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Show J OGDEN RIVER IN J j GEOLOGY. V 1 The last issue of tho press bulletin of the Geological Survey quotes ex- I tenslvely from the Overland Guide- I book, and one of tho articles given I prominence refers to Ogden river and I Is headed, "River Older Than the I Mountains It Drains," as follows: The guidebooks to western travel Issued by the United States Geolog-I Geolog-I leal Survey explain some things which I at first sight seem Inexplicable. How much -more interesting it la to see something of which you know enough to understand and appreciate it wonders! won-ders! Ogden Janyon, a deep cleft through the towering Wasatch Mountains, Moun-tains, overlooking the Great Salt Lake, is one of the show places along the Oregon Short Line, yet many of the thousands of people who have viewed its beauties would have on-Joyed on-Joyed them more had they first read the little statement of geologic history given in the guidebook of the Over-I Over-I land Route. "" Ogden Canyon, a deep notch with bare cliffs of hard pink quartzito on both sides, was cut in the solid rock by the river which flows through it Running .grater .carrying Band and gravel acts as a saw or file and, given time enough, can cut through tho hardestjOksL PgaencRiv.erTWAsJIor- ing west along its present course be foro the lofty Wasatch mountains came into existence. The raising oi the mountains went on slowly foi ages, so slowly that tho river kep( its place by cutting down its over rising bed, carving a deep and narrow nar-row canyon straight through the block of the earth's crust as it rose, In no other way can we rationally account for a river rising on one side of the range and flowing directly across it Movement of the mountain mass has continued down to the present pres-ent time at least there has been recent re-cent disturbance along the base of the Wasatch Range, as is shown by faults which traverse the lake deposits depos-its and the modern alluvia aprons. Some of the breaks are so new as to be devoid of vegetation. The upward movement of the mountains has been so continuous that the river has had no opportunity to widen Its valley, a task which it will begin as soon as the mountains cease rising. In the region now occupied by the Wasatch mountains a number of parallel par-allel faults were developed close together to-gether and the broken pieces of the earth's crust between them were pushed up, the rocks on one side of each crack riding up over those on the other side until a great mountain range was formed where once lay a plain. During the long period of slow earth movement which made these mountains, flat-lying parallel beds of rock were locally turned on edges, crumpled and folded In a wonderfully Intricate manner. These upturned and crumpled rocks are well exposed in Ogden Canyon. The west face of the Wasatch Range is believed to mark the plane of a normal fault at a nearly near-ly vertical crack in the earth's crust, the rocks on the east side of which went up or those on the west side went down. The forces which have raised these mountains are still active, ac-tive, for movement along this fault has disturbed tho surface recently. no . |