| mhorn | Дата: Wednesday, 18.07.2012, 17:22 | Сообщение # 1 |
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| Fortwengler D., Marchand D., Bonnot A., Jardat R., Raynaud D. (2012) Proposal for the Thuoux section as a candidate for the GSSP of the base of the Oxfordian stage // Carnets de Géologie [Notebooks on Geology], Brest, Article 2012/06 ( CG2012_A06), P. 117-136.
pdf: http://paleopolis.rediris.es/cg/CG2012_A06/CG2012_A06.pdf
The Thuoux section, located in South-Eastern Basin of France (coordinates: 44°30'55"E; 5°42'25"N), is a section that satisfies numerous demanding criteria as reference section (GSSP) for the base of the Oxfordian stage. Sedimentation was continuous in that the abundant ammonitic fauna yields no detectable hiatuses. The stratigraphic boundary is located between the Lamberti Zone and the Mariae Zone or more precisely between the Paucicostatum horizon (MARCHAND, 1979) and the Thuouxensis horizon (FORTWENGLER & MARCHAND, 1994a). In this section, there is a perfect mixing between Boreal ammonites (Cardioceratinae) whose species are used as stratigraphic markers and Submediterranean/Subboreal ammonites (Hecticoceratinae, Peltoceratinae and Perisphinctinae) that provide further possibilities for wide correlation of this boundary. Finally, parallel ammonite zonations have been established with great precision (biohorizons and sometimes "sub-biohorizons") in various areas of France, with different palaeoenvironments. The Thuoux section permits correlations with central and eastern Europe as well as North America, based on Cardioceratinae successions, and with South America, using Peltoceratinae. Thickness of the Callovian-Oxfordian transitional beds in the Thuoux section has allowed detailed sedimentological studies and astronomical calibration of the Lower Oxfordian (BOULILA, 2008; BOULILA et al., 2008). The Thuoux section is located at the centre of a set of more than thirty sections where the base of the Oxfordian stage is visible (FORTWENGLER, 1989; FORTWENGLER & MARCHAND, 1994a, b, c, d).
Middle Jurassic - Lower Cretaceous ammonites & aptychi
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