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Show BIG SANDY- COLORADO OR GREEN RIVER. 73 dbliged tcrwedgtf up the wheel as well as we could, and to sink it in the river during the night, to sweH the wood. The bluffs on Big Sandy * present, ed several sections. The strata consisted 4f thin layers of clayey shales, argillaceous gray limestones, and of crystallized sulphate of lime. These strata were seldom more than two or three inches in thickness, the layers of gypsum being about, half an inch. There were also thin laminae of dark slaty shales above the gray limestone. Remains of plants were found, and also some imperfect shells. Near the junction of Big Sandy with Green River some large nodules of ferruginous sandstone were observed, and near them the remains of treos of a large size. The dip was about 5°, a little to the west df south. Upon Green River we came upon a layer of brownish day, of considerable thickness; and from the appearance of the . hills en our right, it is probable that they- are formed by the weathering of this bed of clay. Green River, or the Colorado of the Gulf of California, 1 is here a fine, bold, clear stream, discharging a large quantity of water. In its bed are found rounded stones, consisting principally of detritus of primary rocks. Day's march, only thirteen miles. l Friday', Auguzt 10.- After travelling about four miles, the road leaves Green River and crosses over a ridge dividing it from Black's Fork, one of its tributaries, upon the left bank of which we encamped, with abundance of grass, and wood obtained from the willows which here fringed its banks. The Uintah mountains were distinctly seen for to the south, their sides glittering with inow in the rays of the setting sun. In a ravine of the western blufr of . Green Rive* valley, th6 rocks were partially exposed, particularly some strata of hard white sandstone. They consisted of sandstone in laminae, about fifteen inches thick, and layers of argillaceous shales, and argillaceous A limestone, made up principally of shells. There were evidently, also, - some strata of conglomerate, formed chiefly of serpentine, siehite, and trap. Among the rounded pebbles found near the top of the ravine was one of dark foetid limestone, partially converted iiito marble, and precisely similar to the metamorphic limestone observed flanking the granite chain in the vicinity of the South Pass. A'specimen of fossil wood was also found, which appeared to have been partially converted into lignite. The strata were, as far as could be judged, horizontal, and a section oh the opposite eide of the valley showed the satne sandstone maintaining |