exposed on a 15°–20° S. E. dip, about 100 yards north of the red bridge crossing Mahantango creek at Minnich’s grist and saw mill, The dip soon increases to 40° in an almost continuous exposure, and is then reversed in a wide flat synclinal with 10° dips. Towards Meiserville, the north dip increases somewhat; and opposite Meiser’s mill, blue and black slates dip 30°–35° N. W.
Half a mile below this on the creek, where the Perry road crosses into Chapman township, there is a fine exposure of the (Portage?) rocks dipping N. 16° W. 30°, making high bluffs along the west side of the creek and exposed for some distance along the stream. Still further south the Genessee and Hamilton measures come in on similar dips, until crossing Mahantango creek in Juniata county the Marcellus slates outcrop on the flank of the George anticlinal.
24.—West Perry township in Snyder county.
This township has rudely the shape of a right-angle triangle, the base of which makes its northern line, extending along the crest of Shade mountain for 12 miles, while its perpendicular line on the east is 5 miles in length, extending from the mountain south to West Mahantango creek. Its hypothenuse divides the township and county from Juniata, extending along the upper waters of Mahantango creek for 7 or 8 miles by the meanderings of the stream, and 6 miles further in a straight line across the valley and up the flank of the mountain to the north Oneida crest of the anticlinal. Its area is roughly 30 square miles.
Its drainage is almost entirely eastward through branches of Mahantango creek to the Susquehanna river, although Lost creek takes its rise in the Spiegelmeyer slate valley occupying the summit and the anticlinal of Shade mountain, and flows southwestward to the Juniata,
The structure is largely a continuation of that in Perry township, although the township lines do not extend far enough south to include the several rolls and basins at Troutwell and Meiserville.
