I 3° Quaternary Formations of Southern New Jersey. 



less due to the close proximity of the Raritan clay below, and 

 to the general flatness of the region, which does not favor run- 

 off. Some of the gravel and sand, too, has loam enough with it 

 to make it rather impermeable. 



Along the creek east of Fresh Ponds, the base of the Pen- 

 sauken has an elevation of ioo to no feet a mile and a half 

 southeast of Fresh Ponds, and 70 to 80 feet a mile and a half 

 to the northwest, at Lawrence Brook. In the immediate vicinity 

 of Fresh Ponds, the Cretaceous has been seen in various excava- 

 tions at 90 to 100 feet. About Fresh Ponds, and especially 

 toward Lawrence Brook, bowlders are common at the surface. 



The line of old headlands runs northeast of Aliens Station, 

 through Red Tavern, Union Valley, and Half Acre, to Lower 

 Jamesburg. Along this line, the most projecting headland is 

 between Allentown and New Sharon, along the south side of 

 Assanpink Creek. 



The Pensauken deposits about Jamesburg show that the 

 formation buried and obscured the earlier topography. The 40- 

 foot relief of the Cretaceous surface near Jamesburg was de- 

 stroyed by the building up of the low lands to the level of the 

 higher. The phenomena here therefore duplicate those at Rob- 

 binsville and New Sharon, except that the upbuilding to 150 feet 

 in the latter place is not altogether conclusive, while at James- 

 burg it is ; and the latter case seems to carry the former with it. 

 If this is correct, the Robbinsville region was once built up to a 

 level harmonious with that at Jamesburg, and the non-arkose 

 upper part has been largely removed, leaving the arkose part 

 below relatively more conspicuous than it once was. 



At the southeast, the levels of the Pensauken at Old Church, 

 Red Tavern, Etra, Aliens Station, New Sharon and Egg Tavern, 

 are essentially the same, ranging from 145 to 160 feet. The 

 harmony of these levels and the likeness of the material through- 

 out, point to community of origin. 



Vicinity of Monmouth Junction. — Between Monmouth Junc- 

 tion and Princeton Junction, the Newark shale is capped by 

 Pensauken gravel, the surface of which is below 120 feet in most 

 places, and its base is as low as 80 feet just west of Monmouth 



