G. F. Wright — Unity of the Glacial Epoch. 865 



The true glacial deposits in the Delaware valley below the 

 Water Gap can be readily traced by the distribution of Medina 

 sandstone which forms the crest of Blue Ridge, rising every- 

 where as a solid wall about 1,000 feet above the country to 

 the south. This is a very characteristic and enduring rock, 



Map of the Delaware valley in the vicinity of the Terminal Moraine. 



and forms a large part of the moraine in the counties men- 

 tioned. South of the moraine, on the New Jersey side of the 

 Delaware, within a distance of fifteen miles, there are three 

 low mountain ridges (Scott's, Pohatcong and Musconetcong) 

 separated by valleys. These ridges and valleys run northeast 

 by southwest parallel with Blue Ridge. The mountains con- 

 sist of gneissoid rocks, and are evidently the remnants of three 

 anticlinals which were once covered with strata of Lower Silu- 

 rian limestone and Hudson River slate, remnants of which ap- 

 pear both in the hollows between the ridges and on both the 

 north and their south flanks of the ridges as a whole. South 

 of Musconetcong Mountain stretch the Triassic red shales 

 which cover so much of the central part of New Jersey. But 



