14 
GEOLOGY OF THE SECOND DISTRICT. 
as quite recent, and, in addition to this, as having undergone but little change since the marine 
occupants gave place to the lacustrine. 
On the New-York side there are several small and unimportant valleys which open into the 
Champlain ; the most important are those of Lake George, which has already been spoken 
of as extending to the plains of Saratoga, the Bouquet, Ausable and Saranac. The Bouquet 
is narrow, and runs nearly in the direction of the lake about eight miles, and along the junction 
of the primary with the transition rocks. The Ausable is much more important, and is geo¬ 
logically interesting for the gorges in the Potsdam sandstone through which the Ausable flows. 
The river flows near the southeastern side of this valley, and it is not improbable but it would 
be proper to consider the Ausable and Saranac as but one valley. Considered as one, it ex¬ 
tends twenty miles west of the lake, and north till it terminates in the valley of the St. Law¬ 
rence. It lies in the angle formed by the Great Adirondack on the south, and Lyon and 
Whiteface on the west and northwest. It extends therefore from Keeseville to Champlain, 
and from Plattsburgh to Redford. Geologically, this valley is important and interesting, par¬ 
ticularly as it furnishes a better developement of the lower transition rocks than any other 
part of the State. It is only here that we find the series complete ; the phenomena too of uplifts 
and fractures are finely displayed ; in addition to which, all the elementary principles of 
geology may be found ilhistrated in a field quite accessible. 
I have only to notice one other feature in the valley of the Champlain, viz. the obliquity of 
of its subordinate valleys. Thus, on the west or New-York side they open to the northeast; on 
the east,' nearly to the northwest; though as it regards the latter, their course coincides more 
nearly with the direction of the Green Mountain range ; thus, the valley of Otter creek coincides 
very nearly with that of the lake, or to a north and south direction. These facts, it is true, are 
unij;nportant in themselves, and they are only noticed for the purpose of showing more clearly 
the slope and convergences of the valley; it is only by these facts that this structure can be 
demonstrated. 
Age of the Valley of the Chaviplain .—The question concerning the age of valleys is quite 
as important as that of the mountain system ; in many instances these two inquiries are con¬ 
nected and inseparable from each other, or the determination of one settles that of the other. 
Though it is difiicult to determine the question under consideration with much exactitude, still 
there are two or three facts which are important: 1st, It is a very ancient valley, a fact which 
is proved by the organic remains of the clays and sands which form the present floor of the 
valley. 2d, By the smooth and polished surface of the rocks which compose the ancient floor 
upon which the clays and sands of the post-tertiary, (as the formation has been designated, j 
were deposited-; for we cannot regard therti as having been wholly formed by sudden and vio¬ 
lent movements of the loose materials upon the surface : the whole phenoniena is one of 
moderate force, combined with one of power, but yet of long continuance. 
The ancient floor of this valley is formed by two classes or systems of rocks: 1st, The 
primary, principally gneiss ; and 2d, the lower transition or rocks of the Champlain group, 
as they are denominated in the subsequent pages. The order of events connected with the 
