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Show 262 GEOLOGY OF THE HIGH PLATEAUS. The gorge itself is the work of erosion, and its apparent history is worthy of passing mention. The course of this valley cuts obliquely across the great monoclinal flexure which forms the western flank of the Fish Lake Plateau, and was in process of excavation before that flexure was formed. Like almost all other valleys, its position and direction are quite independent of the structural features of the country, and when the final uplifting took place it did not divert here the course of the drainage. Its only effect was to increase the amount of excavation to be done. The position of the great gorge upon the shoulder of the monocline and running obliquely across it is very striking, and might have given rise to a great deal of speculation as to its origin, were we not able to apply to it the exceedingly simple solution of the antecedence of drainage courses to the structural features of the country and their persistence in spite of changes of great magnitude. At first the interior of the gorge suggests a vast caldera, like those described by Lyell in the Cape de Verde Islands or the Val del Bove at iEtna. But it is neither a caldera nor a Val del Bove, as a study of the surrounding country abundantly proves. Passing across the nearly level summit a distance of 2 miles we reach the southeastern verge of the plateau, whence we may look down upon the beautiful surface of Fish Lake. This sheet of water, about 5 J miles in length and a mile and a half in breadth, is walled in by two noble palisades. The one on which we imagine ourselves to standâ€"the plateau summitâ€"is about 2,600 feet above the water; the other is nearly a thousand feet less lofty. The lake itself is about 8,600 feet above the level of the sea. No resort more beautiful than this lake can be found in Southern Utah. Its grassy banks clad wTith groves of spruce and aspen; the splendid vista down between its mountain walls, with the massive fronts of Mounts Marvine and Hilgard in the distance ; the crystal-clear expanse of the lake itself, combine to form a scene of beauty rarely equaled in the West. The subjects of geological interest to be found in the vicinity are numerous. First may be mentioned the origin of the lake itself. Mr. Howell's first impression was that glaciation had played an important part in its excavation. Mr. Gilbert expressed the opinion that it might have been caused by the sinking of a block between two faults. But I have |