投稿时间:2014-12-24
修订日期:2015-12-18
网络发布日期:2016-02-24
中文摘要:黑龙江省呼玛县天望台山金矿床位于大兴安岭北段,古利库-呼玛火山 断陷盆地边缘的天望台山火山机构北部。文章将该矿床热液成矿期划分为4个成矿阶段:( Ⅰ)石英-黄铁矿阶段;(Ⅱ)石英-金-多金属硫化物阶段;(Ⅲ)石英阶段;(Ⅳ)方解 石阶段。其中,第Ⅱ阶段为主成矿阶段。该矿床流体包裹体相态类型主要为富液两相型和富 气两相型,另 有少量纯液相型和纯气相型。各阶段成矿流体的均一温度峰值区间为:280~320℃→240~2 80℃→220~260℃→200~240℃,成矿流体具有中低温的特点,其盐度、压力、密度和成矿 深度显示出浅成低温热液型矿床的特点。主成矿阶段流体气相成分主要为H2O、CO2、N 2和O2,液相中离子成分主要有Na+、K+、Ca2+和SO2-4、Cl-。主 成矿阶段流体的δDV-SMOW范围为-1635‰~-1319‰,δ18OV-SMOW 范围为-112‰~-91‰,反映成矿流体为大量大气降水和少量岩浆水的混合。主成矿阶 段强 烈的降温降压作用可能是导致成矿元素沉淀成矿的主要机制。此外,本次的流体包裹体研究 结果表明该矿床的成矿流体在主成矿阶段发生过流体不混溶作用。因此,本文认为成矿流体 强烈的降温降压作用,以及伴随着的流体不混溶是天望台山金矿床的成矿机制。
Abstract:The Tianwangtaishan gold deposit is located in the northern segment of Tianwangt aishan volcanic edifice on the margin of Guliku-Huma volcano-graben basin, and l ies in North Da Hinggan Mountains. Four ore-forming stages have been recognized, i.e., quartz-pyrite stage (Ⅰ), quartz- gold-polymetallic sulfide stage (Ⅱ), q uartz stage (Ⅲ), and quartz-calcite stage (Ⅳ). And the metallogenesis mainly occurred in stage (Ⅱ). A large number of liquid-rich two-phase type and gas-ric h two-phase type fluid inclusions, together with a few pure liquid single-phase t ype and pure gas single phase type fluid inclusions, dominated all mineralizatio n stages. Homogenization temperatures of fluid inclusions in four stages are con centrated on 280~320℃→240~280℃→220~260℃→200~240℃, which demonstrates that the ore-forming fluid had intermediate-low temperature characteristics. The sal inities and pressures of ore-forming fluids and the metallogenic depth show the same features as the epithermal deposit. The gaseous content of mass fluid inclu sions is mainly composed of H2O, CO2,N2 and O2, while aqueous component s mainly contain Na+, K+, Ca2+ and SO2-4, Cl-. δDV-SMOW of the fluid is between -1635‰ and -1319‰,whereas δ18OV-SMO W of the fluid is between -112‰ and -91‰, which suggests that the source of or e-forming fluid was made up of a large amount of meteoric fluids with lesser amo unts of magmatic fluids. The intense cooling and depressurization during the mai n stage was the most important reason for the precipitation of metallogenic elem ents. In addition, a study of fluid inclusion assemblages in stage (Ⅱ) suggests that immiscibility occurred during the main ore-forming stage. It is thus held that the intense cooling and depressurization of ore-forming fluid, associa ted with its immiscibility, are the main metallogenic mechanisms of this gold de posit.
文章编号:
中图分类号:P618.51
文献标志码:
基金项目:本文由“大兴安岭北段典型矿床剖析及成矿模式专题研究”项目(编号: SDK2010-25)资助
引用文本:
曾国平,姚书振,何谋春,熊索菲,陈斌.2016.黑龙江省呼玛县天望台山金矿床成矿流体特征与成矿机制研究[J].矿床地质,35(1):85~102ZENG GuoPing,YAO ShuZhen,HE MouChun,XIONG SuoFei,CHEN Bin.2016.Ore-forming fluid and metallogenic mechanism of Tianwangtaishan gold depos it, Heilongjiang Province[J].Mineral Deposits35(1):85~102
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