5 : 
ST. JOHN.] SECTION ALONG LITTLE WIND RIVER. 253 
besmeared in the soft, viscous substance. On the east side of the de- 
pression the successive ranges of low, parallel bluffs that appear farther 
out in the basin show sandstones and variegated clays, and finally a 
heavier mass of brownish drab clays, all dipping gently eastward. The 
latter deposits may be identical with the Colorado group. The above- 
mentioned anticlinal was traced but a few miles to the north of Little 
Wind River, but to the south, where it was examined by Dr. Endlich 
during the previous season, it assumes a more important topographical 
position, where its geological structure may be studied under less unfavor- 
able circumstances than those attending its exhibition in the present 
uarter. 
: The geologic section in the vicinity of North Fork of Little Wind River 
is given below, together with notice of the few observations made in the 
basin area to the east, supplemented by the diagram illustration of an 
accompanying plate, with which closes the account of the too briefly exe- 
cuted observations in this important mountain range. 
Section vicinity of North Fork of Little Wind River. 
No. 1. Archean. Mainly schistose rocks. 
No. 2. Potsdam. Coarse-grained, grayish-buff, reddish-stained, in 
places of a dark-red color, thin-bedded sandstone, with oblique laminated 
layers, and locally quartzitic. The greatest exposed thickness of this 
ledge probably does not exceed 50 feet, but it is probably much thicker. 
Its contact with the metamorphic rocks was not revealed, and the nature 
of the overlying deposits, which readily yield to atmospheric erosion, are 
not conducive to the exposure of the full vertical extent of the horizon. 
In the isolated outliers crowning the heights north of North Fork drain- 
age, the beds incline about N.57° E., at an angle of 10°. 
No. 3. Quebec. Ledges of drab, fragmentary, thin-bedded limestone, 
showing mural exposures of 10 to 25 feet at top, where at one point it 
appears in the summit of the mountain ridge, showing a heavy bed of 
drab-gray, yellow-mottled, even-bedded limestone, with brecciated and 
odlitic layers, containing fucoid-like markings in relief, in form also re- 
sembling certain ramose forms of the coral Chetetes, and the glabella of 
a large Trilobite. These occurrences, which are separated from the pre- 
ceding sandstone, No. 2, by a space probably occupied by shaly passage- 
beds, are met with in a vertical space not exceeding 400 feet. The ledge 
in the summit of the ridge dips 10°, N.52° E. The horizon appears in 
a long line of rusty-weathered mural exposures in the escarpment on the 
south side of the cation. The lithological character of the rock is pre- 
cisely that of equivalent strata met with in the Gros Ventre and Téton 
Mountains, as also on the west flank of the range in the neighborhood of 
Green River Caiion. 
No. 4. Buff-weathered maguesian (?) limestone,in places, forms a rather 
well-marked ledge, 75 to 100 feet +, exposed, and holding the position 
of the so-called Niagara dolomitic horizon. No evidence, however, was 
gained by means of which to satisfactorily determine its age. The above 
ledge is, at least, locally separated from the preceding by slopes over 
soft dirty-buff deposits. 
No. 5. Carboniferous. Grayish-buff, rough-weathered, heavy-bedded 
magnesian limestone, with small jasper nodules and iron concretions, 
weathered in castellated shapes and forming a prominent ledge in the 
escarpments either side of the cation, 200 feet, more or less, in height. 
Contains Zaphrentis, crinoidal fragments, Bellerophon, &c., apparently 
referable to Carboniferous forms. 
