中国寒武纪晚期SPICE事件期间不同相区古海洋环流和海水化学特征以及生物响应：来自碳-硫同位素的证据

寒武纪晚期SPICE碳同位素正漂移事件是一次显著的生物、环境与气候事件。本项目通过对我国华南浙江、湖南和华北山东、河北等地不同沉积相区上寒武统地层剖面和SPICE事件进行系统的沉积地球化学研究，重点开展高分辨率的碳-硫同位素并辅以主微量元素、草莓状黄铁矿和沉积岩相学分析，重建SPICE事件期间不同相区海水碳-硫同位素组成的同步变化和氧化还原状态的变化，探究海洋碳-硫循环、古海洋环流和海水氧化还原状态的时空演变特征。结合前人发表成果，从全球视角探讨SPICE事件期间海洋环境与生物演化之间的耦合关系。此外，本项目通过改进和优化前处理实验方法，除测试全岩晶格硫同位素（CAS）外，还尝试性测试晶体黄铁矿硫同位素和草莓状黄铁矿硫同位素值，并探讨它们的分馏机制，为拓宽硫同位素在环境地球化学的应用提供新思路。

The Steptoean positive carbon isotope excursion (i.e. SPICE) is a significant biological, environmental and climatic event in the late Cambrian. Our project intends to carry out sedimentary geochemical study of the Late Cambrian SPICE event in different facies of South China (e.g., Zhejiang and Hunan) and North China (e.g., Shandong and Hebei), including high-resolution analysis of carbon-sulfur isotopes, major and trace elements, pyrite framboid as well as petrographic studies, in order to reconstruct carbon-sulfur isotope composition and seawater redox conditions at different facies on the continental margin, and explore the spatio-temporal evolutions of carbon-sulfur cycles, seawater redox conditions and paleo-oceanic circulations during the SPICE event. Combined with previous published data, we try to reveal coupling relationship between oceanic environmental changes and biological evolution in a global perspective. Moreover, based on improvement and optimization of sulfur isotope experimental method, sulfur isotopes of carbonate associate sulfate, crystal pyrite and pyrite framboid were analyzed and their fractionation mechanisms were explored. It will finally provide new ideas for broadening the application of sulfur isotopes in environmental geochemistry.