华北板块二叠纪—三叠纪之交火山活动驱动的湖泊缺氧OA

The Siberian Traps volcanism at the Permian-Triassic boundary(PTB),which triggered the end-Permian mass extinction,not only fundamentally restructured marine ecosystems but also profoundly impacted terrestrial ecosystems.To elucidate the coupling between PTB volcanism,terrestrial ecosystem collapse,and lacustrine anoxia,this study investigates lacustrine sediments from the Sunjiagou and Liujiagou formations in the WY-U-01H core(Xiangyuan coalfield,Qinshui basin,North China Plate),employing high-resolution geochemical proxies,including P/Al,V/(V+Ni),V/Cr,and Ni/Co ratios.The results reveal pronounced lacustrine anoxia events in the upper Sunjiagou to lower Liujiagou formations,as indicated by mean values of V/(V+Ni)=0.8,V/Cr=2.8,and Ni/Co=7.2.These events coincide with elevated P/Al ratios,which 2～3 times background values,indicating a strong link between anoxia and enhanced paleoproductivity.These geochemical anomalies are synchronous with global PTB phenomena—including negative carbon isotope excursions,terrestrial/marine extinctions,Hg-Ni anomalies,and volcanic CO2 surges—supporting the hypothesis that Siberian Traps eruptions triggered lacustrine anoxia and productivity spikes via multipronged mechanisms(e.g.,greenhouse gas release,climate warming,and nutrient influx).This study provides critical evidence for volcanism-driven terrestrial environmental changes during the PTB transition,offering insights into predicting modern aquatic deoxygenation under global warming.