The Russian Carboniferous and Permian compared with those of India and America : a review and discussion / by Charles Schuchert.
- Charles Schuchert
- Date:
- 1906
Licence: In copyright
Credit: The Russian Carboniferous and Permian compared with those of India and America : a review and discussion / by Charles Schuchert. 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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![ceras beds of Julfa, tlie fauna contains a proportionately large number of carboniferous forms. It is to the faunas of these deposits, the normal representatives of the pelagic permian [by this the author means a normal marine fauna], not to the local fauna of the Zeclistein, that the permocarboniferous fauna must be compared, if we want to get a clear idea of its rela- tionship to those of the upper carboniferous and permian. Bearing in mind the gradual passage from an upper carbon- iferous to a permian fauna through the intermediate group of rocks, the question to be answered is, which consideration is of the greater importance in defining the boundary between the two systems, the appearance of a new group of cephalo pods, which become of an unparalleled stratigraphical value in mesozoic times, or the presence of a belated fauna, com- posed of forms which are generally not well adapted for the characterization of narrowly limited horizons. “The majority of geologists have decided in favour of the first alternative. Giimbel, Krassnopolssky, Kayser, Waagen, Credner, Munier-Chalmas and A. de Lapparent, Freeh—to enumerate only a small number among them,—are unanimous in regarding tlie permocarboniferous as the lowest division of the permian system” (pp. 87-88). “ In the Mediterranean region three different rock groups have yielded fossil remains of this pelagic development of the permian epoch. These rock groups are the Fusulina lime- stones of the valley of Sosio in Sicily, the Bellerophon lime- stone of South-eastern Tyrol and Friaul, and the Otoceras beds of Julfa in Armenia. All of them are of a rather isolated occurrence and, as far as one may judge from their faunas, of different age. “The lowest position is apparently held by the Fusulina limestone of Sicily. Its cephalopod fauna seems to be more nearly related to the Artinskian one than to those of the Jabi beds of the Salt Range or of the Otoceras beds of Julfa. Ammonites with ceratitic sutures are yet absent. According to Karpinsky’s statement, one species of Medlicottia is identi- cal with an Artinskian form; ten more species are very nearly allied. On the other hand, Karpinsky and Waagen noticed the first appearance of Waagenoceras and Hyattoceras in Sic- ily, two genera which show a much more complicated sutural line than any of the Artinskian Ammonea. Waagen conse- quently places the Fusulina limestone of Sicily on a higher level than the permo-carboniferous stage, but on slightly lower level than the Jabi beds of the upper Productus limestone. . . . “The Otoceras beds of Julfa with their strongly marked triassic affinities must certainly be higher in the upper palaeo- zoic series than the Fusulina limestone at Sosio. They cannot be much different in age from the Otoceras beds of tlie Him-](https://iiif.wellcomecollection.org/image/b22407194_0026.jp2/full/800%2C/0/default.jpg)
