Pleistocene Geology of Moravia Quadrangle 379 
Cortland the development of clay is less conspicuous, as the area 
contains much outwash gravel which I describe in a later section. 
The second area of these lake-bottom deposits is not so typical 
a case. The presence of clay south of Moravia has already been 
alluded to. While this clay may be interpreted as belonging to 
a temporary lake, nevertheless its deposition may be connected 
partially with a static body of long duration. The best illustra- 
tion of it is found flanking the west Wall of the valley near Moravia. 
Here the clays through slumping have assumed a corrugated form 
(fig. 17), mentioned in describing the drift of this region. Perhaps 
the case is not clear as to the controlling cause in this slump- 
ing. One would hardly expect such localization of lake clays 
as this area of slipping indicates. On the opposite side of the 
valley, however, the massive delta deposits (p. 410) indicate less 
quiet waters, as well as an additional source of the finer-textured 
sediments. While elsewhere in the valley only slight areas of this 
same clay have been noted, nevertheless I did not find such exten- 
sive deposits as would necessarily indicate a lake of long duration, 
carrying in suspension a marked amount of this clastic material; 
waters impounded along the valley tongue, or a stagnant portion of 
a valley tongue^^ may have afforded opportunity for its develop- 
ment. It should be remembered, however, that northward from 
the last moraine (p.361) loop which is about a mile south of Mo- 
ravia the valley-bottom obviously is the result of such deposition- 
work, both clastic and organic, as characterized the latest stages 
of the high level lakes. 
It is felt that the study of these lake clays constitutes by itself 
a problem for investigation, and that the few facts here contri- 
buted barely touch the matter. The longitudinal valleys of Central 
New York each furnish more or less that should be studied and 
combined into a more detailed report on this topic. 
DRIFT OF THE UPLANDS. 
To draw a fast line between a region that would be classified as 
upland, and the valley area, is not easy. For the sake of discus- 
sion, however, we will take for the Moravia quadrangle the 1300- 
foot contour in general as the line of demarcation, along valley 
slopes, between upland and valley. On this premises the general 
^’Tarr: Zeitschrift fiir Gletscherkunde, band iii (1908), p. 99. 
