Field work focused on the Kuedinskie Kluchiki locality, Perm region, Urals, Russia, which contains a rich assemblage of diverse fossil organisms including higher plants(equisetophytes, pteridosperms, ginkgophytes, con...Field work focused on the Kuedinskie Kluchiki locality, Perm region, Urals, Russia, which contains a rich assemblage of diverse fossil organisms including higher plants(equisetophytes, pteridosperms, ginkgophytes, conifers, vojnovskyans) represented by stems, leaves and reproductive organs;invertebrates(mollusks, arthropods), and tetrapods(temnospondyl amphibians, seymouriamorphs, cotylosaurs, synapsids, diapsids), as well as bony fishes. General characteristics of the taxonomical composition of the Kuedinskie Kluchiki locality are given. A new peltaspermalean pteridosperm taxon, Compsopteris longipinnata sp. nov., and a voltzialean conifer Archaeovoltzia kuedensis sp. nov. are described. General considerations on the paleoecologic and paleogeographic conditions of the Kuedinskie Kluchiki locality origin are given.展开更多
Basalts from the Late Carboniferous to Early Permian are extensively developed in the central Lhasa subterrane, southern Tibet. Studying the petrogenesis of these rocks may have implications for the late Paleozoic arc...Basalts from the Late Carboniferous to Early Permian are extensively developed in the central Lhasa subterrane, southern Tibet. Studying the petrogenesis of these rocks may have implications for the late Paleozoic arc magmatism along the central Lhasa subterrane uncovering more of the evolution of the Sumdo Paleo-Tethys Ocean and its dynamic mechanism. Basalt samples from the Luobadui Formation in the Leqingla area, NW of Linzhou City in the central Lhasa subterrane, southern Tibet exhibit arc-like geochemical signatures in a subduction-zone tectonic setting characterized by high Al_(2)O_(3) and low TiO_(2) contents, fractionated REE patterns with low Nb/La ratios and high LREE concentrations, and negative HFSE anomalies. Based on their higher Th/Ce, Nb/Zr, and lower Ba/Th, Pb/Nd ratios, slightly negative to positive ε_(Nd)(t) values, and the relatively high Sr-Pb isotopic compositions, these samples were probably derived from partial melting of a depleted mantle source of garnet + spinel lherzolite, metasomatized by subducted sediments around 297 Ma. Modeling of the trace elements indicates that these basalts experienced fractional crystallization of olivine, clinopyroxene and minor plagioclase during magma ascent and eruption. It is proposed that these Late Carboniferous–Early Permian basalts are associated with the northward subduction of the Sumdo Paleo-Tethys Ocean seafloor along the southern margin of the central Lhasa subterrane.展开更多
1.Objective The Emeishan basalts is located in southwest China and northern Vietnam,covering an area of 2.5×10^(5) km^(2)(Zhong YT et al.,2014),which is the first widely recognized large igneous province(LIP)in C...1.Objective The Emeishan basalts is located in southwest China and northern Vietnam,covering an area of 2.5×10^(5) km^(2)(Zhong YT et al.,2014),which is the first widely recognized large igneous province(LIP)in China(Zhang ZS,2009).The Emeishan LIP has attracted a numbers of scholars for the reason that the LIP may play a significant role in the evolution of environment and climate.Yang JH et al.,(2018)pointed out that the weathering of the Emeishan basalts consumed carbon dioxide and caused a decrease in the climate of the early Wuchiapingian.However,the duration and termination of the Emeishan basalts eruption remain in doubt.This paper reports a new discovery of tuffaceous in the middle part of the Upper Permian Wujiaping Formation from the northern margin of the Sichuan Basin,applying of LA-ICP-MS to obtain zircon U-Pb ages of tuffaceous and to constrain the lasted eruption timing of Emeishan LIP.展开更多
文摘Field work focused on the Kuedinskie Kluchiki locality, Perm region, Urals, Russia, which contains a rich assemblage of diverse fossil organisms including higher plants(equisetophytes, pteridosperms, ginkgophytes, conifers, vojnovskyans) represented by stems, leaves and reproductive organs;invertebrates(mollusks, arthropods), and tetrapods(temnospondyl amphibians, seymouriamorphs, cotylosaurs, synapsids, diapsids), as well as bony fishes. General characteristics of the taxonomical composition of the Kuedinskie Kluchiki locality are given. A new peltaspermalean pteridosperm taxon, Compsopteris longipinnata sp. nov., and a voltzialean conifer Archaeovoltzia kuedensis sp. nov. are described. General considerations on the paleoecologic and paleogeographic conditions of the Kuedinskie Kluchiki locality origin are given.
基金the National Key Research and Development Program of China (Grant No. 2022YFF0800903)the National Natural Science Foundation of China (Grant Nos. 42302107, 92162322, 42261144669, 41922022, 42003036)+4 种基金the China Geological Survey (Grant Nos. DD20243512, DD20230008)the National Postdoctoral Research Program of China (Grant No. GZC20232489)the Second Tibetan Plateau Scientific Expedition and Research (Grant No. 2021QZKK0304)Xing Dian Youth Talent Plan of Yunnan Province (Grant No. XDYC-QNRC-2022-0136)the UNESCO: IUGS IGCP-662 Program。
文摘Basalts from the Late Carboniferous to Early Permian are extensively developed in the central Lhasa subterrane, southern Tibet. Studying the petrogenesis of these rocks may have implications for the late Paleozoic arc magmatism along the central Lhasa subterrane uncovering more of the evolution of the Sumdo Paleo-Tethys Ocean and its dynamic mechanism. Basalt samples from the Luobadui Formation in the Leqingla area, NW of Linzhou City in the central Lhasa subterrane, southern Tibet exhibit arc-like geochemical signatures in a subduction-zone tectonic setting characterized by high Al_(2)O_(3) and low TiO_(2) contents, fractionated REE patterns with low Nb/La ratios and high LREE concentrations, and negative HFSE anomalies. Based on their higher Th/Ce, Nb/Zr, and lower Ba/Th, Pb/Nd ratios, slightly negative to positive ε_(Nd)(t) values, and the relatively high Sr-Pb isotopic compositions, these samples were probably derived from partial melting of a depleted mantle source of garnet + spinel lherzolite, metasomatized by subducted sediments around 297 Ma. Modeling of the trace elements indicates that these basalts experienced fractional crystallization of olivine, clinopyroxene and minor plagioclase during magma ascent and eruption. It is proposed that these Late Carboniferous–Early Permian basalts are associated with the northward subduction of the Sumdo Paleo-Tethys Ocean seafloor along the southern margin of the central Lhasa subterrane.
基金jointly supported by the Open Fund of State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Developmentthe Natural Science Foundation of Sichuan Province(Grant No.24NSFSC4125)。
文摘1.Objective The Emeishan basalts is located in southwest China and northern Vietnam,covering an area of 2.5×10^(5) km^(2)(Zhong YT et al.,2014),which is the first widely recognized large igneous province(LIP)in China(Zhang ZS,2009).The Emeishan LIP has attracted a numbers of scholars for the reason that the LIP may play a significant role in the evolution of environment and climate.Yang JH et al.,(2018)pointed out that the weathering of the Emeishan basalts consumed carbon dioxide and caused a decrease in the climate of the early Wuchiapingian.However,the duration and termination of the Emeishan basalts eruption remain in doubt.This paper reports a new discovery of tuffaceous in the middle part of the Upper Permian Wujiaping Formation from the northern margin of the Sichuan Basin,applying of LA-ICP-MS to obtain zircon U-Pb ages of tuffaceous and to constrain the lasted eruption timing of Emeishan LIP.
