2 Quaternary Formations of Southern New Jersey. 



30 to 40 feet per mile to the southeastward. Because of this 

 dip, the several formations strike northeast and southwest, and 

 come to the surface in succession southeast of the outcrop of 

 the Newark series. The belt where the Cretaceous outcrops, 

 has a width ranging from about 10 miles to about 25 miles. The 

 southeastern border of the belt runs roughly from Salem near 

 the Delaware, to the Atlantic coast near Long Branch. 



Formations of Eocene and Miocene age overlie the Cretaceous 

 system, their dip being much the same as that of the older sys- 

 tem. ' Their outcrops continue, in some measure, the belting of 

 the surface occasioned by the outcrop of the successive forma- 

 tions of the Cretaceous system. 



Above the beds definitely correlated with the Miocene, there 

 is another pre-Quaternary formation, or perhaps two forma- 

 tions, dipping somewhat regularly to the southeast much as the 

 underlying beds do. This formation (or the older of the two 

 if there be two) is the Cohansey sand, the age of which has not 

 been definitely determined; but it is probably late Miocene or 

 Pliocene. In some places, the Cohansey sand is overlain by 

 gravel, which has been called, in various annual Reports of the 

 Survey, the Beacon Hill gravel. Whether it is to be regarded 

 as the upper part of the Cohansey formation, or as a separate 

 formation, is an open question. The gravel is perhaps the 

 equivalent of the Lafayette formation farther south, though this 

 is not demonstrated, and is very subordinate in volume to the 

 sand. 



THE QUATERNARY FORMATIONS. 



General Statement. — The belted character of the surface due 

 to the successive outcrops of the Cretaceous and Tertiary beds, 

 is much obscured by the discontinuous mantle of post-Tertiary 

 or Quaternary gravel and sand which overlies Cretaceous and 

 Tertiary alike. In places, and for considerable areas, this mantle 

 conceals all older beds ; but in other areas it is so discontinuous, 

 because of erosion, that the underlying formations are readily 

 seen. This superficial mantle of gravel and sand of Quaternary 

 age corresponds, in a general way, with the surface formations 



