杨庆坤,周万蓬,李德宗.滇东北富锗银铅锌多金属矿集区矿床成因机制及找矿标志[J].有色金属工程,2018,8(3):.
滇东北富锗银铅锌多金属矿集区矿床成因机制及找矿标志
The indicator and genesis of rich Ge-Ag-bearing Zn-Pb polymetallic deposit concentrated district in Northeastern Yunnan,China
投稿时间:2016-10-27  修订日期:2016-11-30
DOI:
中文关键词:  铅锌矿  硫同位素  包裹体  会泽  滇东北
英文关键词:Pb Zn deposit  sulfur isotope  fluid inclusion  Huize  Northeast China
基金项目:中国地质调查局工作项目(12120115041601);江西省教育厅科学技术研究项目(GJJ150554)。
        
作者单位
杨庆坤 东华理工大学地球科学学院
周万蓬 东华理工大学地球科学学院
李德宗 武警黄金部队第十支队
摘要点击次数: 130
全文下载次数: 0
中文摘要:
      滇东北富锗银铅锌多金属矿集区位于扬子板块西缘川黔滇铅锌银多金属成矿域的中南部,关于该矿集区的成矿流体性质及成矿物质来源一直有诸多争论。本文对矿集区内银厂铅锌矿开展了C-O-S同位素及包裹体测温等工作,结合前人的研究资料,对铅锌矿的矿床成因进行了详细的讨论。测得包裹体均一温度为175~275℃左右,与硫化矿的矿物温度计指示的温度一致,表明矿床的成矿温度为中低温。成矿阶段硫化矿的硫同位素变化范围较窄,8.4‰~17.24‰之间,脉石矿物重晶石的δ34S值范围在26.8‰~29.3‰之间,与地幔硫有明显的差异,表明硫源主要来自海相硫酸盐的热化学还原作用。C-O同位素数据显示,成矿期方解石δ13C变化范围在-3.6~-2‰之间,δ18O变化范围在17~18.6‰之间,围岩δ13C为-3.6~-0.7‰,δ18O为19.1~23.1‰,两者较为接近。结合前人对该成矿区进行的C-H-O-Pb-Sr等同位素综合分析以及流体包裹体的均一温度-盐度相关图,认为其成矿物质与古老基底或碳酸盐围岩等有关,成矿流体主要来自地层水。当矿源层随着地壳的演化恰好位于潜水面以下、地下水滞流带以上的还原带范围内时,激发了成矿元素的活性。分散在围岩中金属元素在中-偏碱性的还原环境下溶解成络合离子而迁移,随着成矿流体温度的逐渐下降便在有利的岩性空间、构造条件下聚集沉淀形成具有工业价值的金属硫化物矿床。矿体的控矿空间主要为临近矿源层的各类逆断层附近的次级断裂或层间破碎带等,黄铁矿化、重晶石化是主要的蚀变矿物,地表铁帽是原矿风化产物。
英文摘要:
      The rich Ge-Ag-bearing Zn-Pb polymetallic deposit concentrated district in Northeastern Yunnan is in the south central part of the Pb Zn Ag polymetallic metallogenic domain in Sichuan and Guizhou of the western margin of the Yangtze block of Yunnan, is strictly controlled by fracture zone. The reserves of Zn and Pb and other metals are more than 5 million tons, ore grade is between 35%~25%. But, There are a lot of controversies about the character of the ore forming fluid and the source of ore forming material. In this paper, the sampling of the Yinchang Ag Pb Zn deposit in the ore concentration area is carried out, and the authors had some tests on the C-O-S isotope and fluid inclusion temperature measurement. Combining with previous information, the genesis of the deposit is discussed in detail in the paper. The uniform temperature of the fluid inclusions is about 175-275 ℃, which is consistent with the temperature of the mineral thermometer of the sulphide ore, and the combination of the previous research data indicates that the mineralization temperature of the Yinchang deposit is medium low temperature. The sulfur isotope range of sulfide ore in the metallogenic stage is narrow, 8.4 ‰1000-17.24‰, the barite is between 26.8‰-29.3‰, these are obviously different with mantle sulfur, these show that sulfur source mainly from the thermochemical reduction of marine sulfate. The C-O isotope data shows that theδ13C of the calcite in the metallogenic stages is between 3.6-2‰, 18O is 17-18.6‰, the 13C the surrounding rock of is 3.6-0.7‰, 18O is 19.1-23.1‰, they are closer to each other. Based on the comprehensive analysis of C-H-O-Pb-Sr and other isotopes in this metallogenic region, it is considered that the ore-forming fluid is mainly derived from the formation water of the ancient basement or the surrounding rock. When the ore source layer with the evolution of the earth's crust is located exactly at the reduction zone which is between the dive and groundwater stagnant zone, the activity of ore-forming elements is stimulated. The metal elements which is dispersed in the surrounding rock in reductive environment of alkaline dissolved into complex ion and began to move, when the external physical and chemical conditions change or the primitive fluid encounters the partial acidic atmospheric water, the sulfide deposits of industrial value are formed under the favorable lithologic spatial and structural conditions. The ore controlling space of the ore body is mainly the secondary fault or the interlayer fracture zone near the source layer. Pyritization, baritization are the main alteration minerals, the gossan is weathering products of ore surface.
查看全文  查看/发表评论  下载PDF阅读器
关闭