TERTIARY. 
129 
that they could have been drifted into their present position. The result, then, appears to be, 
that the greater part of the upper portion of the tertiary has been swept away; for it is only 
in sheltered places that the whole formation exists entire. At Port Kent, it is protected by 
Trembleau point; and at Beauport, by a deep ravine. Thus, (fig. 44,) the formation lies 
north of the point, which rises up immediately at the south, protecting it thereby from the 
abrading action of currents of water. At Beauport, the mass of tertiary, containing an 
enormous quantity of shells, is deposited in a narrow gorge one hundred feet deep, through 
which the Beauport river flows, a section of which is given in the annexed diagram, fig. 45. 
45. 
The lower part of the formation is composed of a stiff blue clay, without fossils. Ap¬ 
proaching the upper part, we find it embracing a few pectens, tellinas, myas and terebratu- 
las, all of which are perfect, without injuries from abrasion ; even the delicate terebratula is 
perfect, both hinges being in the natural position. Amidst this lower mass of shells, there are 
numerous water-worn boulders, beneath which the fossils lie uninjured; but, had they all 
been brought together in the form of drift, they would have exhibited evidence thereof, in the 
crushed state of the shells; but as it is, and as they are, all appearances go to prove that the 
whole were deposited in quiet waters while the animals were living, with the probability that 
they were destroyed by an uplift of the country, which raised them above the waters in which 
they were quietly performing their functions. 
The upper part, at Beauport, is composed almost entirely of the Saxicava rugosa; and they 
form a bleached white mass, twelve feet thick, perfectly stratified, and with only sufficient 
sandy matter to form the lines of division between the strata. 
Thickness .—Under favorable circumstances, the tertiary of Lake Champlain accumulated 
to the thickness of about one hundred feet. As it exists, however, on this lake, it is rarely 
over fifteen feet thick; though at Burlington, it forms an exception, where it is probably 
between ninety and one hundred feet. We are liable to be deceived, however, in this parti- 
Geol. 2d Dist. 17 
