本项目选择川东地区石柱冷水溪剖面瓜德鲁普统-乐平统界线粘土岩作为研究对象，在对其界线粘土岩的矿物学和地球化学特征研究的基础上，进行锆石原位微区Hf-O同位素分析，揭示其源区的性质和特征；重点利用化学剥蚀热电离质谱法（CA-TIMS），对界线粘土岩开展高精度的锆石U-Pb定年工作，从而限定川东地区瓜德鲁普统-乐平统界线的绝对年龄，为地质年代表瓜德鲁普统-乐平统界线年龄的进一步修正提供数据支持，同时可以为瓜德鲁普统-乐平统生物灭绝事件与峨眉山大火成岩省的时间耦合关系这一国际地学前沿问题提供实证。

The claystones around the Guadalupian-Lopingian (G-L) boundary at Lengshuixi section in Shizhu County of eastern Sichuan area will be studied in this project. A comprehensive mineralogical, geochemical and zircon in-situ Hf-O isotopic analyses will be carried out on these claystones, in order to clarify the features of the provenances. We plan to conduct the high resolution geochronological investigations into the claystones at the G-L boundary by the Chemical Abrasion-Thermal Ionization Mass Spectrometry (CA-TIMS) method, so as to constrain the age of G-L boundary of eastern Sichuan area. This proposal not only provides the high resolution geochronological data to further constrain the G-L boundary age for the International Chronostratigraphic Chart, but also offers the direct evidence to the temporal relationship between the G-L mass extinction and the Emeishan large igneous province.