1 
432 [Assembly 
The absence of all strata superior to the coal series, (if we except 
some small tracts of Tertiary towards the eastern part of the State,) in 
New-York and Pennsylvania, prove that this great area has never been 
submerged beneath the ocean for any length of time, since the period 
of these ancient depositions. We have proof, however, of the violent 
action of water in the denuding and excavating agency, in the produc- 
tion of valleys and water courses. These phenomena may have been 
caused in part by a sudden submergence, and the rapid passage of a 
wave over the surface. The subsequent changes may have resulted 
from an inland sea, which for a long period remained in possession of 
a large portion of the interior of the continent, ranging at various ele- 
vations. This, in its subsidence, gave rise to small lakes, on the more 
elevated grounds, which, from accumulating waters, burst their barri- 
ers and communicated with those of a lower level or passed off through 
the present w^ater courses to the ocean. 
The theory of an inland sea was advanced many years since ; but 
if we may judge from the manner in which the subject has been treat- 
ed, it was considered visionary, at least. My attention was called to 
this subject by Mr. Roy, civil engineer, of Toronto, U. C. who has 
made many important observations regarding the former elevations of 
this sea or lake. These observations, which have been carried on by 
levelling, at dififeient and distant places, sustain the opinion that this 
lake was stationary at different periods at certain elevations, where well 
defined margins are still observable. Such points have been observed 
in New-York, and we need only to refer to one at present ; that is the 
ridge road or lake ridge, extending from Sodus to the Niagara river. 
These margins or shores of the ancient inland sea, are at the follow- 
ing elevatoons above tide-water, as marked on a plan or section con- 
structed by Mr. Roy. At some of these margins, it remained station- 
ary for a long period, at others for a short time only, depending proba- 
bly on the facility with which the barrier at the great outlet was re- 
duced. 
Feet above the level of the Lake inland. Feet above the level of the sea. 
O. 762 996 
L. 680 914 
G. 420 654 
E. 344 518 
D. 308 542 
