t in the
crystalline rocks of the uplands due to post-Newark deformation
may well have directed the course of the Housatonic after it had
once deserted the limestone ... The deep gorge of the Housatonic
through which the river enters the uplands not only crosses the
first high ridge of gneiss in the rectilinear direction of one
of the fault series, but its precipitous walls show the presence
of minor planes of dislocation, along which the bottom of the
valley appears to have been depressed."[9]

The hypothesis proposed by Professor Hobbs and also the second and
third hypotheses here given involve the supposition of reversal of
drainage, and their validity rests on the probability that the stream
now occupying Still River valley formerly flowed southward. The first
and second hypotheses will be considered in the following section.

[Footnote 9: Hobbs, W. H., Still rivers of western Connecticut: Bull.
Geol. Soc. Am., vol. 13, pp. 17-26, 1901.]

EVIDENCE TO BE EXPECTED IF STILL RIVER HAS BEEN REVERSED

If Still River occupies the valley of a reversed stream, the following
physiographic features should be expected:

1. A valley with a continuous width corresponding to the size of the
ancient stream, or a valley comparatively narrow at the north and
broadening toward the south.

2. Tributary valleys pointing upstream with respect to the present
river.

3. The regional slope not in accord with the present course of the
river.

4. Extensive glacial filling and ponded waters in the region of the
present sources of Still River.

5. Strong glacial scouring at the northern end in default of a glacial
dam at the southern end of the valley, or to assist a dam in its work
of reversing the river. The evidence of glacial erosion would be a
U-shaped valley, overdeepening of the main valley, and tributaries
ungraded with respect to the main stream.

1. A VALLEY WIDE THROUGHOUT OR BROADENING TOWARD THE SOUTH

At the mouth of Still River and for several miles north and south of
it there is a plain more than a mile broad. This plain continues
southward with a width of about one-half mile until, at Brookfield, it
is interrupted by ledges of bare rock. A little distance south of
Brookfield the valley broadens again to one-half mile, and this width
is retained with some variation as far as Danbury. Drift deposits
along the border of the valley make it appear narrower in some places
than is indi