330 Association of American Geologists and Naturalists. 
Upon the surface of this sloping hill is about ten feet of a deposit of 
sand, clay and gravel, saturated with water, and constantly moving 
down the side of the hill. This is evident not only from facts ascer- 
tained in excavating the canal, but also in the fact that the oak trees 
which grew upon the high ground have slidden down and become inter- 
mingled, standing in all directions among the hemlocks which skirt the 
margin of the river below. 
The deposit in which the fossil wood is found, was probably made in 
a lake which was afterwards filled with an accumulation of gravel and 
sand, derived from the outbursting of some reservoir farther south. 
This deposit being pervious to water allows this liquid to pass through 
it, and meeting with an impervious mass below, flows out in the form a 
springs, undermining and carrying down the surface matter. 
In a transverse section extending across the river valley and channel, 
Mr. H. illustrated the changes which had taken place in the direction of 
the Genesee, during a comparatively recent period. 
The river to the south of Portage flows in the bottom of a broad val- 
ley, extending toward the north. At Portageville the stream bends 
around to the left, and after flowing a short distance nearly south, turns 
to the north and northeast, cutting its channel through the rocky slate 
in some places to the depth of three hundred and fifty feet, and forming 
in its passage three falls of sixty six, one hundred and ten, and ninety 
six feet respectively. This channel is narrow with mural banks; but 
a short distance below the lower fall it emerges into a broader valley, 
in a line with the channel to the south of Portage, before it is deflected 
from its course. 
The space between these two points, as shown in the section, is a deep 
broad gorge filled to a great height with clay, sand and gravel. 
This is evidently the ancient channel of the river, and yet after it 
had become filled with this drift the stream found an easier passage by 
excavating the solid rock for three miles, than by removing these loose 
materials. 
Still below this point the river leaves the broad channel and exca- 
vates a gorge through the shales emerging into the broad valley at 
Mount Morris. 
Several other lakes and streams in Western New York exhibit the 
“same phenomena, and although there are northern channels filled with 
drift, the streams often turn at right angles and excavate their course 
through rocky strata. 
The Chair mentioned to the meeting that Prof. ‘Hitehenee 
would favor the Association with a public lecture in the evening 
at 73 o’clock. Adjourned. 
