70 



PHYSIOGRAPHY AXD GEOLOGY OF THE COASTAL PLAIN PROVIXCE. 



The next locality is at White House bluff about 2 miles below Mt. 

 Vernon where the following section is exposed at intervals along the bluff : 



I. Section at White House Blujf. 



Feet 



Pleistocene Ferruginous sand and gravel 10-20 



Ferruginous sand with cobbles up to 12 inches 

 in dianieter 5 



Lower Cretaceous. Patapsco Gray or buff incoherent sand with thin lenses 



of reddish clay 15 



Pinkish or brownish sandy clay with tests of 

 Estheria and leaf impressions including 

 Acrostichopteris longipennis Font., Arau- 

 carites aquiensis Font., Carpolithus brooken- 

 sis Font., Celastrophylliini albaedomus ^Yard, 

 Sapindopsis magnifolia Font., Sapindopsis 

 variabilis Font., Dichotozamites cycadopsis 

 ( Font. ) , Sphenolepis sternbei giana ( Dunk. ) 

 Schenk and Widdringtonites ramosus (Font.) 

 Berry 3 5 



Much cross-bedded and slightly arkosic coarse 

 buff sand, somewhat argillaceous and with 

 scattered pebbles and clay laminae 20-25 



Indurated much cross-bedded and very arkosic 



gray sand with scattered pebbles 20-25 



Total 73-95 



On the south side of Gunston Cove opposite White House bluff the 

 following section is exposed, the Potomac materials extending to the top 

 of tlic bluff : 



II. Section of Gunston Cove Bluff. 



Feet 



Massive buff or gray coarse sand 20 



Gray incoherent irregularly-bedded sand alter- 

 nating with thin lenses of brownish sandy 

 clay carrying undeterminable plant remains 40 

 Greenish sandy chloritic clay weathering to 

 reddish and purplish mottled colors becoming 

 sandy above 20 



Lower Cretaceous. Patapsco 



Total 80 



The next exposure of any extent below Gunston Cove is that at Freestone 

 Point, which, by combining the exposures along the river with those in the 

 deep cut of the E. F. and P. R. R. at this point, give the following section : 



