290 GEOLOGY OF THE HIGH PLATEAUS. 



domes and crags of the Water Pocket fold, huge promontories of red and 

 white massive sandstone, separated by narrow clefts, many of which are 

 cut down to the level of the plain and even lower, so that they carry a 

 portion of the drainage from within the "Circle Cliffs" to the Water Pocket 

 Canon. On the west side of the plain the mesa which looks down upon it 

 is slashed by many narrow and profound canons, which wind about within 

 it and open into the canon of the Escalante. These carry the remaining 

 drainage of the plain — i. e., when there is any to carry, which I warrant is 

 seldom enough. The floor of this cliff-bound area is Lower Trias (Shina- 

 rump), and the walls which inclose it upon the west are Vermilion Cliff 

 Trias, and those upon the east are the same, with the Jurassic sandstone a 

 little beyond them. The plain is barren, treeless, and waterless, so far as 

 known. It constitutes .one of the centers of erosion of this part of the 

 Plateau Country, from which the waste of the strata edgewise has pro- 

 ceeded radially outwards. Probably the Cretaceous was eroded from its 

 surface prior to the Eocene, and the Tertiary afterwards deposited upon the 

 Jura in the same relation as is now seen high up on the flanks of the Aqua- 

 rius. The late erosion has removed the Eocene, the Jura, and the Upper 

 Trias. 



Far to the southeastward, upon the horizon, rises a gigantic dome of 

 wonderfully symmetric and simple form. It is the Navajo Mountain. 

 Conceive a segment of a sphere cut off by a plane through the 70th parallel 

 of latitude, and you have its form exactly. From whatsoever quarter it is 

 viewed, it always presents the same profile. It is quite solitary, without 

 even a foot-hill for society, and its very loneliness is impressive. It stands 

 upon the southern brink of the Glen Canon of the Colorado, at the junction 

 of the San Juan River. Its structure is believed by Mr. G. K. Gilbert to 

 be laccolitic. Its summit has not yet been reached by any exploring 

 party, and the approaches to it from all sides are extremely difficult.* On 

 the north side runs the profound chasm of the Colorado, on the east the 

 canon of the San Juan, and on the west another side gorge. South of 



* Professor l'owell, during his descent of the Colorado River, climbed out of the canon and ascended 

 about half-way to the summit. He believed that if time had permitted he could have gained the top of 

 the mountain. 



