收藏本站
收藏 | 手机打开
二维码
手机客户端打开本文

A hybrid origin for the Qianshan A-type granite,northeast China:Geochemical and Sr-Nd-Hf isotopic evidence

Simon A.Wilde  
【摘要】:正Major and trace element,whole rock Sr and Nd isotope and zircon Hf isotope data are reported for a suite of A-type granites and mafic microgranuiar enclaves from the Early Cretaceous(126±2 Ma) Qianshan pluton,Liaodong Peninsula,east China,with the aim of investigating the sources and petrogenesis of A-type granites.The Qianshan pluton includes hornblende alkali-feldspar granite,graphic biotite granite and mafic microgranuiar enclaves.The hornblende alkali-feldspar granites have high SiO2,Fe2O3T/MgO,K2O+Na2O,Rb,Zr and LREE contents and low Ba and Sr concentrations with strongly negative Eu anomalies.Their high Rb/Sr(87Rb/86Sr = 16.76-24.15) and initial 87Sr/86Sr ratios(0.7215 to 0.7283),negativeεNd(t) values(-14.1 to -16.5) and zircon eHf(t) values(-18.9 to -11.5) indicate they were mainly derived from a crustal source,but with involvement of highεNd(t) and eHf(t) materials.Graphic biotite granites have similar geochemical features and Sr-Nd-Hf isotopic compositions to enclaves, indicating they were the result of crystal fractionation of evolved mafic magmas,but with involvement of lowεNd(t) andεHf(t) materials.The mafic enclaves have an igneous texture and contain acicular apatite,suggesting quenching of mafic magmas that have co-mingled with the host granites.They have low initial 87Sr/86Sr ratios(0.7097-0.7148),negativeεNd(t)(-14.5 to -11.9) and zirconεHf(t)(-17.1 to -6.9) values,and are enriched in LILEs and LREEs and depleted in HFSEs.When coupled with the high MgO(Mg# up to 54),this indicates derivation from an enriched lithospheric mantle source,but contaminated by crustal materials. Geochemical and Sr-,Nd- and zircon Hf-isotopic compositions rule-out simple crystal-liquid fractionation or restite unmixing as the major genetic link between enclaves and host rocks. Instead,magma mixing of mantle-derived mafic and crustal-derived magmas,coupled with crystal fractionation,is compatible with the data.This example shows that at least some A-type granites formed through a complex process involving mantle- and crustal-derived magma mixing,crystal fractionation and infracrustal melting.

知网文化
【相似文献】
中国重要会议论文全文数据库 前10条
1 Simon A.Wilde;;A hybrid origin for the Qianshan A-type granite,northeast China:Geochemical and Sr-Nd-Hf isotopic evidence[A];中国科学院地质与地球物理研究所2006年论文摘要集[C];2007年
2 SIMON A.WILDE;;Multiple sources for the origin of granites:Geochemical and Nd/Sr isotopic evidence from the Gudaoling granite and its mafic enclaves,northeast China[A];中国科学院地质与地球物理研究所二○○四学术论文汇编·第二卷(青藏高原·岩石圈)[C];2004年
3 ;Zircon age and Nd-Hf isotopic composition of the Yunnan Tethyan belt,southwestern China[A];中国科学院地质与地球物理研究所2007学术论文汇编(第三卷)[C];2008年
4 Bor-ming Jahn;Simon A.Wilde;Ching-Hua Lo;Tzen-Fu Yui;;Highly fractionatedⅠ-type granites in NE China(Ⅱ):isotopic geochemistry and implications for crustal growth in the Phanerozoic[A];中国科学院地质与地球物理研究所二○○三学术论文汇编·第一卷(地球动力学)[C];2003年
5 ;Zircon U-Pb and Hf isotopic constraints on the Early Archean crustal evolution in Anshan of the North China Craton[A];中国科学院地质与地球物理研究所2008学术论文汇编[C];2009年
6 ;Rb-Sr and Sm-Nd isotopic systematics of the lherzolitic shergottite GRV 99027[A];中国科学院地质与地球物理研究所第11届(2011年度)学术年会论文集(上)[C];2012年
7 Roger H.Mitchell;;In situ U-Pb age determination and Nd isotopic analysis of perovskites from kimberlites in southern Africa and Somerset Island,Canada[A];中国科学院地质与地球物理研究所第十届(2010年度)学术年会论文集(上)[C];2011年
8 ;Ore-forming fluids associated with granite-hosted gold mineralization at the Sanshandao deposit,Jiaodong gold province,China[A];中国科学院地质与地球物理研究所二○○三学术论文汇编·第五卷(矿产资源与水资源)[C];2003年
9 ;Two linear granite belts in the central-western North China Craton and their implication for Late Neoarchaean-Palaeoproterozoic continental evolution[A];中国科学院地质与地球物理研究所二○○三学术论文汇编·第一卷(地球动力学)[C];2003年
10 ;A further understanding on genesis of Nanyili granite from Bikou area,Northwest margin of Yangtze Plate[A];中国矿物岩石地球化学学会第13届学术年会论文集[C];2011年
中国博士学位论文全文数据库 前1条
1 陈自祥;利用水体中溶解性硝酸根离子中的氮氧同位素组成来识别中国太湖和巢湖水体中氮污染源的研究[D];中国科学技术大学;2012年
中国硕士学位论文全文数据库 前6条
1 李吉人;江西峡江铀矿区金滩花岗岩年代学、地球化学及岩石成因[D];南京大学;2011年
2 时章亮;松潘造山带马尔康强过铝质花岗岩的成因及其构造意义[D];中国地质大学;2010年
3 刘瑾;赤峰地区花岗岩地貌景观的多样性及其价值评价[D];中国地质大学(北京);2012年
4 代伦;内蒙古玻璃忽镜地区二叠纪花岗岩地质地球化学特征研究[D];成都理工大学;2012年
5 余中美;摩天岭岩体脉岩地质地球化学与年代学特征及其与铀成矿关系[D];成都理工大学;2012年
6 范超;飞秒激光剥蚀多接收等离子体质谱原位微区分析黄铜矿中Pb同位素组成研究[D];西北大学;2012年
中国知网广告投放
 快捷付款方式  订购知网充值卡  订购热线  帮助中心
  • 400-819-9993
  • 010-62982499
  • 010-62783978