172 Quaternary Formations of Southern New Jersey. 



limit is at about 70 feet. The material consists of a mixture of 

 glacial gravels with material derived from the Pensauken. There 

 is here a considerable amount of glacial material similar to that 

 at Bakers Basin at an elevation of 60 feet. Traces of the same 

 sort of material are found in the valley above Kingston, at cor- 

 responding levels, but it is not present in quantity. 



A mile north of Griggstown, on the east side of the Millstone, 

 fluvio-glacial gravel is found in relations similar to those west 

 of Penns Neck, opposite Princeton. The remnants are seen 

 along the ravines which lead down to the canal. They suggest 

 that the valley of the Millstone was once filled with glacial gravel 

 up to the 60- to 70-foot level, most of which has since been 

 removed. Some of the remnants appear as miniature ridges, 2 

 to 4 rods across, with probably 3 to 6 feet of gravel of dis- 

 tinctly glacial type. Between Rocky Hill and Griggstown, the 

 merest traces of similar gravel — really little more than scattering 

 pebbles— are found at various points and at harmonious levels. 



North of East Millstone village, the same material is more 

 abundant, and appears as definite terraces, as in the vicinity of 

 Weston and Hillsboro. At East Millstone there is a good deal 

 of sand at 60 to 100 feet, similar to that on the shale slope 

 above Bakers Basin. It is probably eolian. 



The disposition of this glacially derived gravel in the valley 

 of the Millstone does not show decisively how the drainage 

 flowed. The gravel is a bit higher at East Millstone than farther 

 south in the vicinity of Princeton Junction and Trenton; but it 

 is also a little higher at East Millstone than at Weston, farther 

 north. The constitution of the gravel, while not very decisive, 

 suggests drainage to the south, for certain sorts of pebbles 

 characteristic of the gravel of the Delaware are not found at 

 Princeton Junction and north. 



Crosswicks Creek and Doctors Creek. — The formation has 

 considerable development about Yardville at the lower end of 

 Crosswicks Creek, especially below Crosswicks (village). Thence 

 it extends up Back Creek nearly to Newtown, up Doctors Creek 

 beyond Imlaystown, and up Crosswicks Creek to Walnford and 

 beyond. It rises from an altitude of 60 feet near the Delaware, 

 to 120 feet at Imlaystown some 15 miles above, an average 



