黑龙江金厂金矿床成矿作用及找矿标志

发布时间：2018-03-29 22:03

  本文选题：金厂金矿　切入点：流体包裹体　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：黑龙江金厂金矿床位于元古界太平岭隆起与中生代老黑山断陷的交接部位,属于兴凯湖地块南段。该区南邻华北板块北缘,北邻佳木斯、兴凯地块,位于中亚—蒙古构造域和滨西太平洋构造域交接复合区段。本文在金厂金矿床已有地质资料收集整理、野外调研及室内分析测试等基础上,总结区域地质背景和矿体特征,研究了金厂金矿床的流体包裹体特征、同位素特征,分析了矿床成因;并通过物化遥综合分析,总结找矿标志,获得以下主要认识:本文将矿区内矿体分为两类:早期的角砾岩型矿体及晚期的裂隙充填脉型矿体。其中,角砾岩型矿体在矿区内分布较多,包括侵入角砾岩型和坍塌角砾岩型,受北西向断裂控制,在北西向呈串珠产出;裂隙充填型矿体分为环状蚀变岩型、岩浆穹隆型及放射状裂隙充填型矿体,主要集中在半截沟一带,受深部岩浆上侵和塌陷影响形成的环状断裂、放射状裂隙构造。对于角砾岩型矿体,其流体包裹体类型主要是纯气相、气液两相、含子矿物流体包裹体,且J-0、J-11温度最高,J-1温度较低,J-9居中,认为含矿热液以两个岩体为起始中心,沿北东向J-0至J-1和北西向J-11至J-1运移,最终形成各矿(化)体。裂隙充填型矿体的流体包裹体以气液两相及含子矿物流体包裹体为主,Ⅱ号矿体、Ⅲ号脉群及18号矿体成矿温度相近,其中Ⅱ号矿体温度稍高,认为流体从深到浅的顺序为环状蚀变岩型至裂隙充填脉型。通过氢氧同位素数据分析,确定了角砾岩型矿体的流体来源主要是岩浆水,裂隙充填脉型矿体的流体以岩浆水和后期改造水为主。对比δ34SV-CDT(‰)值,裂隙充填脉型矿体中II号矿体稍偏高,18号矿体略偏低;角砾岩型矿体的δ34SV-CDT(‰)值分布较集中,多在2‰~4‰。两类矿体的δ34SV-CDT(‰)值略有不同,但都具有深源硫特征。对比206Pb/204Pb值J-1J-0Ⅱ号矿体;207Pb/204Pb值J-IⅡ号矿体J-0矿体;208Pb/204Pb值J-0J-1矿体Ⅱ号矿体。两类矿体Pb同位素演化稍有不同,但是差别不大,铅同位素数值兼具地幔铅与造山带铅的双重特征,成矿物质主要来源于地幔并有不同程度的地壳物质加入。角砾岩型矿体的找矿标志主要为线性构造的交汇的薄弱部位,以及硅化、黄铁矿化、黄铜矿化等矿化蚀变组合;裂隙充填脉型矿体以环形构造、放射状断裂,及硅化、黄铁矿化、绢云母化、高岭土化为重要的找矿标志。另外,矿区整体以不同岩性、岩相界线的构造薄弱界面,及含子晶、子矿物包裹体和熔融包裹体、高温、高盐度包裹体的出现,表现为金、铜较富集的找矿标志。
[Abstract]:The Jinchang gold deposit in Heilongjiang is located at the junction of the Proterozoic Taiping Ling uplift and the Mesozoic Laoheishan fault depression, and belongs to the southern section of the Xingkai Lake block, which is adjacent to the northern margin of the North China plate to the south, Jiamusi to the north, and Xingkai block to the north. This paper summarizes the regional geological background and orebody characteristics on the basis of geological data collection, field investigation and laboratory analysis and testing of the Jinchang gold deposit. The characteristics of fluid inclusions and isotopic compositions of the Jinchang gold deposit are studied, and the genesis of the deposit is analyzed. The main conclusions are as follows: in this paper, the orebodies in the mining area are divided into two types: the early breccia orebodies and the late fissure-filled vein orebodies, in which the breccia orebodies are more distributed in the mining areas. Including intrusive breccia type and collapse breccia type, controlled by NW fault and produced in NW direction, fissure filling orebodies are divided into annular altered rock type, magmatic dome type and radial fissure filling type orebody. It is mainly concentrated in the area of Banjiagou, which is formed by deep magmatic intrusion and collapse. For breccia type orebodies, the fluid inclusions are mainly pure gas phase and gas-liquid two-phase. The fluid inclusions containing sub-minerals, and the highest temperature of J-0 ~ (-11) and the lower temperature of J ~ (-1) are considered as the center of the hydrothermal fluid. It is considered that the hydrothermal solution of ore-bearing body is centered on two rock masses, and migrates from J-0 to J-1 and J-11 to J-1 from NW to J-1. The fluid inclusions of fissure-filled orebodies are mainly gas-liquid two-phase and submineral fluid inclusions, and the ore-forming temperatures of No. 鈪，

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