PREGLACIAL COURSES OF STREAMS. 191 
It should be remembered that in the Herkimer-Ilion section and the 
Rome-Oneida section these figures may not represent maximum depths 
in the middle of the valley. 
It thus appears that between Harbor and Little Falls a true rock basin 
exists, 18 miles long and having an ascertained depth of nearly 150 feet 
below its lowest or western rim. It is excavated in soft Utica shales. and 
if, as appears, the work was done by the eastward-moving glacier of the 
upper Mohawk valley, it affords a close and interesting parallel to the 
rock basin part of the Finger Lake basins of western New York.* 
PREGLACIAL COURSE OF THE WEST CANADA CREEK 
Only a tentative statement is here offered. Reference to the map (page 
183) shows that West Canada creek turns abruptly from the southwest 
to the southeast about Trenton Falls and enters the Mohawk at Her- 
kimer. It is held as possible that before Glacial time its course may 
haye continued to the southwest, past Holland Patent, along the Nine 
Mile Creek valley to the Mohawk, near Oriskany. The evidences are a 
broad open valley, adequate to the Ohio or Susquehanna, at Holland 
Patent and Stittville, now occupied bya minor stream; the more normal 
arrangement of drainage thus postulated ; massive barriers of glacial 
debris north and east of Holland Patent; superior altitude of West 
Canada valley bottom below Trenton Falls as compared with Holland 
Patent; avery level stretch of some five miles of the West Canada creek 
about Poland, and the constriction of the valley about Middleville. 
The supposition is that morainic obstruction blocked the old channel 
and sent the creek across a col not far from Middleville. 
DIVERSION OF HEADWATERS OF “ROME” RIVER 
The explanation is clear. Glacial erosion at Little Falls and the 
later, eastward, eroding flow of glacial waters would in considerable 
measure cut down the rocky col, while an immense mass of glacial debris 
was discharged into the valley, aggrading its bottom from Rome east- 
_ward. This discharge was mainly from two sources, the upper Mohawk, 
debouching above Rome, and West Canada creek, which, whatever its 
early course was, certainty formed a great outlet by Holland Patent dur- 
ing the recession of the glacier and while its present lower course was 
filled with glacial ice. his is shown by the extensive deposits of gravel 
and sand about Remsen, Trenton Falls, Holland Patent, and for a few 
miles eastward, while below Newport massive tills clog the valley to 
*See A. P. Brigham: Finger lakes of New York. Bull. Am. Geog. Soc., vol. xxv, no. 2, 1893; also 
R.S. Tarr: Lake Cayuga a rock basin. Bull. Geol. Soc. Am., vol. 5, 1893, p. 339. 
XXIX—Bun. Gon. Soc. Am., Von. 9, 1897 
