江南造山带东段赣东北广丰地区翁家岭组凝灰岩SHRIMP锆石U-Pb年龄及地质意义  

Zircon SHRIMP U-Th-Pb dating of the Wengjialing Formation in the eastern segment of the Jiangnan orogenic belt in northeast Jiangxi Province and its geological implications

作　　者：张恒[1] 李廷栋[1] 高林志[1] 耿树方[1] 丁孝忠[1] 刘燕学[1] 吴昊[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037

出　　处：《中国地质》2015年第1期96-104,共9页Geology in China

基　　金：中国地质调查局工作项目(121201011120131);全国油气基础地质研究与编图项目(2011ZX05043-005)联合资助

摘　　要：本文通过对赣东北广丰地区翁家岭组凝灰岩样品中的锆石进行研究,首次测得了翁家岭组凝灰岩SHRIMP锆石U-Pb年龄(841.2±5.1)Ma,约束了翁家岭组形成的时代,明确该套沉积岩为田里片岩之上、桃源组(上墅组)之下的一套地层。根据最新获得的大量高精度年龄数据,确定翁家岭组在层位上与梵净山群、四堡群、冷家溪群、双桥山群相当;覆于翁家岭组之上的桃源组是与侵入到梵净山群、四堡群、冷家溪群、双桥山群的火山侵入岩以及浦江地区"平水群"、江山市"章村组"同时期的火山侵入或喷出产物。江南造山带自西向东在830 Ma期间曾广泛发育一期岩浆活动事件。Zircon dating of tuff bedding from the Wengjialing Formation in the east segment of the Jiangnan orogenic belt within northeast Jiangxi Province is reported for the first time in this paper （841.2±5.1 Ma）, which constrains the age of the Wengjialing Formation, suggesting that it lies above Tianli schist and beneath the Taoyuan Formation. In combination with a large number of high precision ages obtained for the Jiangnan orogenic belt recently, the authors hold that the Wengjialing Formation corresponds to the Fanjingshan Group, the Sibao Group, the Lengjiaxi Group, and the Shuangqiaoshan Group. The Taoyuan Group overlying the Wengjialing Formation was formed in the same period as the volcanic rocks which intruded into the Fanjingshan Group, the SibaoGroup, the Lengjiaxi Group, and the Shuangqiaoshan Group, and also occurred simultaneously with the ＂Pingshui Group＂ in Pujiang City, Zhejiang Province, and the ＂Zhangcun Formation＂ in Jiangshan City, Zhejiang Province. At 830 Ma, a magma event was widely developed from west to east in the Jiangnan orogenic belt.

关 键 词：江南造山带 翁家岭组 凝灰岩 SHRIMP锆石U-PB定年 

分 类 号：P597.3[天文地球—地球化学] P534.3[天文地球—地质学]