190 



the form of a long and acutely tapering wedge, the base of wfiich 

 is traced by the coast of the Atlantic Ocean and Sandy Hook 

 bay — the point being marked by the limit of the firm land north 

 of Salem. A slight inchnation of the surface of this formation 

 may be shown to exist uniformly from its northeastern towards 

 its southwestern extremity. Independently of proofs derived 

 from the known elevation of the country at various points, we 

 have evidence of the correctness of this statement by merely 

 observing the position which the belt occupies in relation to the 

 streams in the different portions of its range. In Monmouth, 

 where it is widest, it includes the head waters of nearly all the 

 streams which empty either into the Atlantic Ocean, or the 

 Raritan and Delaware rivers. But, crossing Burlington, Glou- 

 cester, and Salem counties, its position as we advance south- 

 westward is nearer and nearer to the mouths of the several 

 creeks entering the Delaware. The whole of the strata have 

 been manifestly uplifted to a greater height in Monmouth than 

 elsewhere, which circumstance, in connexion with the less ex- 

 tensive denudation of the northwest side of the belt, readily 

 explains the breadth of the formation in that quarter. 



The area here designated as including the whole of the visible 

 greensand formation, embraces also several local, insulated tracts 

 of the other overlying divisions of the upper secondary series. 

 These are obviously but the remnants of strata which at one time 

 spread themselves extensively over the greensand. The general 

 southeast dip of all these deposits, renders their existence beneath 

 the superficial sands of the region to the southeast extremely 

 probable. To the almo«3t universal destruction of the yellow 

 sand and brown sandstone, which form the two upper strata of 

 the series, we are to ascribe, I conceive, the deep and general 

 covering of loose yellowish and white sands which conceal 

 the rest of the formations throughout so large a portion of the 

 region southeast of the greensand belt. 



Composition of the Greensand or " Marl'^ Formation. 



The greensand formation comprises, strictly speaking, several 

 subordinate beds, all belonging, however, to two principal varie- 

 ties. In the first of these, the green granular mineral is the pre- 



