Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/334

306 F³. bat apparently devoid of iron ore. The anticlinal to the south exhibits a beautiful arch of Oriskany sandstone with dips of 10° and 15° north and south; but this sandstone is very much broken down in this vicinity, everywhere showing beds of loose sand, iron-brown in color, and in places nests of silicious hematite.

At the old plaster mill in the gap of Beaver Dam run the sandstones dip north again, the third anticlinal being south of this point between Postlethwaite’s and the railroad.

West of Union Mills, which stand upon an outcrop of the Oriskany sandstone, the public road closely marks the division between Nos. VII and VIII, the former being washed bare in many places with a scarcely perceptible northwest dip.

Between the railroad and the river, east of Newton Hamilton, the synclinal is occupied by the Marcellus slates; but there is an extremely small thickness of them; for the bed of the river shows at low water level flat ledges of the Oriskany sandstone very well exposed below the Newton Hamilton dam. No. VII seems to be entirely absent along the south side of this synclinal, or else it has been formerly eroded by the action of the Juniata river. It is likewise very poorly exposed in the gap between Newton Hamilton and the Ochre mill, where the Lewistown limestone No. VI makes a broad compound arch between the Gifford and Morrison places, with dips of 10° to 15°, beneath which there is a good exposure of the Lewistown and upper Salina shales.

On the west side of the canal below and north of the Widow Ferguson’s place the limestone has been quarried on a 60° northwest dip, and north of this the Oriskany sandstone shows on the west side of the river, just south of Lane’s house in a spur ending at the canal, where it is 60° thick and dips northwest 20°. Overlying this rock on the north flank of the ridge there is a good exposure of the Marcellus limestone, which attains an unusual thickness in this township.