南岭东段黄峰寨岩体SHRIMP锆石U-Pb年龄及地质意义  

SHRIMP zircon U-Pb dating of the Huangfengzhai pluton in eastern Nanling and its geological implications

作　　者：范飞鹏[1] 肖惠良[1] 陈乐柱[1] 蔡逸涛[1] 李海立[1] 鲍晓明[1] 周延[1] 

机构地区：[1]南京地质矿产研究所,南京210016

出　　处：《华东地质》2016年第3期166-173,共8页East China Geology

基　　金：中国地质调查局地质调查项目"江西竹山-广东澄江地区钨锡多金属矿远景调查"(项目编号:1212011120813);"广东始兴南山坑-良源地区钨锡多金属矿评价"(项目编号:1212011120811);"广东始兴-连平地区钨钼多金属矿调查评价"(项目编号:1212010881305)和"湘赣粤相邻地区钨矿远景调查"(项目编号:1212010533003)

摘　　要：黄峰寨岩体位于南岭钨锡多金属成矿带的东段,对该岩体中的石英二长岩进行SHRIMP锆石U-Pb年龄测定、岩石学和地球化学研究。石英二长岩的SHRIMP锆石U-Pb年龄为231±3 Ma,属中三叠世晚期。岩石学和地球化学特征表明,该岩体具有高硅、富铝、高钾、中碱、高钙的特征,属高钾钙碱性系列弱过铝质S型花岗岩类;微量元素Sr、Ba、Nb、P、Ti强烈亏损,Rb、Th、Ce、Zr、Sm相对富集;稀土元素总量高,轻稀土富集,轻、重稀土分异明显,Eu中等负异常;Hf(t)为-15.25^-2.88,Hf两阶段模式年龄值为1.87~2.22Ga,表明黄峰寨岩体为上地壳底部基性岩部分熔融的产物,推测该岩体可能形成于同碰撞构造环境。The Huangfengzhai pluton is located in the eastern section of tungsten-tin polymetallic metallogenic belt in the Nanling region.This study carried out SHRIMP zircon U-Pb dating and lithological and geochemical anlyzses for quartz monazites from the Huangfengzhai pluton.The results show that a zircon U-Pb age of quartz monzonite from the Huangfengzhai pluton is 231±3 Ma,belonging to late Middle Triassic.Lithological,mineralogical and geochemical analyses suggest that the pluton is rich in Si,Al and Ca,with medium alkali,indicating that the pluton belongs to high-K,calc-alkaline series,weakly-perluminous S-type granitoids.The pluton is also depleted in Sr,Ba,Nb,P and Ti,but relatively enriched in Rb,Th,Ce,Zr and Sm,with highΣREE content,distinct LREE and HREE differentiation,and weak negative Eu anomalies.ZirconεHf(t)values range from-15.25to-2.88 and Hf two-stage model age values are 1.87~2.22 Ga,indicating that the Huangfengzhai pluton was derived from partial melting of mafic rocks at the bottom of upper crust.It can be inferred that the Huangfengzhai pluton might form at a syncollosion tectonic setting.

关 键 词：南岭东段 黄峰寨岩体 印支期 SHRIMP锆石U-PB年龄 HF同位素 

分 类 号：P558.12[天文地球—构造地质学]