Miscellanies. 417 
“ Perhaps the most difficult point to solve, is that which presents 
itself in the fact, that deposits in high latitudes contain animal and 
vegetable remains, presumed by analogy to be unable to exist in 
their temperature at the present period. A change in the earth’s 
axis, would, of course affect the temperature of its surface, but 
whether that can take place under any known law in a sufficient de- 
gree to effect such a change, has certainly not been established. Sir 
John Herschel, has supposed that a change of temperature might 
take place in the change of the es orbit of the earth, which 
becomes gradually more circular.” 
The Tertiary deposit in particular, which has formed so rich a har- 
vest for Mr. Lea, is situated at Claiborne, on the east side of the Al- 
abama river, about ninety miles in a direct line from the Gulf of 
Mexico. It was made known to him by Judge Tait, a citizen of that 
place, in January 1829, from whom he received samples before the 
close of the year, and in the year following, an additional supply, to- 
gether with some notices of their mode of occurrence. These would 
have been made public : at an earlier period but for the rege tet of 
Mr. Lea, with the’ examination ott recent shells. 
From Judge Tait’s ob ti this fe ion which 
at Claiborne, attains an elevation of two hundred feet, spreads ctor 
the whole of South Alabama, (its southern edge commencing about 
ten miles south of Claiborne bluff) and extends as it is believed 
through the whole of the States of Alabama, Mississippi, and ter- 
minates only in the Chickasaw Bluffs of West Tennessee.  — 
The Alabama river passing under the bluff of Claiborne, reveals 
a fine section for geological observations, of which no doubt Judge 
Tait availed himself in the descriptions he gives of the successive strata. 
Beginning at the bottom we are first presented with a bed having the 
thickness of one hundred and twenty feet, which Mr. L. calls a soft 
calcareous rock, through which are occasional scales of mica and 
sprinklings of calcareous matter together with numerous fragments of 
shells consisting generally of Flustre, Cardia, Corbule, Ostre, 
Polute, Natice and Turritelle, but the fragments were too friable 
and imperfect to admit of more satisfactory determination. He hes- 
itates whether, upon this amount of information to include it in the 
Tertiary, or to refer it to an earlier origin. The next stratum in the 
ascending’ series, and which is closely related to the foregoing, is a 
more compact calcareous rock containing micaceous grains of dark 
green sand, a single and imperfect valve of a large Ostrea, a Teredo 
Vou. V.—No. 2. 53 
