云南维西阿南多塘石英斑岩地球化学特征及其地质意义  

Geochemical Characteristics and Their Geological Significance of the Quartz Porphyry in Ananduotang,Weixi County,Yunnan Province

作　　者：李强[1] 左琼华[1] 彭明兴[1] 刘陈明[1] 杨德敏[1] LI Qiang;ZUO Qionghua;PENG Mingxing;LIU Chenming;YANG Deimin(Yunnan Land and Resources Vocational College,Kunming,Yunnan 650217)

机构地区：[1]云南国土资源职业学院,云南昆明650217

出　　处：《地质与勘探》2022年第1期73-85,共13页Geology and Exploration

基　　金：云南省教育厅科学研究基金(编号:2020J0963)资助。

摘　　要：云南维西县阿南多塘石英斑岩是西南“三江”成矿带中段的含(锑)矿斑岩体。为深入分析该岩体岩浆来源及构造环境,开展斑岩主量元素、微量元素和稀土元素地球化学特征研究,结果表明:云南维西阿南多塘石英斑岩属高硅富钾过铝质钙碱性系列。轻稀土相对富集,稀土元素球粒陨石标准化模式图较陡向右倾斜,δCe无异常,δEu中等负亏损。富集不相容元素Cs、Rb和产热元素Th、U、K,高场强元素Zr、Hf等也相对富集,亏损Nb、Sr和Ti。经对比分析认为,该岩体是“三江”成矿带中段江达-德钦-维西陆缘弧演化后期陆陆碰撞形成的新生代富钾石英斑岩,岩浆主要来自上地壳沉积岩,具有碰撞后火山岩的典型特征。Quartz porphyry at Ananduotang,Weixi County of Yunnan Province is an ore-bearing rock-body in the middle section of the Sanjiang metallogenic belt in Southwest China.In order to illuminate the magma source and its tectonic environment,we study the geochemical characteristics of major elements,trace elements and rare earth elements of this porphyry.Results show that this rock belongs to a high-K calc alkaline series.Its LREE is relatively enriched,and the normalized model diagram of REE chondrite exhibits a steep and right inclined feature.There is no anomaly inδCe and medium negative depletion inδEu.It is rich in incompatible elements Cs,Rb and thermogenic elements Th,U and K.High field strength elements Zr and Hf are also relatively enriched,and Nb,Sr and Ti are depleted.Comparative analysis suggests that this porphyry is a Cenozoic K-rich porphyry produced by a continental collision in the late stage of the evolution of the Jiangda-Deqin-Weixi continental margin arc in the middle section of the Sanjiang metallogenic belt.The magma mainly originated from sedimentary rocks in the upper crust with a typical characteristic of post-collision volcanic rocks.

关 键 词：石英斑岩 地球化学特征 阿南多塘 维西县 云南 

分 类 号：P595[天文地球—地球化学]