黑龙江白岭铜锌矿床成矿岩体形成时代及成矿构造背景  

Formation age and tectonic setting of ore-forming rock body in Bailing copper-zinc deposit, Heilongjiang Province

作　　者：薄军委 杨言辰[1] 李骞[2] 马晓阳[2] 韩世炯[1] 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [2]黑龙江省地质矿产局,黑龙江哈尔滨150036

出　　处：《矿床地质》2016年第2期225-244,共20页Mineral Deposits

基　　金：中国地质调查局地质调查项目(编号:1212011120342;12120113098300)的资助

摘　　要：黑龙江白岭铜锌矿床位于兴蒙造山带东段,小兴安岭-张广才岭成矿带中部,是滨东Cu-Mo-PbZn-Fe矿集区矽卡岩型矿床的典型代表。LA-ICP-MS锆石U-Pb年龄显示,与成矿关系密切的正长花岗斑岩的锆石加权年龄为(177.7±1.5)Ma和(175.6±1.3)Ma,表明在早侏罗世滨东矿集区发生过一期重要的岩浆-热液成矿事件,其元素地球化学具有富碱、弱铝质、轻稀土元素富集、Eu中等负异常、富集大离子亲石元素、亏损高场强元素的特点,属于高分异I型花岗岩,具有活动大陆边缘弧岩浆地球化学属性。Rb/Sr比值>3.5,Nb/Ta比值≈11,且极度富集Pb,显示出壳源特征。结合东北地区的构造演化,研究表明白岭铜锌矿床成矿岩体形成于早侏罗世太平洋板块俯冲背景之下,为增厚地壳部分熔融的产物。The Bailing Cu-Zn deposit, located in the eastern Hinggan-Mongolian orogenic belt and the middle Xiao Hinggan Mountains-Zhangguangcai Mountain metallogenic belt, is a typical representative of skarn type deposits in the Bingdong Cu-Mo-Pb-Zn-Fe ore concentration area. Zircon U-Pb age by LA-ICP-MS shows that ore-related syenogranite-porphyry from the Bailing Cu-Zn deposit has weighted average ages of（ 177. 7 ± 1. 5）Ma and（ 175. 6 ± 1. 3） Ma, which indicate that there was an important magmatic-hydrothermal mineralization event that occurred in the Bindong ore concentration area in the Early Jurassic. The syenogranite-porphyry is characterized by rich alkali, weak alumina, light REE enrichment, moderate negative Eu anomaly, enrichment of large ion lithophile elements and loss of high field strength elements, thus belonging to high differentiation I-type granite with geochemical characteristics of active continental margin arc magmatic rock. Trace element features（ Rb / Sr 〉3. 5, Nb / Ta≈11 and extremely concentrated Pb） indicate that the granite porphyry might have originated from the crustal source. Combined with the tectonic evolution in northeast China, the authors hold that the ore-forming rock body of the Bailing Cu-Zn deposit formed in the background of the Pacific plate subduction in the early Jurassic, being the product of partial melting of thickened crust.

关 键 词：地球化学 成矿时代 构造背景 白岭铜锌矿 黑龙江 

分 类 号：P618.41[天文地球—矿床学] P618.43[天文地球—地质学]