60 The American Geologist. July, 1894 
acter. Thej are distinctly marked. Their longer slope and greater 
width make a prominent feature in the topography of Ithaca. Noting 
in addition the depth at which the water Hows, and the small number 
of cascades and water-falls, the conclusion is at once reached that these 
valleys had been acted upon by some agency not now in operation. We 
can observe changes going on in Fall and Cascadilla creeks; we ran 
easily understand how their deep, rocky canons could be formed and 
are still being formed by the action of water and frost upon shale, and 
we can readily see that the conditions which obtained in the formation 
of these valleys could never explain the deep, well-marked valleys of Six- 
Mile creek and the Cayuga Inlet, with their sloping banks and knolls 
and terraces. These deep, well-worn valleys are undoubtedly the result 
of glacial action. The mass of ice which rilled the Cayuga lake basin. 
dividing at its southern extremity, one part — the larger — flowed to the 
south, wearing down the Inlet valley, and the other traversed the Six 
Mile creek valley, both of which were occupied by preglacial streams. 
The scratches on the polished surface of the underlying rocky table, as 
seen at the quarry in front of the buildings of the Cornell University, 
on the eastern edge of the basin, indicate that the glacier followed a di- 
rection a little east of south, corresponding with that of the lake. 
Among the drift accumulations are found bowlders of Oriskany sand- 
stone, and masses of Hamilton shale, formations which occur to the 
north, together with small granitic bowlders. The valley of Six Mile 
creek furnishes some special examples of the drift phenomena. In sev- 
eral places its old channel has been completely choked up with masses 
of morainic debris about which the present stream has been obliged to 
cut its way through deep canons.'"* 
In his comments Prof. Tarr says: 
[1.] " He (Simonds) can easily understand the gorges, but cannot ex- 
plain the broad valleys by erosion, and therefore concludes that "these 
deep, well-worn valleys are undoubtedly the result of glacial action.'" 
As will he seen, in the extract from my article given above. I reached 
my conclusion not oiih for the reason •"that the conditions which ob- 
tained in the formation of these valleys [Fall and Cascadilla creeks] 
could never explain the deep, well-marked valleys of Six Mile creek ami 
Cayuga Inlet." but for other reasons. Thus I distinctly stated that 
'■tin' valley of Six Mile creek furnishes some special examples of tin- 
drift phenomena. In several places its old channel has been completely 
choked up with masses of morainic debris about which the present 
stream has been obliged to cut its way through deep canons." Hence 
my conclusion, in this instance at least, was based upon the actual oc- 
currence of morainic matter, with glaciation as tin Ugitimati inference. 
A.S ;i matter of fact, the presence of a glacier cannot he disputed: and 
if present, does Prot. Tarr. for an instant, believe that it could have 
forced its way through such a valley as that of the preglacial Six Mile 
creek, excavated as it must have been in the thin-bedded Chemung 
♦American Naturalist, vol. xi, pp. 50-51. 
