Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/241

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23.Perry Township in Snyder.

F³. 213

mont, the Oriskany sandstone is exposed on a south east dip 30°, largely shale but carrying some flint and chert, in all 40’ thick.

The Marcellus black slate is exposed for over a mile south of the Oriskany ridge along the road down Mahantango creek, Some impure greenish limestone shows sparingly in the town of Freemont belonging to the Marcellus hori- zon, and dipping southeast into the Sunbnry synelinal.

The Marcellus slates have yielded thoroughly to erosion and create a wide flat narrowing west of Freemont between the two Oriskany sandstone ridges. Just south of the vil- lage they dip 60° 8. E. and after passing over the Slender- dale anticlinal, show again at the first crossroads, dipping only 35°. A short distance below H. Fisher's, thin lime- stone again outcrops on the road apparently dipping stiffly 70°, 8. E.. The horizon of this bed should be somewhat higher at Freemont.

Shadlée s mill and house, 12 miles south of Mt. Pleasant Mills, are built upon an outcrop of Hamilton sandstone dipping 35°, 8. E. and making a noticable ridge east and west bounding the Buckwheat valley of this and West Perry township on the south.

The Genessee yellow fissile shales ave next seen further sonth, sueceeded just north of Reichenbach’s by an out- crop of flaggy sandstones, blue and gray in color, and pos- sibly representing a portion of the Portage division. These rocks again show below the next house somewhat wavy, With a dip varying between 30° and 60°, but averg- ing about 40°, sueceeded by yellow shales and some thin bands of reddish sandstone in the transition measures of the Chemung group on decreased dips of 30° extending south to a right hand branch of the creek.

The Chemung sandstone shows on the south side of the synelinal at the school house near Troutwell on a 10°-15° N. W. dip and with steep southeast cleavage planes. South of theschool the yellow shales come in on a reverse dip, but lie comparatively flat, folding over a broad anticlinal arch, making a high ridge here and finally sink sonthward beneath the Chemung sandstone again, which is well