Cape May Formation — Local Details. 171 



In the region about the headwaters of Cranbury Brook, both 

 branches of the Millstone, and the Assanpink (from Gravel Hill 

 on the northeast nearly to New Sharon on the southwest) , there 

 is much material which is not easily classified. Much of it 

 probably is of Cape May age, or of this age approximately. It 

 is material deposited after the long erosion which followed the 

 deposition of the Pensauken, but is not so definitely connected 

 with the streams as the Cape May formation commonly is. This 

 may be because it is in the region where the valleys are less well 

 defined, and where the deposits are of the piedmont type, rather 

 than of the distinct valley type. This material was mapped by 

 Mr. Knapp as "undifferentiated," but it might be included with 

 the Cape May, if that term be made to cover post-Pensauken 

 deposits in general. 



Cranbury Brook. — The Cape May formation of this valley is 

 disposed as in the valley of the upper Millstone, being confined 

 chiefly to the right bank of the stream. It is fairly distinct up 

 nearly to the head of the valley. It covers the low slopes, and 

 constitutes low benches 10 to 20 feet above the stream. The 

 soil over the formation in this valley, as in the Millstone, is 

 much more sandy than that of the upland. The distinction is 

 recognized in the region by differences of farm, crops. 



The lower Millstone. — At Princeton Junction, the three main 

 branches of the Millstone, Bear Brook,. the upper Millstone, and 

 Cranbury Brook, come together. There is much gravel and 

 sand over the headlands between the lower ends of the streams. 

 Its depth is unknown, but it goes down to and perhaps below 

 the levels of the permanent streams. The upper surface of the 

 formation reaches a maximum altitude of about 70 feet. 



Over the gravel and associated sand there is some sand and 

 loam, which covers higher lands' as well. The loam varies from 

 sandy to clayey. Cuts have revealed the loam as a definite 

 mantle 8 to 10 feet thick in some places, and clearly distinct 

 from its base. Where the loam is sandy, it is eolian, and per- 

 haps all of it had this origin. 



Just south of Kingston, there is a bit of the Cape May forma- 

 tion in the valley of the Millstone, east of the canal. Its upper 



