128 
GEOLOGY OF THE SECOND DISTRICT. 
The tertiary of Champlain is mineralogically composed, in the ascending order, of: 1st, a 
stiff blue clay ; 2d, a yellowish brown clay ; and 3d, of yellowish brown sand. The three 
portions into which the formation is here divided is, however, of little importance, inasmuch 
as the upper part of the clay owes its color principally to weathering, rather than to any im¬ 
portant difference in its composition. The whole contains a sufficient amount of carbonate of 
lime to effervesce briskly with acids, though there appears to be less in the inferior, than in 
the superior part. Sand begins to appear in the yellowish clay, and increases gradually until 
it predominates, and finally becomes a pure siliceous sand. 
This formation, as it appears along the shores of Lake Champlain and the St. Lawrence 
river, is not calculated to excite much attention; consisting, as it generally does, of beds of 
clay, without fossils, or any thing peculiar to attract attention. It is only where the observer 
happens to meet with those portions of it which are fossiliferous, that his interest will be 
much excited. Of the fossils which have been observed, there are about twenty species in 
all. They are, however, very unequally disseminated, and there are only a few localities 
which contain numerous species. The two species generally contained in the formation, are 
the Saxicava rugosa and Tellina groenlandica. In most places along the shore of the lake, 
and of the St. Lawrence river, these two fossils may be found on careful inspection. They 
are in an unmineralized state, rarely filled with clay. In addition to the two species of Mol- 
lusca I have just mentioned, the following I have discovered as existing principally at two 
places, viz. at Port Kent, and Beauport near Quebec : Tritonium anglicum, Tritonium forni- 
catum, Mytilus edulis, Pecten islandicus, Mya truncata, M. arenaria, Tellina, (two species,) 
Turritella, Nucula portlandica. Bulla, etc. (See Plates 1. and 11.) 
Denudations which this mass has suffered since its deposition. 
As has been stated above, the formation in general does not present any striking characters 
by which it would excite particularly the attention of the geologist, except at a very few 
points ; and it is at those points that it appears highly charged with fossils. Now we may 
inquire the cause of this remarkable circumstance. It is true that molluscous animals are 
found congregated at places which are the best adapted to their organization ; and the inquiry 
might arise, whether it was owing to causes connected with structure and function, that so 
few localities are to be found where those remains are deposited ; or whether they may not 
have been drifted into their present position ? 
In answer to these questions, I remark, that the whole deposit bears evidence of having 
been formed under quiet and undisturbed waters, and that the entire formation consists of 
clay, sandy clay and sand; and that it is in the mixture of clay and sand, or towards the 
upper portion of the formation, that the remains principally exist: where, therefore, a mere 
bed of clay is found, we have no fossils. Again, the fact that they preserve their markings 
and edges entire, and valves in place, though many are exceedingly frail, forbids the idea 
