Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/336

308 F³. The Oriskany sandstone measnres are exposed in the north leg of the synclinal at Atkinson’s mills just north of Musser’s saw mill; but the sandstone becomes eroded just west of this point just as was the case with the synclinal ridge to the north. At the school house the No. VI limestone is again exposed on a northwest dip of 70° on the south side of this synclinal, where it was once quarried and burned.

The Oriskany sandstone laps around this local anticlinal roll just east of the school house, and turns westward again to make the curving ridge bounding the main slate valley of the township on the north all the way to Mt. Union. The southeast dip along this monoclinal ridge varies between 20° and 30° and the Oriskany sandslonesandstone [sic] becomes somewhat thinner, rarely showing over 100′ in thickness, The Oriskany shales underlying it, however, seem to take up the thickness lost by the sandstone and all through this ridge are well exposed with a thickness of over 250′.

The Lewistown limestone supporting this shale and outcropping along the north flank of the ridge is in places well exposed too and between Atkinson’s mills and the Juniata river contains from 75′ to 100′ in thickness of good beds. This limestone is opened just below the G. & S. mill at Atkinson’s mills, about 25′ thick and dipping southeast 40°, and makes a fine display at the extensive quarries of the Lucy Furnace Company, located about one-half mile east from the P. R. R., crossing the Juniata below Mt. Union. Nearly 100′ of stone is exposed here upon a dip of 30° towards the south, and is said to furnish six different classes of limestone. The central portion of the series, about 40′ thick, is found to furnish the best furnace stone; but while this is the purest bed of the series the beds above and below it contain good stone, During 1888 this quarry was largely operated for furnishing ballast stone for the P. R. R.

These beds are again well exposed along the public road leading from Lucy Furnace to Newton Hamilton, where the ridge is gapped by a small stream flowing into Long Hollow. The Lewistown limestone here really forms the crest of the ridge and its middle massive member, 40′ thick, is opened