大兴安岭北部比利亚谷铅锌矿黄铁矿Re-Os同位素年龄及He-Ar同位素地球化学特征  

Re-Os isotope age of pyrite and He-Ar isotope of sulfides from the Biliyagu Pb-Zn deposit in the northern Great Xing’an Range

作　　者：马玉波[1] 张勇[1] 李立兴[1] 邢树文 张增杰[1] 张彤 肖克炎[1] 王海坡 范建福[1] MA Yubol;ZHANG Yong;LI Lixing;XING Shuwen;ZHANG Zengjie;ZHANG Tong;XIAO Keyan;WANG Haipo;FAN Jianfu(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,CAGS,Beijing 100037,China;Institule of Geomechanics,CAGS,Beijing 100081,China;Geological Survey of Inner Mongolia,Hohhot,Inner Mongolia 010020,China;The Sixth Institute of Geology and Mineral Resources Develo prment,Imner Mongolia Autonomous Region,Hailaer,Inner Mongolia 021008,China)

机构地区：[1]中国地质科学院矿产资源研究所,自然资源部成矿作用与资源评价重点实验室,北京100037 [2]中国地质科学院地质力学研究所,北京100081 [3]内蒙古地质调查研究院,内蒙古呼和浩特010020 [4]内蒙古自治区第六地质矿产勘查开发院,内蒙古海拉尔021008

出　　处：《地质学报》2022年第4期1265-1278,共14页Acta Geologica Sinica

基　　金：国家重点研发计划项目(编号2017YFC0601303);国家自然科学基金项目(编号41202042);中央级公益性科研院所基本科研业务费专项资金资助项目(编号KK2124、K1211)联合资助的成果。

摘　　要：比利亚谷铅锌矿位于海拉尔-根河中生代火山盆地北西缘的得尔布干成矿带。该矿床赋存于上侏罗统满克头鄂博组酸性火山岩中,受NW向断裂构造控制,主矿体呈脉状产出。由于缺少适合传统放射性同位素定年的矿物,其成矿时代未得到很好的限定,制约了对矿床成因的认识。本文采用矿床中与矿石矿物密切共生的黄铁矿Re-Os同位素定年技术对比利亚谷铅锌矿的成矿时代进行研究。定年结果显示,热液成因黄铁矿Re-Os等时线年龄为133.4±4.4 Ma,与成矿带内其他铅锌矿成矿时间相似,说明得尔布干成矿带内中生代铅锌银矿床基本形成于同一时代。比利亚谷矿床硫化物包裹体He-Ar同位素分析显示,^(3)He/^(4)He比值为0.02~2.37 Ra,^(40)Ar/^(36)Ar比值为293.5~306,表明主成矿期多金属成矿流体主要为地壳流体和饱和大气水的混合,但有少量幔源成分参与。比利亚谷矿床形成于蒙古-鄂霍茨克洋闭合后的碰撞后伸展环境,得尔布干成矿带属于蒙古-鄂霍茨克成矿省的一部分。The Biliyagu Pb-Zn deposit of the Derbugan metallogenic belt is located in the northwest of the Hailar-Genhe Mesozoic volcanic basin. This deposit is hosted in the felsic volcanic rocks of the Upper Jurassic Manketouebo Formation, with mainly veined type ore bodies controlled by the NW-trending faults. Due to lack of suitable minerals for traditional isotopic dating, the ore-forming age remains unknown, which has limited the understanding of the Pb-Zn mineralization. In this study, Re-Os isotopic dating of pyrite associated with galena and sphalerite has been performed to constrain the ore-forming age of the Biliyagu Pb-Zn deposit. Re-Os isotopic dating of hydrothermal pyrite yields an age of 133.4±4.4 Ma, consistent with Pb-Zn mineralization age of the belt, suggesting that the Mesozoic Pb-Zn mineralization in the Derbugan metallogenic belt were generally simultaneous. He-Ar isotopic analyses of fluid inclusions in the sulfides show that the^(3)He/^(4)He and^(40)Ar/^(36)Ar rations are in the range of 0.02~2.37 Ra and 293.5~306, respectively, indicating that the ore-forming fluid in the main metallogenic stage represents a mixture of crustal-derived fluid and saturated atmospheric water, as well as a small amount of mantle-derived components. The Biliyagu deposit was formed in a post-collisional extensional environment after the closure of the Mongolia-Okhotsk ocean indicating that the Derbugan metallogenic belt is a part of the Mongolia-Okhotsk metallogenic province.

关 键 词：比利亚谷铅锌矿 黄铁矿Re-Os同位素定年 HE-AR同位素 成矿时代 成矿物质来源 

分 类 号：P618.2[天文地球—矿床学]