Primitive man in Ohio / by Warren K. Moorehead.

  • Warren K. Moorehead
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Primitive man in Ohio / by Warren K. Moorehead. Source: Wellcome Collection.

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    collectors. Its outline is extremely tortuous, owing to the erosion that has made the whole country a suc- cession of hills and ravines. Throughout its length it forms the cap-rock of the high land, all the super- incumbent material having been either removed or converted into soil. The salient points of the surface in the region being practically in a horizontal plane, while the dip of the rock is to the southeast, it follows that the flint stratum was, at its eastern end, first covered by a considerable thickness of earth. The rounded knolls characteristic of the landscape are in some places eighty feet above the flint. This, however, is not common ; for the most part the overlying earth is only a few feet in depth, and toward the ends or sides of the numerous ridges the flint stands out in relief. Geologically the formation belongs to the car- boniferous or coal-measure rocks, being the last or uppermost layer of the “ Putnam Hill Limestone ” of the Ohio Geological Survey. A fine bed of cannel coal lies one hundred and four feet below the flint, and is mined on a consid- erable scale. Bituminous coal also is found south of the ridge, some distance below the level of the flint stratum ; the exact interval has never been measured. If the Kittaning coal of the Pennsyl- vania Geological Survey were extended thus far toward the west, it would lie about thirty-five feet above the flint. The western extremity of the flint is found in a detached hill in Franklin Township, eight miles
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