投稿时间：2012-04-27
修订日期：2012-06-06
中文摘要:冷水坑铅锌银矿是武夷山北缘中生代火山岩带中独具特色的斑岩型矿床,含矿花岗斑岩侵位于打鼓顶组和鹅湖岭组火山岩地层中。笔者采用SHRIMP 锆石U-Pb测年技术,对冷水坑矿田含矿花岗斑岩与鹅湖岭组晶屑凝灰岩进行了年代学研究。3个晶屑凝灰岩的锆石U-Pb年龄分别为(157.8±1.6) Ma、(157.2±1.5) Ma和(158.2±1.8) Ma, 花岗斑岩形成于(157.6±1.3) Ma。含矿斑岩与其赋存的火山岩活动时间高度一致,是同一构造岩浆活动的产物。与区域上其他火山盆地不同,冷水坑矿田鹅湖岭组与打鼓顶组火山岩属于侏罗系。广泛发育于武夷山北坡中生代火山岩盆地的打鼓顶组与鹅湖岭组火山岩,其活动时间在不同火山盆地也各不相同,不能简单地统一划归为侏罗纪或白垩纪,这套地层的时代应予以重新厘定。区域上该套火山岩活动时间的差异,指示武夷山北缘火山岩浆活动具有阶段性或间隙性的演化过程,且构造背景也有很大不同。冷水坑矿田火山岩与含矿斑岩形成于中国东部陆内挤压构造环境。
Abstract:The Lengshuikeng lend-zinc silver deposit is a porphyry deposit located in northern Wuyi Mountain Mesozoic volcanic belt. The ore-bearing porphyry intruded Daguding Formation and Ehuling Formation volcanic strata. Based on an analysis of the mineralization feature of the deposit, the authas determined SHRIMP zircon U-Pb ages of the ore-bearing porphyry and crystal stuff of Ehuling Formation in the Lengshuikeng orefield. Zircon U-Pb dating yields ages of (157.8±1.6) Ma、(157.2±1.5) Ma and (158.2±1.8) Ma for the volcanic rocks and (157.6±1.3) Ma for the porphyry, respectively. The highly consistent activity time for the ore-bearing porphyry and the volcano rock in the orefield suggests that they resulted from the same tectonic magmatic activity. The age of volcano rocks of Daguding Formation and Ehuling Formation are Jurassic, completely different from the ages of volcanic rock in other Mesozoic volcanic basin in northern Wuyi Mountain area. The Daguding Formation and Ehuling Formation volcanic rocks, which are widely distributed in the Mesozoic volcanic basins on the north slope of the Wuyi Mountain area, were formed in different periods in different basins. Those volcanic strata in this area should be reclassified. The time difference of volcanic activities in different basis implies the stages or interstitial evolution process for the volcano-magmatic activities in northern Wuyi Mountain and in different tectonic settings. The ore-bearing porphyry and the volcanic rocks in the Lengshuikeng orefield were formed in Mesozoic continental extrusion setting in eastern China.
keywords:geochemistry SHRIMP zircon U-Pb geochronology lead zinc silver deposit volcano-magmatic activity porphyry deposit Lengshuikeng Wuyi Mountain
文章编号：
中图分类号：P618.42;P618.43;P618.52
文献标志码：
基金项目:本文为国土资源部公益性行业科研专项经费(编号: 201011011)与国家科技支撑重点项目(编号: 2009BAB43B03)联合资助的成果
引用文本：
孟祥金,徐文艺,杨竹森,侯增谦,李振清,于玉帅,肖茂章,何细荣,万浩章.2012.江西冷水坑矿田火山-岩浆活动时限:SHRIMP锆石U-Pb年龄证据[J].矿床地质,31(4):831~838MENG XiangJin,XU WenYi,YANG ZhuSen,HOU ZengQian,LI ZhenQing,YU YuShuai,XIAO MaoZhang,HE XiRong,WAN HaoZhang.2012.Time limit of volcanic-magmatic action in Lengshuikeng orefield, Jiangxi: Evidence from SHRIMP zircon U-Pb ages[J].Mineral Deposits31(4):831~838
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