. Bulletin of the Geological Society of America. Geology. iyo PROCEEDINGS OF THE CHICAGO MEETING. Figure 3.—Face of lotver Ledge of Niagara Escarpment The rounded and grooved edge is produced by the glacier moving across it. PENEPLAINAL AFFINITIES OF HIGH PLATEAUX OF UTAH BY CHARLES E. KEYES iAl)stract) Prodigious outpourings of lavas over tlie Cordilleran region of western America during Tertiary times give origin at later date to curious landscape idiosyncrasies. PhysiograpMcally, mesa land is almost unique. Nowhere else on the face of the glohe are there so many planation levels persisting
. Bulletin of the Geological Society of America. Geology. iyo PROCEEDINGS OF THE CHICAGO MEETING. Figure 3.—Face of lotver Ledge of Niagara Escarpment The rounded and grooved edge is produced by the glacier moving across it. PENEPLAINAL AFFINITIES OF HIGH PLATEAUX OF UTAH BY CHARLES E. KEYES iAl)stract) Prodigious outpourings of lavas over tlie Cordilleran region of western America during Tertiary times give origin at later date to curious landscape idiosyncrasies. PhysiograpMcally, mesa land is almost unique. Nowhere else on the face of the glohe are there so many planation levels persisting in such close juxtaposition. Nowhere else are so many distinct plains presented one above another through a mile of air above the present general plains surface, or in old sediments through a space of several miles below the same surface. Nowhere else are climatic conditions so favorable for general plains genesis. From the very beginning of each geographic cycle, plain is the characteristic and dominant landscape type. Plateau plain of the desert is the reminiscent record of intracycle planation such as is preserved in no other attainment to baselevel. Of the four great peneplains which spread over the ancestral Rockies since the close of Paleozoic times, the Mid-Tertiary or Miocene savanna seems to be represented in the last lingering traces by the summital flats of the high plateaux. When these few all but vanquished remnants, the high plateaux of Utah and the Mesa de Maya of the eastern side of the Cordillera, finally wither away, as they will shortly, no positive evidences of this once vast peneplain remain. In the high plateaux of Utah lies also the key to the genesis and structure of the Great Basin ranges. Presented by title in the absence of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original wo
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1890
