Historical collections relating to Gwynedd : a township of Montgomery County, Pennsylvania, settled 1698, by Welsh immigrants, with some data referring to the adjoining township of Montgomery, also a Welsh settlement / by Howard M. Jenkins.

  • Howard Malcolm Jenkins
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: Historical collections relating to Gwynedd : a township of Montgomery County, Pennsylvania, settled 1698, by Welsh immigrants, with some data referring to the adjoining township of Montgomery, also a Welsh settlement / by Howard M. Jenkins. Source: Wellcome Collection.

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    “Whether this trap be connected—underground—with the trap of Bowman’s hill, south of Lambertville, on the Del- aware ; or whether it be in any way connected with the great fault of Barrville, Greenville, and Centre, east of Doylestown, is not known. This last fault brings up [in Bucks county] the limestone floor, on which the Mezozoic rocks repose; how deep this floor lies under Gwynedd township is a problem, but it must be at least one or two thousand feet. “ This is absolutely all the geology of Gwynedd that can be generally stated. No region can be more barren of general geological interest. But there are special problems of high scientific interest to be settled by special local work.” Prof. H. Carvill Lewis, of Philadelphia, who has made im- portant studies in the geology of south-eastern Pennsylvania, has been particularly attracted by the plant bed opened in the tunnel referred to by Professor Lesley. In a letter, March 14th, 1884, he says: “I have recently obtained quite a number of fossils, both shells and plants, from the railroad cut at Gwynedd, and find some of them identical with those occur- ring in a certain plant bed on the Schuylkill above Phoenix- ville. There are three fossil horizons near Phoenixville—the bone bed in the old tunnel, the plant bed in some old quar- ries near the north end of the old tunnel, and the shell bed at the lower end of the tunnel. The latter lies probably one thousand feet below the others. I believe the plant bed to be identical with that at Gwynedd. Fossil foot-marks of turtles occur in this bed at Phoenixville; at Gwynedd there occur stems of calamites, seeds of a land plant, marine fucoids, foot- prints, minute shells of a species of Posidonia, etc., showing as at Phoenixville a commingling of fresh water and marine or- ganisms. The theory that the Triassic deposit was made by a great north-east flowing river, which, in the neighborhood of Phoenixville, widened to become a marine estuary, emptying into the ocean near the mouth of the Hudson, is confirmed by