500 The Formation of Cape Cod. [ August, 
Through most of this distance it is very rocky, some of its blocks 
being twenty to thirty feet or more in diameter. Its further 
course is mostly modified drift with occasional boulders, passing 
east-north-east to Mill hill, Orleans village, and the south-east side 
of Town cove, beyond which it is concealed beneath the ocean. 
The conclusion of Mr. Clarence King,! that Naushon island 
which he examined, forms part of a terminal moraine of the con- 
tinental ice-sheet, seems to explain the accumulation of this 
remarkable series of hills. The border of the ice, after falling 
back from its farthest limit, stopped at this line or re-advanced to 
it, and afterwards remained nearly stationary through a long 
period, in which the materials that it contained were being con- 
tinually brought forward and deposited. In many places these 
would be pushed into very irregular heaps and ridges by slight 
retreats and advances of the ice margin. At the same time we 
should also expect that thick beds of ground moraine would be 
gathered beneath the ice near its termination. The withdrawal of 
the ice-sheet would then leave these deposits as upper and lower 
till, one overlying the other in a long but broken and undulating 
range. 
The angle of this range at North Sandwich shows that the 
portion of the ice-sheet on the west and that on the east pushed 
against each other here, the motion and slope of each being 
directed toward its line of frontal moraine. The medial moraine 
produced where their slope came together north from the angle 
of their terminal line, is presented in Rocky, Manonet and Pine 
hills, which form a gigantic ridge in the east part of Plymouth, 
four miles long from north to south, with a continuous height 
three hundred to four hundred feet above the sea. Abundant 
angular boulders of all sizes up to twenty feet in diameter strew 
its surface. At the north end of this ridge the sea has under- 
mined its base, forming a steep slope sixty feet in height. A sec- 
tion here showed twenty feet of upper till, yellowish, with abun- 
dant large and small boulders, nearly all of them angular, under- 
lain by lower till, dark bluish gray, with small glaciated stones, 
exposed for twenty feet vertically but concealed below. The bed 
of boulders which forms the shore at this point came mostly from 
the upper stratum, and their sharp corners and edges have since 
been worn away by the waves. 
oc oe: 1 Proceedings of Boston Society of Natural History, Vol. xix, p. 62. 
