126 STRATIGRAPHY THE MONONGAIIELA SERIES. 



bridge piers. The bridge at Vadis, where the stone was used, 

 was built in 1903, but the rock had disintegrated badly when 

 examined in 1914. Here the stone is massive, readily splitting 

 into large blocks, and considering the ease with which it may 

 be handled, its use would perhaps be justified where rough 

 masonry is desired. 



In Gilmer the Weston Sandstone becomes a much more 

 prominent horizon, being frequently hard and massive and 

 making a steep bluff a short distance above the Pittsburgh 

 Coal horizon, but sometimes having a flaggy nature and a 

 greenish gray color. Its occurrence is general along the out- 

 crop of the Monongahela Series. Numerous sections in Chap- 

 ter IV show its thickness and character. 



THE REDSTONE LIMESTONE. 



The Redstone Limestone of J. J. Stevenson, named from 

 its relation to the Redstone Coal, and belonging a few feet 

 below this coal, is frequently found in Lewis and Gilmer, be- 

 ing the only outcropping limestone in the two counties that 

 can be put to possible economic use, but being far inferior in 

 thickness to the same horizon as it appears in the more north- 

 ern counties of the State. Its best development is found in 

 Hackers Creek, Freemans Creek, Courthouse and Skin Creek 

 Districts, Lewis. In Gilmer it is poorly represented, being 

 often entirely absent from the measures. As observed in 

 northeastern Lewis, it varies from 2 to 4 feet in thickness, 

 being gray and hard on fresh fracture, but weathering to a 

 yellow color. It proved to be an important stratigraphic hori- 

 zon, coming as it does between the Redstone and Pittsburgh 

 Coals so that its presence in conjunction with an exposure 

 of either coal removed all doubt as to the correlation, because 

 no other limestone occurs in these two counties near either 

 of these coals, the only exception noted being an exposure 

 of the Upper Pittsburgh Limestone published in the Weston 

 Section in Chapter IV. 



The following exposure of the Redstone Limestone was 

 observed on the Perry White Farm in Freemans Creek Dis- 

 trict, Lewis, on Left Fork of Freemans Creek, 1.3 miles south- 

 east of Churchville : 



