VA RIA TION A ND EQUI VA LENCE OF SA ND STONE 465 



having a thickness of over 300 feet. These are broken in a few 

 places by shaly intervals, one of which, about 200 feet from the 

 base, carries a coal of workable thickness. The sandstones are 

 more massive in this locality than in the vicinity of Charleston, 

 and the upper part of the formation is a particularly prominent 

 feature in the topography of the region. In comparing this with 

 the Charleston section, which is regarded as the type, it is clearly 

 seen that the section so far described is almost an exact counter- 

 part, but in the Blue Creek region coarse sandstones are known 

 above the limits just given, which appear to have no equivalents 

 in the Charleston section. The first bed shows a thickness of 

 about 25 feet and it occurs about 100 feet above the top of the 

 regular sandstone section ; the other appears to have a thickness 

 of from 10 to 20 feet, and it lies approximately 200 feet above 

 the top of the regular section. The beds of conglomerate are 

 separated by soft shale, m which reds and greens are of common 

 occurrence. In this section it is manifest that the upper con- 

 glomerates should not be classed with the Charleston sandstone, 

 since they are separated from it by a distinctly shaly interval. 



Along Elk River, from Clendenin to Clay, the Charleston 

 sandstone is well developed, and gives a rough and rugged topog- 

 raphy. The fourth section, shown in Fig. 2, was obtained by 

 Mr. Charles Butts near the mouth of Big Sycamore Creek, where 

 the horizon of the flint appears to be near water level. It is 

 true that the flint does not show, and it is possible that its hori- 

 zon is not exposed, but all the evidence seems to point to the 

 fact that the horizon of the flint is either at or below the grade 

 of the railroad. Although broken by a number of thin, shaly 

 partings, the section consists of a sandy series from near rail- 

 road grade to a height of 510 feet. The lower part resembles 

 that found on Blue Creek and also the typical section at Charles- 

 ton. At a height of 320 feet the rocks are concealed, 

 and it is possible that there is 15 or 20 feet of shale at this 

 point. If such is the fact, it would seem to mark the upper 

 limit of the Charleston sandstone as known at the type locality, 

 but lithologically the section cannot be broken at this point, for 

 the material above is essentially the same as that below. At 



