On the evidence afforded by fossil plants, as to the boundary line between the Devonian and Carboniferous rocks / by Samuel Haughton.

  • Haughton, Samuel.
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: On the evidence afforded by fossil plants, as to the boundary line between the Devonian and Carboniferous rocks / by Samuel Haughton. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    even of new families, together with plants intermediate between Ferns and Equisetacese, and primitive forms of Cycads andConifers, of which he says no one has yet had an idea. On the other hand, the Carbo- niferous Flora contains a totally distinct group of forms, which are highly characteristic of the lower Carboniferous beds. Among these are mentioned:— Calamitcs transitionis.— Gopp. Calamites caimajformis.—F. A. Romer. Megaphy turn Hollcbenii.— Cotta. Knorria (several species). Noeggerathia Rueckeriana.—Gopp. These geologists have adopted this remarkable distinction of Floras as the principle of their subdivision of Thuringian and Saxon rocks into Devonian and Carboniferous, and the result of the adop- tion of this principle has already been a great extension of the ter- ritories of the lower Carboniferous period. 2. In the Rhenish provinces of Prussia, where the Devonian rocks are typically developed, this remarkable Devonian Flora has not been, so far as I am aware, as yet observed; but the lower Carboniferous Flora is extensively developed, containing the same plants as in Thu- ringia, and never descending into the typical Devonian beds. 3. In the Bas Boulonnais, iu France, there is a remarkable group of lower Carboniferous beds, which have been described by Mr. Austen and Mr. Sharp. These beds have been considered by successive ob- servers as Silurian, Devonian, and Carboniferous, but there is no doubt at present as to their true position ; they are Carboniferous, de- scending in their lowest members into the disputed territory between Carboniferous and Devonian. I believe them to be altogether Carbo- niferous, in proof of which it is almost sufficient to mention that the very lowest beds in the district contain the well-known Carbonife- rous fossils:— Terebratula ambigua; Terebratula pleurodon; Spirifer disjimctus; Cyrtia laminosa; Orthis rcsupinata ; and do not contain the characteristic Eifelian fossils of either the upper or lower groups. Immediately above the limestone and dark shale, containing these