广西大厂笼箱盖岩体黑云母花岗岩锆石裂变径迹年龄及其地质意义  

Zircon fission track (ZFT) age of the Longxianggai pluton in Dachang of Guangxi and its geological significance

作　　者：吴建标 胡云沪[1,2] 皮桥辉[1,2] 韦朝文 李国 杨雄 杨红亮 于会冬 鲁迪 WU Jianbiao;HU Yunhu;PI Qiaohui;WEI Chaowen;LI Guo;YANG Xiong;YANG Hongliang;YU Huidong;LU Di(Earth Science Institute,Guilin University of Technology,Guilin 541004,Guangxi,China;Guangxi Key Laboratory of Exploration for Hidden Metallic Ore Deposits,Guilin University of Technology,Guilin 541004,Guangxi,China;Faculty of Land Resource Engineering,Kunming University of Science and Techology,Kunming 650093,Yunnan,China;Southwest Institute of Geological Survey,Geological Survey Center for Nonferrous Metals Resources,Kunming 650093,Yunnan,China)

机构地区：[1]桂林理工大学地球科学学院,广西桂林541004 [2]桂林理工大学广西隐伏金属矿产勘查重点实验室,广西桂林541004 [3]昆明理工大学国土资源工程学院,云南昆明650093 [4]有色地质调查中心西南地质调查所,云南昆明650093

出　　处：《地质通报》2020年第4期512-522,共11页Geological Bulletin of China

基　　金：国家自然科学基金项目《运用独居石和磷钇矿U-Pb法精确测定卡林型金矿成矿年龄》(批准号:41563004);《晚太古代海水硫酸根硫同位素的非质量分馏效应研究:来自方柱石的证据》(批准号:41973042);广西自然科学基金项目《钦杭结合带南西段高州杂岩变形变质作用及独居石变质年代学研究》(编号:2017GXNSFAA198336)。

摘　　要：广西大厂多金属矿田是世界级的特大型锡多金属矿床,是中国第二大产锡基地;笼箱盖岩体作为区内规模最大的岩体,与成矿有着密切关系。本文运用锆石裂变径迹测年方法制约多幕岩浆侵入活动时限,探讨其与成矿时空关系。研究表明,笼箱盖岩体的锆石裂变径迹年龄分布在160~70 Ma之间,并可划分为多个年龄组,分别为160~150 Ma、120~100 Ma和90~70Ma,具有3期明显的次热历史,揭示笼箱盖岩体的形成经历了3期岩浆侵入活动。大厂多金属矿田的成矿与早白垩世(120~100 Ma)环太平洋板块俯冲影响下的岩石圈伸展期的花岗岩侵位事件相关。岩浆侵入活动不仅为成矿提供部分含锡多金属及对活化迁移成矿元素有利的挥发性气体的初始热流体,还为早期矿化的下部地层中成矿物质迁移、富集提供强大的热能和必要的物理化学条件。The Dachang polymetallic orefield in Guangxi is a world-class superlarge tin polymetallic deposit and the second largest tin production base in China.As the largest pluton in this area, Longxianggai pluton is closely related to mineralization.In this paper, zircon fission track dating method was used to restrict the time limit of multi-episode magmatic intrusion activity and explore its temporal and spatial relationship with mineralization.The results show that the zircon fission track ages of the Longxianggai pluton range from 160 Ma to 70 Ma, and can be divided into several age groups, i.e., 160 ~ 150 Ma, 120 ~ 100 Ma and 90 ~ 70 Ma, respectively.It obviously has three stages of thermal history, which reveals that the formation of Longxianggai pluton experienced three stages of magmatic intrusion.The metallogenesis of the Dachang polymetallic orefield was related to the granite emplacement during the lithospheric extension period under the influence of the subduction of the 120 ~ 100 Ma circum-Pacific plate in the Early Cretaceous (120 ~ 100 Ma).Magmatic intrusion activity not only provided the initial thermal fluid with some tin bearing polymetallic and volatile gases favorable for the activation and migration of ore-forming elements but also provided strong thermal energy and necessary physicochemical conditions for the migration and enrichment of ore-forming materials in the lower strata of early mineralization.

关 键 词：锆石裂变径迹 岩浆侵入活动 笼箱盖岩体 大厂多金属矿田 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学]