广东河台金矿糜棱岩化过程构造-流体成矿研究  

Structure-fluid related mineralization during the mylonitization process in the Hetai goldfield,Guangdong Province

作　　者：朱江建[1,2,3] 陈广浩[4,5] 龚贵伦[1,2,6,3] 易金[1,2,3] 蔡建新[4,5] 龚朝阳[7] 黄栋林[7] 曾乔松[1,2] 林舸[1,2] 

机构地区：[1]中国科学院矿物学与成矿学重点实验室 [2]广州地球化学研究所,广东广州510640 [3]中国科学院研究生院,北京100049 [4]中国科学院边缘海地质重点实验室 [5]南海海洋研究所,广东广州510301 [6]中国人民武装警察部队黄金第十一支队,湖南宁乡410600 [7]广东高要河台金矿,广东肇庆526127

出　　处：《地学前缘》2011年第5期67-77,共11页Earth Science Frontiers

基　　金：国家重点基础研究发展计划"973"项目(2007CB411402);中国科学院广州地球化学研究所创新项目(A15-030513)

摘　　要：为了探讨糜棱岩化过程中的成矿作用,文章对广东河台金矿进行了构造流体过程的数值模拟研究。根据力的分解、显微构造及运动学涡度分析以及与模拟结果的对比,提出108°方向的双向挤压作用可能是本区糜棱岩化带形成时的力学环境。数值模拟结果结合前人研究成果表明,体积应变增量异常带有利于糜棱岩化和流体的聚集以及糜棱岩化过程中成矿作用的进行,并为后期的热液成矿作用提供容矿构造。结合前人研究成果,限定糜棱岩化带形成时的温度为300～500℃,形成时代为212～168Ma,糜棱岩化过程中的成矿温度主要集中于300～340℃,成矿时代主要集中于197～168Ma。糜棱岩化作用可能形成未达到工业品位的含矿糜棱岩化带,在此基础上叠加后期热液成矿作用,形成了河台金矿床。A numerical modeling of the structure-fluid process during mylonitization was conducted in order to investigate the possibility of gold mineralization related to mylonitization.Based on stress analysis and microstructural studies and comparison with modeling results,it is proposed that the study area was under compression in the direction of 108° during the formation of the mylonitized zones.The results of numerical modeling,together with previous studies,suggest that anomalous belts of volumetric strain increment are favorable for mylonitization and syn-mylonitization mineralization,and provide favorable site for later hydrothermal mineralization.It is proposed that mylonitization took place from 212 to 168 Ma at temperature from 300 to 500 ℃,and the syn-mylonitization mineralization process occurred from 197 to 168 Ma at temperature from 300 to 340 ℃.Uneconomic mineralization may have been produced during mylonitization,which was upgraded by later hydrothermal mineralization to form the Hetai gold deposit.

关 键 词：河台金矿 糜棱岩化带 动力环境 数值模拟 体积应变增量 

分 类 号：P54[天文地球—构造地质学] P618.51[天文地球—地质学]