No. 161.] 
121 
the Saranac, Clintonville, to Willsborough or Essex, would pass 
along the junction of the same rocks on the east; the whole interior, 
therefore, of the northern counties, from Essex on Champlain to 
Alexandria bay on the St. Lawrence, is primitive. Up all the large 
rivers, however, in this territory, the transition may pass beyond 
the boundaries we have marked for it. At the south again, at 
Little-Falls the primitive comes to a point, as it were, somewhat 
like its termination at Malone. We suppose, for we have not ex- 
amined very accurately the southern boundaries, that a line drawn 
from Little-Falls to Caldwell, would mark the south eastern limit 
of the primitive. From Little-Falls to Alexandria bay the same 
line would mark the southwestern borders of the primitive rocks. 
We shall perceive, from the boundaries we have given to the pri- 
mitive rocks, that the shape of the country in which they appear 
^s the surface rock, is like a lozenge, some irregularities being left 
out of view. We therefore give the above as a correct outline of 
the extent of the formations in the 2d geological district. Correct 
in general, but in some particulars of minor importance, there may 
be some points where it is not literally true. Corrections of those 
points must be left to the future, when our investigations will be 
confined to territories of less extent. 
As yet we have said nothing of the alluvial and diluvial depo- 
sites; not because those formations do not exist in this district, but 
because our information is not sufficient to enable us to speak con- 
fidently of their extent; and besides, they will come up more pro- 
perly when we make our report on the geology of the counties. 
There are, however, two districts of some extent which are un- 
derlaid with one or both of these kinds of deposition. One of them 
is in the vicinity of Glen's Falls, the other in and about Clintonville 
and Keeseville. The former extends from Glen's Falls several 
miles on the way to Caldwell, at the head of Lake George; it 
spreads out to a great extent south into the county of Saratoga. 
It is mostly a siliceous sand, underlaid by a stratum of clay. The 
sand and the clay at the falls, are each from 10 to 15 feet thick. 
Reposing on the blue limestone, their dip corresponds to the rock 
beneath, which is 5° or 6° to the S. E. 
The most interesting question concerning these sandy deposites 
is, in relation to their origin. As they contain no marine or fresh 
water relics, it is not probable that they were deposited on the bot- 
tom of a lake or the sea, hence the inference is, that they were 
[Assem. No. 161.] 16 
