上扬子古生代海相碳酸盐的锶同位素组成及主要控制因素

Based on the research of stratigraphy, analysis of sedimentary facies and sequence stratigraphy, and the controlling of diagenetic alteration of samples, in Paleozoic marine carbonate sections, Southwest China, we measured the 87Sr/86Sr ratio of carbonate rocks and fossils. And then we established the strontium isotope evolution curve for Paleozoic marine carbonate. The widely international correlation of the strontium isotope curve shows the notion of a global consistency in strontium isotope composition of marine carbonates. The various geological events, such as sedimentation, global sea level change，orogenic events, weathering rate, rifting and mass extinction controlled the strontium isotope composition and evolution of Paleozoic marine carbonates, Upper Yangtze Platform. According to the fundamental principle of strontium isotope stratigraphy, we attempted to date the boundary ages of Frasnian/Famennian and Devonian/carboniferous for Longmenshan Devonian section, to suggest the age adscription for Jiusi Formation and Shangsi Formation of Carboniferous-Permian section in Guizhou, the boundaries of middle/upper Cambrian and lower/middle Cambrian of XiouShan Cambrian section in Chongqing, and the boundaries of Devonian/carboniferous, upper/lower Carboniferous, and Carboniferous/ Permian of Majiaoba carboniferous section in Jiangyou, Sichuan. In addition, we also applied the strontium isotope stratigraphy to the research of clastic diagenesis in order to estimate the effect of marine facies and non-marine facies on diagenesis, suggesting three models of strontium isotope composition and evolution for carbonate cements in clastics from different sedimentary basins.

在地层学、沉积学及碳酸盐样品成岩蚀变研究的基础上，获取上扬子地区典型剖面古生代代表原始海水组成的锶同位素数据，建立演化曲线；研究全球事件对锶同位素组成及演化的控制作用；为沉积学、矿床学、地球化学及地层学等相关学科提供基础资料，将我国古生代锶同位素数据融合到全球锶同位素地层学数据库中，使我国海相地层锶同位素研究与国际接轨。