Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/206

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178 F³.
E. V. d’Invilliers, 1889.

The Marcellus and Hamilton measures outcrop along the Franklin township line, the first exposure showing a streak of Marcellus limestone, only a few inches of impure greenish-gray rock, immediately overlaid by black slate; dip N. 15° W. 30. The Hamilton slate and thin sandstone follow further north, creating as usual a sharp ridge and showing frequent exposures on a 30° N. W. dip.

On the next road west the Chemung rocks, largely a gray and bluish sandy slate, are exposed close to the Adams township line, above J. Moyer’s house, on a dip of N. 15°–20° W. 25°. Dark gray and black slates follow southwards on the same dip to the forks of the road at M, Gerheart’s, frequently exposed and probably representing the Genessee measures. The low and sharp ridges intervene between this point and Middle creek, evidently composed of the Hamilton measures although there are no good exposures.

Further west, Middle creek flows largely through a Marcellus and Hamilton slate valley, the entire width of No. VIII in this portion of the field not being over two miles and the higher Chemung beds, largely eroded along the line of the Northumberland synclinal.

19. Spring township in Snyder county.

This is also a new township, erected out of parts of Beaver and West Beaver, and extending north and south for about 7 miles between the crests of Jack’s and Shade mountains, and about 4 miles wide along the Middle Creek valley, with an area of about 24square miles. Adams and Beaver townships lie to the east of it and West Beaver to the west, while the two mountain crests confine it north and south.

Adamsburg is the only place of prominence within the township, an active growing town, situated on the Sunbury and Lewistown railroad, about 2 miles west of Beavertown, and a place nearly as large in population as the county seat.

Middle creek forks in this township into a number of branches which together collect all the drainage from both mountains and the valley to the west and carry it eastward to the river below Selinsgrove. Swift run is its most im-