%0 Journal Article
%T Zircon geochronology and geological implications of ore-bearing porphyries from Zhongdian arc<br>中甸岛弧成矿斑岩的锆石年代学及其意义
%A REN JiangBo
%A XU JiFeng
%A CHEN JianLin
%A <br>任江波
%A 许继峰
%A 陈建林
%J 岩石学报
%D 2011
%I 
%X Hypabyssal porphyries associated with porphyry copper deposits are widely distributed in Zhongdian island arc in the northwest of Yunnan Province. The LA-ICPMS zircon U-Pb method is used to date the formational age of the porphyries in western and eastern side of the Zhongdian island arc. Zircons separated from Xuejiping ore-bearing porphyry in the western side of Zhongdian yielded mean 206Pb/238Pb ages of 213.4±1.5Ma. Meanwhile zircons separated from Qiansui quartz dioritic porphyrite in the eastern side of Zhongdian yielded mean 206Pb/238Pb ages of 217.1±1.5Ma. These ages are consistent with those of high-precision zircon geochronology reported by other porphyries in this area, which indicate they are coeval and without obvious different ages between western and eastern side porphyries in the Zhongdian island arc. Together with other published geochronological data, these Indo-porphyries related to mineralization were predominantly formed at 223~211Ma and spatially exhibited a planar-shaped distribution. All of these zircons display the same REE patterns with extremely high CeN/CeN* and relatively weak EuN/EuN* ratios, which hints that the magma formation experienced a condition of high oxygen fugacity. We suggest that these porphyries related copper deposits are probably related to the westward subduction of the Ganzhi-Litang ocean plate during Late Triassic. The melts from subducted slab with relatively high oxygen fugacity and fertile in metal possibly play an important role in promoting mineralization of the porphyry copper deposits.
%K LA-ICPMS
%K Oxygen fugacity
%K Zhongdian island arc
%K Indosinian<br>LA-ICPMS
%K 氧逸度
%K 中甸岛弧
%K 印支期
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=B0A3094CBEF84E91127D5D549C9998D9&yid=9377ED8094509821&vid=DB817633AA4F79B9&iid=9CF7A0430CBB2DFD&sid=958E9523684D01F0&eid=EB52A6667DDA964A&journal_id=1000-0569&journal_name=岩石学报&referenced_num=0&reference_num=25