投稿时间:2014-05-26
修订日期:2014-12-27
网络发布日期:2015-03-04
中文摘要:宝山斑岩型铜多金属矿床位于九瑞矿集区西北部,隶属于九江-瑞昌铜金矿田,为长江中下游铜金成矿带、大冶-九江成矿亚带的组成部分。对宝山岩体的花岗闪长斑岩进行LA-MC-ICP-MS U-Pb同位素测年,获得其锆石U-Pb年龄为(147.81±0.48) Ma(MSWD=1.07);首次对宝山矿床的辉钼矿进行Re-Os同位素定年,获得矿床的成矿年龄:6件辉钼矿的Re-Os同位素模式年龄范围为(146.1±2.2) Ma~(148.7±2.0) Ma,加权平均年龄为(147.42±0.84) Ma,等时线年龄为(147.7±1.2) Ma。成岩年龄与成矿年龄在误差范围内一致。辉钼矿的Re含量指示宝山矿床的成矿物质来自于壳幔混源。宝山矿区的成岩、成矿时代与九瑞矿集区典型岩体和矿床的成岩、成矿时代相似,也与长江中下游地区铜陵、安庆和鄂东南(部分地区)的典型铜多金属矿床的成岩、成矿时代基本一致,都属于长江中下游成矿带早白垩世多金属成矿事件的一部分。
Abstract:Located in the northwestern part of the Jiujiang-Ruichang ore concentration area, the Baoshan porphyry Cu polymetallic deposit belongs to the Jiujiang-Ruichang Cu-Au orefield and is a component part of the Daye-Jiujiang metallogenic subzone along the Middle-Lower Yangtze River Cu-Au metallogenic belt. The U-Pb LA-MC-ICP MS dating of the zircons from Baoshan granodiorite porphyry yielded an age of (147.81±0.48) Ma(MSWD=1.07). Six molybdenite samples separated from the Baoshan deposit were used for Re-Os dating, which yielded the model ages ranging from (146.1±2.2) Ma to (148.7±2.0) Ma, weighted average age of (147.42±0.84) Ma and an isochron age of (147.7±1.2) Ma. These ages suggest that the mineralization in the Baoshan deposit was genetically associated with the granodiorite porphyry, and the rock- and ore-forming process was continuous. The Re content of molybdenite indicates that the ore-forming materials were derived from the mixture of the mantle and the crust. These data indicate that ages of the intrusion and orebody from the Baoshan deposit are almost identical with ages of other typical magmatic intrusions and deposits in the Jiujiang-Ruichang metallogenic belt, and even similar to ages of typical Cu polymetallic ore deposits in Tongling, Anqing and part of southeast Hubei in the Middle-Lower Yangtze River metallogenic belt, all being part of the Early Cretaceous polymetallic metallogenic events in the Middle-Lower Yangtze River metallogenic belt.
keywords:geochemistry zircon U-Pb age molybdenite Re-Os age porphyry copper-polymetallic deposit metallogenic setting Baoshan deposit Jiujiang-Ruichang ore concentration area
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中图分类号:P618.41
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基金项目:本文由国家十二五科技支撑计划课题(项目编号:2009BAB43B03,2011BAB04B03)、国家深部探测技术与实验研究专项(SinoProbe-03-06)和国土资源部公益性行业科研专项项目(项目编号:201311166(SinoProbe-03-07))联合资助
引用文本:
贾丽琼,徐文艺,杨丹,杨竹森,王梁.2015.江西九瑞地区宝山斑岩型铜多金属矿床锆石U-Pb和辉钼矿Re-Os年龄及其地质意义[J].矿床地质,34(1):63~80JIA LiQiong,XU WenYi,YANG Dan,YANG ZhuSen,WANG Liang.2015.Zircon U-Pb and molybdenite Re-Os dating of Baoshan porphyry Cu polymetallic deposit in Jiujiang-Ruichang ore concentration area of Jiangxi Province and its geological significance[J].Mineral Deposits34(1):63~80
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