豫西荥阳P?Tr之交孙家沟组沉积环境及古气候变化

荥阳万山地区出露的孙家沟组陆源碎屑岩沉积，保存了丰富的二叠纪—三叠纪之交陆相沉积记录，有助于探究二叠纪末生物大灭绝事件前后陆相沉积环境和古气候的变化规律。在实测野外地质剖面的基础上，结合传统岩性分析、粒度分析、沉积相分析和微量元素地球化学分析，综合分析了研究区孙家沟组的沉积环境及其古气候变化特征。结果表明:孙家沟组主要为早中期的河流沉积过渡为三角洲平原亚相和三角洲前缘亚相的陆相浅水富氧沉积环境；孙家沟组沉积期的古气候主要为温暖湿润，前期出现了几次干热变化，且整个沉积期风化剧烈。

Sedimentary Environment and Paleoclimate Variations of the Sunjiagou Formation at the P-Tr Boundary in Xingyang Area,Western Henan Province

The terrestrial clastic rocks of the Sunjiagou Formation exposed in the Wanshan area， Xingyang， preserve the continental sedimentation at the Permian?Triassic boundary， which is helpful for studying the changes of continental sedimentary environment and paleoclimate at the mass extinction at that time. This comprehensive study is based on measurements of geological profiles of the sedimentary environment and paleoclimatic changes in the Sunjiagou Formation， combining traditional lithological analysis， grading analysis， sedimentary facies analysis and trace element geochemical analysis. It is concluded that the sedimentary environment of the Sunjiagou Formation was mainly fluvial in the early and middle period， then was transformed into a continental shallow-water oxygen-rich environment of delta plain and delta front subfacies. The paleoclimate of the Sunjiagou Formation was warm and humid， with several dry and hot changes occurring in the middle， and severe weathering of the whole formation.