Analyzed the geochemistry features of Caiyuanzi diabase from Dongehuan area and found that: the content of rare erath elements was much higher,w(SiO2)was 39. 19% -53.31%; w( La)/w( Sm) and w( LREE)/w( HREE) was low which showed the fractionation of light-heavy rare earth was not obvious; w( Ia)/w( Yb) was 1.90 ~4. 34 wich showed light enrichment of light rare earth; Eu was no abnormalities which showed no plagioclase fractional crystallization in the di-agenetic process; Nb and Ta was no obviously abnormalities which showed less contamination of primitive magma by crust materials. Geochemistry analysis showed obviously ocean island basalts,the formation age was at later Early Proterozoic end-eraly mesoproterozoic,and a large number of mantle matter upweliing. Dongchuan diabase should be product of continental rift extensional,massive upweliing of mantle material,asthenosphere upweliing of lithospheric tectonic background.%详细分析了东川菜园子地区辉绿岩的地球化学特征,结果表明稀土元素总量较高；w( SiO2)为39.19％～53.31％;w(La)/w( Sm)和w(LREE)/w(HREE)低,反应轻重稀士元素分馏不明显；w( La)/w( Yb)为1.90～4.34,指示轻稀土轻度富集;Eu基本无异常,说明在成岩过程中无斜长石分离结晶；未见Nb、Ta明显异常,说明原始岩浆受地壳物质混染较少.地球化学显示出明显的洋岛玄武岩特征,其形成时代在早元古代末期-中元古代早期,同期康滇地区大量地幔物质上涌.东川地区辉绿岩墙应是大陆裂谷拉张、大量地幔物质上涌、软流圈上隆的岩石圈伸展构造背景下的产物.
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