辽东翁泉沟硼矿区二长花岗岩脉锆石U-Pb年龄及对成矿时代的制约  

ZIRCON U-Pb DATING OF MONZOGRANITE DIKES IN WENGQUANGOU BORON OREFIELD,EASTERN LIAONING:Constraints on Metallogenic Age

作　　者：赵岩[1,2] 李生辉 杨中柱 张朋 陈井胜[1,2] 张璟 陈聪[1,2] ZHAO Yan;LI Sheng-hui;YANG Zhong-zhu;ZHANG Peng;CHEN Jing-sheng;ZHANG Jing;CHEN Cong(Shenyang Center of China Geological Survey,Shenyang 110034,China;Key Laboratory of Deep Mineral Resources Exploration and Evaluation,Liaoning Provincial Department of Natural Resources,Shenyang 110032,China;Liaoning Non-Ferrous No.103 Geological Team Co.,Ltd.,Dandong 118008,Liaoning Province,China)

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034 [2]辽宁省自然资源厅深部矿产资源探测与评价重点实验室,辽宁沈阳110032 [3]辽宁省有色地质103队有限责任公司,辽宁丹东118008

出　　处：《地质与资源》2022年第3期342-350,共9页Geology and Resources

基　　金：国家重点研发计划项目“华北克拉通辽东/胶东重要成矿区带金多金属矿深部预测及勘查示范”(2018YFC0603804);中国地质调查局地质调查项目“东北地区铜金稀有金属矿产地质调查”(DD20221678-03).

摘　　要：辽东地区翁泉沟硼矿区露天采场产出一条切穿硼矿体的二长花岗岩脉.本研究采集了该二长花岗岩脉的薄片、化学分析样品,并进行锆石LA-ICP-MS U-Pb年代学测试分析.该二长花岗岩脉具有高SiO_(2)含量,为71.82%~75.68%,较高的Na_(2)O+K_(2)O含量,为8.41%~10.57%,属钙碱性-高钾钙碱性系列花岗岩.岩脉中锆石颗粒呈自形柱状,CL图中较黑,因铀含量较高引起.U-Pb上交点年龄为1842±29 Ma,其中9个测点得出1842±30 Ma的加权平均年龄,反映了该花岗岩脉侵位于古元古代晚期,同时翁泉沟硼镁铁矿成矿应早于该时代.此年龄与前人研究古元古代胶辽吉造山过程中变质作用峰后时间相吻合,反映了古元古代造山作用过程中伴随了硼矿成矿事件.A monzogranite dike cuts through the ludwigite orebody in the open pit of Wengquangou boron deposit,Liaodong Peninsula.Samples of the dike are collected for thin section and zircon LA-ICP-MS U-Pb geochronology analysis.The monzogranite dike is characterized by high SiO_(2) content(71.82%-75.68%)and high Na_(2)O+K_(2)O content(8.41%-10.57%),belonging to calc alkali-high K calc alkaline series granite.The zircon grains in the dikes are euhedral column in shape and dark in the CL image due to the high uranium content.The U-Pb upper intercept age is 1842±29 Ma,among which 9 testing points yield the weighted average age of 1842±30 Ma,indicating that the emplacement age of dike was Late Paleoproterozoic and the Wengquangou ludwigite deposit should be formed earlier.The age is consistent with the post-peak time of metamorphism in the Paleoproterozoic Jiao-Liao-Ji orogeny,reflecting the boron mineralization occurred during the process.

关 键 词：锆石LA-ICP-MS U-PB年龄 胶辽吉造山带 翁泉沟硼镁铁矿 辽宁省 

分 类 号：P619.2[天文地球—矿床学] P597.1[天文地球—地质学]