中国西南地区中-晚二叠世峨眉山大陆溢流玄武岩（ELIP）是被国际研究者广泛认可的大火成岩省之一，其涉及地球内部运行机制和过程、资源成矿作用和生物环境效应等多个地学前沿领域，具有重要的科学研究意义。ELIP喷发形式和喷发持续时间的精确确定对于揭示峨眉山玄武岩喷发所蕴含的全球气候变化和确定其与End-Guadalupian生物大灭绝之间的相关性具有重要指示作用。但到目前为止，这一重要问题并未得到很好限定。本项目拟通过峨眉山玄武岩各熔岩流所记录的瞬时古地磁场方向，结合古地磁场长期变化规律，确定峨眉山玄武岩的喷发形式和净喷发持续时间（不包括>500年的火山休眠期）；并将地心轴向偶极子场假说与磁性地层学研究相结合，确定峨眉山玄武岩的总喷发持续时间（包括火山休眠期）。这将为峨眉山大火成岩省研究提供一个精确的喷发时限年代结果，有效解决了其他方法对较短岩浆喷发持续时间（万年数量级）限定的缺陷。

The Emeishan continental flood basalts (ELIP) in southwestern China is widely recognized as one of the large igneous provinces by the international geosciences community. It is of great scientific research significance for its involving the working mechanism and process of Earth’s interior, the resource enrichment and mineralization, and the evolution of biology and environments. The form and the precise duration of the ELIP eruption are important to determine its impact on the environment and its relationship with the End-Guadalupian biological mass extinction. However, they remain poorly constrained yet. In this project, based on the regularity of the geomagnetic field long-term variation, we intend to estimate the form and the net duration (excluding quiescent intervals which >500 years) of the eruption by analyzing the instantaneous geomagnetic directions recorded by lava flows. And according to the GAD (the geocentric axial dipole) analyses and the magnetostratigraphic study, we intend to estimate the total duration (including intervals of volcanic quiescence) of the ELIP eruption. That will provide superior precise duration results for the ELIP, which effectively solved the defects of other methods that is not available to limit a shorter magma erupting duration.