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    邹滔, 王京彬, 王玉往, 龙灵利. 新疆克拉玛依岩体的岩浆混合作用成因:岩石地球化学证据[J]. 中国地质, 2011, 38(1): 65-76.
    引用本文: 邹滔, 王京彬, 王玉往, 龙灵利. 新疆克拉玛依岩体的岩浆混合作用成因:岩石地球化学证据[J]. 中国地质, 2011, 38(1): 65-76.
    ZOU Tao, WANG Jing-bin, WANG Yu-wang, LONG Ling-li. Magma mixing in the Karamay rock body of west Junggar,Xinjiang: evidence from geochemistry[J]. GEOLOGY IN CHINA, 2011, 38(1): 65-76.
    Citation: ZOU Tao, WANG Jing-bin, WANG Yu-wang, LONG Ling-li. Magma mixing in the Karamay rock body of west Junggar,Xinjiang: evidence from geochemistry[J]. GEOLOGY IN CHINA, 2011, 38(1): 65-76.

    新疆克拉玛依岩体的岩浆混合作用成因:岩石地球化学证据

    Magma mixing in the Karamay rock body of west Junggar,Xinjiang: evidence from geochemistry

    • 摘要: 提要:新疆西准噶尔地区克拉玛依花岗质岩体中发育大量闪长质微粒包体,并形成有岩浆混合成因的岩浆混合岩——石英闪长岩。包体成分主要为闪长质,显微镜下具有岩浆岩结构,岩浆混合特征十分明显,如:针状磷灰石,角闪石包裹辉石残晶,长石斑晶的溶蚀环带等特征。岩体中寄主岩石、岩浆混合岩、闪长质微粒包体、闪长玢岩脉分别代表岩浆混合演化过程中两端元岩浆按不同比例混合的产物。在岩石地球化学方面,包体与寄主岩石的主要氧化物之间具有良好的线性关系,寄主岩石和包体的稀土元素配分曲线和微量元素蛛网图形态相似;各种地球化学元素参数特征显示,寄主岩石与包体在岩石形成过程中发生过成分交换及均一化。特征元素比值及同位素等特征表明,闪长质包体的端元岩浆可能为幔源基性岩浆,寄主岩石的端元岩浆可能是以壳源为主的酸性岩浆。岩石地球化学特征进一步佐证了该区岩浆混合作用的存在,同时也暗示岩浆混合作用可能是新疆北部后碰撞过程中重要的岩浆活动形式。

       

      Abstract: Abstract:The Karamay intrusive body in west Junggar of Xingjiang is associated with abundant dioritic microgranular enclaves and magma mixed rock of quartz diorite. Under microscope, the enclaves consist mainly of diorite and are of magmatic texture. The enclaves exhibit excellent evidence for magma mixing and mingling, such as long prisms of apatite, malcrystalline augite wrapped in hornblende, and etched girdle of feldspar. Host rocks, magma mixed rocks, dioritic microgranular enclaves and diorite porphyrite dykes of the Karamay rock body are products of different proportions of magma mixing. Geochemically, the major oxide content of the dioritic enclaves, magma mixed rocks and their host rocks all have the same linear trends in the plot. The patterns of REE and trace elements and isotopic signatures of the dioritic enclaves and magma mixed rocks are similar to those of the host granites. Exchanges of elements occurred between the enclaves and the host rocks and almost reached equilibrium. The ratios of characteristic elements and isotopic signatures show that the source rock of the dioritic enclaves is the mantle-derived basic magma, and that the host rock is the crust-derived acidic rock. The geochemical characteristics of the rock further prove the existence of magma mixing in the Karamay rock body, suggesting that the magma mixing was an important style of post-collisional magmatism in northern Xinjiang.

       

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