Carnegie Institution of Washington Publication, Issue 207

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Carnegie Institution of Washington, 1915 - Science
 

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Page 95 - That a great physical change took place soon after the deposition of the Mahoning sandstone rocks, the present basal members of the Conemaugh series, must be conceded, since no red beds whatever are found from the base of the Pottsville up to the top of the Allegheny, and none worth considering until after the epoch of the Upper Mahoning sandstone. "The sudden appearance or disappearance of red sediments after their absence from a great thickness of strata is always accompanied by a great change...
Page 85 - Viewed from the standpoint of change in physical conditions, the proper place for such a dividing plane between the Conemaugh and Allegheny beds would be the first general appearance of red rocks, near the horizon of the Bakerstown coal about 100 feet under the Ames or Crinoidal limestone horizon. That a great physical change took...
Page 55 - It is more or less cellular and, in places, cancellated. Irregular nodules of limonite are here and there imbedded in it. Its cherty hardness and fracture are not due to the presence of silica, as one is tempted to infer, but are characters belonging to it as a dolomite. It is a durable...
Page 55 - Bluff rests a persistent stratum of dolomite, varying in thickness from less than a foot to 5 feet or more. * * * It is a true dolomite, containing with the carbonate of lime an equal or even greater percentage of carbonate of magnesia. * * * Though not of great thickness, it is an important member of the upper Permian of southern Kansas and northern Oklahoma, owing to its persistence, which makes it a convenient horizon of reference. * * * The stone is nearly white in fresh fracture, weathering...
Page 86 - That a great physical change took prace soon after the deposition of the Mahoning sandstone rocks, the present basal members of the Conemaugh series, must be conceded, since no red beds whatever are found from the base of the Pottsville up to the top of the Allegheny, and none worth considering until after the epoch of the Upper Mahoning sandstone. "The sudden appearance or disappearance of red sediments after their absence from a great thickness of strata is always accompanied by a great change...
Page 56 - The line of outcrop of the Day Creek in Oklahoma is not continuous; nevertheless, it is found in numerous localities, and on account of its distinctive lithological appearance it is always easily recognized. It is displayed on many of the hills of Woodward County, not only north of the Cimarron, but also between the Cimarron and the North Canadian and south of the latter stream. In...
Page 52 - The Enid formation includes all the rocks of the red beds from the ba.se of the Permian to the lowermost of the gypsum ledges on the eastern slope of the Gypsum Hills. The top of this formation, however, is not a plane, since the gypsum beds, which mark its uppermost limits, are found to be more or less lenticular when traced for long distances.
Page 55 - ... ordinary cross beddings, at first glance gives the impression of dips, anticlines, synclines, etc., that have been produced by lateral pressure, the dips, however, bein.g in various directions. * * * The Red Bluff beds exhibit the most intense coloration of any of the rocks of the series. When the outcrops are wet with recent rains their vividness of color is still greater, and the contrasts of their almost vermilion redness with other colors of the landscape is most striking.
Page 81 - Spirorbis, ostracods, and gastropods, generally regarded as fresh- water, together with occasional fish, amphibian and reptilian bones. Insect remains are sometimes found well preserved in the shales. The marine limestones of the lower half of the formation are the most persistent and lithologically uniform beds, but these have suffered contemporaneous erosion and locally failed to form, owing to the unfavorable conditions, such as the presence of shoals in the sea and continuous sedimentation from...
Page 86 - Conemaugh may well be considered as the 'beginning of the end' of the true Coal Measures, both from a lithological as well as a biological standpoint, and hence it is possible that the best classification aside from the conveniences of the geologist, would leave the Mahoning sandstone in the Coal Measures, and place the rest of the Conemaugh, as well as the Monongahela series above, in the Permo-Carboniferous. This reference is also confirmed by the character of the fauna and flora, both of which...

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