PUBLICATIONS. 359 
the north, much of which is of such a size and shape as to suggest that 
ice may have assisted in its transportation, though no glaciated material 
has been found in it. The advanced stage of decay observed in the 
pebbles and bowlders of this deposit shows that it_has been long 
exposed to the action of the atmosphere, or perhaps more properly, to 
the percolation of surface water. The third deposit, the Jamesburg, is 
markedly heterogeneous. It is more loamy than the preceding, but 
contains cobbles and even bowlders of large size, some of which 
differ in character from those of the Pensauken, and were derived from 
different sources ; glaciated bowlders are occasionally found. An impor- 
tant change in geography, at least, if not in reference to glaciation, is 
thus indicated. ‘The lithological characteristics of the fourth stage are 
not stated, but presumably they are such as would result from a work- 
ing over and commingling of the material composing the three earlier 
deposits. It is thus evident that the lithological differences in the 
several divisions of the Yellow Gravel are sufficient in themselves to 
warrant a subdivision of what was formerly considered the record of a 
single period of deposition. 
The Beacon Hill gravel was laid down on the even and uneroded 
surface of the Cretaceous. Elevation followed and stream channels 
were sunk through the gravel and into the marl beneath. In these 
channels in part, the Pensauken was deposited during subsequent sub- 
mergence. In the Pensauken there are fragments of ferruginous con- 
cretions derived from the Cretaceous ; these are absent from the Beacon 
Hill gravel, showing as do other facts, that the Cretaceous terrane was 
not cut by stream channels until after the first division of the Yellow 
Gravel was laid down. Another elevation followed the Pensauken 
stage, and during a subsequent submergence the Jamesburg was spread 
over the channeled surface of the second deposit. The fourth stage 
of submergence was of minor importance; its records are confined to 
the seaward margins of the region, and vary in elevation from twenty- 
five to forty-five feet. This is evidence of a moderate submergence 
subsequent to the Jamesburg stage, or may possibly represent a halt 
in the process of upheaval that closed that time of deposition. Thus, 
by unconformities, the Yellow Gravel is shown to belong to at least 
three periods of subsidence, separated by intervals during which the 
region was elevated and exposed to erosive agencies. 
The Beacon Hill gravel is known from its stratigraphic position to 
be post-Cretaceous. While evidence of its precise position in the 
