174 Quaternary Formations of Southern New Jersey. 



In the valley of Back Creek, the formation rises but little above 

 its level at Yardville, and is ill denned. 



Up to Cross wicks (village) the valleys of Doctors and Cross- 

 wicks creeks are close together, and the divide between them is 

 low, and covered with the Cape May gravels and sands, which 

 seem to have been deposited by Crosswicks, rather than by 

 Doctors Creek. Both streams, have cut through the formation, 

 revealing the Cretaceous below. Along both creeks, the Cape 

 May formation is developed chiefly on the right bank of the 

 stream, and where distinctly developed, it appears in the form 

 of terraces. The terraces are not persistent, and not always 

 distinct, for their upland limit is ill defined in many places, because 

 the slopes above are low and gentle, leaving the upland edge of 

 the terrace poorly marked topographically. Along both creeks 

 there is eolian sand on the left banks, at the levels where the Cape 

 May should be, though the sand occurs up to levels somewhat 

 higher than those appropriate to the Cape May formation. There 

 is such sand on the left bank of Doctors Creek above Yardville, 

 and on the left banks of both creeks, farther up. Along both 

 creeks the left bank is slightly higher than the right, the excess 

 being due to eolian deposits. In the upper parts of both valleys 

 the formation is less well developed. Instead of appearing in the 

 form of flat-topped terraces, it lines the valley bottoms. Its 

 slopes toward the stream are in part at least due to erosion since 

 the gravel and sand were deposited. 



On Doctors Creek, a mile and a half northeast of Crosswicks 

 village, there is a terrace of sand and fine gravel at an eleva- 

 tion of 60 feet. Up Doctors Creek, the formation rises to 90 feet 

 at Allentown, and more rapidly above, up to a point a mile or 

 more above Imlaystown. Three-fourths of a mile west of Allen- 

 town, there is a well-defined terrace at 70 to 80 feet, which 

 appears to represent the height of the filling in the Cape May 

 epoch. On the south side of the creek there are higher sands 

 (90 to 95 feet) which are probably eolian, which seem to go with 

 the Cape May formation, or to be subsequent to it. 



At Allentown there is some 20 feet of Cape May material, more 

 than at any point below down to Yardville, and more than at 



