1877.] Surface Geology of Eastern Massachusetts. 581 
coincides with the strike of the rocks than where it is transverse 
to the strike. Thus, in Essex and Middlesex counties the trends 
of one half the ponds deviate more than twenty degrees from the 
mean, while in Worcester County the proportion is only one 
fourth. 
One of the most remarkable facts in the distribution of glacial 
detritus, or drift, in Massachusetts is the comparatively great 
depth to which it has been accumulated over the southeastern 
portion of the State. There is a marked paucity of rock out- 
crops in the southern half of Plymouth County; south of Plym- 
outh and east of Middleborough they are rarely met with; and 
Barnstable County is absolutely destitute of them. It is not 
improbable that the solid rocks in this region are so’ deeply 
buried by the unconsolidated superficial deposits that if the 
latter were removed, the whole of Barnstable County’and a 
considerable part of Plymouth County would be invaded and 
covered by the sea. Professor Edward Hitchcock, in discussing 
this subject, estimated the maximum depth of the drift in this 
region at not less than three hundred feet; and he evidently 
believed it to exceed this. Certainly here, if anywhere, we may 
expect lake basins and river valleys to exhibit in their forms and 
trends a complete independence of the underlying rocks. This 
expectation is justified by the facts. There is not in the region 
under consideration a stream of any considerable size that has 
not a north and south course, although the strike of the un- 
derlying rocks undoubtedly approximates east and west. As a 
result of this parallelism of the water-courses, we find no streams 
of any importance cutting the north and south coast-lines; the 
Western shore of Cape Cod Bay between Elisha’s Point and Scus- 
set Harbor is almost unbroken by debouching streams, and Buz- 
zards Bay receives not a single tributary from its eastern shore, 
Coast-lines transverse to the direction of glacial action, on the 
contrary, are fretted with river mouths and long, fiord-like bays 
and inlets, asthe northern shore of Buzzards Bay and the south- 
“rn coast of Falmouth. The evidence from the lake basins is 
t as unequivocal as that from the rivers, Measurements of 
all but the smallest basins between Orleans and a curved line 
extending from Kingston southerly to the mouth of Wareham 
il convex to the west and including Simpson’s Pond, give 
- and south as the average trend or direction of the major 
lameters, and 2.7 as the ratio of the length to the breadth, or 
mean elongation, 
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