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基于贵州织金剖面的二叠系—三叠系界线的岩石薄片鉴定及古生物化石识别,划分出了2种碳酸盐岩沉积相、2种亚相和5种微相;有机质碳同位素组成测试结果表明晚二叠世时期有机质的δ13Corg值(-27.7‰)向早三叠世时期的δ13Corg值(-28.3‰)逐渐偏负,反映了有机质类型由高等植物向低等微生物变化的过程;全岩的δ13Crock值由晚二叠世(-24.2‰)向早三叠世(-20.9‰)变大,反映了二叠纪末期生物大灭绝事件造成了海洋生物的消失,进而引起12C在海洋中强烈富集;织金剖面二叠系与三叠系界线上下的Fe-HR/Fe-T、Fepy/Fe-HR以及微量元素V/(V+Ni)与V/(V+Cr)比值大小,反映了二叠纪末期该区域的海水为氧化环境或弱还原环境,而三叠纪初期海水处于还原作用与铁化作用,在盆地内部没有发生硫化作用;V/Ni的值从晚二叠世的0.97~1.97向早三叠世的1.67~7.33明显变大,表明水体逐渐加深的过程,该结论与沉积微相变化相符;在生物演化上,从二叠纪末期的有孔虫—藻屑—三叶虫生物组合演变到三叠纪初期小型介壳—微生物组合带,反映了二叠纪末期到三叠纪初期中国南方统一的两幕式生物灭绝与演化样式。
Based on the identification of the thin sections of the Permian-Triassic boundary line and the identification of paleontology fossils, two carbonate sedimentary facies, two subfacies and five microfacies were identified. The organic carbon isotope composition test The results show that the δ13Corg values (-27.7 ‰) of the organic matter in the Late Permian gradually degenerate to the δ13Corg values (-28.3 ‰) in the Early Triassic, reflecting the process of the organic matter type changing from higher plants to lower microorganisms. The δ13Crock value of the rocks increased from Late Permian (-24.2 ‰) to Early Triassic (-20.9 ‰), reflecting the disappearance of marine life caused by the end-Permian bio-extinction events and the subsequent rise of 12C in the oceans (Fe-HR / Fe-T, Fepy / Fe-HR) and the ratios of V / (V + Ni) to V / (V + Cr) in the Zhijin section of the Permian and Triassic boundaries , Which reflects that the seawater in this area was oxidized or weakly reduced at the end of the Permian. However, seawater was reduced and ironized in the early Triassic, and no sulfidation occurred in the basin. The V / Ni value increased from the late Permian From 0.97 to 1.97 in the world to 1.67 to 7.33 in Early Triassic, it became clear that the process of water body deepening deepened. This conclusion Which is consistent with the changes of sedimentary microfacies. From the biofacies evolution, the assemblage of foraminiferal-algal-trilobite assemblages from the end of Permian to the small Microfacies-microbial assemblages in the early Triassic, reflecting the end of Permian to the end of Tri The Double Extinction and Evolutionary Pattern of Unification of South China in Early Tillage.