【作者】 徐文喜；

【导师】 张德会；

【作者基本信息】 中国地质大学（北京） ， 地球化学， 2009， 博士

【摘要】 黑龙江省东宁县金厂金(铜)矿田是一个正在勘查中的特大型矿田。论文从岩浆岩特征及其演化、矿床地质特征、成矿流体地球化学、矿床成因及找矿方向等方面开展了深入的研究工作,取得了以下主要成果:(1)岩浆活动分为印支晚期和燕山中期两个旋回,印支晚期包括一个火山活动阶段和3个侵入活动阶段,燕山中期包括2个阶段;岩浆主要来自原始地幔,演化过程中有地壳物质混染。矿化赋存于印支晚期侵入岩中,但Au(Cu)矿化与早白垩世花岗斑岩有密切的时空和成因联系,表明花岗斑岩是成矿母岩。(2)矿田分为隐爆角砾岩型、脉型和细脉浸染型3种矿体类型。矿化分为5个成矿阶段,其中石英-黄铁矿阶段、多金属硫化物-石英阶段为主要成矿阶段。围岩蚀变组合分带自深到浅依次为:钾化带、绢云母化带、青磐岩化带、泥化带,矿化主要赋存在钾化带和绢云母化带中。成矿时代为110Ma左右。(3)矿体石英中包裹体类型复杂,从熔体、熔流包裹体到流体包裹体均有;流体包裹体中含子晶包裹体十分发育,而富气包裹体与含子晶包裹体共存,显示出成矿流体具有沸腾的特征;子晶中常见黄铜矿,表明流体富含铜。流体包裹体均一温度为160->600℃,主要成矿阶段温度为300-450℃,盐度为1.40～73.96%NaCl,属于典型的斑岩金(铜)矿床流体特征。成矿物质主要为岩浆来源,流体沸腾是金属沉淀的主要原因。成矿深度约为2-3千米。(4)矿田具有空间分带规律:从西到东,矿物组合由中高温到中低温矿物组合;元素由Mo、Cu到Au、Ag;成矿的深度由大到小。主要矿体的元素具有轴向分带序列,从上到下为:Hg-Cu-Bi-Au-Ag-Ni-Co-As-Mo-Sb-Pb-Zn,为逆向分带,预示着深部仍可能有盲矿体存在;与Au成矿关系密切的元素组合为Ag、Cu、As、Sb、Bi、Hg。(5)矿田内3种矿体类型同属于一个斑岩成矿系统。综合矿床地质、岩浆岩特征及其演化、围岩蚀变、成矿流体、成矿元素组合、矿床分带等特征,论证了矿床成因类型为斑岩型金(铜)矿床,初步建立了金厂金(铜)矿田成矿模式,指出矿区深部有巨大找矿前景。更多还原

【Abstract】 Jinchang gold(copper)deposit in Dongning County, Heilongjiang Province, is one of the classic gigantic ore fields under exploration. The author carried out an in-depth study in the characteristic and evolution of igneous rocks, geological features, ore-fluid geochemistry, metallogenesis and prospecting orientation aspects, and achieved the following main outcomes:(1) The sequence of magmatic activity of the ore field has went through Late Indosinian and Mid-Yanshanian, in which Late Indosinian is consist of a volcanic activity stage and three intrusive activity stages, and Mid-Yanshanian includes two stages. The magma mainly came from primitive mantle, and there is contamination of crustal materials in the evolution. The mineralization occurs in intrusive rocks of Late Indosinian, but the Au (Cu) mineralization is related closely to the granite porphyry of Lower Cretaceous in space-time and metallogenesis, indicating the granite porphyry is metallogenetic parent rock.(2) Mineralization of gold bodies in the Jinchang gold deposit was divided into three types: cryptoexplosion breccia type, vein type and veinlet-disseminated type. The gold mineralization is comprised of 5 stages from early to late, and quartz-pyrite stage and multimetal sulfide type-quartz stage are the main stage of mineralization. The wall rock alteration consists of 4 zoning, from deep to shallow, potassic zone, sericitization zone, propylitization zone and argillization zone. The deposit was formed about 110 Ma.(3) The fluid inclusion type in the quartz of ore body is complicated, ranging from melt inclusion and melt-fluid inclusion to fluid inclusion, and halite-bearing inclusions are well developed. Studies have shown that vapor-rich fluid inclusions and halite-bearing inclusions coexisted in mineralization fluid indicating boiling characterization. Chalcopyrite is common as daughter minerals, which indicate that the mineralization fluid has a high metal content of copper. The homogenization temperature of fluid inclusions in hydrothermal stage is 160-600℃, while the temperature of the main stage of mineralization is 300-450℃, the salinity is 1.40～73.96% NaCleqv, which indicate that the ore fluid is belong to typical porphyry gold (copper) deposit fluid. The metallogenic materials are mainly from magma, and the fluid boiling is major reason for metal precipitation. The metallogenetic depth is from 2 to 3 km. (4) The ore field has zonation regularity in space. From west to east, the mineral assemblage is corresponding from medium-high temperature to medium-low temperature mineral assemblage, element assemblage is from Mo and Cu to Au and Ag, and the mineralization depth is from deep to shallow. The main ore body has the characteristic of axial element zoning sequence, which, from top to bottom, is Hg-Cu-Bi-Au-Ag-Ni-Co-As-Mo-Sb-Pb-Zn. We can see that the element zoning sequence is inverse zoning which indicates that there might be a blind ore body in deep part. The Ag, Cu, As, Sb, Bi and Hg element assemblage is related closely to the Au mineralization.(5) Three ore body types in the ore field belong to the same porphyry metallogenic system. Combining the characteristic and evolution of igneous rocks, geological features, wall alteration, ore-fluid geochemistry, metallogenic element assemblages and mineral deposits zoning characteristics, the author proved that the deposit belong to porphyry gold (copper) deposit type, and initially established metallogenic model of gold (copper) ore field in Jinchang, and pointed out a great ore-prospecting potential in deep.更多还原