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Show ,, 190 EXPLORATION OF THE OARONS OF THE <JOLORADO. (The plateaus and tables, the faults, and folds, and the escarp~ents, due to displacement and erosion, are exhibited in bird's-eye view, Figure 72 and also in section and bird's-eye view, Figure 73.) ' CLU~l!'S OF EROSION. I have said that the upper surface of the district adjacent to the Grand Canon is tho summit of the rocks of Carboniferous Age. North of the Grand Canon, from forty to sixty miles, we find rocks of later age, standing in cliffs, the escarpments of which face the south. '!'here are four lines of these, preserving, in their courses, a general parallelism. Going north from the Grand Canon, we first meet with the Shin-ar' -ump Cliffs, a step to a bench, low, and much broken. Capping the cliffs, we find conglomerate, over which are scattered many fragments of silicified wood, known to the Indians as the arrows of Shin-au' -av, or Shin-ar' -ump. Still proceeding north, we como to a second line of cliffs, with soft beds below, and harder beds above, known as the Vermilion Cliffs. 'rhe rocks exposed in these two lines of cliffs have been, by courtesy, called 'l1rias, but without sufficient paleontological evidence. 'rhe third line of cliffs has a gray, homogeneous sandstone at the base, and a capping of limestone, containing Jurassic fossils. Above this line we have many hills, carved out of beds of Cretaceous Age, and above and beyond these hills, a line of cliffs, the summit of which is of Tertiary Age. The faces of these upper cliffs are stained with red oxide of h·on, and they are called the Pink Cliffs. The dip of the beds is to the north; the stl·ike east and west; and as these are cliffs of erosion, they follow the strike in a general way, and hence have an easterly and westerly trend. The ascent from the foot of the Shin-ar'-ump Cliffs to the summit of the Pink Cliffs is but 4,000 feet; but as tho dip is to the north, in the direction of the ascent, the thickness of the beds passed over is much greater, being more than ten thousand feet. I have said that these lines of cliffs have an easterly and westerly course, but they deviate greatly from this general direction in many places. Wherever a north and south fault is found, tho block which has been thrown down has its lines of cliffs carried southward, or toward tho axis of upheaval, P u.rin Plu.teau. Virgen Vtlllcy. Pine Valley Mountain. I'll I i1~ l"olol. Echo Cldi'M. Mtll'hlo C1tlion. Ea11t Kuiltab Fol<l. J{uibab I'lntcnu. WciiL Kuiltab Foltl. Kanab Plat can. Hurricane :Fault. Sbi'-vwi ts P latenu. Grund Wash l~u n lt. Ornnd Wuf!lt. |