a [ 174] 
assign it any place in the seale of formations. The other specimen, No, 
104, is a compact serpentine, having the aspect of a greenstone trap; and, 
from the account given, is probably interstratified with the limestone. ; 
limestone is more friable and chalky than any specimen previous! iced. 
Longitude 1103°, latitude 414°—The specimens from this re 
very peculiar and remarkable. The first is a friable or pulverulent green 
calcareous sand, unctuous to the touch, but remaining unaltered on exposure. 
to the atmosphere. Its character is very similar to the green sands of New 
Jersey; but it is of a brighter color, and less charged with iron. The 
green limestone. The singularity of the specimen, and that which first 
attracted my attention, was the efflorescence of a salt upon its surface, 
which appears to be, in part, chloride of sodium. Supposing this to be ac- 
cidental, 1 broke a specimen, and, after a day or two,a similar efflorescence 
appeared from the fresh fracture; leaving no doubt but the salts arise from 
decomposition of substances within the stone itself. 
ngitude 111°, latitude 413°; Muddy river.—These specimens are of a 
yellowish-gray oolitie limestone, containing turbo, cerithium, &c. The 
rock is a perfect oolite; and, both in color and texture, can scarcely be dis- 
A few miles up this stream, Captain Frémont has collected a beautiful 
series of specimens of fossil ferns. The rock is an indurated clay, wholly” 
destitute of carbonate of lime, and would be termed a “fire clay.” These 
are probably, geologically as well as geographically, higher than the oolite 
specimens, as the rocks at this place were observed to dip in the direction 
of N. 65° W. at an angle of 20 degrees. This would show, conclusively, 
that the vegetable remains occupy a higher position than the oolite. As- 
sociated with these vegetable remains, were found several beds of coal, dif- 
feringin thickness. The section of strata at this place is as follows: 
ft. in. 
Sandstone - - = - : n - ae Be 
Coa! - - - - « ‘ = es BAS; 
oa : . r = rE - ® ae ae 
Indurated clay, with vegetable remains - ~~ - . +. 20 0 
Clay. : 2 : . r - : a. 5, 0 
Clay - < = Ke pa i : x 5 0 3 
Coal - = . * - 7 : Z 
Clay E ic = 2 : . 2 * 5 z oO. 
Coal - = - = “ — fe a ees 
The stratum containing the fossil ferns is about 20 feet thick; and above 
it are two beds of coal, each about 15 inches. These are succeeded by a 
tS 
