1894.] Geology and Petrography. 887 
from its character and position, the author states that the study of this 
formation leads to the following conclusions: 
(1) The original yellow gravel is Pre-plistocene. (2) The time of 
its deposition was followed by an epoch of elevation and extensive 
erosion of long duration. (3) Then came a period of depression dur- 
ing which the Columbia deposits were made, equivalent in age with the 
first glacial deposits. (4) Again an epoch of elevation' and erosion, 
when the degradation and redistribution of the original formation went 
forward. (5) An epoch of slight depression. (6) Subsequent eleva- 
tion to the extent of forty to sixty feet, followed by the present subsi- 
dence. (Ann. Rept. Geol. Surv. New Jersey for 1892). 
