黑龙江省科洛河韧性剪切带型金矿床地质、地球化学特征及成因

Geological and geochemical characteristics of Keluohe ductile shear zone type gold deposit in Heilongjiang Province and its genesis

科洛河金矿床位于黑龙江省多宝山成矿带内,受北东向科洛河—霍龙门—西峰山韧性剪切变形带控制,金矿体呈北东向脉状、透镜状、疏缓波状赋存于韧性剪切带内,为蚀变糜棱岩型矿体。围岩蚀变主要有硅化、黄铁矿化、绢云母化、绢英岩化、绿泥石化等,为矿区重要的找矿标志。韧性剪切带控制着区内金矿床(点)的分布,在矿床范围内对矿化带、矿体的空间产状、形态和规模起决定性的控制作用,构成区域内最重要的控矿构造和赋矿构造。岩石地球化学特征表明,区域内糜棱岩、糜棱岩化花岗岩及中生代闪长(玢)岩,均富Na、Al,富集Rb、Ba、Th等大离子亲石元素(LILE),轻微亏损Zr、Hf、Ta等高场强元素(HFSE),强烈亏损Nb、P、Ti元素,具有典型岛弧火山岩的特征,为原始地幔演化与地壳物质混染的产物,为成矿提供了重要物源和热源,形成了典型的韧性剪切带型金矿床。

Keluohe Gold Deposit is located in the Duobaoshan metallogenic belt of Heilongjiang, which is controlled by the NE trending Keluohe -Huolongmen -Xifengshan selves as vein, lenticular and undulating occurrence in the ductile shear zone. The gold orebodies present them- ductile shear zone, forming the altered mylonite type orebodies. Wall rock alterations are mainly silicification, pyritization, sericitization, beresitization, and ehloritization, which are good ore-prospecting criteria for the area. Ductile shear zone controlled the distribution of the gold deposits （points） in the district. The decisive control of spatial appearance ,form and scale of mineralization belts and orebodies within the deposit makes ductile shear zone the principal ore-controlling and depositing structure. The mylonite, mylonitized granite and the Mesozoic diorite（porphyrite） are all chemically rich in Na and Al, enrich LILE （Rb, Ba and Th） , are lightly deficient in HFSE （Zr, Hf and Ta） and strongly deficient in Nb, P, Ti, indicating the typical characteristics of island arc volcanic rocks that were the interactive product of primitive mantle evolution and crust materials, and the important material source and heat source for mineralization. And so a typical ductile shear zone type gold deposit was formed.