黑龙江省东宁县金厂金矿成矿作用分析及找矿思考

Gold mineralization analysis and prospecting considerations of Jinchang Gold Deposit in Dongning County,Heilongjiang Province

金厂金矿床为特大型金矿床,矿化类型包括隐爆角砾岩筒型、裂隙充填型、似层状微细脉浸染型和蚀变岩型,且以隐爆角砾岩筒型和裂隙充填型矿化为主。矿区主要存在印支晚期、燕山晚期2期岩浆活动。对矿床基本特征和成矿作用的分析认为,燕山晚期花岗斑岩体与金矿体在空间上紧密相伴,形成时间上较为一致,发育有成矿流体出溶的直接证据,提供了成矿的物质、流体和热动力条件,是成矿的地质体;大面积发育的印支晚期闪长质和花岗质岩浆岩只是赋矿围岩,闪长玢岩体主要与铅锌矿化有关;成矿潜力尚需深入研究,区域隆升可能导致矿床的风化剥蚀,深部找矿前景值得深入思考;下步找矿应着重考虑花岗斑岩体发育地带、存在东西向构造带、存在多金属硫化物矿化和石英-黄铁矿脉型矿化叠加等因素。

Jinchang Gold Deposit is a super large-scale gold deposit. Its mineralization type includes crypto-explosive breccia type,fissure filling type,layer-like micro-fine grain dissemination type and alteration type,dominated by crypto-explosive breccia type and fissure filling type mineralization. 2 phase magmatic activities namely the late IndoChinese and late Yanshanian existed in the deposit. Analysis of the basic features and mineralization of the deposit considers that granitic porphyry in late Yanshanian is closely related with gold-copper ore body in space and their formation period is close; there is direct evidence of ore-forming fluids exsolution,which provides ore-forming materials,fluids and thermodynamic conditions,indicating that the granitic porphyry in late Yanshanian is the ore-forming geologic body; the late Indo-Chinese dioritic and granitic magmatite developing in large areas are merely ore-hosting wall rocks and the dioritic porphyrite is mainly related with lead and zinc mineralization; the metallogenic potentials still needs further research,the regional uplift can lead to weathering and denudation of the deposit and the deep prospecting prospects need further considerations; next-step prospecting should focus on granitic porphyry development zones,EW tectonic belt,polymetallic sulfide mineralization and quartz-pyrite vein type mineralization superposition.