Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/394

366 F³. The Oriskany sandstone No. VII seems to be almost entirely absent here, the Lewistown measures being almost immediately succeeded and overlaid by the Marcellus slates in Spruce Hill township.

In the next gap about two miles west of Academia, between Allenville and the Tuscarora creek, an almost identical section is exposed.

The Lewistown limestone and Oriskany sandstone make a prominent ridge here, curving gently towards the northwest so as to admit quite an area of the Marcellus slates along the south side of the township between the ridge and Tuscarora creek. In the elevated valley between the limestone ridge and the ore ridge, the Bloomsburg red shales are well exposed at Jacobs’ Mill on a 40° S. E. dip and about 300 yards up the stream the Ore sandstone shows on the road just below the mill dam, about 15′ thick, and dipping S. 36° E. 30°. Some little soft fossil ore has been thrown out at this point, and as the ridge rises amply from the creek this point would offer advantages for mining, if the ore bed was of sufficient thickness and good quality. Neither of these facts could be ascertained, but the ore seen at the opening was very fair.

The reddish-brown and olive slates which underlie the Ore sandstone show here about 200′ thick, and as usual make a very conspicuous outcrop on account of the thin, but frequent ribs of a block sandstone which accompanies the slate and shales and weathers but slightly.

The anticlinal passes in the vicinity of W. Leach’s house with nearly flat dips; and going north to Boone’s house the brown and olive slates are repeated with beds of sandstone from 4′-6′ thick at the forks of the road on a northwest dip of 45°. Slate and shale, generally reddish and brown in color, occur almost without interruption northward on dips increasing to 60°, presenting a sectonsection [sic] of rocks from 300′–350′ in thickness up to the Ore sandstone in the north leg of the anticlinal, which shows just south of Bratton’s house with a similar dip.

The fossil ore measures are all concealed; but there was