%0 Journal Article
%T Geochronology, geochemistry and geological significance of Late Triassic magmatism in Qingchengzi orefield, Liaoning<br>辽宁青城子铅锌多金属矿田晚三叠世岩浆岩年代学、地球化学及地质意义
%A DUAN XiaoXi
%A LIU JianMing
%A WANG YongBin
%A ZHOU LingLi
%A LI YongGui
%A LI Bin
%A ZHANG Zhuang
%A ZHANG ZuoLun
%A <br>段晓侠
%A 刘建明
%A 王永彬
%A 周伶俐
%A 李永贵
%A 李斌
%A 张壮
%A 张作伦
%J 岩石学报
%D 2012
%I 
%X The Qingchengzi orefield which lies in geotectogene of Liaodong rift is an important polymetallic mineral district in northern China for its clustering several large Pb-Zn,Ag and Au deposits.A phase of Late Triassic magmatism,represented by Shuangdinggou biotite monzogranite and Xinling granite,is intimately related to polymetallic mineralization.LA-ICPMS zircon U-Pb age of 224.2±1.2Ma was obtained for the Shuangdinggou intrusion.Geochemical data for the Shuangdinggou intrusion reveal SiO2 content of 69.07%～71.31%,while K2O accounts for 3.53%～5.22% and Na2O for 3.87%～4.14%,indicating it belongs to high K calc-alkaline series.Al2O3 content ranges between 12.46%～14.48% and A/CNK<1 suggest metaluminous feature.Trace element geochemistry of the biotite monzogranite displays high total REE content and demonstrate strong fractionation between light and heavy REE elements (La/Yb) N=35.43～79.01,LREE/HREE=23.09～35.10] and minor negative Eu anomalies(δEu=0.68～0.97) .The biotite monzogranite also shows LILE(such as Rb,Th,K,Pb) enrichment and HFSE(including Nb,Ta,P,Ti) depletion,with unusual high Ba and Sr,low Y and Yb abundances manefesting adakitic geochemical signature.Based on above-stated petrological and geochemical data it is inferred that the biotite monzogranitic magma might be derived from the partial melting of a thickened lower crust with prominent garnet and rutile retained in the residual assemblages,and magma mixing is probably involved based on the unusually high Nb/Ta ratio(18.4～21.2) .It is suggested that slab break-off during the process of Yangtze Craton and North China Craton continental deep subduction in Late Triassic may be responsible for the ore-related magmatism.
%K Zircon U-Pb dating
%K Adakitic intrusions
%K Syn-collisional granite
%K Qingchengzi orefield
%K Liaoning<br>锆石U-Pb年代学
%K 埃达克质岩石
%K 同碰撞花岗岩
%K 辽宁青城子矿田
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=7D4B0212F9173E1AD33A611211C19CE4&yid=99E9153A83D4CB11&vid=D3E34374A0D77D7F&iid=0B39A22176CE99FB&sid=240CB58995465C01&eid=6EEC242D0D8BE428&journal_id=1000-0569&journal_name=岩石学报&referenced_num=0&reference_num=28