470 MM, Ss Wis fT SON 
tion of the valley (at 4) is in the clay, and brickyards are located 
there. 
If the broad valley southwest from Turners Falls between 
the Greenfield trap ridge and the northwest bluff of Montague 
Plain was cut out by the modern river, it is remarkable that the 
cutting should have ceased a few feet above the rocks. But as 
Fig.c 
these are beautifully glaciated and buried under a thin cover of 
drift, it is hard to believe the water has actually flowed over 
them. Moreover a curious remnant of sandplain (7) standing on 
the northwest ‘corner of Montague Plain (at C) seems to indicate 
that ice filled this valley all through the building of the plain. 
The wearing back of the bluff has cut away most of this sand- 
plain, but a section near Mr. Burnet’s discloses the foreset 
beds and some of the topset. Sands on that side would have 
come from the hills to the northwest by the valley of the Falls 
River. 
Kettles like those of the east valley we are wont to associ- 
ate with drift-buried ice blocks. From the alignment with the 
old upper valley of the Connecticut, as seen in the northeast 
corner of the map, this chain of depressions might represent the 
burial in outwash sands of the decayed remnants of a valley ice 
tongue, the sands being supplied from the earlier revealed hills 
to north and east. The ice-tongue here however must have 
rested above the clays, unlike the tongue to the northwest. If 
this inference is correct, as the clay floor at & seems to make it, 
we must suppose the clays were laid down during a withdrawal 
of the ice-front from this area while it was either laked or 
depressed beneath the sea, and that subsequently the ice 
advanced again to southward, reaching its valley-tongue out 
over the clays where in the final melting of the ice it rolled 
