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Show 46 GEOLOGY OF THE HIGH PLATEAUS. These traces are less conspicuous on the eastern terraces than upon the southern, but are seldom absent In the Great Basin west of the plateaus there is no evidence of any such general uplifting in the later periods, at least within many leagues of the High Plateaus, although local disturbances of no small magnitude have occurred, and doubtless the southwestern ranges have gained notably in altitude. It is interesting to compare the structural forms produced by the displacements of the High Plateaus and Kaibabs with those observed in other countries and in other parts of the Rocky Mountain Region. The earliest ideas acquired by geologists concerning mountain structure were derived from the study of the Alps and Jura The conspicuous fact there presented is plicationâ€"waves of strata like the billows of the ocean rolling into shallow waters, and often a more' extreme flexing until the folds become closely appressed. With the extension of observation among the" other mountain belts of Europe, and wherever the traces of great disturbance among the strata were found, the same phenomenon of repetitive flexing was discerned, seldom amounting to " close plication," but undulating in greater or less degree. At a later period, when geology was colonize 1 in America, its systematic researches were first prosecuted in the Apala-chians, where the same order of facts was presented in a degree of perfection and upon a scale of magnitude far surpassing the original types of Switzerland. At a still later period the geologists who inaugurated in the Sierra Nevada and Coast Ranges the. study of the Rocky system disclosed another grand example of the same relations. Thus the increase of observation has been for many years strengthening the original induction that plication and.mountain-building are correlative terms. But the rapid and energetic surveys of the remaining portions of the Rocky Mountain Region have within a few years brought to light facts of a different order. From the eastern base of the Sierra Nevada to the Great Plains are very many mountain ranges, a large proportion of which have come under the scrutiny of geologists; and of those which have been hitherto studied sufficiently to justify any conclusions concerning their structure not one has been found to be plicated. Not one of them presents any recognizable analogy to the structure which is so remarkably typified in |