. Nanjemoy Compact greensand containing fossils in 



lower 2 feet. Principal fossil is Veneri- 

 cardia potapacoensis. A few other small 

 pelecypods are present 8 



Total 18 



For several miles below the preceding locality Eocene greensand appears 

 at the base of low sections rising in places to about 10 feet above the water. 

 At a point between 6 and 8 miles below Burke's Bridge the river strikes 

 a high upland. When it first touches it the slope is concealed by vegetation 

 but about one-quarter mile below this point the following section could be 

 made out, although the exposure is very poor. 



