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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![alayas, although the latter certainly hold a somewhat higher stratigraphies! position, and they may consequently be placed on a level with the upper Prodnctns limestone or with the Ciiidrn group of the Salt Range. “ The youngest of the three rock groups is probably the Bel- lerophon limestone of South-eastern Tyrol. Its fauna is a very peculiar one, species identical with those known outside this rock group being almost completely absent. The predomi- nance of palaeozoic types induced Staclie to fix the homotaxis of these beds as upper permian, whereas Giimbel supposed them to be of lowest triassic age. . . . “ In none of these three permian rock groups of the Med- iterranean region is a normal sequence of marine beds exposed, with the possible exception of the JBelleroplion limestone of the Carnian Alps, which, however, is underlaid by an enor- mous mass of unfossiliferous limestones and dolomites. Their correlation must consequently be based on palaeontological evidence alone” (pp. 90-91). Recently, Schellwien and Kossmat (Monatsber. No. 9, Deutsch. Geol. Gesellsch., 1905, pp. 357-9) found in the Bellerophon limestone (usually regarded as the topmost Per- ruian of the Alps) of Krain, west of the Laibach plain, a fauna consisting in the main of brachiopods, corals, and Fora- minifera. As yet the fossils are not worked out of the matrix, but the following species are determined: Richtofenia aff. lawrenciana, Productus indicus, P. abichi, Marginifera ovdlis, and Lonsdaleia indica. In regard to these fossils Schellwien concludes as follows :— “ The finding of this fauna dispels all doubt as to the Per- mian age of the Bellerophon limestone. The value of this discovery in fixing the time position of this limestone, how- ever, is overshadowed by the greater one,—that of fixing the chronologic position of the Productus limestone [of India], the correlations of which, as is known, are still at variance. The fossil-bearing beds of the Bellerophon limestone are everywhere in close association with the lower Werfen beds [Triassic]: in southern Tyrol the boundary between the Wer- fen deposits and the Bellerophon limestone is difficult to estab- lish. At Krain the fossiliferous zones of the Bellerophon limestone are also separated, but by a thin dolomite series from the Trias. These upper dolomites introduce micaceous layers and gradually pass into the Werfen slates, with their well- known bivalve fauna. The Bellerophon limestone, therefore, can represent only the highest zone of the Permian, and for the Productus limestone the same view may also be affirmed. Worthy of note is the fact that of this fauna of the Bellero- phon limestone, it is also not only those of the higher zones of the Indian Productus limestone but likewise forms of the](https://iiif.wellcomecollection.org/image/b22407194_0027.jp2/full/800%2C/0/default.jpg)
