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[Assembly 
in the ledge, whose upper surface was grooved and scratched in the 
usual manner, but which passed beneath the upper layers, and from 
above which, layers had been removed by quarrying, showing conclu- 
sively that this surface had been abraded previous to the desposition of 
the upper portion of this rock, and that this upper portion was deposited 
upon an abraded surface. If I was not deceived in the examination of 
this locality, then there is one instance which can in no sense be called 
modern. Still the instances which generally fall under our observation, 
appear much nearer our own times than the one specified, for the com- 
mon abrasions which appear on the rock along the valley of Cham- 
plain, whatever that rock may be, is beneath the tertiary, which is a 
thin deposit of clay and sand. If then, those grooves and scratches 
were made just anterior to the deposit of the tertiary, then they were 
made in comparatively recent times, for the organic relics of this for- 
mation belong to those genera and species which now inhabit our seas. 
Without consuming farther time and space in the consideration of the 
period when those abrasions were made, I will proceed to the conside- 
ration of the causes by which they were produced, or the theories which 
have been advanced to explain them. 
One of the most prominent theories which has been advanced to ac- 
count for abrasions, grooves, scratches, &c. is that which assigns the 
waters of the Noachain Deluge as the cause. This deluge, it is main- 
tained, swept over the land with immense force, broke up the founda- 
tions of the rock, bore their fragments along with impetuosity, deeply 
scratched and ground those surfaces of the solid strata over which they 
passed. In this theory there is much plausibility, and something that 
commends itself to our assent. Still it is found, when tested, to be 
quite objectionable. One objection only need be adduced, viz: that the 
Noachain Deluge is much too recent an event to apply to the case in 
question ; for as has already been remarked, the abraded surfaces are 
beneath the tertiary of Champlain, which though a thin deposit in the 
valley specified, still must have required too long a period for deposi- 
tion, to have been formed since that catastrophe. 
Another which has been offered, and is still supported and maintain- 
ed by Geologists, is the iceberg theory. Icebergs or icefloes are known 
to be driven out to sea, and to bear along rocks and stones, which, as 
the ice melts, are dropped into the sea, and thus they become the in- 
struments of spreading widely the fragments of the solid strata. Ice- 
