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Show 54 FROM FORT LARAMIE TO FORT BRIDGER. stone and calcareous rocks, cemented in an argillaceous matrix. The general direction of the strata was nearly horizontal, but there were evident local displacements, caused apparently by subterraneous ijpheavings. In some cases the strata were declined as much as 30°, and in opposite directions, within a short space. In many places large quantities occurred of the fragments of primary rocks, resulting, most probably, from the decomposition of conglomerate: the sandstone was often good, although generally too scaly for building purposes. CHAPTER III. FROM FORT LARAMIE TO FORT BRIDGE*. Wednesday^ July 18.- Taking leave of our friends at Fort Laramie, we continued our journey this morning. The next place where we shall meet with a human habitation will be Fort Bridger, on Black's Fork of Green River, distant about four hundred miles. While the train followed the travelling track, I took a road nearer the river, and examined a quarry which the workmen from the fort are here opening. The strata exposed in the bluffs were principally gray sandstone, with some thin calcareous layers, the general dip being south and south- west about 17°. On the opposite bank of the river, which is high and covered with pine, the inclination appeared to be much greater. The fossils were quite imperfect. The only ones that could be descried were abundant remains of encrinites. The limestone at the quarry is dark, carboniferous, with conchoidal fracture, and slightly foetid. It lies in layers of six or eight inches thick, and is immediately overlaid by slaty shales and gray sandstone. A considerable number of Productussemi- reticulatuAvrza found in it, as well as in the sand between the layers: some specimens of a large sort of oyster lay in a nearly horizontal position. Some imperfect fossils were also obtained from the sandstone. The general surface is formed of strata of grayish sandstone and clay, the former varying hrhardness, some being very friable, while others are exceeding hard, especially some which were slightly coloured by oxide of iron. |