NATURAL SCIENCES OF PHILADELPHIA. 
259 
resembling, as he supposed, those of oaks and willows. (See his section pub- 
lished by us in the Proceedings of the Academy of Natural Sciences of Phila- 
delphia, May, 1857.) 
Proceeding northward from the last mentioned localities, we find on reaching 
the Loup fork of Platte river, near the eastern limits of the Pawnee reservation, 
outcrops of the light colored Inoceramus beds already mentioned, (No. 3, Ne- 
braska section,) near the water's edge ; and at the mouth of Loup fork, on the 
Platte, the red sandstone No. 1, so often referred to, crops out near the river 
margin, v/hile the Lioceramus beds are seen in the bluffs above it. Going down 
the Platte in a direction nearly contrary to the dip of the strata, we find this 
sandstone rising up so as to form near the mouth of Elk Horn river, bluffs some 
sixty feet in height. Here it seems to rest directly upon Carboniferous rocks. 
Continuing on down the Platte, we find this red and yellow sandstone rising 
higher and higher in the hills until we come within five or six miles of the 
Missouri, where it is seen with its base elevated near sixty feet above the Platte; 
and there are probably outlines of it between that point and the Missouri at 
greater elevations. So that we here find the same formation which at Smoky 
Hill river is elevated about twelve hundred feet above the level of the Missouri 
at Fort Leavenworth, and seven hundred feet above the same horizon near Little 
Blue river, has by the gradual north-western dip of the strata, sunk to within 
about one hundred feet of the Missouri at the mouth of the Platte.* 
Ascending the Missouri from the localities just mentioned, we see occasional 
exposures of the upper Carboniferous rocks, which gradually sink lower and lower 
until they pass beneath the river near Florence, to be succeeded by the reddish 
and yellow sandstones, &c., of No. 1, — (Nebraska section.) Above this, occa- 
sional exposures of this formation are seen with its characteristic fossil leaves, 
•along the river; and at several localities, some thirty miles below the mouth of 
Big Sioux river, it forms perpendicular escarpments of yellowish sandstone 
rising from the water's edge to an elevation of about eighty feet ; while at a 
higher point, back on the summits of the Hills, the same calcareous beds are 
seen, containing Inoceramus problematicus. Here at a quarry in the sandstone 
(formation No. 1,) some twenty feet above the level of the river, one of us (Dr. 
H.) collected a large number of fossil leaves, some of which are identical with 
species found by us in this rock at the Smoky Hill locality already mentioned. 
The sketches of leaves sent by us to Professor Heer were mostly drawn from 
specimens collected at this locality. 
At the mouth of Big Sioux river a low bluff of this formation, not more 
than fifteen or twenty feet in height, is seen, and on the hills back a little from 
the river at a higher elevation the same Inoceramus bed crops out at several 
places, and is used for making lime. At another locality, about eight or ten 
miles up the Big Sioux river, which comes in from the north west, one of us 
(Dr. H.) saw No. 1, containing its characteristic fossil leaves, directly beneath 
No. 2, of the Nebraska section. This exposure presented the following beds in 
the descending order: 
1st. 20 feet exposed of light gray limestone and marl, ) No. 3 of 
containing Inoceramus Problematicus. ) Nebraska Sec. 
2d, 45 feet dark laminated clay with ferruginous ) No. 2 of 
concretions containing fish scales / Nebraska Sec. 
3d. 15 feet exposed above the edge of the water, con- '\ 
sisting of yellowish friable sandstone, with a | No. 1 of 
thin bed of impure lignite above, and some y Nebraska 
layers of various colored clay below, contain- j Section, 
ing dicotyledonous leaves. J 
* The gradual descent of the Missouri river makes its surface at Fort Leavenworth, about three 
hundred feet lower than at the mouth of the Platte, hence the exposures of No. 1, seen at the lat- 
ter locality, one hundred feet above the Missouri, are some four hundred feet above the level of 
the Missouri at Fort Leavenworth, and of course about three hundred feet lower than the Little 
Blue river outcrops. The dip, however, is greater than this would indicate, for the strata incline 
towards the north west, while the mouth of Platte river, is north east of the Blue river localities. 
1858.] 
