192 TRANSACTIONS OF THE [1892 



leiits have not yet been identified in New Jersey, unless 

 they should prove to be the same as those beneath the 

 mixed clays north of Trenton. 



The fine white sand occurs in belts of variable thick- 

 ness, ranging from sixty feet on the upper Severn river 

 to five feet in Kent and Cecil counties, near the Elk river. 

 This sand is overlaid by white or pinkish white, plastic 

 clay of fine texture, from three to fifteen feet in thickness. 



Next above this, however, often rests a stratum of 

 brown sandstone, sometimes substituted by a laminous 

 type of brown clay-stone, which carries the asphalt-like 

 laminated black stratum that lies next under the typical 

 part of the Alternate Clay Sands. 



Above this is a series of fine white sands alternating with 

 layers of pale drab, sandy clay, which are no more than 

 an inch in thickness in some sections, while they widen 

 out into strata many feet thick in other exposures. In 

 some parts of this member, pale marbled fine clays take 

 the place of one or two of the thicker beds of unicolored 

 drab clay. Above this rests the brownish, flaky clay, 

 which is loaded with the leaves and remains of trees and 

 plants. This latter stratum is the underlying member of 

 the great Black Marl bed, which forms in many places the 

 summit of the Alhirujpean formation. 



The great beds and layers of White Sandstone belong- 

 ing to this formation are in place in the coarse member, 

 composed of sandy clay and sand, which underlies the 

 Alternate Clay Sands series. 



Allowance must be made for the denudation and erosion 

 which has obscured the relative position of the White 

 Sandstone. In some places it rests upon the mixed sands 

 of more or less reddish or brownish color, as on the south- 

 western shore of the Severn river above Valentine's creek ; 

 in the estuary of this creek it rests in the white sands, 

 both above and below tide level. 



