Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/351

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
38.Fayette in Juniata.
F³. 323

Through the Lost Creek gap southwest from here the road passes along the flank of the Oneida conglomerate and sandstone gradually descending into the creek, but rising geologically towards the red Medina sandstone on its descent. Near the contact of Nos. IVa and IVb a small drift has been started just north of the road in some rather dark-colored shales for the purpose, it was stated, of developing coal. It is needless to say that the attempt was quickly abandoned when the drift struck a solid bed of yellow sandstone dipping southeast at an angle of 30°: but the attempt here is only another illustration of the blind work of prospectors, actuated by dishonest motives or by gross ignorance.

Southwest from here the road and creek pass over a belt of the red Medina sandstone and shales, whose outcrop is largely concealed and whose rocks make an elevated plateau but slightly higher than the two ribs of gray and white sandstone enclosing them. The white Medina No. IVc crest is also deeply notched by Lost creek; but besides displaying a great profusion of sharp, angular white sand- stone bowlders, it shows no good exposure of the Medina rocks in place.

The Ore sandstone series has but a single mountain outcrop in this township, forming a terrace ridge on the south flank of Shade mountain, running east and west from Snyder county to the Fermanagh township line. The sandstone itself here is from 10′ to 15′ thick,. and is underlaid by from 15′ to 20′ of hard, argillaceous shales, under which the Danville ore beds should occur.

West of Lost creek this ore terrace lies much closer to the mountain flank than east of the creek, so that it may be inferred that the dips are greater along that part of the range. None of the ore beds associated with these rocks have been opened along the mountain flank, although in places their presence is indicated by the usual outcrop of hematite or altered fossil ore.

The Slenderdale or “Slim Valley,” which extends between the mountain Ore Sandstone ridge on the north and the Slenderdale ridge on the south, is everywhere about one-