Г 
——— 
161 
lakes or, possibly, in the case of the lowest plains, in the sea. 
Most of these lakes were undoubtedly truly glacial, —that is, 
enclosed partially, sometimes wholly, by solid walls of ice. 
The kettles, dimpling the sand plains, it is well understood, are 
due to the subsequent melting of masses of ice which were 
buried in the stratified deposits; and the steep and sharply- 
defined marginal slopes which the sand plains often present are 
doubtless in part the natural, free, growing edges or fronts of 
the deltas, and in part due to the subsequent melting of walls 
of ice against which either flood-plain or delta deposits had 
been accumulated, the sand and gravel, as it was thus grad- 
ually let down, naturally assuming the maximum declivity. 
The Nantasket Peninsula, being then surrounded by deeper 
water than at present and even more remote than now from the 
main land and the mouths of rivers, was almost exempt from 
these delta and flood-plain deposits. The higher plains are 
entirely wanting here, and the lowest, which varies usually 
from fifteen to twenty-five or thirty feet in height, is developed 
in only a very scanty and fragmentary manner, as on the south 
side of Point Allerton. In Cohasset and Scituate the plain, 
having usually a height of from forty to sixty feet, is well devel- 
oped at intervals. It forms the comparatively level land along 
the railroad between Hingham and Cohasset Village ; and in the 
northern part of the village, and especially between Little 
Harbor and the railroad, it is a very typical plain, this part 
of the village being designated as the Plain“ on the published 
maps of the town. It rises quite abruptly 45 feet from the 
marshes of Little Harbor and, deeply dimpled with beautiful 
kettles, slopes gently down on the south to the marshes and 
James River. One of the kettles, on the north side of Beach Street 
near the Plain, has long been known as the **Punch Bowl"; 
and several of them hold permanent ponds, the pond near the 
south end of the Common being an example. When this plain 
was formed, the ice must have completely filled the basin of 
Little Harbor ; and the stream supplying the detritus probably 
OCCAS. PAPERS, B. S. N. Н, IV. 1l. 
