60 J. J. STEVENSON — CARBONIFEROUS OF APPALACHIAN BASIN 



shales, one of which, directly underlying the Connoquenessing, is shown 

 on the east side of Chestnut Hill. 



In the northern part of Fayette county, beyond the Youghiogheny 

 river, the sandstone mass appears rarely to exceed 60 feet, and almost 

 invariably it rests on a thin coal bed. The sandstone shows a thin 

 coal bed below the middle which probably represents the Mount Savage. 

 The Sharon shales are thin, for the lowest ore bed is but 25 feet below 

 the sandstone — a decided contrast with the thickness at a few miles 

 north and south. Beyond the Youghiogheny, in Dunbar, the sandstone 

 mass is certainly more than 70 feet thick and rests on a coal bed, below 

 which are clays, thin sandstones, and ores for 100 feet, with thin coal 

 beds at 49, 62, and 83 feet. At a few miles farther south, on the west 

 side of the mountain, the Sharon portion is but 70 feet, with much red 

 shale and five thin streaks of coal, while near by it is 80 feet with three 

 coal streaks 8 to 9 inches thick ; but at ten miles farther south the 

 thickness is only 45 feet, with apparently but two coals aside from the 

 persistent bed underlying the sandstone mass.* 



On the east side of Chestnut hill, along the national road in Fayette 

 county, the Homewood (Piedmont) sandstone is apparently not more 

 than 25 feet thick, and shows some layers of pebbles, rarely larger than 

 a pea, while the lower sandstone appears to be not more than 50 or 60 

 feet and comparatively fine in grain. The Sharon division here and 

 southward is not less than 120 feet thick and is more shaly than at the 

 exposures along the Youghiogheny. The Mount Savage coal bed is 

 present, with a thickness of at most 4 feet, but only one of the lower 

 coals was seen in the ore pits. The opportunities for study of the lower 

 division were very good twenty-five years ago, for at that time the iron 

 ores were of much local importance, and were mined extensively to 

 supply furnaces along the western slope of Chestnut hill, in Fayette and 

 Westmoreland counties ; but those ores are no longer esteemed, and all 

 work was abandoned many years ago, so that during a restudy of the 

 region it was found impossible to obtain any details or even to verify 

 the measurements already reported. Southward the lower division be- 

 comes thinner and the sandstone mass thicker. At the most southerly 

 measurement within Fayette county the shales below the Connoquenes- 

 sing are little more than 50 feet.f 



Thus far in the description of Laurel and Chestnut hills the whole 

 section below the massive sandstones has been regarded as belonging to 

 the Sharon portion of the section, for the reason that they were separated 

 from the Pottsville by Stevenson in his reports on the region. But the 



* J, J. Stevenson (KK), 1877, pp. 142, 174, 187, 195, 196, 210, 261. 

 f J. J. Stevenson (K 3), pp. 68, 7i. 



