【作者】 曹烨；

【导师】 李胜荣；

【作者基本信息】 中国地质大学(北京) ， 矿物学、岩石学、矿床学， 2012， 博士

【摘要】 本文运用成因矿物学的方法，对金矿床进行了系统的造岩矿物学、矿石矿物学、包裹体矿物学、同位素地质学和找矿矿物学的研究，并对矿床成因、控矿因素和成矿规律进行了总结，圈出了3个的富矿段远景区。确定了矿床成因类型为岩浆期后热液型脉状金矿床，划分4个成矿阶段，确定了矿物的生成顺序，整个成矿作用总体经历了从氧化→还原→氧化的过程，金的主成矿期为还原环境。矿石中常见独立金矿物，金矿物的成色较低（442-926），多为银金矿；矿石矿物主要有黄铁矿、闪锌矿、方铅矿、黄铜矿、磁铁矿和磁黄铁矿。麻棚岩体和脉岩均属亚碱性系列中的高钾钙碱性系列，二者具有埃达克质岩石的特征。得出了可能的岩石成因，玄武质岩浆底侵下地壳，导致太古宙TTG基底部分熔融产生花岗质岩浆，玄武质岩浆和花岗质岩浆混合后再经历分离结晶作用，并且在其上升侵位过程中受到了地壳的混染。麻棚岩体和脉岩的结晶年龄为130Ma，含金石英脉中的锆石年龄为1433Ma-2530Ma，不能代表石英脉的结晶年龄。综合石英的Ar-Ar和Rb-Sr年代学研究认为，石湖金矿的成矿年龄的上限为130Ma。碳酸盐的δ¹³C、矿石Pb同位素、S同位素、黄铁矿He-Ar同位素研究得出，成矿物质、成矿流体的来源有明显地地幔物质的参与，同时与地壳物质进行了强烈地交换。石英H-O同位素反映了成矿流体的特点为岩浆水或变质水与大气水的混合。提出前寒武纪基底为矿源层。石英中主要有富CO₂和富H₂O两类流体包裹体。成矿流体属中高温、中低盐度K⁺-Na⁺-Ca²⁺-Cl^--SO₄^2-型，气相成分以H₂O和CO₂为主，其次为少量CH₄、C₂H₆、Ar和N₂。估算了成矿深度为5.93km-8.03km，平均7.02km，为中浅成矿床。提出石湖金矿是中生代克拉通破坏使软流圈物质上涌并与岩石圈物质相互作用的结果。预测了三个富矿段远景区。第Ⅰ远景区：180m至100m中段的北部19线至31线，3线至11线。第Ⅱ远景区：50m中段以下的27线或31线以南，以及3至15线。第Ⅲ远景区：在0m或50m中段以下3线以南地段。更多还原

【Abstract】 The Shihu deposit, which is a well known quartz vein type gold deposit in thenorthern part of the Taihang orogen of the North China craton （NCC）, is hosted byductile-brittle faults within Archean metamorphic core complex of the Fuping Group.The ore genesis, ore-controlling factores and metallogenic laws were discussed, andthe two new prospecting targets in the Shihu gold deposit were predicted based on thedata of rock-forming mieneralogy, ore mineralogy, inclusion mienralogy, isotopicgeochemistry and prospecting mineralogy .The Mapeng granitic stock is one of the most important plutons in the Shihu areawas emplaced into the Archean Fuping complex. Mafic enclaves are randomly foundthroughout the granitic plutons. The composition of total tocks and rock-formingmineralogical chemistry indicated that the pluton is adakitic rock with pronouncedmixture of crust and mantle. The pluton mainly contains magmatic zircons with theage at ca. 130Ma, and also includes minor inherited zircon （1.7².5Ga） probablycoming from the basement.40Ar/39Ar and Rb-Sr geochronology suggest themineralized quartz vein formed during Mesozoic era. Therefore, it is suggested thatthe age of 130Ma could be the upper limit of the metallogenic age of the Shihu golddeposit.Native gold is common minerals in the ore. The fineness of native Au is low,from 442 to 926. The ore minerals are mainly pyrite, sphalerite, galena, chalcopyrite,magnetite and pyrrhotite. The isotopic ratios （sulfer and lead of sulfides, carbon ofcarbonate, and He-Ar of pyrite） indicate that the metallogenic materials were mainlyderived from low crust, which were markedly interacted with mantle fluids. Moreover,the H-O isotopic ratios of quartz fluid inclusions suggested that the ore-forming fluidscould be mainly magmatic water, which were mixed by meteoric water of variousextents at different ore-stage.The fluid inclusions in quartz can be classified into the two types:CO₂-NaCl-H₂O and NaCl-H₂O types. The densities and pressures of the inclusionsthat were calculated according to the measured temperatures and salinities athomogenization of the inclusions, indicated the metallogenic depths could befrom5.93 to 8.03 km with average depth at 7.20 km. The vapor phase in these inclusionswas dominated by CO₂, H₂S, CH₄, C₂H₄, N₂and Ar except for H2O. The anion andcation of liquid phase were determined to be Cl^-, SO₄^2-, and Na⁺, K⁺with minor Mg²⁺ and Ca²⁺. The chondrite-normalized rare earth element （REE） patterns of fluidinclusions in quartz and pyrite apparently differentiated each other. The REEpatternsof quartz were charachterized by relatively enrichment of light rare earth elements andpositive Eu anomalies, but the REE patterns of pyrite have negtive Eu anomalies.Thermoelectricity, cell parameter and decrepitation temperature of pyrite, as wellas thermoluminescene and cell parameter of quartz were measured, which suggestedthat the Au ore bodies have stable occurrence, continous extension and weakdenudation. The two new prospecting target areas were predicted in the deeperregions （below 180 m level） at the 19-31 exploration line and 3-11 exploration line .Geodynamic background of the Shihu and other gold deposits in the northTaihang orogen was summarized. Plutonic rocks and the gold deposit were formedduring the same geological duration in whichlarge scale lithosphere thinning of NorthChina craton and crustal-mantle interaction occurred. Underplating of basaltic magmain the lower crust resulted in partial melting of TTG-dominated Archean basementrocks, producing granitic melts. Mixture between the basaltic and granitic magmas invariable proportions spawned hybrid magmas that evolved, coupled with assimilationof country crustal rocks during magma ascent, which formed the Mesozoic magmas inthe Taihang orogen. It was such interaction that caused intensive felsic magmatism,the "Mesozoic Metallogenic Explosion" in eastern China, and the consequentformation of most gold deposits in the North Chine Craton.更多还原