陕西铅硐山大型铅锌矿床热水沉积岩相特征

陕西凤县铅硐山大型铅锌矿床赋存于中泥盆统吉维特晚期之上的热水沉积岩相中，其微相可划分为热水沉积岩相、热水沉积－交代岩相、热水同生沉积岩相及后期改造的热水沉积岩相。其岩石中高SiO_２、FeO、CaO、MgO、MnO、As、Sb、Cu、Pb、Zn、Ag、B、Ba等元素，是由富Fe２＋、Si４＋的Ca２＋－Mg２＋－K＋－HCO－_３－Cl－型成矿流体、富Si４＋的Ca２＋－Mg２＋－SO２－－Cl－（CO_２－CO－H_２O）型成矿流体及高盐度的海水三者相互混合，而引发的同生沉积－交代作用所形成。成矿热流体大规模运移的机理是泥盆纪秦岭微板块在深部向华北板块俯冲挤压，使流体向上运移，浅表拉伸形成盆地，而使沿同生断裂上升的成矿流体迁移到三级盆地中，从而形成了热水沉积岩相。不同流体混合及酸碱性、氧化－还原性的骤变是造成矿质大量沉淀的机理，三级热水盆地及矿层上覆砂炭泥质岩层是矿层良好的赋存空间和保存条件。

Characteristics of Sedimentary Facies of Hydrothermal for Qiantongshan Giant Lead-zinc Ore Deposit,Feng County,Shanxi Province

Qiantongshan giant lead-zinc ore deposit,Feng County,Shanxi Province occurs at Middle Devonian sedmentaty facies formed by hot fluid. With higher contents of SiO_２、FeO、CaO、MgO、MnO、As、Sb、Cu、Pb、Zn、Ag、B、Ba,five sedmentary-metasomatic, syngenetic-sedimentary subfacies formed by hot fluid and sedimentary subfacies of hot fluid imposed by epigenetic hot fluid.These subfacies were formed by syngenetic sedimentation and metasomatism which were produced by mixing of Ca２＋－Mg２＋－K＋－HCO－_３－Cl－type of ore forming fluid with higher contents of Fe2+adn Si4+,Ca２＋－Mg２＋－SO２－－Cl－（CO_２－CO－H_２O）type of ore-forming fluid with higher contents of Si4+and sea water with higher salinity.Migration mechanism of ore-forming fluid at large-scale were possible caused by the compression produced by the Qinling subplate subducing into the Huabei plate deeply.Ore-forming fluid migrated up along syngenetic fault and moved into basins which were caused by the extension of Earth Crust at surface.So sedimentaty facies of hot fluid occured.