近期对科马提岩以及许多大火成岩省中的苦橄岩进行的水含量分析以及地幔潜能温度的研究表明，无论是太古宙还是显生宙的大火成岩省的形成都和含水的地幔柱有关。晚二叠纪的峨眉山大火成岩省（ELIP）位于扬子克拉通西缘，目前主流观点认为其是由地幔柱形成的。前人根据大量的岩石地球化学工作将ELIP分为西区、中区和东区；证明了位于西区的大理、宾川的苦橄岩和玄武岩地幔源区的水含量高于2500×10-6。然而对于其他区域玄武岩源区的含水性还不清楚。文章以位于中区的二滩剖面底部高钛型玄武岩为研究对象，采用单斜辉石斑晶反演的方法研究恢复了其原始岩浆的水含量。结果表明，单斜辉石斑晶水含量范围为76×10-6 ~424×10-6, 对应的平衡熔体水含量为3.01 wt%。在考虑分离结晶影响后，恢复的原始岩浆水含量达到2.71±0.95 wt%。该水含量略低于大理苦橄岩水含量，与宾川苦橄岩相当。而计算的地幔源区水含量最低估计为1357×10-6，该值低于大理、宾川苦橄岩的源区水含量，但仍显著高于正常洋中脊玄武岩和洋岛玄武岩源区。ELIP中不同区域的苦橄岩和玄武岩都存在高水含量，这表明在ELIP的形成和演化过程中水都扮演了很重要的角色。
Recent research on the water content and mantle potential temperature of komatiites and picrites has found that the genesis of both Archaean and Phanerozoic large igneous provinces is related to hydrous mantle plume. The Late Permian Emeishan large igneous provinces (ELIP) is located in the western margin of the Yangtze craton in SW China, which is also considered as the effect of mantle plume. ELIP was divided into western zone, middle zone and eastern zone based on the work of geology and geochemistry in previous study. The previous study on the water contents for the picrites and basalts from Dali and Binchuan demonstrated that the water content in the mantle source in the western zone is higher than 2500×10-6. However, the water content of source in other zones is still not clear, which makes it difficult to understand the role of water in the genesis of ELIP. Here, we estimated the water content of the mantle source of the high-Ti basalts in the lower part of Ertan sesstion, in the middle zone of ELIP, by the mothed of clinopyroxene phenocrysts. The result shows that the H2O content of clinopyroxene phenocrysts is 76×10-6-424×10-6, and the H2O content of the corresponding melt is 3.01 wt%. Considering the effect of fractional crystallization of minerals, the H2O content of primary magma is estimated to be 2.71±0.95 wt%, which is slightly lower than that of Dali picrites, and similar to that of Binchuan picrites. The estimated H2O content in mantle source of Ertan high-Ti basalts is 1357×10-6, which is lower than that of Dali and Binchuan picrites, but significantly higher than that of mid-ocean ridge basalts and ocean island basalts. The high H2O content of basalts and picrites in different areas in ELIP thus indicates that water plays an important role in both the genesis and the evolution of ELIP.
