Report on the Geology of the High Plateaus of Utah, with Atlas

Page 24

24 GEOLOGY OF THE HIGH PLATEAUS. Eocene, the High Plateaus have risen from 10,000 to 12,000 feet, while the adjoining Basin areas have risen from 5,000 to 6,000. As we pass from the Basin eastward and ascend the High Plateaus we mount the long slopes of great monoclinal flexures, or scale the giant cliffs which had their origin in the long major faults which traverse the district from south to north. As we pass westward from the heart of the Plateau Province and ascend the High Plateaus, we ascend cliffs of erosion. The fact that those cliffs which had their origin in displacement, with very rare exceptions, face westward, has attracted much attention and has received various interpretations. It seems to me that the explanation is exceedingly, almost amusingly, simple. The country to the east of them, and also the belt of country which they occupy, has been elevated from 5,000 to 6,500 feet above the country to the west of them. These figures express, of course, relative vertical displacements. The passage from west to east across the belt of country, which may be called the border-land between the two provinces, discloses a succession of faults and monoclinal flexures which are the obvious results of such a displacement.