西秦岭温泉花岗岩体岩浆混合作用的地球化学信息  

THE GEOCHEMICAL INFORMATION OF THE MAGMA MIXING FROM THE WENQUAN GRANITE IN THE WESTERN QINLING

作　　者：李永军[1] 刘社华[1] 李注苍[1] 李英[1] 

机构地区：[1]长安大学地球科学与国土资源学院,西安710054

出　　处：《地质与勘探》2003年第6期33-36,共4页Geology and Exploration

基　　金：中国地质调查局地质调查项目(编号:20001300010171)资助。

摘　　要：西秦岭温泉岩体是壳、幔岩浆混合的产物。寄主岩石属铝过饱和钙碱性系列,贫CaO富FeOtot,ANKC值大于1.1,NK/A值均小于0.9,富Mo、Sn、Bi、W等高温热液成矿元素及Co、Ni、Cr等亲铁元素,LREE/HREE为10～15。基性端元暗色微细粒镁铁质包体及基性岩墙,富Na2O、K2O,而贫FeOtot,异常富集轻稀土和Ba、Rb、Sr、Zr、Th、Hf、Nb等大离子亲石元素,而贫Co、Ni、Cr等亲铁元素,LREE/HREE为9.98～13.5,异常富轻稀土。由两端元岩浆混合形成的岩浆混合暗色花岗岩,地球化学特征介于两端元间,并有显著的过渡特征、双扩散性、均一化和依从关系,反映了重要的岩浆混合信息。The Wenquan granite in the western Qinling is the product of the mixing of crust and mantle magmas, and belongs to the aluminum super-saturation and calc-alkali series. The host rocks are characterized by poor in CaO, rich in FeOtot with the ANKC more than 1.1 and the NK/A lower than 0.9, and higher hypothermal metallogenic elements such as Mo, Sn and Cr. The basic mafic magmatic elements have rich in Na2O、K2O and poor in FeOtot, and rich in such as Ba,Rb,Sr,Zr,Th,Hf and Nb, but have poorer siderophile elements. The abnormal distribution of the trace elements indicates the noticeable exchanging and complying between these two. The ratio of LREE/HREE is 10～15 in host rocks, and 9.98～13.5 in basic parts because of the magmas mixing, and the intensively migmatized monzonitic granite shows the remarkable transition between crust and mantle.

关 键 词：花岗岩体 地球化学 岩浆混合 温泉 岩石化学特征 

分 类 号：P58[天文地球—岩石学] P632[天文地球—地质学]