Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/299

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31.Granville in Mifflin.
F³. 271

and farm purposes. It is, however, more largely quarried for road ballast. The Lewistown limestone shales come in on the top of this quarry, showing a thickness somewhat over 100′. The middle ridge north of this point is much higher than either of the two others.

At J. A. Shaw’s, near the south base of this central ridge, the lower part of the middle Lewistown division is exposed on the crest of an anticlinal with dips of 60° and 40° north and south, Limestone forms the crest of the third ridge at the road crossing, and north of Snyder’s blacksmith shop shows a dip of S. 30° E. 30°. A little south of the crest the main member is partially opened 20′ thick upon the same dip.

L. Aurand’s limestone quarry is about ½ a mile west from the blacksmith shop and just south of the new school house on the Ferguson valley road. It has been opened in the north leg of this synclinal and shows about 40′ of thin and cherty beds on a S. 35° E. dip of 25°. One band, about 10′ thick, divided into layers, from 6 inches to 1 foot in thickness, shows a fair quality of dark blue stone; but the balance is rather inferior. This quarry now belongs to Mrs. A. Kochendoffer, and is operated entirely for local farm use.

On the crest of this same ridge some 2½ miles further west and south of the new Ellen chapel, the middle division of the limestone formation is exposed on a dip of S. 30° E. 80°, and in the gap in this ridge along the western side of the township through which Strode’s Mill run flows, the limestone formation outcrops between the Ferguson valley road and the small mill dam but nowhere very well exposed.

Glass-sand quarries.

The Oriskany sandstone measures are very well exposed in all three ridges of this township, and attain a thickness of over 100′ in addition to the Stormville shale formation which is usually associated with No. VII and occurs between the sandstone and the top of the Lewistown limestone formation No. VI.