248 
GEOLOGY OF THE THIRD DISTRICT. 
a mound, requiring only to be insulated and rounded at the part now attached, to be like the 
one in the midst of the flat. It would appear that the whole of the flat was once filled with 
the same material of which the mound is composed, the removal of which left the mound, it 
having held a neutral position. 
There is another elevation, which would pass for a mound, were it seated in a plain or 
flat; it is in Fulmer valley, Herkimer county, to the right of the road going up the valley. 
The mounds which I have seen, descending a part of the Ohio river, were at the junction 
of a tributary with that river; appearing to have been caused by the removal of alluvial 
banks, the mounds holding the position of an eddy, with the two opposing currents which 
swept away those parts within their vortex. In the same manner it is easy to conceive, that 
when two bodies of water meet at right angles, carrying loose materials, the greatest deposit 
would take place where their forces neutralize each other ; and from the circular movement 
which results, a mound in form would be produced. Those seen, however, appeared to have 
been caused by the removal of contiguous parts, and not by accumulation. 
That mounds are also of artificial origin, and the work of the aboriginal inhabitants, is also 
unquestionable, from the observations of Dr. Locke of Ohio, and other western observers. 
In New-York, earth-works of art have been met with, showing that the same labor could also 
have thrown up the earth in the form of a mound. These earth-works were seen, one near 
Elmira, the first year of the survey ; and a second to the south of Fort-Plain, near the mouth 
of Oxtungo creek. The points chosen were just where two water-courses meet, the sides of 
the bank being steep. These works are placed at a few hundred yards from the point of 
junction, and consist of a bank of earth extending from creek to creek, gently sloping on the 
outside of the triangle, the ditch from which the earth was taken to form the bank being 
within the triangle. These works appear to have been made for the purpose of entrapping 
deer; it being easy to pass over into the area, but not so easy to return if pursued. They 
are here noticed, to show that works of earth were formed by the original people of the 
country, and that mounds may have been formed by them also; and that undeniably, as in 
the flat to the southeast of Marcellus village in Onondaga county, they are the result of what 
are termed natural causes, and belong to the quaternary period. 
