BANDED CLAYS. 23 
of the preceding retreat which had collected lower down? On the retreat of 
this ice the layers should be relatively coarse, as they are in this case, and by a 
continuing retreat the layers should become progressively thinner, just as they 
actually do. As to the depth of water in the valley, during this time, the in- 
crease in the thicknesses of the coarse components of the deposits would indi- 
cate either shallower water or warmer seasons. In any event the water was 
probably no deeper than it had been. The great size of the contortions and the 
cutting off of the folds and crumplings would indicate, in the case of an iceberg, 
a much larger berg than those which took part in the contortions found in the 
lower pit. The evidence, so far observed, points to an ice advance and not to 
iceberg action. So far I have found no cut-off folds nor rock material in zone 
(No. 24). It is possible that this zone was crumpled by shearing produced 
by the over-riding of the ice which crumpled zone (No. 26), above it. 
By a count of the annual deposits at least 2,100 years are represented in 
the entire thickness of fifty-eight feet of these clays. Above the last contorted 
zone just described there occur about 460 double deposits to the highest part 
of the section. It has seemed to me that these layers register a retreat of the 
glacier. No account has been taken of the layers destroyed by the dragging 
of ice over the bottom. It is probable that several hundreds were thus oblit- 
erated. In any event, from all the evidence which these deposits present, it 
would appear, on the seasonal hypothesis, that there was glacial ice not a great 
distance from this Woodsville locality, for possibly 2,500 years. The retreat 
was probably not so fast as the retreat of the glaciers in Alaska or of glaciers 
in many other parts of the world at the present time. 
On account of the consolidation of some of the gravel in the layer Number 
6, these clays may be older than the last Wisconsin advance. No overlying 
till has been found, and no fossils discovered although microscopic fragments 
of macerated wood are plentiful. Future discoveries may reveal the exact 
age of these clays. The protected position of the deposit, in the lee of a steep 
hillside on the north, might have made it possible for this clay body to have 
escaped destruction by Wisconsin ice. 
Banded clays are not rare between Wells River and MelIndoes on. the 
Vermont side of the river, a distance of eight miles. Although most of these 
deposits were examined, no close study has been made of them. It is sufficient 
to say that they all show the regular banding well marked. On the eastern 
side of the river, above Woodsville for eight miles, as far north as Monroe, 
exposures of clays near the road are lacking, although in the banks of the river 
there are several exposures. 
