VARIATION AND EQUIVALENCE OF SANDSTONE 46 1 



in which he stated that the Stockton coal (so-called Upper 

 Freeport bed of the Kanawha valley) carries a flora resembling 

 the Clarion; that the coal bed occurring in the Charleston sand- 

 stone in the vicinity of Clendenin on Elk River contains plants 

 belonging to the Kittanning group ; that fossils from a higher 

 horizon, but still within the sandstone beds at Clay, are found 

 in the Freeport group of the Allegheny valley, and that the 

 Charleston sandstone is not equivalent to the Mahoning sand- 

 stone of Pennsylvania. 



These conclusions were not generally accepted. Dr. I. C. 

 White maintained that land plants varied irregularl}-, and that 

 when they conflict with stratigraphic evidence the latter should 

 be given the preference and the former disregarded. He main- 

 tained that the Mahoning sandstone is continuous in outcrop 

 from Pennsylvania to the Kanawha valley, and that consequently 

 his original determinations are correct. In order to be certain 

 of his position Dr. White again took the field and traced the 

 outcrops of the formations in question across the state of West 

 Virginia, and the result was the complete verification, in his own 

 mind, of his former conclusions.^ 



In discussing Mr. David White's paper the present writer 

 called attention to the fact that the Charleston sandstone is a 

 complex formation composed of overlapping lenses of coarse 

 sandstone, and that in tracing it in any direction from the type 

 locality it is doubtful if the original limits can be identified and 

 maintained. He also showed that this variation from point to 

 point might easily explain the apparent continuity of the sand- 

 stone outcrop from Pennsylvania to the Kanawha valley, and at 

 the same time allow the diagonal extension of the Allegheny 

 floras across the sandy belt. The conditions which permit such 

 phenomena are shown diagrammatically in the following sketch 

 (Fig. I ) representing an ideal section of the Charleston-Mahoning 

 sandstone from Pennsylvania to the Kanawha valley. The sand- 

 stone formation is conceived as being made up of a number of 

 overlapping plates which gradually descend lower and lower in 



"'Geological Horizon of the Kanawha Black flint," Bull. Geol. Soc. Am., Vol. 

 XIII, pp. 119-26. 



