Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/269

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28.Menno Township in Mifflin.
F³. 241

slowly approach each other. The crest of the arch bends more and more towards the southwest in the six miles through this township, and it is marked by a series of sink-holes as well as by frequent exposures of limestone with opposing dips. Entering on the east from Greenwood furnace ore-bank, it reaches Kishacoquillas creek about midway between the pike and the southern outcrop of the limestone, and keeps this geographical position until it passes out of the county at the west end of the township.

The arch is broad and flat, with steeper dips however on the south side than it has on the north. In consequence of this the limestone belt, which averages about two miles in width, is divided unevenly by the anticlinal, three-fourths of it lying on the north side and one-fourth to the south.

Along the pike near Annville the north dip is scarcely more than 10° or 12°. The limestone is slightly quarried north of the Amish church and south of Matier’s S. M., dipping at the latter place about 20° to 25° towards the northwest. Near the village of Allenville there are numerous good exposures and some few small quarries; but none of them show a very extensive rock-section although all show a good smooth limestone.

There are some few exposures, mainly in the Trenton member of the limestone formation, along the back valley road which is alternately in slate and limestone all the way to the Union township line. South of Allenville the dip of the limestone on the south side of the axis is about 35°.

About ½ mile east of the McVeytown road over Jack’s mountain a good exposure of limestone was seen in a field on the south side of the public road where some excellent beds, 30′ to 40′ thick, have been quarried on a dip of S. 30° E., 45°. Very nearly the same strata outcrop for a mile or more east along this road and have been opened in a number of small quarries all of which show about the same dip.

There is a fine bluff of blue limestone about 50 yards north of the road on the property of Samuel Wills and about 1½ miles east of the brick school house. The dip here is S., 35° E. 52°; the stone is good and somewhat massive, which is not generally the character of these upper