382 
Frank Carney 
valley is 'wide and deep; for this reason a lobe of ice reached into 
this valley, extending far in advance of the front of the ice-sheet. 
But this valley itself is near the center of a greater basin, occupied 
by the Finger Lakes included between Otisco lake on the east and 
Canandaigua lake on the "west. The effect of this Finger Lake 
basin on the general outline of the ice-front is 'well shown in Cham- 
berlain’s map of the terminal moraine of the ‘‘Second Glacial 
Epoch. The proximity of such a deep valley just west of the 
Moravia sheet, and the fact that the southern half of this vallev 
trends to the southeast, together with the fact that the sheet lies 
in the eastern half of the Finger Lake basin, accounts for the 
general northeast-southwest direction which the ice-front main- 
tained as it gradually withdrew across the area. 
While it is easy in the principal valleys of the sheet to map the 
longer halts of the ice as indicated by the loops, there was much 
uncertainty in definitely correlating the drift of the uplands with 
these loops. Two reasons particularly contribute to this con- 
dition: (i) The uplands contain irregular relief; in consequence 
the ice-front was also irregular, assuming new positions more 
frequently than in the valleys. (2) The work of marginal streams 
tended to blend the drift of these shorter halts. West of the Free- 
ville-Moravia valley, there is slightly more system in the moraine; 
also in the southeast corner of the quadrangle distinct moraines 
were mapped. 
In certain localities the moraine is characteristically developed. 
I will describe some of these, attempting at the same time to corre- 
late them with general changes in the position of the ice; plate XII 
gives hypothetical chronological positions of this ice-margin. 
But the following discussion does not always consider the moraines 
in their supposed order of origin : 
{a) The high points in the extreme southeast corner of the 
quadrangle were the first of the sheet to be ice-free. A beauti- 
fully developed moraine skirts these slopes. Between it and the 
westernmost of the hills the drainage from the ice-front escaped. 
In places this moraine is kame-like; one well gives a record of 70 
feet mostly of gravel. 
ib) Following this halt of the ice a second position is indicated 
by a belt of thickened drift cornmencing east of Mud Pond and 
S. GeoL Surv., Third Annual Report (1883), plate xxxiii. 
