Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/283

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30.Derry in Mifflin.
F³. 255

Both members of the Salina group, as well as the lower Clinton rocks are exposed on the Kishacoquillas creek in the vicinity of Yeagertown. North of the village the soil is generally gray, largely due to the decomposition of the calcareous shales of the upper Salina group here reposing in the synclinal. At the Ferguson valley road however there is an excellent exposure of the Bloomsburg red-shale with some thin sandstone and a little olive and blue slate all dipping S. 30° E., 75°. About 100 yards further north and nearer the grist mill, a reverse dip of 75° to the northwest is seen in similar measures, although the olive and green shales predominate here and really make the crest of the Ferguson valley axis, under which the Ore sandstone and its fossil ore beds lie buried at least 400′.

The Ferguson valley road practically divides the Bloomsburg red shale from the upper Salina measures, although some few red bands are seen between the road and the limestone ridge to the south. The latter rocks show generally thin bedded blue limestone and shale dipping S. 35° E., 35.° Ascending the ridge they become thicker, until near the summit some good limestone beds outcrop, although it is probable that the best beds of the series have been eroded at this point. Lime, however, is quarried and burned at a small quarry on the summit of the ridge where the stone is somewhat twisted and is both shaly and siliceous.

Along the south base of this ridge the limestone and shales dip fully 70° to the northwest, so that the synclinal basin containing the limestone measures is very much compressed at this point.

This section is repeated on the next ridge south, only here the entire limestone series is present, the hill being capped with a small outcrop of Oriskany sandstone. The south dip in this ridge is about 50°; but the north dip is very steep, if not slightly overturned. A test drift had been put in at this point through the Stormville shales a little beneath the Oriskany sandstone outcrop on Hort’s property with the object of finding iron ore. It does not seem to have been successful.