广西猫儿山花岗岩及其相邻基底地层岩石地球化学特征与成矿潜力  

Geochemical characteristics and metallogenic potential of Maoershan granite and its adjacent basement strata in Guangxi

作　　者：李若坚 陈远荣[1] 谷瑞祺 黎家财 蒋鑫 农悦瑾 王展宇 严翔 LI Ruojian;CHEN Yuanrong;GU Ruiqi;LI Jiacai;JIANG Xin;NONG Yuejin;WANG Zhanyu;YAN Xiang(College of Earth Sciences,Guilin University of Technology,Guilin 541006,Guangxi,China)

机构地区：[1]桂林理工大学地球科学学院,广西桂林541006

出　　处：《中国地质》2020年第2期528-537,共10页Geology in China

基　　金：国家科技支撑项目(2014BAB05B00);有色及贵金属隐伏矿床勘查教育部工程中心项目(2015GCZX006)资助。

摘　　要：通过对猫儿山花岗岩及其相邻基底地层进行地球化学与成矿潜力研究,发现猫儿山花岗岩具有高硅(SiO2=67.61%~83.16%)、富钾(K2O=3.75%~6.28%)、富铁(FeO^T=1.85%~5.38%)、贫钠(Na2O=0.08%~3.06%)、贫镁(MgO=0.14%~1.28%)、过铝质(A/CNK的平均值为1.49)的特征,稀土元素总量较高,轻稀土富集,Eu显示负异常(δEu=0.15~0.46),为主要形成于后造山构造环境的强过铝质S型花岗岩。同时,猫儿山花岗岩及其相邻基底地层的元素组合、烃类组分具有继承性关系,花岗岩主要来源于基底地层的部分熔融,W、Sn、Bi具备良好的成矿潜力。换言之,基底地层不仅为大规模的岩浆活动提供了物质基础,同时也为花岗岩浆进一步分异形成钨锡多金属矿化(矿床)提供了成矿物质来源。Through studying the geochemical characteristics and metallogenic potential of Maoershan granite and its adjacent basement strata, it is found that the granite is characterized by high silicon(SiO2=67.61%-8.316%), rich potassium(K2 O=3.75%-6.28%) and iron(FeOT=1.85%-5.38%), depleted sodium(Na2 O=0.08%-3.06%), poor magnesium(MgO=0.14%-1.28%),peraluminous nature(the average of A/CNK being 1.49), relatively high total amounts of rare earth elements, and enriched light rare earth elements, with Eu negative anomaly(δEu=0.15-0.46), suggesting that it was formed in the post-orogenic tectonic environment and belonged to strongly peraluminous S-type granite. At the same time, the results show that the element assemblages and hydrocarbon composition of Maoershan granite and its adjacent basement strata had inherited relationship. The granite was mainly derived from the partial melting of the basement strata. W, Sn and Bi had good metallogenic potential. All these data show that the basement strata in this area not only provided a material basis for large-scale magmatic activities but also provided a source of ore-forming materials for further differentiation of granite pulp to form tungsten-tin polymetallic deposits.

关 键 词：地球化学特征 烃类组分 成矿潜力分析 花岗岩 基底地层 地质调查工程 猫儿山 广西 

分 类 号：P588.12[天文地球—岩石学]