SECTIONS ALONG THE MATTAPONI RIVEE AND ITS TRIBUTARIES. 135 



VI. Section right bank of Rappahannock River, one-half mile below 



Botvler's Wharf and opposite Sharp's Wharf. 



Feet 

 Pleistocene Sand and gravel 20 



Miocene. Calvert Dark greenish-gray sandy clay full of fossils 



most of which are well preserved 12 



Total 32 



The strata with similar characteristics are exposed for almost a mile 

 along the shore. 



VII. Section right bank of Rappahannock River one-half to one mile 



below preceding section. 



Feet 

 Pleistocene Yellow sand and sandy clay 14 



Miocene. Calvert Dark green argillaceous sand full of fossils 



principally Area stammea, Venus, Fulgur 

 coronatum, Turritella pleieia, Ostrea, Dental- 

 ium attenuatum, numerous small pelecypods, 

 etc 4 



Greenish-gray, compact clay layer with thin 

 sand laminae 13 



Dark green argillaceous sand or sandy clay with 

 fossils; Area stnminea, Veniis, numerous 

 small pelecypods, etc 2 



Total 33 



The beds rise slightly toward the east and the lower fossil layer was 

 observed to a height of 6 feet about one-half mile below where the section 

 was taken. 



SECTIONS ALONG THE MATTAPONI RIVER AND ITS TRIBUTARIES. 



The Calvert formation outcrops in many places in the Mattaponi Eiver 

 valley and is remarkably uniform in its lithologic characteristics in the 

 various exposures. Calvert strata are present along the entire course of 

 this stream from near Bowling Green where it enters the Coastal Plain to 

 its junction with the Pamunkey Eiver at West Point. The formation out- 

 crops in the tributary streams in the vicinity of Bowling Green but dips 

 gently to the southeast and for many miles is exposed as a thin band in 

 the low river bluifs lying between the Nanjemoy formation beneath and the 

 Pleistocene above. A few miles above Walkerton the Nanjemoy formation 

 disappears beneath the water level and the Calvert strata occupy all the 

 lower portion of the exposed sections of the river bluffs. 



