首页 | 本学科首页   官方微博 | 高级检索  
     

浙江安吉多金属矿区石英二长斑岩岩石化学特征和锆石U-Pb年龄及其地质意义
引用本文:唐燕文,谢玉玲,李应栩,邱立明,刘保顺,李媛,张欣欣,姜研岑,韩宇达,周俊杰. 浙江安吉多金属矿区石英二长斑岩岩石化学特征和锆石U-Pb年龄及其地质意义[J]. 现代地质, 2012, 26(4): 647-655
作者姓名:唐燕文  谢玉玲  李应栩  邱立明  刘保顺  李媛  张欣欣  姜研岑  韩宇达  周俊杰
作者单位:北京科技大学土木与环境工程学院,北京,100083
基金项目:科技部公益性行业基金项目,“十二五”国家科技计划项目
摘    要:为了解浙江安吉多金属矿区岩浆作用的性质及其与成矿作用的关系,对区内石英二长斑岩的地球化学和年代学展开研究。地球化学结果表明,该岩脉高硅(w(SiO2)=65.91%~66.72%)、富碱(w(K2O+Na2O)=7.82%~8.26%)、高钾(w(K2O)/w(Na2O)=1.58~1.82),铝饱和指数A/CNK=0.86~0.91,轻稀土元素和大离子亲石元素Rb、Th、K相对富集,铕弱负异常,Ba、Sr和高场强元素Nb、Ti、P相对亏损,属准铝质―钾玄岩系列。铝饱和指数及结晶分异指数显示,该岩脉属I型花岗岩系列。年代学结果表明,该岩脉锆石U-Pb年龄为(137.3±1.6)Ma,与区内杂岩体同期。据野外证据,该岩脉的侵位时代指示北东向湖州―学川大断裂在(137.3±1.6)Ma左右再次活动,且该时间也为北西向孝丰―三门湾大断裂再度活跃的最早年龄。区内岩浆作用、成矿作用基本同期,岩体与矿化又具有密切的空间关系,表明区内成矿作用和岩浆活动密切相关。

关 键 词:浙西  Pb-Zn多金属矿床  孝丰―三门湾大断裂  湖州―学川大断裂  锆石U-Pb定年  成矿时代

Geochemical Characteristics and Zircon LA-ICP-MS U-Pb Ages of Quartz-Monzonite Porphyry in Anji Polymetallic Ore District of Zhejiang and Their Geological Implications
TANG Yan-wen , XIE Yu-ling , LI Ying-xu , QIU Li-ming , LIU Bao-shun , LI Yuan , ZHANG Xin-xin , JIANG Yan-cen , HAN Yu-da , ZHOU Jun-jie. Geochemical Characteristics and Zircon LA-ICP-MS U-Pb Ages of Quartz-Monzonite Porphyry in Anji Polymetallic Ore District of Zhejiang and Their Geological Implications[J]. Geoscience of Geosciences, 2012, 26(4): 647-655
Authors:TANG Yan-wen    XIE Yu-ling    LI Ying-xu    QIU Li-ming    LIU Bao-shun    LI Yuan    ZHANG Xin-xin    JIANG Yan-cen    HAN Yu-da    ZHOU Jun-jie
Affiliation:(Civil and Environmental Engineering Institute,University of Science and Technology Beijing,Beijing 100083,China)
Abstract:In order to get further understanding about the magmatism and its relationship with mineralization,the geochemical characteristics and zircon U-Pb age of quartz-monzonite porphyry in Anji polymetallic ore district in western Zhejiang have been studied.Quartz-monzonite porphyry is characterized by high SiO2(65.91%-66.72%),alkali-rich(Na2O+K2O=7.82%-8.26%),potassium-high(K2O/Na2O=1.58-1.82) and A/CNK=0.86-0.91.Based on the results from A/CNK-A/NK and SiO2-K2O diagrams,quartz-monzonite porphyry belongs to the quasi-aluminous rock and shoshonite series.In chondrite normalized REE distribution patterns,all the samples are LREE-enriched and with weak negative anomaly in Eu(δEu=0.75-0.81).In primitive mantle normalized trace elements spider diagram,the large-ion lithophile elements(e.g.Rb,Th and K) are high concentrations,but Ba,Sr and the high field strength elements(e.g.Nb,Ti and P) are relatively depleted.The aluminized indexes(A/CNK) of all the samples are less than 1.1 and all the differentiation indexes(DI) are about 77,so quartz-monzonite porphyry belongs to I-type granite.Zircon U-Pb dating by LA-ICP-MS shows this porphyry emplaced at(137.3±1.6) Ma of Early Cretaceous and has a similar age with the Wushanguan complex.Considering that quartz-monzonite porphyry exists along Huzhou-Xuechuan fault and is cut off by Xiaofeng-Sanmenwan fault,this age indicates that Huzhou-Xuechuan fault was activated in Early Cretaceous and also constrains the earliest time when Xiaofeng-Sanmenwan fault activated.The magmatism formed in the same time with mineralization,and mineralization also has a close relationship with the complex body in space,so it is believed that the mineralization is related to the magmatism in this study area.
Keywords:western Zhejiang  Pb-Zn polymetallic deposit  Xiaofeng-Sanmenwan fault  Huzhou-Xuechuan fault  zircon U-Pb dating  metallogenic epoch
本文献已被 CNKI 万方数据 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号