大兴安岭旁开门金银矿床赋矿围岩的锆石U-Pb年龄及其地质意义  

U-Pb dating of zircons from host rocks of Pangkaimen gold-silver deposit in Great Xing'an Range and its geological implications

作　　者：唐臣 杨帆[2] 孙景贵[2] 王清海[3] 陈行时 张斌 李怡欣[2] 柴鹏 刘勇胜[4] 

机构地区：[1]黑龙江省地质调查研究总院,哈尔滨150036 [2]吉林大学地球科学学院,长春130061 [3]吉林大学东北亚国际地学研究与教学中心,长春130026 [4]中国地质大学地质过程与矿产资源国家重点实验室,武汉430074

出　　处：《世界地质》2011年第4期532-537,共6页World Geology

基　　金：国家自然科学基金(40772052;41172072);中国地质调查局计划工作项目(资[2010]26-06);黑龙江省地质矿产局地质调查研究院课题(3R1101604422)联合资助

摘　　要：大兴安岭旁开门金银矿床赋存在上侏罗统甘河组基性岩和下白垩统富林组中酸性火山岩中,其赋矿围岩蚀变流纹岩中单颗粒锆石U-Pb年龄测定表明,21个成分点中有1组不谐和年龄(141±2Ma、129±2 Ma)和3组谐和年龄,后者的加权平均值分别为116.2±3.4 Ma、112.5±1.1 Ma和108.2±4.2 Ma。结合锆石晶形和CL图像特征,进一步确定流纹岩的成岩时代为早白垩世晚期,岩浆房冷却到岩浆热液期经历约8 Ma,成矿作用与富林组火山作用有关,发生在108 Ma之后,其成矿与中国东北部陆缘晚中生代浅成热液金矿大规模成矿时代相一致。The Pangkaimen Au-Ag deposit in Great Xing＇an Range is concentrated in Upper Jurassic Ganhe Formation basic volcanic rocks and Lower Cretaceous Fulin Formation intermediate and intermediate-acid volcanic rocks. The single-zircon U-Pb ages for host surrounding altered rhyolite rocks are dated, and the 21 component dot can be subdivided four groups age： one group shows discordant age （141±2 Ma, 129± 2 Ma）, while three groups show concordant ages （the weighted averages as 116. 2 ±3.4 Ma, 112. 5± 1.1 Ma and 108.2 ±4. 2 Ma, respectively）. According to the crystalline shape of zircons and CL image characters, the rhyolite formed in late Early Cretaceous, and it took about 8 Ma from magma chamber cooled down to magmatic hydrothermal. Mineralization is related to volcanism of Fulin Formation, which happened later than 108 Ma. The mineralization occurred concurrently with the later Mesozoic large scale epithermal Au deposits of continental margin in northeastern China.

关 键 词：流纹岩 单颗粒锆石U-PB年龄 旁开门金矿床 大兴安岭 

分 类 号：P597[天文地球—地球化学] P618.51[天文地球—地质学]