中文摘要：

为了深入探讨扬子地块西南缘的玉凤和巴马辉绿岩是否受到峨眉山地幔柱活动的影响,对其进行了主量元素、微量元素及锆石 U-Pb 年龄测定。结果表明,它们属于钙碱性系列和高钾钙碱性系列,具高铝低镁特征,轻稀土富集,Ti/Y＆gt;500、Nb/La=0.75～0.85、Th/Ta=1.75～2.38、Ta/H〉0.1；锆石 LA-ICP-MS U-Pb 年龄分别为255.3±3.9 Ma 和257.6±2.9 Ma。初步认为,它们可能源自亏损地幔并受到少量地壳物质的混染作用,且均显示出大陆板内玄武岩的特征,应为峨眉山玄武质岩浆活动的产物。

英文摘要：

To reveal whether or not Emeishan mantle plume had effects on Yufeng and Bama diabases,which locate at the southwest margin of the Yangtze block,this article tested major element contents,trace element abundances and ages of the diabases.The result showed that the diabases are calc-alkali or high potassium calc-alkali,charac-terized by high Al content and low Mg content,LREE-enriched,Ti/Y〉500,Nb/La=0.75--0.85,Th/Ta=1 .75--2.38,Ta/Hf〉0.1 .The LA-ICP-MS zircon U-Pb age results indicated that Yufeng and Bama diabases were e-rupted at 255.3＆#177;3.9 Ma and 257.6＆#177;2.9 Ma,respectively.We believe that they probably derived from depleted mantle with minor crust material contamination and belonged to continental intraplate basalts,and therefore, should be products of the Emeishan basaltic magma.