Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/251

Rh The Triester valley axis crosses the railroad only a short distance south of Milroy and a little below the road leading to Siglerville. The crest of the anticlinal shows dips of N. 20° W., 40° and S. 20° E., 60°. Going east along the Siglerville road, the north dips decline in strength to 20° in good blue limestone, well exposed in the vicinity of Ramsey’s and MeNitt’s houses, and on the west side of the stream. The No. III slate is met with on a 20°, S. E. dip just after crossing the streams at F. McClintic’s place, but the cleavage planes in the slate dip from 70° to 80° to the southeast and must not be taken for the real stratification. The road-cut in these slates is an extensive one. The slates are generally shaly and brown in color, although containing several bands of hard calcareous deep blue layers, which are largely made up of an impure limestone. The north end of the exposure exhibits the slates brushed up and folded, they are very much crushed. There may be a small fault here, north of which the dip is about 60° N. W., but it is small and insignificant, and does not appear to have any lateral extension.

The Triester valley anticlinal is also well marked at Siglerville, passing just south of the school house and exhibiting there a splendid exposure of excellent blue limestone, On the east side of a small creek in a quarry about 150′ are seen, dipping S. 30° E., 70°. This may possibly be an overturned dip, as in the next 200 yards and near the bend of the road, the rocks do not dip more than 35° or 40°. There are several sink holes in this part of the valley along the crest of the anticlinal, interrupting the visible flow of the stream just as is the case along the main creek south of Milroy.

About 2½ miles east of Siglerville the limestone of the valley is completely covered up by the next higher formation, No. III Hudson River shales and slates, which continue from that point east to occupy the valley exclusively into Union county.

At the forks of the road 1½ miles east of Siglerville, a small exposure of limestone with dips of 25°, N. W. and 40°, S. E. serve to once more locate the position of the