Address delivered at the meeting of the Association of American Geologists and Naturalists, held in Washington, May, 1844 / By Henry D. Rogers.

  • Rogers, Henry D. (Henry Darwin), 1808-1866.
Date:
1844
Catalogue details

Licence: Public Domain Mark

Credit: Address delivered at the meeting of the Association of American Geologists and Naturalists, held in Washington, May, 1844 / By Henry D. Rogers. Source: Wellcome Collection.

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    materials of those underlying crystalline aggregates. North of the James river, the coal lies in two, and in some places in three distinct seams, and is confined to the lowest hundred and fifty feet of the series ; but south of that river, it forms one huge stratum, which though very variable, is frequently from twenty to forty feet thick,* and what is re¬ markable, the principal bed is separated by only a few feet, and some¬ times by not more than a few inches, of carbonaceous shale from the granitic floor. By Maclure this formation was referred to the period of the old red sandstone, and more recently Mr. Richard C. Taylor assign¬ ed it to the so called “ transition carboniferous deposits but my broth¬ er having during the last three years investigated its fossil vegetation, finds not only a general agreement, but a specific identity between some of its forms and those of the oolite coal of Europe; and he has there¬ fore in a paper in our Transactions, stated that he feels “ no hesitation in referring the formation to a place in the oolite system on the same general parallel with the carbonaceous beds of Whitby and Brora, that is, in the lower part of the great oolite group.” The most abundant of the coal plants are the Equisetum columnare, a large species of Zamites, a beautiful fern, Tamiopteris magnifolia, and Tceniopteris scitaminea; and the remains of these four species, occurring interlaminated with the coal and immediately upon it in great profusion, appear to have fur¬ nished the materials of the stratum. No traces of the Stigmariajficoi- des, so universally associated with the older or palseozoic coal, can be discovered in the soft slates in contact with the coal of this formation. Of animal remains, the most interesting is a small fish four or five inch¬ es long, referred by Mr. W. C. Redfield to the genus Catopterus. It is perhaps worthy of remark that this genus Catopterus of Mr. Redfield, Jr. contains three other species which characterize the meso- zoic red sandstone deposits of both Connecticut and New Jersey, and that therefore while there remains some doubt as to the existence of true Falceonisci in our American red sandstone, and consequently as to any generic link between it and the Permian strata of Europe, of which the genus Palseoniscus is so definitive, this red sandstone is related by such a link in the genus Catopterus to a formation of the oolitic epoch. Thus even as respects its ichthyolite remains, the affinities of the red sandstone are obviously rather to the mesozoic than the palseozoic rocks. Cretaceous Period.—But if the memorials are scanty of the early and middle mesozoic periods, those of the last or cretaceous age are * See Reports Geol. Survey of Virginia ; also, Memoir in Trans, of Geol. Soci¬ ety of Pennsylvania, by Mr. R. C. Taylor.