Early Carboniferous) Examensarbete Vid Institutionen För Geovetenskaper
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The Tournaisian (Early Carboniferous) Examensarbete vid Institutionen för geovetenskaper Foraminifers From the Kuznetsk Basin ISSN 1650-6553 Nr 303 (South-West Siberia, Russia): Taxonomy, Biometry, Biostratigraphy Clémentine Colpaert The Tournaisian (Early Carboniferous) Foraminifers From the Kuznetsk Basin Revised Tournaisian foraminiferal assemblages of Kuznetsk Basin (Siberia, Russia) provide new accurate stratigraphic correlations for the Taidon and (South-West Siberia, Russia): Fominskoe formations, and palaeobiogeographic hypotheses for western Siberia. Microfacies analyses of Old Belovo Quarry, Artyshta village Section as well as Taxonomy, Biometry, Biostratigraphy Starobachaty village Section reveal four main types of wackestone or packstone with different skeletal grains, some foraminifers and very rare incertae sedis algae. The environments of deposit may be reconstructed as located in distal parts of inner ramps and proximal parts of mid ramp. If the unilocular foraminifer are relatively abundant in all the microfacies, the plurilocular ones occur only in bioclastic neomicrosparitized wackestone deposited in the shallower parts of the carbonate ramp. As the Tournaisian inner ramp is narrow, and only preserved in the Old Belovo Quarry, the Taidon and Fominskoe formations yield quite rare plurilocular Clémentine Colpaert foraminifers. They belong mainly to the superfamily Septabrunsiinoidea, and more precisely to the genera Septabrunsiina and Pseudoplanoendothyra. Rarer Granuliferella and Endothyra are sporadically present. The presence of Granuliferella and some “Devonian” Lazarus-genera allow to correlate the Taidon Formation with the MFZ3 to MFZ5 biozones defined in the Belgian stratotypes, and its top, with Endothyra, to the biozones MFZ5 and/or MFZ6. The Fominskoe Formation, overlain by series previously dated as earliest Viséan, corresponds to the whole late Tournaisian (MFZ6-MFZ8). The previously obtained data and our new analyses of foraminiferal faunas presented herein support the hypothesis that two migrations occur between Siberia and Palaeotethys ocean from latest Famennian to late Tournaisian. The first radiation event, during the Hastarian (= early Tournaisian) might be responsible for migration of Septabrunsiina species which are probably opportunistic and endofaunal organisms. The second radiation event occurs during the early Ivorian (= earliest Tournaisian). It should be responsible of the dispersion of more diversified forminifers such as Granuliferella, Pseudoplanoendothyra and Endothyra. The presence of many similarities between the Chinese and Siberian foraminiferal assemblages suggest that the migration occurred probably through the Chinese islands due to the global transgression of the sea level at the end of the Tournaisian as well as the occurrence of several tropical carbonate platforms. As the Lower Carboniferous is characterised by the occurrence of freely interconnected tropical and equatorial seas favourable for the development of foraminifers, the different sea level changes have mainly controlled the evolution of foraminiferal populations, their scattering following by isolation of population, endemism and finally, gathering. They have influenced the relations between Siberia and other terranes such as those of the Palaeotethys ocean or North-America areas. Uppsala universitet, Institutionen för geovetenskaper Examensarbete E1, 30 hp i Paleobiologi ISSN 1650-6553 Nr 303 Tryckt hos Institutionen för geovetenskaper, Geotryckeriet, Uppsala universitet, Uppsala, 2014. Examensarbete vid Institutionen för geovetenskaper ISSN 1650-6553 Nr 303 The Tournaisian (Early Carboniferous) Foraminifers From the Kuznetsk Basin (South-West Siberia, Russia): Taxonomy, Biometry, Biostratigraphy Clémentine Colpaert Supervisors: Daniel Vachard, Irina Timokhina, Olga Obut, Claude Monnet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