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Show 42 GEOLOGY OF THE HIGH PLATEAUS. meaning that none existed, we do find at the very summits unmistakable indications of the action of local and very small glaciers, with beautifully preserved terminal morains. But I have never seen a morain in the High Plateaus at a lower level than 8,500 feet, and 9,000 feet may be considered as the mean level at which they are first encountered. We find even these only on portions of flanks which bound the loftiest parts of the tabular summits, showing that the loftiest parts alone accumulated ice and generated small glaciers. This will not seem surprising even to those who hold strongly pronounced views on the subject of the Glacial period if we assume that during that period the plateaus stood considerably lower than at present. That they did stand lower then is not improbable. We cannot look to the Glacial period, therefore, for the discovery of any cause which would retard the process of erosion; but, on the contrary, we find in its moister climate reasons for thinking that it may have been notably more rapid than now.* I have discussed this subject at some length, because the age of these faults is very important in the geology of the region, and is even more important to the southern and southwestern portions of the Plateau Province, if possible, than to the High Plateaus. They are associated with the later history of the canons and cliffs and with the climatal changes of the province in the most intimate manner. The evolution of that region has long since shown a tendenc}^ to cluster; it has even taken form; around certain marked events of which one of the most prominent was the faulting, and the consequences of these faults reach out in a manner which cannot be appreciated until the whole region is described and the history of its constituent parts delineated ; a work which I trust will be accomplished in the near future. They everywhere betray in numberless ways their recency, and I have presented only that evidence which strikes the eye at once where we first encounter them. But while they are all comparatively recent some are older than others. The two Kaibab faults in particular are apparently older than the rest, at least in part Those greater faults which cut through the heart of the * Whether erosion would proceed faster under the action of ice than of running water is a question which I do not raise. If, has no present bearing. |