1879. ] The Formation of Cape Cod. 555 
coast of New England the sea was depressed in the glacial period 
below its present height. The submarine channel of Hudson 
river shows that after this time it sank five or six hundred feet 
lower than now, apparently because the south part of the glacial 
sheet had been melted, greatly diminishing its attractive force at 
this latitude. With the more complete departure of the ice the 
sea-level has been restored to approximately the same condition 
as before the glacial period, being still rising on the eastern coast 
of the United States at the rate of about a foot, or less, in a hun- 
dred years. 
The channels which we ive described as occurring on the 
plains that slope southward from the series of hills, are best 
shown on Cape Cod, in Falmouth and eastward to Cotuit harbor, 
which is the region directly south from the angle of the terminal 
moraine and from its highest hills, which in this portion of its 
course are composed mainly of modified drift; in other words, 
they occur most abundantly where the drainage from the melting 
ice-sheet must have been greatest, including all the floods poured 
down from the ice-fields along the line between Falmouth village 
and North Sandwich, those that converged toward the angle of 
the ice-margin, and those which brought down its vast frontal 
hills of gravel and sand along several miles eastward. Some of 
the hollows containing ponds, which are found frequently on these 
plains, may have been left unfilled because masses of ice remained 
there while gravel and sand were rapidly deposited about them; 
but probably in most cases they are due to unequal deposition, 
though with unobstructed drainage. 
North and north-north-west from the angle of the moraine, a 
most irregular belt of kame-like modified drift in ridges, hills, pla- 
teaus and hollows of every shape, but generally with a north-to- 
south trend, reaches to Kingston, a distance of nearly twenty miles. 
These deposits are finely seen along the road from North Sand- 
wich by Great and Little Herring, Bloody and Long ponds. The 
elevations are fifty to one hundred feet above the depressions, and 
one hundred to two hundred feet above the sea. The material is 
obliquely bedded sand and coarse gravel, with pebbles up to one 
foot in diameter. Boulders are rare or entirely wanting for some 
-eight miles, till we reach Pine and Manomet hills, already described, 
which seem to constitute a medial moraine of coarsely rocky ~ 
unmodified drift, ET by ice-currents without the agency 
VOL. XIII,—No, IX, 
