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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...of these shales that in that part of the area lying west of the Cornwall Railroad the effective dip toward the north must be much less than 12, because the shales outcrop on the south side at elevations between 700 and 800 feet, and just south of the mines their croppings are barely 100 feet lower. East of the railroad the strata may be somewhat more steeply inclined, as higher and higher horizons of the Mesozoic strata come into contact either with the diabase dike or with the slates which adjoin it for nearly 2 miles eastward from Miners village. In this direction it seems that the carbonaceous shales are overlapped by higher beds of sandstone and red shales, so that their contact with the Paleozoic rocks may lie well back from the edge of the diabase dike and some distance below the lowest Mesozoic strata locally exposed by the stream cuttings. In Lancaster County (PIs. II and III), beyond the southern edge of the sill, lower and lower Mesozoic strata emerge, with east-northeast strikes and constantly increasing northward dips, until the boundary with underlying slates is encountered about 2 miles south of Penryn. The basal contact on this side of the Mesozoic belt is a nearly straight line, trending slightly south of west, extending from Ilopeland past Brickerville to the bend of Chickies Creek, just north of Whiteoak station, and thence nearly to Mastersonville, where it takes a more southerly course, reaching Susquehanna River at Bainbridge. Near this southern boundary the dips of the Mesozoic strata are steep and locally are even overturned. Allowing for the observed gradually decreasing inclination toward the north, we have an estimated thickness of strata amounting to about 6,500 feet between the bottom of the Mesozoic and the group of carbonaceous...
