Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/214

186 F³. side of the Northumberland synclinal has not been quarried at all and creates a much lower ridge capped with loose chert of the Oriskany sandstone.

In the gap of Beaver creek, north of Adamsburg, a very imperfect but instructive section of No. VI and No. VII can be obtained on the west side of the creek. The former is massive; slightly opened along the roadside and about 100′ thick, though not continouslycontinuously [sic] exposed. Geologically above it on a N. W. dip of about 40° there are about 100′ of sandy calcareous Stormville shales ending upwards with a rib of blue flint, representing the Oriskany sandstone, from 25′–30′ thick. Overlying this after a short interval of decomposed slate there is a band of reddish-yellow slate streaked with black seams and about 10′ thick, with a wavy structure. The exposure has been made in quarrying the different beds for road purposes. The same flinty character of No. VII was noticed in the gap north of Beavertown, where the underlying Stormville shale was largely covered by a mantle of white chert from the decomposition of higher outcrops of the Oriskany sandstone.

Markle’s quarry is a long side hill cut on the east side of the Beaver creek gap just north of Adamsburg, where the limestone dips about 35° N. W. and has been opened in a number of continuous but shallow cuts, in all about 200′ long, nowhere exposing more than 40′ of stone. Operations have been confined largely to the upper part of No. VI and the eastern end of the exposure, as opened, is fully 100′ higher in elevation than the kilns at the western end of the quarry.

The loose stone along the outcrop is largely gathered and burned for farm use, coal here costing $2.75 a ton. The ridge here is bold and sharp and an excellent opportunity is presented through the gap made by Beaver creek for opening an extensive quarry at this point. The limestone is of good quality.

The first quarries west of Beaver creek are opened on the summit of the ridge in close proximity to one another, south from the house of Mr. A. Snooks. The ridge is of monoclinal structure and a number of quarries of more or