428 
Frank Carney 
or by the fringing tongues or dependencies that fed out into the 
valleys as the ice-sheet advanced and again as it retreated, and 
whether more erosion was done by the Wisconsin ice than by an 
earlier invasion, are pertinent questions. Observations made 
in the Ticino valley of Italy,^® and in other valleys through 
which glaciers have fed from mountainous regions, indicate 
that valley glaciers performed much erosion; but in these 
valleys the ice moved downhill, whereas in central New York the 
valleys sloped the other way. Furthermore in New York there 
is evidence of erosion, as in the Laborador pond valley of the 
Tully quadrangle, producing a ‘Through” valley where appar- 
ently two streams formerly headed against each other. It does 
not seem to be clearly demonstrated that over-deepening and 
“through” valleys are the products solely of valley glaciers. 
Again, if the erosion of the Owasco valley was accomplished bv 
dependencies of the retreating Wisconsin ice we should find 
drift-loops in the parts of the valley not now drowned by the lake, 
and in the lake part lateral moraines correlating with loops; 
on the Moravia sheet I did not find loops near enough to the 
over-deepened part of the valley to indicate that the erosion was 
due to tongues of ice appended to the retreating Wisconsin sheet. 
If an earlier invasion did not extend farther south than the general 
location of Chamberlin’s “ Moraine of the Finger Lake Region,”^® 
we can conceive how the alteration of these valleys may have been 
accomplished by glaciers somewhat of the alpine type, belonging 
to a pre-Wisconsin ice-sheet. 
Striae. 
The thin drift in many portions of the uplands, and the altitude 
of the axes of rock salients have made obvious the direction of ice- 
motion over several parts of the Moravia quadrangle. While 
many scores of readings were taken in the particular areas, the 
average of these in most cases has been used in Plate XII which 
locates the most pronounced striated surfaces. 
The glacial scratches we now read represent in the majority of 
W. M. Davis: Appalachia, vol. ix (1900), “Glacial Erosion in the valley of the 1 
Ticino,” pp. 136-56. j 
U. S. Geol. Surv., Third Annual Report (1883), pp. 353-60. | 
