湖南省双峰县大坪铷矿地球化学特征及成矿作用  

Geochemical Features and Mineralization of the Daping Rubidium Ore Deposit in Shuangfeng County,Hunan Province

作　　者：文春华[1,2] 张进富 肖冬贵 蒙正勇 林碧海 于玉帅 

机构地区：[1]中南大学地球科学与信息物理学院,长沙410083 [2]湖南省地质调查院,长沙410116 [3]中国地质调查局武汉地质调查中心,武汉430205 [4]中国地质调查局花岗岩成岩成矿地质研究中心,武汉430205

出　　处：《地质科技情报》2017年第6期94-103,共10页Geological Science and Technology Information

基　　金：国家重点研究发展计划"深地资源勘查开采"重点专项(2017TFC0602402;2016YFC0600205);湖南省自然科学基金项目(2017JJ3138);中国地质调查局调查项目(DD20160056);湖南地质矿产勘查开发局科研项目(201703-02)

摘　　要：大坪铷矿位于湖南省双峰县紫云山岩体中,铷矿体呈近东西向条带状产于紫云山复式花岗岩体顶部,是一处富铷花岗岩型稀有金属矿床。白云母花岗岩地球化学研究表明:主量元素具高SiO_2(73.27%~74.72%)、高分异指数DI(86.83~93.28),和高铝饱和指数(A/CNK=1.55~1.76),为高分异花岗岩及过铝质岩石,具较低的MgO(0.01%~0.36%)和TiO_2(0.01%~0.16%);微量元素富集Rb、Ta和Nb而强烈亏损Sr、Ba和Ti;稀土元素总量较低[w(∑REE)=8.24×10^(-6)~124.44×10^(-6)],具显著铕负异常(δEu=0.09~0.33),稀土元素配分图出现"M"型四分组效应。地球化学特征反映出紫云山复式花岗岩经历了高程度的分异演化过程,并在岩浆演化到晚期阶段F、H_2O等挥发分逐渐富集,由于F与稀有金属元素有较强的亲和力,形成络合物一起迁移和富集,当岩浆演化到晚期发生了熔体-流体不混溶作用稀有金属配合物被破坏,铷以类质同像形式在白云母花岗岩中富集成矿。Daping Rb ore deposit, the EW direction banding Rb ore body located at the top of Ziyunshan rock in Shuangfeng, Hunan Province, is a Rb rich rare metal deposit. The geochemical characteristics of muscovite granite are as follows., major elements with high contents of SiO2 （73.27%-74. 72%）, DI（86. 83-93.28） and A/CNK（1.55-1.76）, extremely low contents of MgO （0. 01%-0. 36%） and TiO2 （0. 01%-0.16%）. The major elements show that muscovite granite is highly evolved granites and peralumi- nous rocks. Trace elements are low ∑REE（8.24 × 10-6 -124. 44× 10-6） contents, with significantly Eu （δEu=0. 09-0. 33） anomalies and M-type tetrad effects. They are strongly enriched in Rb, Nb and Ta, but depleted in Ba, Sr and Ti elements. All the characteristics show that the Ziyunshan composite granite was formed through high differentiation of magma. At the later magma stage, volatile such as F and H2O enrichment which together with rare metal formed to complexes migration and enrichment. F-rare metal complexes was disturbed at the later magma stage when melt-fluid immiscibility occurred. Therefore, Rb can be rich in muscovite granite inform of isomorphism.

关 键 词：大坪地区 铷矿 紫云山岩体 白云母花岗岩 地球化学 

分 类 号：P588.12[天文地球—岩石学]