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Shuzhong Shen - One of the best experts on this subject based on the ideXlab platform.
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Mid-Permian (End-Guadalupian) Extinctions
Encyclopedia of Geology, 2021Co-Authors: Jun Chen, Shuzhong ShenAbstract:Abstract The end-Guadalupian mass extinction (i.e., pre-Lopingian crisis) has been recognized as a major biotic crisis in Earth's history for nearly three decades. As more and more evidence has been gathered in recent years, our understanding of this event has been enhanced and to some extent changed. Fossil evidence suggests that the end-Guadalupian mass extinction is not as severe as originally thought, and only happened at the community level and was taxonomically selective. The turnovers of major marine fossil groups occurred at different temporal levels, therefore the total duration is relatively extended, especially compared to the sudden end-Permian mass extinction. The nature of the turnover of terrestrial organisms around the Guadalupian-Lopingian boundary (GLB) is so far poorly known. Biostratigraphic constraints suggest that it most likely occurred in the latest Capitanian-earliest Wuchiapingian, a stratigraphic interval between the conodont Jinogondolella xuanhanensis and Clarkina dukouensis zones. Substantial environmental changes coincided with the end-Guadalupian mass extinction, including the largest sea-level fall, and major climate and ocean chemistry (e.g., δ13Ccarb, δ34S, and 87Sr/86Sr) changes. Considering evidence available within a unified temporal framework, the largest regression of the Paleozoic and Emeishan LIP (Large Igneous Province) volcanism are the most likely primary triggers, while other previously suggested causes such as long-term cooling, rapid fluctuations in seawater temperatures, ocean anoxia, explosive volcanism and cooling, and methane outburst with low atmospheric oxygen are either not supported by direct evidence, or were only secondary causes.
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a new changhsingian brachiopod fauna from the xiala formation at tsochen in the central lhasa block and its paleogeographical implications
Journal of Paleontology, 2019Co-Authors: Yichun Zhang, Feng Qiao, Shuzhong ShenAbstract:Permian faunal affinity in the Lhasa Block plays a critical role in reconstructing its paleogeographic evolution. Cisuralian and Guadalupian faunas have been described from the Lhasa Block, but very few Lopingian (late Permian) brachiopods have been reported so far. In this paper, a new diverse brachiopod fauna consisting of 17 species of 17 genera and an unidentifiable Orthotetoidea is described from the uppermost part of the Xiala Formation at the Aduogabu section in the central part of the Lhasa Block. The age of this fauna can be assigned to the Changhsingian (late Lopingian) as indicated by the associated foraminifers Colaniella parva (Colani, 1924) and Reichelina pulchra Miklukho-Maklay, 1954. Characteristic brachiopods include Spinomarginifera chengyaoyenensis Huang, 1932, Haydenella wenganensis (Huang, 1932), and Araxathyris cf. dilatatus Shen, He, and Zhu, 1992. They also generally suggest a Changhsingian age. Paleobiogeographically, this fauna is uniformly composed of typical Tethyan elements represented by Spinomarginifera Huang, 1932 and Haydenella Reed, 1944, and some cosmopolitan elements, but no typical cold-water taxa of Gondwanan affinity. This is in contrast to the contemporaneous brachiopod faunas from the Tethys Himalayan region that are characterized by typical cold-water taxa of Gondwanan affinity, e.g., Costiferina indica (Waagen, 1884), Retimarginifera xizangensis Shen et al., 2000, Neospirifer (Quadrospina) tibetensis Ding, 1962. Thus, it is strongly indicative that the Lhasa Block had drifted into a relatively warm-water regime during the Changhsingian. An analysis of the paleobiogeographic change of brachiopods in the Lhasa Block throughout the entire Permian further suggests that the Lhasa Block probably had rifted away from the northern peri-Gondwanan margin between the latest Cisuralian and middle Guadalupian, that is, the Neotethys Ocean had opened before middle Guadalupian.
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Integrative timescale for the Lopingian (Late Permian): A review and update from Shangsi, South China
Earth-Science Reviews, 2019Co-Authors: Dongxun Yuan, Charles M Henderson, Shuzhong Shen, Hua Zhang, Jun Chen, Quan-feng ZhengAbstract:Abstract The Lopingian is the uppermost series of the Paleozoic and it is bracketed by two major biological events, including the pre-Lopingian crisis and the end-Permian mass extinction (EPME). A high resolution temporal framework is essential to understand the patterns and causes of the extinction. Lopingian strata of South China have been intensively studied because three GSSPs have been defined in the region. Based on the review and updates to data from the Shangsi section as well as correlation with the Meishan section, the time framework for the Lopingian is revised, including biostratigraphy, chemostratigraphy, magnetostratigraphy, cyclostratigraphy and geochronology. The temporal framework is constrained by both precise geochronologic data and a high resolution conodont succession, and provides the possibility that the current high resolution marine international standard can also be applied to nonmarine strata by means of geochronology, magnetostratigraphy and cyclostratigraphy. The entire Lopingian high resolution conodont succession is for the first time, since the Lopingian Series was adopted as the international standard, recognized at a single section in South China and the succession correlates very well with the Lopingian GSSP sections at Penglaitan and Meishan. The Permian-Triassic boundary (PTB) of the Shangsi section is constrained to the basal 6 cm interval of Bed 28b in view of ammonoids, bivalves, conodonts, U-Pb ages and the EPME. The mass extinction interval is between Bed 27 and lower Bed 28a according to the EPME pattern at the Shangsi section, and the alternative interval between extinct Permian species and new Triassic species is from upper Bed 28a to lower Bed 28b. Unitary Association (UA) analysis of Lopingian conodonts reveals 15 unitary association zones (UAZs) based on seven important Lopingian sections of South China. Most of the UAZs correlate well with the standard biozonation, except for UAZ 3 to UAZ 5 and UAZ 12. The correspondence between UAZs and standard conodont biozones at the Shangsi section provides a practical example to understand controls on conodont UAZ determination. The Lopingian conodont succession is temporally calibrated by geochronologic ages, identified 405-kyr eccentricity cycles, and a Monte Carlo analysis at the Shangsi and Meishan sections. Updated ages for the base of the Lopingian and base of the Changhsingian are provided.
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Biostratigraphy constraining strontium isotopic stratigraphy and its application on the Lopingian (Late Permian)
Science China Earth Sciences, 2015Co-Authors: Xinchun Liu, Shuzhong Shen, Wei Wang, Yue Wang, Xiangdong Wang, Chen Xiaozheng, Liu Jing, Wenqian Wang, Changqun CaoAbstract:The Lopingian is one of the fastest rising periods of seawater strontium isotopic ratios (87Sr/86Sr) in earth history, and its mechanisms and increasing rates of the 87Sr/86Sr evolution were still disputed widely. These disputations among researchers were caused mainly by timeframe selection (sections’ thickness or data of radiometric ages), and different stratigraphic boundaries and un-upmost dated ages. This paper examined published 87Sr/86Sr data of the Lopingian, and projected them on timescales based on evolutionary and age constrained conodonts fossils. 87Sr/86Sr evolution vs fossil constraining timescales was re-established in this period. This research suggests: (1) 87Sr/86Sr excursion projects on fossil zones can truly support 87Sr/86Sr evolutionary pattern in the period; (2) 87Sr/86Sr evolution provides a new approach for stratigraphic research of marine carbonate sections in lieu of biostratigraphic data; (3) 87Sr/86Sr stratigraphy works on marine carbonate sections of different sedimentation rates even between different basins; (4) the 87Sr/86Sr data and its shift was dependent on samples materials and chemical treatment methods; (5) the increasing rate of marine water 87Sr/86Sr in the Late Permian is suggested as 5.4×10−5/Ma or slightly lower; (6) sedimentation age and its 87Sr/86Sr of the Lopingian marine carbonate suggested as: D PRO=259-(R S−0.70695)/5.4×10−5±1 Ma.
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late guadalupian to Lopingian permian carbon and strontium isotopic chemostratigraphy in the abadeh section central iran
Gondwana Research, 2013Co-Authors: Shuzhong Shen, Yichun Zhang, Wei Wang, Xinchun Liu, M N Gorgij, Seishiro Furuyama, Akihiro Kano, Xiao Zheng ChenAbstract:Abstract The Abadeh section, well-exposed in the Hambast Valley in central Iran, has long been one of the most extensively studied sections because of its continuous carbonate-dominated strata from Lower Permian to Lower Triassic. However, biostratigraphy and correlation with the equivalent sequences in other regions remain controversial. In this paper both carbon isotope excursion (δ 13 C carb ) and strontium isotope ratio ( 87 Sr/ 86 Sr) based on bulk carbonate samples have been measured to serve as chemostratigraphical proxies to estimate the three different chronostratigraphical boundaries in the Lopingian at the Abadeh section, including the Permian–Triassic Event (PTEB), the Guadalupian–Lopingian (GLB), and the Wuchiapingian–Changhsingian boundaries (WCB). These three boundaries are important for understanding the marine biological evolution around this critical interval. Based on the δ 13 C excursions, the rising trend of 87 Sr/ 86 Sr and the value around 0.7073, and the occurrence of microbialite beds, the Permian–Triassic event boundary (= Bed 25 at the Meishan section) is suggested at − 0.5 m below the base of the main microbialite bed. The GLB is suggested at − 46.5 m based on the position of the minor δ 13 C carb negative depletion, coupled with the values between 0.7069 and 0.7070 of 87 Sr/ 86 Sr and its beginning point of the rising trend, which is above the lowest value 0.7068 of 87 Sr/ 86 Sr ratio in the Paleozoic. The relationship between section thickness and their high-resolution depositional age (projecting age) is interpolated for the whole Lopingian using locally weighted regression scatter plot smoother (LOWESS) of strontium isotopic ratio. Based on the negative δ 13 C excursion and the value 0.7072 of 87 Sr/ 86 Sr ratio, the WCB is estimated at 1 m above the lithologic boundary between Unit 6 and Unit 7, much lower than the boundary defined by previous conodont biostratigraphy, but similar to other index fossils. This boundary is projected as ca. 254.6 Ma in 87 Sr/ 86 Sr-age projecting model and is close to zircon U/Pb dating age from South China.
David P.g. Bond - One of the best experts on this subject based on the ideXlab platform.
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size variations in foraminifers from the early permian to the late triassic implications for the guadalupian Lopingian and the permian triassic mass extinctions
Paleobiology, 2020Co-Authors: Yan Feng, Haijun Song, David P.g. BondAbstract:The final 10 Myr of the Paleozoic saw two of the biggest biological crises in Earth history: the middlePermian extinction (often termed the Guadalupian–Lopingian extinction [GLE]) that was followed 7–8 Myr later by Earth's most catastrophic loss of diversity, the Permian–Triassic mass extinction (PTME). These crises are not only manifest as sharp decreases in biodiversity and—particularly for the PTME—total ecosystem collapse, but they also drove major changes in biological morphological characteristics such as the Lilliput effect. The evolution of test size among different clades of foraminifera during these two extinction events has been less studied. We analyzed a global database of foraminiferal test size (volume) including 20,226 specimens in 464 genera, 98 families, and 9 suborders from 632 publications. Our analyses reveal significant reductions in foraminiferal mean test size across the Guadalupian/Lopingian boundary (GLB) and the Permian/Triassic boundary (PTB), from 8.89 to 7.60 log10 μm3 (lg μm3) and from 7.25 to 5.82 lg μm3, respectively. The decline in test size across the GLB is a function of preferential extinction of genera exhibiting gigantism such as fusulinoidean fusulinids. Other clades show little change in size across the GLB. In contrast, all Lopingian suborders in our analysis (Fusulinina, Lagenina, Miliolina, and Textulariina) experienced a significant decrease in test size across the PTB, mainly due to size-biased extinction and within-lineage change. The PTME was clearly a major catastrophe that affected many groups simultaneously, and the GLE was more selective, perhaps hinting at a subtler, less extreme driver than the later PTME.
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Size variations in foraminifers from the early Permian to the Late Triassic: implications for the Guadalupian–Lopingian and the Permian–Triassic mass extinctions
Paleobiology, 2020Co-Authors: Yan Feng, Haijun Song, David P.g. BondAbstract:The final 10 Myr of the Paleozoic saw two of the biggest biological crises in Earth history: the middlePermian extinction (often termed the Guadalupian–Lopingian extinction [GLE]) that was followed 7–8 Myr later by Earth's most catastrophic loss of diversity, the Permian–Triassic mass extinction (PTME). These crises are not only manifest as sharp decreases in biodiversity and—particularly for the PTME—total ecosystem collapse, but they also drove major changes in biological morphological characteristics such as the Lilliput effect. The evolution of test size among different clades of foraminifera during these two extinction events has been less studied. We analyzed a global database of foraminiferal test size (volume) including 20,226 specimens in 464 genera, 98 families, and 9 suborders from 632 publications. Our analyses reveal significant reductions in foraminiferal mean test size across the Guadalupian/Lopingian boundary (GLB) and the Permian/Triassic boundary (PTB), from 8.89 to 7.60 log10 μm3 (lg μm3) and from 7.25 to 5.82 lg μm3, respectively. The decline in test size across the GLB is a function of preferential extinction of genera exhibiting gigantism such as fusulinoidean fusulinids. Other clades show little change in size across the GLB. In contrast, all Lopingian suborders in our analysis (Fusulinina, Lagenina, Miliolina, and Textulariina) experienced a significant decrease in test size across the PTB, mainly due to size-biased extinction and within-lineage change. The PTME was clearly a major catastrophe that affected many groups simultaneously, and the GLE was more selective, perhaps hinting at a subtler, less extreme driver than the later PTME.
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Latitudinal selectivity of foraminifer extinctions during the late Guadalupian crisis
Paleobiology, 2009Co-Authors: David P.g. Bond, Paul B. WignallAbstract:A global database of middle–upper Permian foraminiferal genera has been compiled from the literature for 75 Guadalupian and 62 Lopingian localities, grouped into 32 and 19 operational geographical units respectively. Cluster analysis reveals that five distinct Guadalupian provinces were reduced to four in the Lopingian, following the disappearance of the Eastern Panthalassa Province. Extinction magnitudes across the Guadalupian/Lopingian (G/L) boundary reveal that, in the remaining provinces, there is a strong regional variation to the losses at low paleolatitudes. The Central and Western Tethys Province experienced a markedly lower extinction magnitude, at both provincial and global levels, than the Eastern and Northern Tethys Province. Panthalassa experienced a high extinction magnitude of endemics, but a global extinction magnitude similar to that recorded in Central and Western Tethys. This regional bias is seen in both the fusulinacean and non-fusulinacean foraminifera, although fusulinaceans suffered much higher magnitudes of extinction. The regional selectivity also persisted during the subsequent Lopingian radiations, with the Central and Western Tethys Province recording the greatest magnitudes. Thus, of 35 new genera recorded globally from the Lopingian, 27 of these are recorded in Central and Western Tethys, compared to five and 12 genera respectively in Panthalassa and in Eastern and Northern Tethys. The Emeishan large igneous province erupted within the Eastern and Northern Tethys Province and may have been a factor in the high extinction–low radiation regime of this region. Regression (and consequent shallow-marine habitat loss) also appears to have been a significant factor. A major, but brief, late Guadalupian regression is best seen in those areas that suffered the greatest extinction losses.
Yukio Isozaki - One of the best experts on this subject based on the ideXlab platform.
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Development of Deep-Sea Anoxia in Panthalassa During the Lopingian (Late Permian): Insights From Redox-Sensitive Elements and Multivariate Analysis
Frontiers in Earth Science, 2021Co-Authors: Tetsuji Onoue, Katsuhito Soda, Yukio IsozakiAbstract:The end-Permian mass extinction (EPME) was the most severe mass extinction event of the Phanerozoic, and was associated with the development of global oceanic anoxia. The intensification of ocean anoxia preceded the EPME, but the degree of intensity and timing of oceanic redox changes in the mid-Panthalassa Ocean remain debated. Here we present the results of geochemical and multivariate statistical analyses of a late Guadalupian to Lopingian (middle–late Permian) bedded chert succession from the Iwaidani section, Japan, which preserves pelagic deep-sea facies from the ocean floor to the lower flank of a mid-Panthalassan seamount. The entire section yields a low manganese-enrichment factor (MnEF < 1), suggesting that suboxic conditions has appeared in the depositional environment already in the late Guadalupian. Enrichment factors of other redox-sensitive trace-elements (e.g., vanadium and uranium) and principle component analysis (PCA) of major element data show the development of suboxic to weakly anoxic conditions across the Guadalupian/Lopingian boundary. Subsequently, anoxic conditions, as inferred from enrichments in U, Mo, Ni, Cu, Zn, and Tl, were developed during the middle Lopingian. Extremely high concentrations of U and Mo (enrichment factors of ~6 and ~5500, respectively) indicate that H2S-rich euxinic conditions developed during the latest Lopingian and around the time of the EPME. The cause of the shift toward more reducing conditions in the early–middle Lopingian is unknown, but PCA results suggest that the euxinic conditions occurred in association with intensified continental weathering in response to a temperature rise during the ca. 200 kyr before the EPME.
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Rapid sea-level change in the Late Guadalupian (Permian) on the Tethyan side of South China: litho- and biostratigraphy of the Chaotian section in Sichuan.
Proceedings of the Japan Academy. Series B Physical and biological sciences, 2008Co-Authors: Yukio Isozaki, Jianxin Yao, Masafumi Saitoh, Noritada Kobayashi, Harutaka SakaiAbstract:The Capitanian (Late Guadalupian) Maokou Formation at Chaotian in northern Sichuan, South China, is composed mainly of shallow marine shelf carbonates deposited on the Tethyan side of South China. By detailed field mapping and scientific drilling, we newly found out unique fossil assemblages and a sharp lithologic change in the upper part of the Maokou Formation. The main part of the Maokou Formation (over 130 m thick) is composed of algal packstone with Wordian-Capitanian large-tested fusulines, rugose corals and other sessile benthos, whereas the Uppermost Member (13 m thick) is composed of black limy mudstone/chert with Capitanian offshore biota (ammonoids, radiolarians, and conodonts). The topmost Capitanian conodont zones are missing; however, the Maokou Formation is disconformably overlain by 260±4 Ma volcanic ash (Wangpo bed) and the Early Lopingian Wujiaping Formation with plant-bearing coaly mudstone and shallow marine carbonates (packstone). The newly identified facies change indicates that northern Sichuan has experienced rapid sea-level changes in the late Guadalupian, i.e., first a transgression in the mid-Capitanian and then a regression across the Guadalupian-Lopingian boundary. As the end-Guadalupian is characterized by a global regression, such a volatile sea-level fluctuation, in particular the sea-level rise, is unique to the Tethyan side of South China. The newly recognized relatively deep-water late Guadalupian sequence adds new paleo-environmental information and further provides a paleotectonic interpretation of the low-latitude eastern Tethyan margin immediately before the end-Guadalupian mass extinction.(Communicated by Ikuo KUSHIRO, M.J.A.)
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The occurrence of giant bivalve Alatoconchidae from the Yabeina zone (Upper Guadalupian, Permian) in European Tethys
Gondwana Research, 2008Co-Authors: Dunja Aljinović, Yukio Isozaki, Jasenka SremacAbstract:Abstract The Permian gigantic bivalve family Alatoconchidae forms a member of the tropical shallow marine fauna intimately associated with the Tethyan warm-water-adapted Verbeekinidae fusulines, such as Neoschwagerina and Yabeina . The Velebit Mountains in central Croatia is one of the nine areas in the world that yielded Alatoconchidae, as first reported early in the 1970 s. In addition to the Neoschwagerina Zone (Wordian, Middle Guadalupian) originally described, we newly found Alatoconchidae from the Yabeina Zone (Capitanian, Upper Guadalupian) from the Brusane area in the central Velebit Mountains. Alatoconchidae occur in three stratigraphic levels of the Velebit Formation composed of black fusuline/algal wackestone/packstone with Yabeina . Although fragmented, the Alatoconchidae shell reach sizes over 40 cm long, and possess unique morphology with a lateral flange plus a prominent prismatic external layer in the double-layered shell structure. Our results confirm, for the first time in Europe and thus in the western Tethyan domain, that the stratigraphic range of the gigantic bivalve family extends up to the Capitanian as well as in the superocean Panthalassa. As no occurrence has been reported from the overlying Lopingian (Upper Permian), Alatoconchidae likely became extinct globally at the end of the Guadalupian, i.e., through the Guadalupian–Lopingian boundary mass extinction.
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fusuline biotic turnover across the guadalupian Lopingian middle upper permian boundary in mid oceanic carbonate buildups biostratigraphy of accreted limestone in japan
Journal of Asian Earth Sciences, 2006Co-Authors: Ayano Ota, Yukio IsozakiAbstract:Abstract Two sections in Upper Middle to Lower Upper Permian shallow-water limestones at Kamura and Akasaka in southwest Japan were analyzed for detailed lithostratigraphy and biostratigraphy. Both sections represent ancient seamount-capping carbonate buildups developed on a basaltic basement in a mid-oceanic environment. The occurrence of abundant Tethyan fusulines allows the recognition of well-defined biostratigraphic zonation in both sections and their mutual correlation. The Upper Guadalupian (Middle Permian) Lepidolina / Yabeina Zone is overlain conformably by the Lower Lopingian (Upper Permian) Codonofusiella – Reichelina Zone with a 13 m-thick transitional interval barren of index taxa. The Guadalupian–Lopingian (G–L) boundary is marked by the First Appearance Datum (FAD) of the Lopingian Codonofusiella – Reichelina assemblage in both sections. This study recognizes for the first time the G–L boundary horizon in a mid-oceanic shallow-water environment. In addition, the shallow-water carbonates in the study sections record the extinction of the Middle Permian large-sized fusuline family Verbeekinidae at the G–L boundary in mid-Panthalassa, as well as in shallow-water Tethyan shelf areas, demonstrating positively that the G–L boundary mass extinction occurred on a global scale. The abrupt elimination of large-shelled fusulines, followed by the domination of small-shelled fusulines may indicate that environmental stress occurred at the end of Guadalupian. The dying-out of symbiotic algae may have caused the selective extinction of the large-shelled fusulines.
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Fusuline biotic turnover across the Guadalupian–Lopingian (Middle–Upper Permian) boundary in mid-oceanic carbonate buildups: Biostratigraphy of accreted limestone in Japan
Journal of Asian Earth Sciences, 2005Co-Authors: Ayano Ota, Yukio IsozakiAbstract:Abstract Two sections in Upper Middle to Lower Upper Permian shallow-water limestones at Kamura and Akasaka in southwest Japan were analyzed for detailed lithostratigraphy and biostratigraphy. Both sections represent ancient seamount-capping carbonate buildups developed on a basaltic basement in a mid-oceanic environment. The occurrence of abundant Tethyan fusulines allows the recognition of well-defined biostratigraphic zonation in both sections and their mutual correlation. The Upper Guadalupian (Middle Permian) Lepidolina / Yabeina Zone is overlain conformably by the Lower Lopingian (Upper Permian) Codonofusiella – Reichelina Zone with a 13 m-thick transitional interval barren of index taxa. The Guadalupian–Lopingian (G–L) boundary is marked by the First Appearance Datum (FAD) of the Lopingian Codonofusiella – Reichelina assemblage in both sections. This study recognizes for the first time the G–L boundary horizon in a mid-oceanic shallow-water environment. In addition, the shallow-water carbonates in the study sections record the extinction of the Middle Permian large-sized fusuline family Verbeekinidae at the G–L boundary in mid-Panthalassa, as well as in shallow-water Tethyan shelf areas, demonstrating positively that the G–L boundary mass extinction occurred on a global scale. The abrupt elimination of large-shelled fusulines, followed by the domination of small-shelled fusulines may indicate that environmental stress occurred at the end of Guadalupian. The dying-out of symbiotic algae may have caused the selective extinction of the large-shelled fusulines.
Jian-wei Shen - One of the best experts on this subject based on the ideXlab platform.
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microbial carbonates as contributors to upper permian guadalupian Lopingian biostromes and reefs in carbonate platform margin setting ziyun county south china
Palaeogeography Palaeoclimatology Palaeoecology, 2005Co-Authors: Jian-wei ShenAbstract:Permian (Guadalupian and Lopingian) reefs in Ziyun County, southern Guizhou, southwestern China, occur in a carbonate platform margin setting. Guadalupian reefs (Maokouan) are characterized by sponges, calcimicrobes, microbialites (as microencrusters) and syndepositional calcite cement. Global sea level falling in the latest Guadalupian changed the reef biotopes. Lower Lopingian (Wuchiapingian) deposits reflect a rapid transgressive-regressive cycle; reefs were not developed during that time, although coral biostromes are common. However, microbial carbonates occur commonly in these biostromes, including dark-coloured, homogeneous microbialite, free-growing microbes, Shamovella and Archaeolithoporella (interpreted to be problematic microbial deposits). Upper Lopingian (Changhsingian) reefs were formed by sponges, microbialites, Shamovella, Archaeolithoporella, automicrite and syndepositional calcite cement. Common primary encrustations consist of thin, homogeneous, subparallel layers of Archaeolithoporella, which is an important reef builder particularly throughout the Lopingian reef succession. Secondary encrustations are characterized by dark-coloured, homogeneous microbialite containing thin thalli that alternate with light-coloured microspar/pseudospar. Reef-building organisms (e.g., sponges, Archaeolithoporella, calcimicrobes and hydrozoans) were bound, lithified and preserved by syndepositional calcite cement and microbially precipitated micrite (automicrite). In Changhsingian reefs of the Shitouzhai Limestone, microbial carbonate (e.g., micritic peloidal crusts and automicrite layers) encrusted the top, sides and undersides of in situ organisms and also grew on their upper surface as thick accumulations. Radiaxial fibrous calcite cement is present, but is not common. Abundant microbial carbonates in the Guadalupian to Lopingian reefs in Ziyun indicate that microbial precipitation of calcium carbonate played a vital role in the development of Permian reefs in this platform margin setting. (c) 2004 Elsevier B.V. All rights reserved.
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Microbial carbonates as contributors to Upper Permian (Guadalupian¿Lopingian) biostromes and reefs in carbonate platform margin setting, Ziyun County, South China
Palaeogeography Palaeoclimatology Palaeoecology, 2005Co-Authors: Jian-wei ShenAbstract:Permian (Guadalupian and Lopingian) reefs in Ziyun County, southern Guizhou, southwestern China, occur in a carbonate platform margin setting. Guadalupian reefs (Maokouan) are characterized by sponges, calcimicrobes, microbialites (as microencrusters) and syndepositional calcite cement. Global sea level falling in the latest Guadalupian changed the reef biotopes. Lower Lopingian (Wuchiapingian) deposits reflect a rapid transgressive-regressive cycle; reefs were not developed during that time, although coral biostromes are common. However, microbial carbonates occur commonly in these biostromes, including dark-coloured, homogeneous microbialite, free-growing microbes, Shamovella and Archaeolithoporella (interpreted to be problematic microbial deposits). Upper Lopingian (Changhsingian) reefs were formed by sponges, microbialites, Shamovella, Archaeolithoporella, automicrite and syndepositional calcite cement. Common primary encrustations consist of thin, homogeneous, subparallel layers of Archaeolithoporella, which is an important reef builder particularly throughout the Lopingian reef succession. Secondary encrustations are characterized by dark-coloured, homogeneous microbialite containing thin thalli that alternate with light-coloured microspar/pseudospar. Reef-building organisms (e.g., sponges, Archaeolithoporella, calcimicrobes and hydrozoans) were bound, lithified and preserved by syndepositional calcite cement and microbially precipitated micrite (automicrite). In Changhsingian reefs of the Shitouzhai Limestone, microbial carbonate (e.g., micritic peloidal crusts and automicrite layers) encrusted the top, sides and undersides of in situ organisms and also grew on their upper surface as thick accumulations. Radiaxial fibrous calcite cement is present, but is not common. Abundant microbial carbonates in the Guadalupian to Lopingian reefs in Ziyun indicate that microbial precipitation of calcium carbonate played a vital role in the development of Permian reefs in this platform margin setting. (c) 2004 Elsevier B.V. All rights reserved.
Changqun Cao - One of the best experts on this subject based on the ideXlab platform.
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Biostratigraphy constraining strontium isotopic stratigraphy and its application on the Lopingian (Late Permian)
Science China Earth Sciences, 2015Co-Authors: Xinchun Liu, Shuzhong Shen, Wei Wang, Yue Wang, Xiangdong Wang, Chen Xiaozheng, Liu Jing, Wenqian Wang, Changqun CaoAbstract:The Lopingian is one of the fastest rising periods of seawater strontium isotopic ratios (87Sr/86Sr) in earth history, and its mechanisms and increasing rates of the 87Sr/86Sr evolution were still disputed widely. These disputations among researchers were caused mainly by timeframe selection (sections’ thickness or data of radiometric ages), and different stratigraphic boundaries and un-upmost dated ages. This paper examined published 87Sr/86Sr data of the Lopingian, and projected them on timescales based on evolutionary and age constrained conodonts fossils. 87Sr/86Sr evolution vs fossil constraining timescales was re-established in this period. This research suggests: (1) 87Sr/86Sr excursion projects on fossil zones can truly support 87Sr/86Sr evolutionary pattern in the period; (2) 87Sr/86Sr evolution provides a new approach for stratigraphic research of marine carbonate sections in lieu of biostratigraphic data; (3) 87Sr/86Sr stratigraphy works on marine carbonate sections of different sedimentation rates even between different basins; (4) the 87Sr/86Sr data and its shift was dependent on samples materials and chemical treatment methods; (5) the increasing rate of marine water 87Sr/86Sr in the Late Permian is suggested as 5.4×10−5/Ma or slightly lower; (6) sedimentation age and its 87Sr/86Sr of the Lopingian marine carbonate suggested as: D PRO=259-(R S−0.70695)/5.4×10−5±1 Ma.
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High-resolution δ13Ccarb chemostratigraphy from latest Guadalupian through earliest Triassic in South China and Iran
Earth and Planetary Science Letters, 2013Co-Authors: Shuzhong Shen, Charles M Henderson, Dongxun Yuan, Hua Zhang, Vladimir I. Davydov, Changqun Cao, Samuel A. Bowring, Jonathan L. Payne, Bo Chen, Yichun ZhangAbstract:Large carbon cycle perturbations are associated with the end-Permian mass extinction and subsequent recovery, but Late Permian (Lopingian) carbon cycle dynamics prior to the mass extinction event remain poorly documented. Here we present a high-resolution δ13Ccarb chemostratigraphic framework from latest Guadalupian to earliest Triassic time, calibrated with high-resolution conodont biostratigraphy and high-precision geochronology. We observe two large negative excursions in δ13Ccarb, the first in uppermost Guadalupian strata and the second at the end of the Changhsingian stage, and between these events distinctive excursions from the middle Wuchiapingian to the early Changhsingian. The end-Changhsingian excursion represents a major reorganization of the global carbon cycle associated with the end-Permian mass extinction. However, the extent to which the end-Guadalupian and Wuchiapingian/Changhsingian boundary excursions result from local versus global controls remains unresolved. Regardless of their underlying causes, these three excursions provide chemostratigraphic markers for global correlation of Lopingian strata.
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High-resolution Lopingian (Late Permian) timescale of South China
Geological Journal, 2010Co-Authors: Shuzhong Shen, Charles M Henderson, Hua Zhang, Changqun Cao, Samuel A. Bowring, Wei Wang, Yue Wang, Yichun ZhangAbstract:The Lopingian represents the last epoch of the Palaeozoic Era and is bracketed by two severe biotic mass extinctions associated with dramatic environmental changes. The Lopingian Epoch lasted about 7 millions years and was also bracketed by large volcanic eruptions with the Emeishan volcanics at the base and the Siberian traps at the top. Considerable data have accumulated recently and in this paper we attempt to summarize these findings in a high-resolution Lopingian (Late Permian) timescale that integrates currently available multiple biostratigraphic, isotope chemostratigraphic, geochronologic and magnetostratigraphic data. In South China at least 13 conodont zones, multiple polarity zones and large carbon isotope fluctuations in the Lopingian are recognized and provide the high-resolution calibration that is essential to study this Late Permian interval characterized by Earth's largest biotic extinction. We also present a global correlation chart for the marine Lopingian Series. Copyright © 2010 John Wiley & Sons, Ltd.
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Ostracods from the Lopingian and Permian-Triassic boundary beds at the Gyanyima section in southwestern Tibet, China
Palaeoworld, 2007Co-Authors: Sylvie Crasquin-soleau, Shuzhong Shen, Changqun CaoAbstract:Ostracods are reported for the first time in the Late Permian Lopingian to earliest Triassic carbonate sequence in the Ngari region, southwestern Tibet, China. Fifty-three species are recognized, of which 19 are illustrated. One new species (Carinaknightina tibetensis n. sp.) is described and one species is renamed (Bairdia wangi n. nom.). The ostracod fauna as a whole is very similar to those in the Palaeo-Tethys and characteristic of warm water platform deposits. The Early Triassic ostracod assemblages in the section show no substantial difference from the Lopingian assemblages. The palaeoenvironments of the Late Permian and earliest Triassic appear to be open marine with normal salinity and oxygen concentration; there are no indications of anoxic conditions in the Early Triassic in the studied area. © 2007 Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier Ltd. All rights reserved.
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the carbon isotope excursion on gssp candidate section of Lopingian guadalupian boundary
Earth and Planetary Science Letters, 2004Co-Authors: Wei Wang, Changqun Cao, Yue WangAbstract:An isotopic stratigraphically well-documented outcrop in Penglaitan, Guangxi Province, South China, has been proposed as a candidate GSSP for the Lopingian–Guadalupian boundary. Correlatable outcrops from the west wing (Tieqiao section) and east wing (Penglaitan section) of the Laibin Syncline exhibit synchronous excursions in carbon isotopes. The isotopic excursions (δ13C) show the best placement of the boundary may lie at the base of Bed 6k which coincides with the Clarkina postbitteri conodont zone and with eustatic change. δ13C increases during the uppermost Guadalupian (Jinogondolella granti conodont zone from the top of 3c to the base of 6i). A δ13C peak value of 5‰ is located at the transition between these two conodont zones and is suggested as a proxy for the transition from transgression to regression. A gradual depletion of carbon isotopes occurs in the C. postbitteri zone from Bed 6e to 7b, and this gradual δ13C excursion also suggests the sequences around the Guadalupian–Lopingian boundary at the candidate section are conformable. During the middle-later C. postbitteri zone a 3.5‰ dramatic δ13C depletion is recorded at the Tieqiao section, but only a 2‰ depletion at the deeper facies Penglaitan section, synchronous with conodont zones that mark eustatic changes.
