Pensauken Formation — Local Details. 127 



There is no indication of a pre-Pensauken valley between 

 Penns Neck and Princeton, lower than 90 feet. Nowhere else 

 in the immediate vicinity is the Pensauken as low as at Princeton 

 Junction. Its base here is about 80 feet above sea level, rarely 

 below 70 feet. 



Small remnants of Pensauken occur at about 120 feet south- 

 west of Princeton, and at 100 to 108 feet south of Port Mercer. 

 The Pensauken mantle here is thin and contains much shale. 

 Locally more than half the material is of this sort. Some of the 

 shale-gravel beds suggests, but do not prove, shore action. 



Two small patches of Pensauken occur at Lawrenceville, at an 

 elevation of about 120 feet. Larger areas are on the divide at 

 an elevation of about 120 feet a mile and a half east of Law- 

 renceville, and on the divide at 100 to no feet between Port 

 Mercer and Lawrence Station, centering about Qarksville (p. 

 122). 



There are also outlying areas of the formation to the south- 

 east. East of New Sharon, Aliens Station, Hightstown and 

 Cranbury Station, there are several small outlying areas of non- 

 arkose gravel, correlated with the Pensauken. They have no 

 distinctive features, as compared with similar areas farther 

 southwest. 



Just east of New Sharon, east of Aliens Station, just south of 

 Etra (Milford), and at Old Church and Red Tavern, the arkose 

 Pensauken grades into non-arkose, and the Cretaceous base 

 rises rather promptly at the same time. Farther east the gravel 

 remnants regarded as Pensauken are isolated and higher. 

 Southwest of Red Tavern, the arkose phase rarely is higher than 

 130 feet, but the non-arkose phase rises to 150, 170 and 180 feet, 

 toward the Clarksburg-Perrineville hills. East of these hills, 

 along the Millstone, Pensauken gravels rise even to 200 feet in 

 a belt extending from Bergen Mills on the north, to within a 

 mile of Charleston Springs on the south. These gravels appear 

 to be associated with the Millstone River in origin. 



Between Cranbury Brook and Fresh Ponds. — Within the area 

 roughly outlined by the villages of Plainsboro, Cranbury, Union 

 Valley, Jamesburg, Rhode Hall, Fresh Ponds, Deans, and Mon- 



