摘要
与阳储岭钨多金属矿床密切相关的燕山期岩体主要由4个岩石单元组成,分别是似斑状二长花岗岩、似斑状细粒黑云母花岗闪长岩、花岗闪长斑岩、花岗闪长岩。在系统的野外地质调查基础上,开展了岩相学和地球化学分析,探讨了杂岩体的成因及主要岩石单元的活动时序。研究表明,阳储岭花岗岩体具有高硅、过铝质特征,岩石富集K、Rb,亏损Sr和Ba元素,高场强元素Zr、Hf富集不明显,Nb、Ti元素强烈亏损,U、Th相对富集。REE显示弱Eu亏损的较小斜率的右倾模式,微量元素原始地幔标准化蛛网图总体上呈左高右低的趋势,说明阳储岭岩体主要岩石均应属于高分异的I型花岗岩。从岩石的Rb/Sr、Rb/Nb、Zr/Hf及Ti/Zr值与地壳平均值和地幔平均值对比研究,表明岩浆来源于壳源物质与幔源物质的混合。基于以上稀土元素指标及主微量元素的哈克图解分析,阳储岭岩体轻、重稀土元素的分异程度高,暗示其可能由早期的似斑状二长花岗岩→似斑状细粒黑云母花岗闪长岩→花岗闪长斑岩→花岗闪长岩演化趋势,这与野外观察到的岩浆侵入时序较为一致。
The Yanshanian rock mass closely related to Yangchuling tungsten polymetallic deposit is mainly composed of four rock units,namely porphyritic adamellite,porphyritic fine-grained biotite granodiorite,granodiorite porphyry and granodiorite.On the basis of systematic field geological investigation,petrography and geochemical analysis are carried out,and the genesis of complex and the activity sequence of main rock units are discussed.The research shows that the Yangchuling granite body is characterized by high silicon and peraluminum,and the rock is rich in K,Rb,but deficient in Sr and Ba,while the enrichment of high-field elements Zr and Hf is not obvious,while Nb and Ti are strongly deficient,while U and Th are relatively rich.REE shows a right-leaning model with a small slope of weak Eu deficit,and the standardized spider web map of trace elements in the original mantle shows a trend of high left and low right,indicating that the main rocks of Yangchuling rock mass should belong to highly differentiated I-type granite.Comparing the Rb/Sr,Rb/Nb,Zr/Hf and Ti/Zr values of rocks with the average values of crust and mantle,it is shown that magma comes from the mixture of crust-derived materials and mantle-derived materials.Based on the above REE indexes and Huck diagram analysis of major and trace elements,the differentiation degree of light and heavy REE in Yangchuling rock mass is high,suggesting that it may evolve from early porphyritic adamellite→porphyritic fine biotite granodiorite→granodiorite porphyry→granodiorite,which is consistent with the magmatic intrusion time series observed in the field.
作者
徐裕敏
王天晨
王文锋
尹青青
项新葵
XU Yumin;WANG Tianchen;WANG Wenfeng;YIN Qingqing;XIANG Xinkui(Branch No.3,Jiangxi Geological Survey,Jiujiang 332100,Jiangxi,China;Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 611756,Sichuan,China)
出处
《中国钨业》
CAS
2023年第2期8-21,共14页
China Tungsten Industry
基金
江西省科学技术厅国家科技奖后备培育项目(20203AEI91004)。
关键词
阳储岭岩体
燕山期
I型花岗岩
岩浆活动时序
壳幔岩浆混合
岩浆演化
Yangchuling
Yanshanian
I-type granite
metallogenic chronogenesis
mixed source of crust and mantle
magmatic evolution
