%0 Journal Article
%T Petrogenesis of Lincang granites in Sanjiang area of western Yunnan Province: Constraints from geochemistry, zircon U-Pb geochronology and Hf isotope
滇西三江地区临沧花岗岩的岩石成因:地球化学、锆石U-Pb年代学及Hf同位素约束
%A KONG HuiLei
%A DONG GuoChen
%A MO XuanXue
%A ZHAO ZhiDan
%A ZHU DiCheng
%A WANG Shuo
%A LI Rong
%A WANG QiaoLin
%A
孔会磊
%A 董国臣
%A 莫宣学
%A 赵志丹
%A 朱弟成
%A 王硕
%A 李荣
%A 王乔林
%J 岩石学报
%D 2012
%I
%X The Lincang granites in southern Lancangjiang zone of Sanjiang area,located in the west of Yunnan Province,are mainly composed of biotitic monzogranites.The SiO2 and Al2O3 of the granites range 66.84% ~ 73.99% and 12.94% ~ 15.23%,averagely 69.72% and 14.44% respectively.The K2O/Na2O ratio is high,ranging 1.42 ~ 30.1,with average of 8.66.A/CNK varies from 1.06 to 8.59,averagely 2.61,and mostly > 1.1.So Lincang granites are high-K calc-alkaline and peraluminous to strongly peraluminous series.Lincang granites are also enriched in LILEs and Pb,but strongly depleted in HFSEs.The REE content is between 198.2 × 10-6 and 359.2 × 10-6(average 252.5 × 10-6),with(La/Yb) N ratios of 7.87 ~ 17.62(average 11.19) and δEu of 0.34 ~ 0.57(average 0.48).The intrusion is remarkably characterized by enriched LREE and depleted HREE.The chondrite-normalized REE patterns show strong negative Eu anomalies.The zircon U-Pb ages of the two samples are 219.19 ± 0.99Ma and 219.69 ± 0.67Ma,belonging to Late Triassic.The SiO2-P2O5,SiO2-Zr,K2O-Na2O relationship and ACF plot indicate that the Lincang granites are S type granites,which mainly derive from clay-poor psammite.Lincang granites can be dropped into the group of post-collisional granites in the Rb-Y + Nd discrimination diagram.In addition,Lincang granites have the features of low-Sr and high-Yb in the Sr-Yb discrimination diagram,which is in accordance with the granites in southeastern China.Lincang granites have homogeneous zircon Hf isotopic composition.Their zircons have negative εHf(t) values(-14 ~-11) and old Hf isotope crust model ages(1.95 ~ 2.15Ga),suggesting that Lincang granites were formed by partial melting of old crust.Therefore,we consider that Lincang granites were formed in post-collisional stage between the Burma-Thai-Malaysia and Simao block in the Late Triassic.
%K Zircon U-Pb geochronology
%K Geochemistry
%K Hf isotope
%K Lincang granites
%K Sanjiang area of western Yunnan
锆石U-Pb年龄
%K 地球化学
%K Hf同位素
%K 临沧花岗岩
%K 滇西三江
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=480439D8C603FECA56B1CD67B894299C&yid=99E9153A83D4CB11&vid=D3E34374A0D77D7F&iid=94C357A881DFC066&sid=5A66347DEC1DE6F4&eid=193F3A809807D248&journal_id=1000-0569&journal_name=岩石学报&referenced_num=0&reference_num=69