Abstract Severe global climate change is proposed to be the major cause of the Permian-Triassic boundary (PTB) mass extinction, while details about the response process are still in debate. In this study, we present geochemical and pyrite morphological data from an Upper Permian-Lower Triassic shale succession in the Western Hubei Trough, northern South China. The stratigraphic evolutions of paleoclimate, paleoredox condition and paleosalinity are analysed. Our data support that regional tectonics, collision of the South China Craton and the North China Craton, may have played a major role in hydrographic and redox evolution of the Western Hubei Trough, suggesting anoxia may not be a worldwide cause of marine PTB biocrisis. On the other hand, an extensive comparison between marine and terrestrial successions supports that global warming in the Late Permian may have induced enhanced supply of freshwater to the ocean and the flooding of seawater across the boundary between marine and fresh to brackish waters due to sea-level rise, leading to dilution of seawater, while global cooling in the Permian-Triassic transition may have induced reduced supply of freshwater to the ocean, leading to increase of seawater paleosalinity. On the land, both global and regional climate changes may have controlled the freshwater supply to water bodies, leading to fluctuation of watermass paleosalinity. Our data support that anomalous changes of watermass paleosalinity triggered by paleoclimate changes may have played a role in the PTB biocrisis.

中文翻译：

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二叠纪—三叠纪过渡时期（鄂西地区、华南地区）古气候古海洋演化及其地质意义

摘要 严重的全球气候变化被认为是二叠纪-三叠纪边界（PTB）大灭绝的主要原因，而有关响应过程的细节仍在争论中。在本研究中，我们提供了华南北部湖北海槽上二叠统-下三叠统页岩序列的地球化学和黄铁矿形态数据。分析了古气候、古氧化还原条件和古盐度的地层演化。我们的数据支持区域构造，华南克拉通和华北克拉通的碰撞，可能在鄂西海槽的水文和氧化还原演化中发挥了重要作用，表明缺氧可能不是海洋 PTB 生物危机的全球性原因。另一方面，海洋和陆地演替之间的广泛比较表明，二叠纪晚期的全球变暖可能导致海洋淡水供应增加，以及由于海平面上升导致海水泛滥越过海洋和淡水到咸水之间的边界，导致海水稀释，而二叠纪-三叠纪过渡期的全球变冷可能导致海洋淡水供应减少，导致海水古盐度增加。在陆地上，全球和区域气候变化可能控制了水体的淡水供应，导致水团古盐度的波动。我们的数据支持古气候变化引发的水团古盐度异常变化可能在 PTB 生物危机中发挥了作用。