%0 Journal Article
%T Geochronology and geochemistry of the Early Palaeozoic granitoids in Baoshan block, western Yunnan and their implications<br>滇西保山地块早古生代花岗岩类的年代学、地球化学及意义
%A DONG MeiLing
%A DONG GuoChen
%A MO XuanXue
%A ZHU DiCheng
%A NIE Fei
%A XIE XuFeng
%A WANG Xia
%A HU ZhaoChu
%A <br>董美玲
%A 董国臣
%A 莫宣学
%A 朱弟成
%A 聂飞
%A 谢许峰
%A 王霞
%A 胡兆初
%J 岩石学报
%D 2012
%I 
%X The Pinghe granitoid pluton,located in the Baoshan block of the Tethyan belt,western Yunnan,consists mainly of granite and monzogranite with subordinate granodiorite.Zircon U-Pb ages of 480 ～ 486Ma for four samples from this pluton indicate that this pluton was emplaced during the Early Ordovician.The Pinghe granitoids are high-K calc-alkaline and peraluminous,with K2O/Na2O > 1 and A/CNK = 1.07 ～ 1.13.These rocks are enriched in large-ion lithophile elements(LILEs),light rare-earth elements(LREEs) (La/Yb) N =4.33 ～7.05]and Pb,and depleted in high field-strength elements(HFSEs).They show similar chondritenormalized REE patterns,with negative Eu anomalies(δEu = 0.25 ～ 0.48).58 analyses from four samples have a wide range zircon εHf(t) values(-12.4 ～-3.0) and varying Hf-isotope crustal model ages(2.2 ～ 1.7Ga).Such geochemical signatures indicate that the Pinghe granitoids are S-type granite in character and were derived mainly from anatexis of ancient crustal materials(such as greywacke) with varying contributions from mantle-derived components.The Pinghe granitoids are geochemically comparable to the coeval silicic metavolcanic rocks reported in the central Lhasa Terrane.It is suggested that the Baoshan block may represent a part of an Early Paleozoic magmatic arc in the Gondwana continental margin facing the proto-Tethyan Ocean.
%K Early Palaeozoic granitoids
%K Geochemistry
%K Zircon Hf isotope
%K Baoshan block
%K Western Yunnan<br>早古生代花岗岩类
%K 地球化学
%K 锆石Hf同位素
%K 保山地块
%K 滇西
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=480439D8C603FECAF2D20A761A4FD705&yid=99E9153A83D4CB11&vid=D3E34374A0D77D7F&iid=94C357A881DFC066&sid=C13C5D291D09385A&eid=AA2E209AD442C5CC&journal_id=1000-0569&journal_name=岩石学报&referenced_num=0&reference_num=66