广东阳春盆地锡山岩体岩石地球化学、年代学和氧逸度特征及其对锡成矿作用的制约

发布时间：2018-11-03 18:22

【摘要】：南岭地区以富集有色金属和稀有金属矿产以及与此有关的多旋回、多成因的花岗岩著称。本文从岩相学、岩石化学、微量元素、稀土元素地球化学、年代学和氧逸度特征等方面研究了锡山岩体,讨论了锡矿化与花岗岩岩体的成因联系、氧逸度特征对锡成矿的影响。锆石U-Pb定年的结果表明,锡山岩体和马水龙田岩体分别侵位于80Ma和77Ma。通过主微量元素和稀土元素特征对比,说明锡山岩体和马水龙田岩体具有同源同演化特征。有充分的证据表明,锡山岩体为陆壳部分熔融的岩浆演化到晚阶段的产物,锡矿化与黑云母花岗岩有直接的成因联系,矿化发生在岩浆期后气化-高温热液阶段。锡山岩体黑云母所代表的氧逸度低于Ni-NiO线,锆石Ce~(4+)/Ce~(3+)比值为7.48~77.37,平均值为26.63,与南岭地区其他含锡花岗岩的比值类似。这些氧逸度特征表明,锡山岩体属于还原性花岗岩体,低氧逸度和云英岩化对锡的富集成矿产生了积极的作用。
[Abstract]:Nanling area is famous for its enrichment of non-ferrous and rare-metal minerals and associated polycyclic and polygenetic granites. In this paper, the authors have studied the Xishan rock body from the aspects of petrography, petrochemistry, trace elements, geochemistry of rare earth elements, geochronology and oxygen fugacity characteristics, and discussed the genetic relationship between tin mineralization and granite rock mass, and the influence of oxygen fugacity characteristics on tin mineralization. The results of zircon U-Pb dating indicate that the Xishan and Mashilongtian intrusions are located at 80Ma and 77 Ma, respectively. By comparing the characteristics of main trace elements and rare earth elements, it is shown that the Xishan and Mashuilongtian rock bodies have the same evolution characteristics. Sufficient evidence indicates that the Xishan rock body is the product of magma evolution from partially melting continental crust to the late stage. Tin mineralization is directly related to biotite granite, and mineralization occurs in the post-magmatic stage of gasification and high temperature hydrothermal stage. The oxygen fugacity of biotite in Xishan rock body is lower than that of Ni-NiO line. The ratio of zircon Ce~ (4) / Ce~ (3) is 7.48 ~ 77.37, with an average value of 26.63, which is similar to that of other tin bearing granites in Nanling area. These oxygen fugacity characteristics indicate that the Xishan rock body belongs to the reductive granite body and the low oxygen fugacity and the dolomization play a positive role in the enrichment and mineralization of tin.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.44

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