Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China
Measured lithostratigraphic sections of the classic Permian-Triassic non-marine transitional sequences covering the upper Quanzijie, Wutonggou, Guodikeng and lower Jiucaiyuan Formations at Dalongkou and Lucaogou, Xinjiang Province, China are presented. These measured sections form the framework and...
Published in: | Journal of Asian Earth Sciences |
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Pergamon-Elsevier Ltd
2015
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Online Access: | http://hdl.handle.net/1885/59996 https://doi.org/10.1016/j.jseaes.2008.06.005 |
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Australian National University: ANU Digital Collections |
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Keywords: algal bloom biostratigraphy carbon isotope chemostratigraphy depositional sequence environmental stress lithostratigraphy magnetostratigraphy miospore mudstone P-T conditions palynomorph Permian-Triassic boundary sandstone sequence stratigra Biostratigraphy C-isotopes China Non-marine Xinjiang Province |
spellingShingle |
Keywords: algal bloom biostratigraphy carbon isotope chemostratigraphy depositional sequence environmental stress lithostratigraphy magnetostratigraphy miospore mudstone P-T conditions palynomorph Permian-Triassic boundary sandstone sequence stratigra Biostratigraphy C-isotopes China Non-marine Xinjiang Province Metcalfe, Ian Foster, C B Afonin, S.A. Nicoll, Robert Mundil, Roland Xiaofeng, Wang Lucas, S.G. Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China |
topic_facet |
Keywords: algal bloom biostratigraphy carbon isotope chemostratigraphy depositional sequence environmental stress lithostratigraphy magnetostratigraphy miospore mudstone P-T conditions palynomorph Permian-Triassic boundary sandstone sequence stratigra Biostratigraphy C-isotopes China Non-marine Xinjiang Province |
description |
Measured lithostratigraphic sections of the classic Permian-Triassic non-marine transitional sequences covering the upper Quanzijie, Wutonggou, Guodikeng and lower Jiucaiyuan Formations at Dalongkou and Lucaogou, Xinjiang Province, China are presented. These measured sections form the framework and reference sections for a range of multi-disciplinary studies of the P-T transition in this large ancient lake basin, including palynostratigraphy, vertebrate biostratigraphy, chemostratigraphy and magnetostratigraphy. The 121 m thick Wutonggou Formation at Dalongkou includes 12 sandstone units ranging in thickness from 0.5 to 10.5 m that represent cyclical coarse terrigenous input to the lake basin during the Late Permian. The rhythmically-bedded, mudstone-dominated Guodikeng Formation is 197 m and 209 m thick on the north and south limbs of the Dalongkou anticline, respectively, and 129 m thick at Lucaogou. Based on limited palynological data, the Permian-Triassic boundary was previously placed approximately 50 m below the top of this formation at Dalongkou. This boundary does not coincide with any mappable lithologic unit, such as the basal sandstones of the overlying Jiucaiyuan Formation, assigned to the Early Triassic. The presence of multiple organic δ13C-isotope excursions, mutant pollen, and multiple algal and conchostracan blooms in this formation, together with Late Permian palynomorphs, suggests that the Guodikeng Formation records multiple climatic perturbation signals representing environmental stress during the late Permian mass extinction interval. The overlap between the vertebrates Dicynodon and Lystrosaurus in the upper part of this formation, and the occurrence of late Permian spores and the latest Permian to earliest Triassic megaspore Otynisporites eotriassicus is consistent with a latest Permian age for at least part of the Guodikeng Formation. Palynostratigrahic placement of the Permian-Triassic boundary in the Junggar Basin remains problematic because key miospore taxa, such as Aratrisporites spp. are not present. Palynomorphs from the Guodikeng are assigned to two assemblages; the youngest, from the upper 100 m of the formation (and the overlying Jiucaiyuan Formation), contains both typical Permian elements and distinctive taxa that elsewhere are known from the Early Triassic of Canada, Greenland, Norway, and Russia. The latter include spores assigned to Pechorosporites disertus, Lundbladispora foveota, Naumovaspora striata, Decussatisporites mulstrigatus and Leptolepidites jonkerii. While the presence of Devonian and Carboniferous spores and Early Permian pollen demonstrate reworking is occurring in the Guodikeng assemblages, the sometimes common occurrence of Scutasporites sp. cf. Scutasporites unicus, and other pollen, suggests that the Late Permian elements are in place, and that the upper assemblage derives from a genuine transitional flora of Early Triassic aspect. In the Junggar Basin, biostratigraphic data and magnetostratigraphic data indicate that the Permian-Triassic boundary (GSSP Level) is in the middle to upper Guodikeng Formation and perhaps as high as the formational contact with the overlying Jiucaiyuan Formation. |
format |
Article in Journal/Newspaper |
author |
Metcalfe, Ian Foster, C B Afonin, S.A. Nicoll, Robert Mundil, Roland Xiaofeng, Wang Lucas, S.G. |
author_facet |
Metcalfe, Ian Foster, C B Afonin, S.A. Nicoll, Robert Mundil, Roland Xiaofeng, Wang Lucas, S.G. |
author_sort |
Metcalfe, Ian |
title |
Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China |
title_short |
Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China |
title_full |
Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China |
title_fullStr |
Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China |
title_full_unstemmed |
Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China |
title_sort |
stratigraphy, biostratigraphy and c-isotopes of the permian-triassic non-marine sequence at dalongkou and lucaogou, xinjiang province, china |
publisher |
Pergamon-Elsevier Ltd |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/59996 https://doi.org/10.1016/j.jseaes.2008.06.005 |
geographic |
Canada Greenland Norway |
geographic_facet |
Canada Greenland Norway |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Journal of Asian Earth Sciences |
op_relation |
1367-9120 http://hdl.handle.net/1885/59996 doi:10.1016/j.jseaes.2008.06.005 |
op_doi |
https://doi.org/10.1016/j.jseaes.2008.06.005 |
container_title |
Journal of Asian Earth Sciences |
container_volume |
36 |
container_issue |
6 |
container_start_page |
503 |
op_container_end_page |
520 |
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1766020446121099264 |
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/59996 2023-05-15T16:30:43+02:00 Stratigraphy, biostratigraphy and C-isotopes of the Permian-Triassic non-marine sequence at Dalongkou and Lucaogou, Xinjiang Province, China Metcalfe, Ian Foster, C B Afonin, S.A. Nicoll, Robert Mundil, Roland Xiaofeng, Wang Lucas, S.G. 2015-12-10T22:55:11Z http://hdl.handle.net/1885/59996 https://doi.org/10.1016/j.jseaes.2008.06.005 unknown Pergamon-Elsevier Ltd 1367-9120 http://hdl.handle.net/1885/59996 doi:10.1016/j.jseaes.2008.06.005 Journal of Asian Earth Sciences Keywords: algal bloom biostratigraphy carbon isotope chemostratigraphy depositional sequence environmental stress lithostratigraphy magnetostratigraphy miospore mudstone P-T conditions palynomorph Permian-Triassic boundary sandstone sequence stratigra Biostratigraphy C-isotopes China Non-marine Xinjiang Province Journal article 2015 ftanucanberra https://doi.org/10.1016/j.jseaes.2008.06.005 2017-04-10T22:55:19Z Measured lithostratigraphic sections of the classic Permian-Triassic non-marine transitional sequences covering the upper Quanzijie, Wutonggou, Guodikeng and lower Jiucaiyuan Formations at Dalongkou and Lucaogou, Xinjiang Province, China are presented. These measured sections form the framework and reference sections for a range of multi-disciplinary studies of the P-T transition in this large ancient lake basin, including palynostratigraphy, vertebrate biostratigraphy, chemostratigraphy and magnetostratigraphy. The 121 m thick Wutonggou Formation at Dalongkou includes 12 sandstone units ranging in thickness from 0.5 to 10.5 m that represent cyclical coarse terrigenous input to the lake basin during the Late Permian. The rhythmically-bedded, mudstone-dominated Guodikeng Formation is 197 m and 209 m thick on the north and south limbs of the Dalongkou anticline, respectively, and 129 m thick at Lucaogou. Based on limited palynological data, the Permian-Triassic boundary was previously placed approximately 50 m below the top of this formation at Dalongkou. This boundary does not coincide with any mappable lithologic unit, such as the basal sandstones of the overlying Jiucaiyuan Formation, assigned to the Early Triassic. The presence of multiple organic δ13C-isotope excursions, mutant pollen, and multiple algal and conchostracan blooms in this formation, together with Late Permian palynomorphs, suggests that the Guodikeng Formation records multiple climatic perturbation signals representing environmental stress during the late Permian mass extinction interval. The overlap between the vertebrates Dicynodon and Lystrosaurus in the upper part of this formation, and the occurrence of late Permian spores and the latest Permian to earliest Triassic megaspore Otynisporites eotriassicus is consistent with a latest Permian age for at least part of the Guodikeng Formation. Palynostratigrahic placement of the Permian-Triassic boundary in the Junggar Basin remains problematic because key miospore taxa, such as Aratrisporites spp. are not present. Palynomorphs from the Guodikeng are assigned to two assemblages; the youngest, from the upper 100 m of the formation (and the overlying Jiucaiyuan Formation), contains both typical Permian elements and distinctive taxa that elsewhere are known from the Early Triassic of Canada, Greenland, Norway, and Russia. The latter include spores assigned to Pechorosporites disertus, Lundbladispora foveota, Naumovaspora striata, Decussatisporites mulstrigatus and Leptolepidites jonkerii. While the presence of Devonian and Carboniferous spores and Early Permian pollen demonstrate reworking is occurring in the Guodikeng assemblages, the sometimes common occurrence of Scutasporites sp. cf. Scutasporites unicus, and other pollen, suggests that the Late Permian elements are in place, and that the upper assemblage derives from a genuine transitional flora of Early Triassic aspect. In the Junggar Basin, biostratigraphic data and magnetostratigraphic data indicate that the Permian-Triassic boundary (GSSP Level) is in the middle to upper Guodikeng Formation and perhaps as high as the formational contact with the overlying Jiucaiyuan Formation. Article in Journal/Newspaper Greenland Australian National University: ANU Digital Collections Canada Greenland Norway Journal of Asian Earth Sciences 36 6 503 520 |