Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/388

360 F³. its percentage being put at about 30 per cent of iron and 35 per cent of insoluble residue, besides being high in phosphorus.

The section along the Juniata river shows very nearly the same characteristics as along Licking creek. The Ore sandstone is not well exposed on either side of the Lost creek ridge anticlinal, but the underlying Clinton shales show north dips of 15° and south dips of 30° with various minor local rolls, due to the flattening of the axis at this point.

The first railroad cut above Mifflintown shows the Bloomsburg red shales near the brick yard on a southeast dip of 35°, and a good exposure of these and the underlying rocks can be seen along the track going north. The overlying upper Salina rocks are slightly twisted in Patterson with north and south dips of 12 and 35 respectively, but soon settle to the southeast dip into the main Mifflintown synclinal, occupied by a strip of the lower Lewistown limestone measure, tapering as it extends westward for about eight miles to Allenville, in Beale township.

South of Mifflintown there is an almost uninterrnpted and very interesting exposure of the Salina rocks of nearly 1500′ along the railroad, commencing at a point about 300 yards south of Patterson station at an exposure of lime shales, olive-gray sandstone and red and gray shale on a 35° N. W. dip. The exposure consists of a thick mass of variegated lime shale and slates, containing here and there thin bands of gray sandstone from 5′–15′ thick, and bands of red shale, from 10′–20′ thick, the whole thrown into a series of graceful anticlinal and synclinal folds. Some of these folds are tightly compressed, the rocks rising nearly vertically from each side of the basin; others are broad and wavy, producing wide arches and carrying a thickness of 50′ or 60′ for some distance along the railroad in a succession of sinuous curves.

The estimated thickness of rocks here exposed is about 400′ but the same beds are so frequently duplicated as to deceive an observer not conversant with this fact. Viewed