湖南白马山—龙山金矿带包裹体-同位素地球化学及成矿流体特征  

Inclusion-isotope geochemistry of the Baimashan-Longshan gold metallogenic belt in Hunan and its ore-forming fluids′ characteristics

作　　者：吴继承[1] 王金荣[1] 欧建 汪双双[1] 杨淑芬[1] 李已华[2] 

机构地区：[1]兰州大学资源环境学院,甘肃兰州730000 [2]武警黄金技术学校,湖北襄樊441002

出　　处：《矿产与地质》2007年第6期673-678,共6页Mineral Resources and Geology

摘　　要：文章测试了白马山—龙山金矿带中龙山、古台山、高家坳一带金矿床的石英包裹体水的δ18D‰、δ18O‰值,龙山、古台山一带金矿床石英δ18D值具有相似变化范围,变化范围为-59‰^-66‰,极差不大(7‰),分析结果认为本区成矿流体与区域液体主要为大气降水。而高家坳一带金矿中石英δD值变化较大为-57.7‰^-87.7‰,极差达30‰,矿液为封存于地层中的原生水与大气降水混合而成。龙山一带金矿床硫化物的δ34S值变化不大,大部分样品集中在-2.0‰^+2.0‰之间,硫主要来源于深部岩浆,少量来自于地层。产于中泥盆统半山组中的高家坳一带金矿硫化物δ34S值变化范围大,集中在6.21‰~22.25‰的,反映其硫主要来自沉积岩层的硫化物。这些同位素特征表明,白马山—龙山金矿带经历了多期成矿作用,早期为成矿流体与大气降水混合成矿;晚期为地下热水为主,有变质水及岩浆水混合的混合型成矿溶液。The δ18D‰,δ18O‰ of the liquid inclusion in quartz of the Longshan,Gutaishan and Gaojia'ao gold deposit in the Baimashan-Longshan gold metallogenic belt has been tested.It has found that the δ18D value of the quartz of the Longshan gold deposit has a similar changing range with that of the Gutaishan gold deposit,that is-59‰～-66‰ with a small range of 7‰,and the analyzing results has believed that the ore-forming fluids and regional liquid of this area are mainly precipitation.Besides,the δ18D value of the quartz in the Gaojia'ao gold deposit has a larger changing range,that is-57.7‰～-87.7‰ with the range reaching 30‰,and the ore fluids are precipitation mixed with the original liquid sealed in strata.The changing range of the δ34S value of the sulfide in the Longshan gold deposit is small with most samples' ranges focusing-2.0‰^+2.0‰,and the sulfur mainly comes from deep magma with a little from strata.Whereas,the changing range of the δ34S value of the sulfide in the Gaojia'ao gold deposit occurred in the Banshan Formation of Middle Devonian is larger with the range concentrating on 6.21‰~22.25‰,which shows that the sulfur mainly comes from the sulfide held by sedimentary rocks.The isotope characteristics have shown that the Baimashan-Longshan gold ore belt has experienced several ore-forming phases,of which the earlier phase is the ore-forming fluids mixed with precipitation,while the later phase is mainly underground hydrotherm and some mixing ore-forming fluids combined by metamorphose liquid and magmatic water.

关 键 词：流体成矿 成矿特征 同位素地球化学 白马山-龙山金矿带 湖南 

分 类 号：P618.51[天文地球—矿床学]