232 
[Assembly 
Port Kent and Keeseville on the New- York side; and the shale, the 
grauwacke and gray limestone of Burlington, on the Vermont side. 
Fig. 16. 
B 
A 
i 
A, Port Kent; B, Burlington; C, Sharp Shins; a, sandstone resting on 
the primary rocks; 6, shale; c, grauwacke sandstone; gray limestone. 
We have at these points the whole formation in place in the order of 
superposition, except the transition limestone, which is of course con- 
cealed by the water of the lake, for the shales every where rest up- 
on or terminate this stratum. 1st. We have the sandstone of Port 
Kent dipping beneath the waters of the lake and towards the east, and 
resting on the primary rocks. 2d. On the Burlington side the first stra- 
tum w^hich appears, is the shale; then 3d. The grauwacke sandstone, 
and finally the gray limestone. Now the most important fact in this 
section is the position of the last member of the group, the gray lime- 
stone. It is a stratum which in Berkshire county, and other parts of 
the country, has generally been placed among the primary rocks; it is 
identical with the limestone at the base of Saddle mountain, and which 
covers more or less of the western flank of the green mountains. As 
yet I have not been able to find any very distinctive difference between 
it and the white and gray marbles along the whole range just mention- 
ed. No one has ever doubted the priniary character of these marbles, 
yet, if the preceding views are correct, will they not have to be re- 
moved into the transition class ? That there is a well marked diflfer- 
ence between the marbles and what I have in another place described as 
the true prima7y limestone j I cannot doubt. The whole matter evident- 
ly requires a re-examination, and if the above remarks lead only to this 
result, I shall be repaid the labor of all the attention I have bestowed 
upon them, though other opinions than those expressed above are finally 
adopted. 
Tertiary of Champlain. 
In the report for last year this formation was spoken of, but no at- 
tempt was made, at that time, to determine the extent or character of 
the beds. I have since ascertained that they consist of clays and sands. 
