石炭纪中期（谢尔普霍夫期-巴什基尔早期）发生了一次生物多样性危机事件。虽然在这次事件中仅有24%的海洋动物属级分类单元发生灭绝，但是海洋生态发生了剧烈的变化，海洋动物的演化速率显著降低。McGhee等（2012）认为Serpukhovian生物多样性危机事件对生态系统的影响程度在显生宙的大灭绝事件中位列第五。目前的研究认为这次生物多样性危机主要跟晚古生代冰期开始有关。然而，晚古生代冰期开始的原因及其对海洋环境变化和生物危机事件的影响机制还有争议。我们将以多硫同位素和碳同位素为主要手段来重建石炭纪中期古海洋化学条件的时空变化，并结合生物地层资料，探寻这一地史时期古环境变化和海洋动物演化之间的相互作用机理。

The Mid-Carboniferous (Serpukhovian to early Bashkirian) witnessed one of most severe biotic crises over the Phanerozoic. Though only 24% of marine genera were lost in this crisis, rates of origination and extinction for marine animal dropped to low levels. This biodiversity crisis is ranked fifth in ecological impact by McGhee et al. (2012) and was attributed to the onset of the late Paleozoic ice age (LPIA). However, there are still lots of controversy over the cause of LPIA and its impact on the marine environmental changes and the biotic crises. We propose to study chemical evolution of the Mid-Carboniferous by examining multiple S-isotope and C-isotope of marine sedimentary rocks. By integrating of the geochemical data with the detailed biostratigraphy data, we aim to reconstruct paleoenvironmental changes during Mid-Carboniferous and its relation with marine animal evolution.