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Show 170 EXPLOI~ATION OF TilE OA.NONS 011' TDE COLOUADO. 'fhe bird's-eye view (Figure 61) is intended to show these topographic feature . The e cnrpment below, and in the foreground, represents the Orange Cliffs, at the foot of Labyrinth Canon; the second escarpment) the Book Cliffs, at the foot of Gray Canon; the third, away in the distance, the Brown Cliffs, at the foot of the Cauon of Desolation. It will be seen that tho three tables incline to the north, and are abruptly terminated by cliffs on the south. For want of space the whole view is shortened. In the three canons there are three distinct series of beds, belonging to three distinct geological periods. In the Canon of Desolation we have 'rmtiary sandstones; in Gray Canon, Cretaceous sandstones, shales, and impure limestones; between the head of Labyrinth Canon and the foot of Gray Canon, rocks of Cretaceous and Jurassic Age are found, but they aro soft, and have not withstood the action of the water so as to form a canon. rrhese formations differ not only in geological age, but also in structure and color. It will bo interesting to notice how these structural differences affect the general contour of the countiy, and modify its scenic aspects. In the description of the three canons in the l1istory of their exploration, the attentive reader has already noticed the great variety of geological and topographic features observed as we p•a ssed along. Let us now take a view of the three lines of cliffs. The Brown Cliffs are apparently built of huge blocks of rock, exhibiting plainly the lines of stratification. The beds are usnaUy massive and hard, and break with an angular fi·acture. The whole is very irregular, and set with crags, tower , and pinnacles. The upper beds of the Book Cliffs are somewhat like those last described, and they form a cap to extensive laminated beds of blue shales, in which we see exhibited the curious effects of rain sculpture. The wholo face of the rock is set witi> buttrGsses, and these are carved with a fret-work of raised und tounded lines, that extend up and down tho face of the >·ock, and unite below in large ridges. The little valleys between the o ridgolets aro tho olw.nnels of rills that roll down the rocks during the storms, awnady sfr. om one standpoint you may look upon millions of these little waterLabyriuth Canon is cut through a homogeneous sandstone. 'fho features of tho canon itself have boon described, but tho cliffs with which it 1•.. Gl - D•a rd , t!·OY 0 viow or •~:en ro · Torro.co Canons. |