Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/315

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
32. Oliver.33. Bratton.Mifflin.
F³. 287

The limestone is next exposed in the gap made by a small stream entering the river near its gap in Chestnut ridge; several massive ledges of limestone outcrop here a little distance north of the pike dipping at angles of 85° to the northwest and with the very best facilities for opening a large and economical quarry in them. The exact chemical character of the stone here is not known by actual test; but many of the layers in the central portion of the exposure seem to present a series of good beds 40′ or 50′ thick and in every way suitable for quarrying advantageously.

The lack of railroad facilities is naturally against development of the limestone beds in this township, as compared to places where the quarry products can be transferred almost directly into cars; but many smaller operations might be advantageously started for the local supply of farm and plaster lime, as has been done in many other places in the district.

The Bloomsburg red shale crops out in the first ridge south of the pike between the gap and McVeytown, the road running through an elevated valley of the upper Salina lime shales. West of McVeytown the dip remains at very steep angles and in places is even overturned, until in about 1½ miles it settles down to about 60° and keeps that angle almost to Wayne township. At this point there is a compound anticlinal roll which serves to spread the limestone formation over a belt of country nearly ½ mile wide. But the effect of the twisting and crushing of the limestone seems to have been one deteriorating the quality of the limestone itself, so that crossing over the ridge to the river at this point almost all the limestone seen was made up of very small and brittle beds, which fractured in irregular shapes and appear to contain a comparatively small amount of good stone.

In the synclinal, however, immediately north of the river and which westward deepens in Wayne township to hold the Oriskany sandstone rocks quarried by the Enterprise Sand Company, the limestone becomes more regularly bedded and seems of better quality than where it was so much twisted to the north.