黑龙江东安金矿床锆石U-Pb年龄及其地质意义  

ZIRCON U-Pb AGES OF DONGAN GOLD DEPOSIT IN HEILONGJIANG PROVINCE:Geological Implication

作　　者：马芳芳[1] 孙丰月[1] 李碧乐[1] 薛明轩[1,2] 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [2]黑龙江省有色金属地质勘查707队,黑龙江绥化152054

出　　处：《地质与资源》2012年第3期277-280,共4页Geology and Resources

摘　　要：通过LA-ICPMS锆石原位定年方法,对黑龙江东安金矿成矿期脉岩流纹斑岩进行了年龄测定.结果显示,与矿化关系极为密切的流纹斑岩的U和Th含量分别为269.1×10-6～956.0×10-6和202.2×10-6～1276.8×10-6,Th/U比值介于0.43～1.80之间.流纹斑岩206Pb/238U年龄的加权平均值为109.6±1.7 Ma,与区内浅成低温热液金矿的成矿年龄相近,共同记录了本区早白垩世晚期的一次重要成岩成矿事件,反映了早白垩世晚期岩石圈大规模伸展减薄的动力学背景.The age of the rhyolite porphyry, which is closely related to mineralization in Dongan gold deposit, is tested with LA-ICPMS zircon dating method. The results show that, the U contents of the rhyolite porphyry range from 269.1×10-6 to 956.0×10-6, while the Th contents, from 202.2×10-6 to 1276.8×10-6, with Th/U ratio between 0.43 and 1.80. The age of rhyolite porphyry is （ 109.6±1.7 ） Ma, which is synchronous with other epithermal gold deposits in the area. It implies the large-scale lithospheric extension and thinning in the late period of Early Cretaceous.

关 键 词：锆石U-PB年龄 地质意义 矿化关系 东安金矿床 黑龙江省 

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