84 Quaternary Formations of Southern New Jersey. 



material southeast of the line A-B, Fig. 42, though some chert 

 is present in most places. 



Among the finer sandy constituents of the formation, glauco- 

 nite is absent or rare at most places along the northwest border 

 of the formation. Along the center of the belt it is present in 

 small quantity in many places, and southeast of the line A-B 

 there are considerable beds of Pensauken sand in which glauco- 

 nite grains make up 10 per cent, or more of the whole. 



The changes in the constitution of the formation from north- 

 west to southeast outlined above are less distinct below Wood- 

 bury than farther north. This is perhaps because the remnants 

 of the formation remaining at the south are less extensive than 

 those to the north, and form a less adequate basis for com- 

 parison. 



These changes in the coarseness and in the petrographic con- 

 stitution of the formation are intelligible if the formation was 

 deposited primarily by land waters flowing to the main valley, 

 from the northwest on the one side, and from the southeast on 

 the other. The waters from the former direction brought in 

 materials from the north and west, the coarse being deposited 

 first. The drainage from the southeast, flowing over different 

 formations, brought in different materials, and their coarser 

 parts were left first, near the southeast margin of the broad 

 area of aggradation. Toward the center of the belt the ma- 

 terials from opposite directions are much mingled. 



It seems probable that a similar distribution of materials w^ould 

 exist if the broad valley under consideration were submerged 

 during the deposition of the Pensauken formations. If 

 it were converted into a sound, rivers would have contributed 

 sediment to its borders from either side, and the waves of either 

 shore would have acquired materials from the formations found 

 there, the coarser being carried out lesser distances from the 

 shores. Even in this case much of the material must have been 

 contributed by rivers, for the shores of the sound would no- 

 where have touched granitic rocks, or Paleozoic sandstone and 

 quartzite. They would have touched the red shale and trap rock 

 of the Newark series; but it is not clear how materials from 



