33^ Frank Carney 
Physiography of the Moravia Sheet. 
STRATIGRAPHY. 
The rocks outcropping in this region belong to the Devonian 
Period, representing the formations from the Hamilton to the 
Portage inclusive. The higher areas bear the Portage which 
contains many arenaceous layers interspersing the sandy shale. 
The Genesee is best exposed about Montville and in the gorge of 
Dry Run. The Tully limestone has been cut by the Owasco 
Inlet valley, and may be studied to advantage along the eastern 
wall from a point about one mile north of Moravia southward 
nearly to Locke. Fig. 6 gives the contact of the Hamilton and 
Tully, also of the Tully and Genesee at the falls in Dry Run. 
These formations disintegrate readily. The Portage contains 
no very heavy beds. The Tully, as shown by fig. 6, consists 
of several beds. This formation resists weathering better than 
the others, but its slight thickness, nowhere more than fifteen feet, 
does not enable it to form much of a shoulder or cliff on the valley 
wall. 
THE SEVERAL CLASSES OF VALLEYS. 
The valleys of this area appear to fall into four classes: (i) 
Those of greatest maturity; (2) those of a more recent cycle; (3) 
those of inter-glacial development; (4) those of post-glacial carv- 
ing. 
(i) Those of Greatest Maturity: Of the oldest valleys in the 
quadrangle Fall Creek is the most typical (fig. 2). The valley 
of this creek heads near the north margin of the quadrangle (fig. 
i), possibly a little north in the Skaneateles sheet. Its exact 
origin is somewhat indefinite because of burial by glacial drift. 
The valley, however, opens towards the south and in the vicinity 
of McLean joins a wider valley which leads from Cortland, trend- 
ing southwestward towards Ithaca. The valley of Fall Creek 
apparently is in topographic adjustment with this wider valley. 
There are also certain mature tributaries of the former valley, parti- 
cularly one which heads north from Summer Hill joining the major 
valley south of Groton City. Other arms of equal maturity 
(fig. 3) may be observed. 
To this same drainage cycle perhaps belong the wide contours 
which represent a former valley leading southwestward from 
