LA-ICP-MS and 40Ar/39Ar isotopic analysis were carried out to constrain the ages of volcanic rock ( Daguding Formation and Ehuling Formation) , granite porphyry and nappe structure in the Lengshuikeng deposit, Jiangxi Province. The Daguding Formation was formed during the Late Jurassic with U-Pb age of 160. 8 ± 1. 9Ma. The Ehuling Formation was formed in an intermittent and multi-period magmatic activity, which began at 159Ma and reached its climax at 146. 6 ± 2. 2Ma. The zircons from granite porphyry in Lengshuikeng yield U-Pb ages ranging from 163. 6 ±2. 1 to 154. 3 ±3.0Ma. The nappe structure F2 firstly activated during Caledonian with a 40Ar/39Ar age of 398. 5 ±2. 6Ma, and reactivated after 146. 6Ma, leading to the superimposition of Sinian System upon Ehuling Formation and broken the granite porphyry in Lengshuikeng deposit.%江西省冷水坑矿区火成岩-构造演化一直缺少系统的年代学制约.作者运用LA-ICP-MS锆石U-Pb和40Ar/39Ar测年技术,对冷水坑矿区两套火山岩地层(打鼓顶组和鹅湖岭组)、含矿花岗斑岩和主推覆断层F2进行了年代学测试,结果表明,打鼓顶组流纹质含角砾熔结凝灰岩形成于160.8±1.9Ma,鹅湖岭组合角砾熔结凝灰岩则具有间歇性和多期喷发特点,其最初活动时间为159Ma,而主体形成于146.6±2.2Ma；矿区含矿花岗斑岩与打鼓顶组、鹅湖岭组几乎同期形成,年龄介于163.6 ±2.1Ma～154.3±3.0Ma之间；研究区构造活动起始时间不晚于加里东期,推覆断层F2中保留有40Ar/39Ar年龄为398.5±2.6Ma的构造活动痕迹,中生代重新复活,导致震旦系叠覆于鹅湖岭组之上,年龄晚于146.6Ma,可能对含矿斑岩体起破坏作用.
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