黑龙江省老柞山金矿床成矿流体特征及矿床成因  

Characteristics of Ore-Forming Fluid and Genesis of Laozuoshan Gold Deposit,Heilongjiang

作　　者：吴猛 李怡欣 刘桂香[4] Wu Meng;Li Yixin;Liu Guixiang(College of Earth Sciences,Jilin University,Changchun 130061,China;Geological Minerals Testing and Application Institute of Heilongjiang Province,Harbin 150036,China;Shandong Gold Resources Development Co.,Ltd,Jinan 250100,China.;Shenyang Geological Survey Center,China Geological Survey,Shenyang 110034,China)

机构地区：[1]吉林大学地球科学学院,长春130061 [2]黑龙江省地质矿产测试应用研究所,哈尔滨150036 [3]山东黄金资源开发有限公司,济南250100 [4]中国地质调查局沈阳地质调查中心,沈阳110034

出　　处：《吉林大学学报（地球科学版）》2018年第5期1353-1364,共12页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(40772052);中国地质调查局地质调查项目(12122011085530)~~

摘　　要：黑龙江省老柞山金矿床位于兴蒙造山带东段佳木斯地块的中北部,是佳木斯金多金属成矿区的一座大型矿床,金主要赋存在NW向、NWW向的张性断裂及花岗岩和钙质大理岩、钙质片麻岩的接触构造带内,成矿与矽卡岩密切伴生。根据野外和室内研究,成矿阶段可划分为矽卡岩阶段、氧化物阶段、早期石英硫化物阶段、晚期石英硫化物阶段和石英-方解石阶段。为揭示流体演化过程,本文选择石榴子石、石英和方解石开展了流体包裹体研究。包裹体岩相学显示,流体包裹体类型有含子晶三相、气液两相(富液相、富气相)、纯液相和纯气相包裹体。测温结果表明:从早到晚均一温度依次为448~462、240~509、166~480、118~360和57~230℃;在矽卡岩阶段盐度(w(NaCl))为9.21%~10.37%,在氧化物阶段为1.73%~13.77%,中低盐度,在早期石英硫化物阶段为1.73%~23.71%和23.64%~39.66%,在晚期石英硫化物阶段为3.05%~6.44%,在石英-方解石阶段为1.73%~11.95%。高温中低盐度且富含CO_2、H_2O和少量CH_4的初始成矿流体,在氧化物阶段流体"沸腾",CO_2逃逸,生成磁铁矿;在早期石英硫化物阶段流体持续沸腾,pH值升高,由氧化转化为还原,卸载金和毒砂、黄铁矿等硫化物;在晚期石英硫化物阶段温度降低,卸载方铅矿、闪锌矿等低温矿物和金。因此,推测老柞山金矿床属于矽卡岩型金矿床。The Luozuoshan gold deposit is located in the north-center of Jiamusi massif of Eastern of Xingmeng orogenic belt,which is a large deposit in the Jiamusi gold metallogenic area.The ore bodies are hosted in the NW and NWW trend extension fractures and the contact zone between the granite and calcareous marble and gneiss,and the mineralization is closely associated with skarn.According to the field and laboratory studies,the authors divided the mineralization process into five stages,i.e,skarn,oxide,early sulfide,late sulfide,and quarts-calcite stages.The inclusion petrography shows that the fluid inclusions are mainly composed of daughter-crystal bearing inclusions,gas-liquid inclusions(incl.rich liquid and rich gas inclusions),pure liquid inclusions,and pure gas inclusions.The measured temperatures indicate that the homogeneous temperatures were 448 462℃,240 509℃,166 480℃,118 360℃,and 57 230℃from early to late respectively.The salinities of mineralization were w(NaCl)9.21%10.37%in skarn stage,1.73%13.77%in oxide stage,1.73%23.71%and 23.64%39.66%in early sulfide stage,3.05%6.44%in late sulfide stage,and 1.73%11.95%in quarts-calcite stage.During the oxide stage,the initial ore-forming fluid was of high temperature,low-medium salinity,and rich in CO 2,H 2O and a little CH 4.The fluid boiled,resulting in the escape of CO 2 and formation of magnetite.The fluid continued to boil at the early sulfide stage,which caused the increase of pH value,the transformation of the fluid from oxidation to reduction,and the deposition of gold and arsenopyrite.With the temperature decrease at the late sulfide stage,the low temperature minerals precipitated,such as galena,sphalerite,and gold.It is presumed that the Laozuoshan gold deposit is a skarn type gold deposit.

关 键 词：佳木斯地块 老柞山金矿床 流体包裹体 流体演化 矿床成因 

分 类 号：P618.51[天文地球—矿床学]