Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/238

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210 F³.
E. V. d’Invilliers, 1889.

The Slenderdale anticlinal of Juniata county expires just south of Freemont in the Marcellus black shale, and rising westward like the Shamokin synclinal it elevates a spur or knob of Oriskany sandstone and Lower Helderberg limestone on the West Perry line, southwest of Freemont.

Going down the Mahantango creek, one of the river synclinals is passed a short distance north of Troutwell, holding Chemung rocks No. VIII. An anticlinal of these same rocks succeeds just south of the village, and a second synclinal along the Chapman line north of Meiserville. From here south the rocks all rise to the southeast towards the Georgetown anticlinal beyond the township limits, in Juniata county.


The rock series extends from the Medina white sandstone No. IVc of Shade mountain, up to the base of the Chemung rocks No. VIII in the Troutwell synclinal.

The Clinton measures, holding the Ore sandstone and Iron sandstone, outcrop between the base of Shade mountain and the Klopperdale valley; but the exposures are very meager, owing to the increasing dip of the rocks and the approach of these measures towards the mountain flank, upon which they really make a terrace.

The Bloomsburg red shale makes a distinct band of red land east and west through the township from Garman’s saw mill on the east to the west Perry line. No ore has been opened in any part of the Clinton measures in this township, although there can be but little doubt of the presence of the Bird’s Eye fossil ore bed in just as good condition as it is in Washington township, only the steeper dip here prevents an economical development in the absence of all water gaps.

The upper Salina lime shales create a fertile strip south of the lower Salina red beds, upon dips of from 40°–60° S. E. The valley is quite elevated here, and is locally called the Hiester valley though essentially a continuation of the Klopperdale valley of Washington and Penns townships.

The Lower Helderbarg limestone makes a very promi-