黑龙江省东宁县金厂金矿床角砾岩筒型金矿化特征及找矿评价标志

发布时间：2018-05-06 02:36

本文选题：角砾岩筒 + 金矿床　；参考：《吉林大学》2017年硕士论文

【摘要】：金厂矿床位于我国黑龙江省东宁县境内,是由武警黄金部队第一支队发现的一处特大型金矿床。大地构造位置处于太平岭隆起与老黑山断陷的交接部位。矿区内地层出露较少,断裂构造发育,呈“米”字型构造格局,岩浆岩侵入体广布,先后有五期岩浆侵入活动发生。矿区内有三种矿化类型:角砾岩筒型、细脉浸染型以及环状、放射状裂控型,其中角砾岩筒型矿化是金厂矿区内已发现的规模最大的矿体类型,资源量占矿床总资源量的44%。前人对于矿区内的角砾岩筒缺乏系统的比较,对该类型矿化的找矿评价标志总结得也不够完善,基于此,本文对矿区内的角砾岩筒进行了系统的分类研究及成因研究,以期为找矿勘查工作提供理论支撑。角砾岩筒主要分布于燕山期花岗岩与印支期闪长岩接触带及各类断裂构造的交汇附近,平面上多呈椭圆形或近圆形,剖面上呈筒状或漏斗状。根据含金性及矿物组合的差异将矿区内的角砾岩筒划分为金-铜±钼型角砾岩筒、单金型角砾岩筒以及贫矿型角砾岩筒三种类型。金-铜±钼型角砾岩筒矿石矿物以黄铜矿、黄铁矿为主,其次有少量辉钼矿、赤铁矿、磁铁矿、方铅矿、闪锌矿和自然金,其中Au和Cu均达到工业品位;单金型角砾岩筒矿石矿物以黄铁矿为主,其次有少量黄铜矿、方铅矿、闪锌矿、毒砂和自然金,其中仅Au达到了工业品位;贫矿型角砾岩筒矿石矿物较少,以黄铁矿为主,方铅矿、闪锌矿次之,含矿性极差,不具备工业价值。角砾岩型矿石胶结物石英中原生流体包裹体非常发育,主要有四种类型的包裹体:含固体子矿物多相流体包裹体(S型)、气相-富气相流体包裹体(V型)、含NaCl子矿物三相流体包裹体(SL型)、气液两相流体包裹体(VL型)。流体包裹体显微测温特征及成矿流体氢氧同位素组成显示,角砾岩筒型矿体的成矿流体为挥发相、高温高盐度溶液与熔浆的混合物,大气降水参与程度不高。硫同位素组成显示矿床中的硫为深源岩浆硫,主要来源于地幔,有少量地壳硫加入,结合铅同位素组成特征,推测成矿物质主要来源于地幔,同时有不同程度的地壳物质混入。前人同位素测年成果及本次测试结果显示,角砾岩筒型矿床成矿年龄大约在102.9±2.7 Ma左右;故本文认为角砾岩筒型矿床的形成主要与燕山晚期花岗斑岩(109±2.4Ma)的侵入活动有关,之后的闪长玢岩(97.5±1.1Ma)的侵入活动对角砾岩筒进行了叠加矿化。角砾岩筒的空间分布与矿区内的岩浆岩接触带、断裂构造交汇、矿化蚀变分带及遥感解译出的环状构造存在密切的联系,角砾岩筒型矿体显示出明显的低阻高极化特征,此外,三种类型的角砾岩筒在矿石矿物组合、黄铁矿标型特征、流体包裹体显微测温特征以及土壤地球化学特征等方面存在一定差异,这些为总结角砾岩筒型矿体的找矿评价标志提供了依据。
[Abstract]:The Jinchang deposit, located in Dongning County, Heilongjiang Province, is a super large gold deposit discovered by the first detachment of the Armed Police Gold Army. The tectonic position is located at the junction of Taiping Ridge uplift and Laoheishan fault depression. There are few outcrops in the interior of the mining area, the fault structure is developed, and the magmatic intrusions are widespread, and magmatic intrusions occur in five periods. There are three types of mineralization in the mining area: breccia tube type, vein-impregnated type and annular, radial type, in which breccia tubular mineralization is the largest type of orebody found in Jinchang Mine area, and the resource amount accounts for 44% of the total resources of the deposit. For the lack of systematic comparison of breccia barrel in mining area, the evaluation marks of prospecting for this type of mineralization are not well summarized. Based on this, a systematic study on classification and genesis of breccia tube in mining area has been carried out in this paper. In order to provide theoretical support for prospecting and exploration work. The breccia barrel mainly distributes near the junction of Yanshanian granite and Indosinian diorite contact zone and all kinds of faulted structures. Most of them are elliptical or nearly circular on the plane and the section is tubular or funnel-shaped. According to the difference of gold bearing property and mineral assemblage, the breccia barrel in the mining area is divided into three types: gold-copper 卤molybdenum breccia tube, single gold-type breccia tube and ore-poor breccia tube. The main ore minerals of gold-copper 卤molybdenum breccia barrel are chalcopyrite and pyrite, followed by a small amount of molybdenum, hematite, magnetite, galena, sphalerite and natural gold, among which au and Cu reach industrial grade. The ore minerals of single gold breccia barrel are mainly pyrite, followed by a small amount of chalcopyrite, galena, sphalerite, arsenopyrite and natural gold. Galena, sphalerite is the second, the ore-bearing property is extremely poor, and does not have industrial value. The primary fluid inclusions in quartz, a breccia type mineral cement, are well developed. There are mainly four types of fluid inclusions: multiphase fluid inclusions containing solid subminerals, gas-rich fluid inclusions (V-type), three-phase fluid inclusions with NaCl subminerals (SL type) and gas-liquid two-phase fluid inclusions (VL type). The microthermometric characteristics of fluid inclusions and the hydrogen and oxygen isotopic composition of ore-forming fluids show that the ore-forming fluids of breccia tubular orebodies are volatile phase, the mixture of high-temperature and high-salinity solution and slurry, and the participation of atmospheric precipitation is not high. The sulfur isotopic composition of the deposit shows that the sulfur in the deposit is a deep magmatic sulfur, mainly derived from the mantle, with a small amount of crustal sulfur added. Combined with the characteristics of lead isotopic composition, it is assumed that the ore-forming material is mainly derived from the mantle, and that there are different degrees of crustal material mixed in. The results of previous isotopic dating and this test show that the ore-forming age of breccia tubular deposits is about 102.9 卤2.7Ma, so it is considered that the formation of breccia tube-type deposits is mainly related to the intrusive activity of granitic porphyry (109 卤2.4 Ma) in the late Yanshanian period. The subsequent diorite-porphyrite intrusion of 97.5 卤1.1 Ma has superimposed and mineralized the breccia tube. The spatial distribution of breccia tube is closely related to the contact zone of magmatic rock, the intersection of fault structure, the mineralization alteration zone and the ring structure interpreted by remote sensing. The breccia tube-type orebody shows obvious characteristics of low resistivity and high polarization. There are some differences among the three types of breccia tubes in mineral assemblages, pyrite typomorphic features, microthermometric characteristics of fluid inclusions and soil geochemistry, etc. These results provide a basis for summarizing the criteria for prospecting and evaluation of breccia tubular orebodies.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.51

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