The transition between Permian and Triassic(252.4 Ma) is marked by the most devastating extinction the biosphere ever went through.Although its cause stays unclear,it is admitted that this mass extinction originated i...The transition between Permian and Triassic(252.4 Ma) is marked by the most devastating extinction the biosphere ever went through.Although its cause stays unclear,it is admitted that this mass extinction originated in the conjunction of several global events: tectonic(Pangaea closing),volcanic(Siberian traps), magnetic(reversal of superchron),climatic(end of Permian glaciation) and eustatic(tecto-and ther-展开更多
In the South Yellow Sea Basin,Mesozoic–Paleozoic marine strata are generally well developed with large thickness,and no substantial breakthroughs have been made in hydrocarbon exploration.Through research,it is belie...In the South Yellow Sea Basin,Mesozoic–Paleozoic marine strata are generally well developed with large thickness,and no substantial breakthroughs have been made in hydrocarbon exploration.Through research,it is believed that the Upper Permian–Lower Triassic can be regarded as a long-term base-level cycle.Based on drilling data,characteristics of the lithology–electric property combination cyclicity,and the special lithology,the long-term base-level cycle was divided into five medium-term base-level cycles(MC1–MC5).On this basis,the Permian–Triassic sedimentary systems and their filling model were analyzed in accordance with the change of base-level cycle and transition of sedimentary environment,as well as characteristics of the drilling sedimentary facies and seismic facies.The results show that there were six sedimentary systems(fluvial,delta,tidal flat,open platform,restricted platform,and continental shelf)developed in the Upper Permian–Lower Triassic,the sedimentary systems were distributed such that the water was deep in the northwest and shallow in the southeast,and there were two base-level cycle filling models(a relatively stable tidal flat facies and a rapidly transgressive continental shelf facies to stable platform facies)developed in the Upper Permian–Lower Triassic.These models can provide a basis for evaluation of the Mesozoic–Paleozoic hydrocarbon geology in the South Yellow Sea Basin.展开更多
An objection has been lodged against the traditional P/C boundary which were still upholded by International Subcommission on Permian Stratigraphy, International Commission on Stratigraphy, IUGS. And the rationality t...An objection has been lodged against the traditional P/C boundary which were still upholded by International Subcommission on Permian Stratigraphy, International Commission on Stratigraphy, IUGS. And the rationality to take the base of the Montiparus Zone as the P/C boundary is comprehensively demonstrated.展开更多
二叠纪末生物大灭绝(The end-Permain mass extinction, EPME)作为全球地质历史时期最大的灭绝事件,导致了约75%的陆生物种和约81%的海生物种的灭绝,全球范围内的陆生植被、昆虫和陆地四足脊椎动物历经了快速和毁灭性的打击,显著灭绝的...二叠纪末生物大灭绝(The end-Permain mass extinction, EPME)作为全球地质历史时期最大的灭绝事件,导致了约75%的陆生物种和约81%的海生物种的灭绝,全球范围内的陆生植被、昆虫和陆地四足脊椎动物历经了快速和毁灭性的打击,显著灭绝的海洋物种包括■、三叶虫、棘皮动物和珊瑚等,大部分灭绝或者被替代的物种包括腕足类、双壳类、放射虫、有孔虫和菊石等,EPME生物灭绝具有区域性、选择性和阶段性等特点。西伯利亚大火成岩省(the Siberian large ignous province, SLIP)的爆发与EPME时间高度耦合,SLIP及其连带的一系列次生事件被认为是EPME的主要驱动力,同时也是滞缓生物复苏的主要因素。海洋缺氧、海水升温等部分次生事件的持续时间、强度和区域分布仍存争议,且单一次生事件不能独立支撑EPME,EPME是多个因素综合叠加作用的结果。SLIP爆发促使埋藏在内陆盆地和大陆架沉积物中的温室气体向大气圈大量释放,全球气候快速变暖导致陆地危机先行发生,极端干旱天气促进了森林野火的频发和陆地生态系统的崩溃;大陆风化加剧使得大量碎屑注入海洋造成严重的富营养化、海底生物缺氧、海洋酸化和海洋古生产力紊乱等,致使海洋灭绝事件的发生,陆地灭绝的滞后性导致陆地危机的结束时间晚于海洋灭绝事件。二叠纪末全球性的环境突变对地球生态系统产生了巨大的影响,通过综述EPME演变过程,深入探讨引起生物大灭绝的原因,对了解二叠纪末全球生态系统崩溃和预测今后类似地质事件的发生具有重要意义。展开更多
在20世纪90年代,有学者认为峨眉山大火成岩省(Emeishan Large Igneous Province,ELIP)大规模火山活动与二叠-三叠系之交(Permian-Triassic Boundary,P-TB)的生物大灭绝事件在时间上有耦合关系,随后的40Ar/39Ar同位素测年结果也显示峨眉...在20世纪90年代,有学者认为峨眉山大火成岩省(Emeishan Large Igneous Province,ELIP)大规模火山活动与二叠-三叠系之交(Permian-Triassic Boundary,P-TB)的生物大灭绝事件在时间上有耦合关系,随后的40Ar/39Ar同位素测年结果也显示峨眉山大火成岩省是晚二叠世形成的。但是,近些年大量的SHRIMP U-Pb测年结果表明,ELIP大规模火山喷发约在～260Ma;因此有研究认为,ELIP火山活动与中二叠世瓜德卢普期末(end-Guadalupian)的生物灭绝事件在时间上联系更加紧密。至于P-T界线生物大灭绝,现在多数学者认为是,由于西伯利亚大火成岩省火山强烈活动释放大量气体和火山灰所造成环境变化引起的。最近,我们在ELIP东部的贵州盘县峨眉山玄武岩系剖面中发现顶部发育厚度达近百米的凝灰岩层,其LA-ICP-MSU-Pb法测年结果为251.0±1.0Ma,与浙江煤山剖面中二叠系-三叠系边界处黏土层或火山灰层的锆石U-Pb年龄接近。因此,峨眉山玄武岩喷发结束的时间应该在P-T边界,与西伯利亚大火成岩省的主体喷发时间一致。新的测年结果暗示了ELIP火山活动与地球历史上最大的一次生物灭绝事件(P-T边界)可能存在着成因联系。展开更多
文摘The transition between Permian and Triassic(252.4 Ma) is marked by the most devastating extinction the biosphere ever went through.Although its cause stays unclear,it is admitted that this mass extinction originated in the conjunction of several global events: tectonic(Pangaea closing),volcanic(Siberian traps), magnetic(reversal of superchron),climatic(end of Permian glaciation) and eustatic(tecto-and ther-
基金Projects(41506080,41702162)supported by the National Natural Science Foundation of ChinaProjects(DD20160152,DD20160147,GZH200800503)supported by China Geological Survey+1 种基金Projects(XQ-2005-01,2009GYXQ10)supported by China Ministry of Land and ResourcesProject(201602004)supported by the Postdoctoral Innovation Foundation of Shandong Province,China
文摘In the South Yellow Sea Basin,Mesozoic–Paleozoic marine strata are generally well developed with large thickness,and no substantial breakthroughs have been made in hydrocarbon exploration.Through research,it is believed that the Upper Permian–Lower Triassic can be regarded as a long-term base-level cycle.Based on drilling data,characteristics of the lithology–electric property combination cyclicity,and the special lithology,the long-term base-level cycle was divided into five medium-term base-level cycles(MC1–MC5).On this basis,the Permian–Triassic sedimentary systems and their filling model were analyzed in accordance with the change of base-level cycle and transition of sedimentary environment,as well as characteristics of the drilling sedimentary facies and seismic facies.The results show that there were six sedimentary systems(fluvial,delta,tidal flat,open platform,restricted platform,and continental shelf)developed in the Upper Permian–Lower Triassic,the sedimentary systems were distributed such that the water was deep in the northwest and shallow in the southeast,and there were two base-level cycle filling models(a relatively stable tidal flat facies and a rapidly transgressive continental shelf facies to stable platform facies)developed in the Upper Permian–Lower Triassic.These models can provide a basis for evaluation of the Mesozoic–Paleozoic hydrocarbon geology in the South Yellow Sea Basin.
文摘An objection has been lodged against the traditional P/C boundary which were still upholded by International Subcommission on Permian Stratigraphy, International Commission on Stratigraphy, IUGS. And the rationality to take the base of the Montiparus Zone as the P/C boundary is comprehensively demonstrated.
文摘二叠纪末生物大灭绝(The end-Permain mass extinction, EPME)作为全球地质历史时期最大的灭绝事件,导致了约75%的陆生物种和约81%的海生物种的灭绝,全球范围内的陆生植被、昆虫和陆地四足脊椎动物历经了快速和毁灭性的打击,显著灭绝的海洋物种包括■、三叶虫、棘皮动物和珊瑚等,大部分灭绝或者被替代的物种包括腕足类、双壳类、放射虫、有孔虫和菊石等,EPME生物灭绝具有区域性、选择性和阶段性等特点。西伯利亚大火成岩省(the Siberian large ignous province, SLIP)的爆发与EPME时间高度耦合,SLIP及其连带的一系列次生事件被认为是EPME的主要驱动力,同时也是滞缓生物复苏的主要因素。海洋缺氧、海水升温等部分次生事件的持续时间、强度和区域分布仍存争议,且单一次生事件不能独立支撑EPME,EPME是多个因素综合叠加作用的结果。SLIP爆发促使埋藏在内陆盆地和大陆架沉积物中的温室气体向大气圈大量释放,全球气候快速变暖导致陆地危机先行发生,极端干旱天气促进了森林野火的频发和陆地生态系统的崩溃;大陆风化加剧使得大量碎屑注入海洋造成严重的富营养化、海底生物缺氧、海洋酸化和海洋古生产力紊乱等,致使海洋灭绝事件的发生,陆地灭绝的滞后性导致陆地危机的结束时间晚于海洋灭绝事件。二叠纪末全球性的环境突变对地球生态系统产生了巨大的影响,通过综述EPME演变过程,深入探讨引起生物大灭绝的原因,对了解二叠纪末全球生态系统崩溃和预测今后类似地质事件的发生具有重要意义。
文摘在江西修水四都镇东岭村发现了一个连续的、出露完好的二叠纪-三叠纪界线地层剖面。在剖面中有一段厚约2.1m 的地层具有指示海平面下降的岩石组构。这段地层的底部为红色的碳酸盐颗粒岩。红色是颗粒表面的红色铁染,成分为褐铁矿,是出露地表风化形成的。这层红色颗粒岩之上有约2.0 m 的去白云石化灰岩,其中保留了原来粉晶白云石的晶形。去白云石化作用是白云岩受淡水影响而发生的,指示海平面下降事件。这段地层之上是厚1m 的颗粒岩和灰泥岩,代表浅水潮下环境。其上是二叠系-三叠系的界线。这段地层之下的地层中生物丰富多样,并且有复(蜒)、钙藻等大绝灭前的生物。这段地层及其以上的地层中生物种类很少,(蜓)、钙藻等已经消失,表明集群绝灭事件开始于这段地层之下,生物大绝灭的发生与海平面下降事件的发生是基本同时的。由此认为,可能是海平面下降有关的环境剧变事件引发了二叠纪末的集群绝灭事件。
