Shaler.] 
580 
[April 16 
Dr. John S. Flagg, Dr. Selah Merrill, Mrs. Charles H. Ramsay, 
Messrs. C. J. Maynard, W. E. Sheldon, John A. Thompson, George 
F./Topliff, and Dr. H. V. Wilson. 
General Meeting, April 16, 1890. 
Mr. Samuel Wells in the chair. 
The following papers were read : 
NOTE ON THE VALUE OF SALIFEROUS DEPOSITS AS 
EVIDENCE OF FORMER CLIMATAL CONDITIONS. 
BY N. S. S HALER. 
[Published by permission of the Director of the TJ; S. Geological Survey.] 
For some years I have been incidentally engaged seeking evi- 
dence which might be of valire in determining the conditions of 
climate in former geological periods. The facts already in the pos- 
session of geologic science enable us to assert that the strata formed 
in certain periods in particular portions of the earth were accumu- 
lated during times of greater rainfall than now exist in the same 
lands. Such peculiarities of climate are attested not only by the 
existence of sediments which indicate large precipitation through 
the presence of rapidly accumulated fragmental materials, but the 
organic remains, such as those accumulated in Carboniferous strata, 
are also of value in the determination. Proofs of arid climate are 
not so well afforded by the character of the materials deposited or 
the fossils remains which they enclose. For some time it indeed 
seemed to me almost hopeless to seek for facts which would serve to 
establish the existence of arid periods in the past history of vari- 
ous countries. At length, however, it became evident that the phe- 
nomena of salt deposits afford a kind of evidence of great value in 
this determination. I hope in the near future to present in some 
detail the assemblage of evidence which may be drawn from this 
store. In the present writing, I propose briefly to set forth the 
general results of the inquiry. 
