22 SEASONAL DEPOSITION IN AQUEO-GLACIAL SEDIMENTS. 
group, three feet thick, has deposits averaging one half inch each. Above 
these layers comes a contorted zone three feet thick with no stony material 
mixed with it or lying on it. The layers in this contorted zone are not over 
one third of an inch thick.’ Above this zone come annual layers one foot six 
inches thick (No. 25). The couples are one half inch thick at the bottom, they 
gradually thin down to one fourth of an inch at the top. Above this group 
comes a contorted zone which varies in thickness between three feet and six 
feet (No. 26). (See Plate 10, fig. 1.) The annual deposits, in most of this zone 
are not over one eighth of an inch thick. The tops of the folds have, in places, 
been cut off considerably. Lying on this deformed mass is rock-flour several 
inches thick. I found one angular rock-fragment only in this rock-flour. 
Above the rock-flour, alternating layers of fine sand and clay appear, averaging 
about two: inches thick (No. 27). Inside of five feet these thick deposits thin 
down to not over one half inch to the annual deposit, and from this point to the 
top of the clay-pit the layers gradually grow thinner, until near the top, about 
eighteen inches below the edge of the pit, they are not over one eighth of an inch 
thick. The total thickness of these upper layers is about thirteen feet (No. 27, 
28, and 29). The uppermost eighteen inches appear to be unstratified clay such 
as would wash down from the slope above the pit. These topmost seasonal 
layers differ from those in the lower twenty-five feet of the Woodsville deposit 
in the ratio of the fine and coarse components of the annual deposits which are 
about equal in thickness here, while lower down the ratio is two to one in favor 
of the fine component. 
The deposits above (No. 23) need an explanation. We have seen that in 
the lower pit the contorted zones grow thinner upward and that ending with 
(No. 21) the contortions were only four inches thick. From this point upward 
there are no contortions visible for nine feet. Then comes the contorted zone 
(No. 24) with a thickness of three feet. This zone will be discussed later after 
(No. 26). In the layers of group (No. 25), gradual thinning is noted and then 
comes the large contorted zone (No. 26). From the thinning of the layers in 
No. 25, 26 it would appear that the glacier had retreated rather rapidly. The 
highly contorted zone (No. 26) would indicate something more than dragging 
icebergs. It would appear as if these contortions meant, perhaps, ploughing 
by a relatively thin glacier. It might be objected that such a glacial advance 
should be heralded by thicker deposits instead of such thin layers. Would 
it not be highly probable, however, that such thick deposits would be destroyed 
by the advance of the ice over them, leaving only the contorted thinner layers 
