Fluid Inclusions of Orogenic Gold Deposits in the Zhongchuan Area,Western Qinling and Their Geological Significance

Orogenically-derived gold deposits of the Zhongchuan area in the western Qinling are distributed in the exo-contact thermal metamorphic zone. The country rocks hosting the deposits are predominantly of Devonian age with low-grade metamorphism and strong deformation with the ore deposits directly controlled by multi-level tectonic systems. Three types of inclusions from these deposits have been recognized: CO2-H2O, CO2-rich, and aqueous. The ore-forming fluids were mainly CO2-NaCl-H2O type characterized by rich CO2, low salinity, high temperature and immiscibility. Incorporated with earlier isotopic data, the regional geological setting and features of diagenesis and metallogeny, it can be concluded that the ore-forming fluids were derived from deep magma and mixed with meteoric and metamorphic water. The deposits formed during an intra-continent collisional orogeny, and some of the materials derived from the deep might have been involved in the ore-forming process.

The Palaeomagnetic Study of the MineralizationAge of Gold Deposits in the Xiong' ershan Area,Henan Province

Based on palaeomagnetic studies of the Precambrian gold deposits in the Xiong'ershan area, Henan Province, the authors infer that the ore-forming processes of the Beiling alteration-type gold ore deposit and the Dianfang breccia-type gold ore deposit started in the Proterozoic, and was superimposed by later mineralization, whereas the mineralization age of the Jiguanshan quartz- vein type gold ore deposit is Yanshanian.

Geochemical Tracing of Ore-forming Material Sources of Carlin-type Gold Deposits in the Yunnan-Guizhou-Guangxi Triangle Area --A Case Study of the Application of the Combined Silicon Isotopes Geochemistry and Siliceous Cathodoluminescence Analysis

Abstract This paper deals with characteristics of silicon isotope compositions and siliceous cathodoluminescence of host rocks, ores and hydrothermal silicified quartz of the Carlin-type ore deposits in the Yunnan-Guizhou-Guangxi triangle area. The study shows that primary silicified quartz is nonluminescent but quartz in host rocks and secondary silicified quartz are luminescent by the action of cathode rays. Correspondingly, silicon isotope compositions of host rocks, ores and hydro6thermal quartz veins are clearly distinguished. In strata from the Middle Triassic to the “Dachang” host bed, δ30Si of the host rocks ranges from 0.0% ?0.3%, while that of primary ore-forming silicified fluids from ?0.1% to ?0.4%; in the Upper Permian and Lower Carboniferous strata and Indosinian diabase host beds, δ30Si of the host rocks is from ?0.1% to ?0.2% and that of the primary silicified quartz veins from 0.3 % ?0.5 %. This pattern demonstrates the following geochemical mineralization process, primary ore-forming siliceous fluids migrated upwards quickly along the main passages of deep-seated faults from mantle to crust and entered secondary faults where gold deposits were eventually formed as a result of permeation and replacement of the siliceous ore-forming fluids into different ore-bearing strata. This gives important evidence for the fact that ore-forming fluids of this type of gold deposits were mainly derived from upper mantle differentiation and shows good prospects for deep gold deposits and geochemical background for large and superlarge gold deposits.

Lead Isotope Studies of Massive Surphur-Iron-Gold Deposits in the Tongling Area, Anhui Province

Pb isotope ratios and their variation have been measured and explained on ores of massive S-Fe-Au depos-its hosted in the Middle-Upper Carboniferous, on feldspars from diorite bodies closely related tomineralization and on whole rocks from ore-hosting strata (carbonate rocks) in the Tongling area, Anhui Prov-ince. Through a comparison of Pb isotope features of these geological bodies, it has been suggested that oresubstances of the deposits were derived from ore-hosting strata. In the meanwhile, the measurement of ore Pbisotopes of different mineralization types of the same deposit indicates that different mineralization types havedistinct Pb isotope characteristics, showing the potentiality of the Pb isotopic method used in mineral explora-tion.

Formation of the Micro-Disseminated Strata-bound Gold Deposits, With Special Reference to Structural Evolution, Miliang Area, Zhen'an County,Shaanxi Province, China

Based on detailed geologic study, the important role of structuring in the formation of gold deposits in the area is discussed with special reference to structural evolution. Syngenetic faulting contemporaneous with tectonic-volcanic events is thought to be responsible for providing the ore-forming material at depth. The lithofacies formed by highly alternating deposition of terrestrial and carbonate detritus is chemically characterized by the assemblage of Au-Sb-As,constituting a favorable source bed for the activation and enrichment of gold. This gold source bed has undergone four major stages of structural deformation, accompanied by multi-staged alteration and mineralization.

Gold Deposition by Boiling or Cooling Without Boiling: Genesis ofthe Sangchon Gold Deposits,Hadong Area, South Korea

In order to understand the mechanism(s) of gold precipitation in the anorthosite-hosted Sangchon gold deposits in the Hadong area, Korea, chemical speciation and reaction path calculations were accomplished by geochemical modeling. The modeling consisted of three-step procedures: reaction with anorthosite, then the simple cooling of the reacted fluid, and finally the boiling of metalliferous fluid. The principal vein minerals of the Sangchon deposits consist of quartz, sericite, kaolinite, pyrite, galena, chalcopyrite, sphalerite and acanthite. The sulfide mineralization is typically zoned from pyrite (preferentially at vein margins) to galena and sphalerite (toward vein center). Electrum is intimately associated with pyrite ± chalcopyrite and sphalerite. By comparing the results of modeling with the observed mineral assemblages and paragenesis, the most appropriate evolution path of ore fluids was suggested as follow: reaction of a single fluid with anorthosite at 300℃, then the isobaric cooling of the fluid at temperatures from 250° to 100℃, and then the boiling and cooling of the fluid due to the decrease of pressure and temperature. Calculations also show that all of the observed alteration minerals formed due to fluid-anorthosite interaction at early period, whereas most of sulfides and electrum were precipitated mainly due to cooling. The abundance of gold in veins depends critically on the ratio of total base metals plus iron to sulfide in the aqueous phase, because gold is transported as Au(HS) 2 -whose solubility is very sensitive to the sulfide activity. Our results of geochemical modeling generally fit to the observed mineral assemblages and mineral composition, indicating the usefulness of numerical simulation for elucidating the genesis of gold deposits.

Ar-Ar Dating on the Metallogenesis of the Dongchuang Gold Deposit in the Xiaoqinling Area

The Dongchuang gold deposit in the Xiaoqinling area is an orogenic-type lodegold deposit. It is one of the few superlarge (>100 t Au) deposits in China. Although it has beenargued that it was formed in the Mesozoic, related isotopic age data have not been reported inprevious studies. Based on detailed geological study, the authors have carried out isotopic datingon various metallogenic generations. The ore-forming process of the Dongchuang gold deposit consistsof four stages: coarse-grained pyrite-bearing quartz veins (stage I), fine-grained pyrite-quartzveinlets (stage II), multi-sulfides (stage III) and carbonate-quartz veinlets (stage IV). Ar-Ardating on mineral separates of stages I, II and III yields plateau ages of 142.9 +- 2.9 Ma, 132.2 +-2.6 Ma and 128.3 +- 6.2 Ma, respectively. Sericite separates from stage II assemblage also yield anAr-Ar isochron age of 132.6 +- 2.7 Ma, similar to the Ar-Ar plateau age. These results suggest thatthe Dongchuang gold deposit was mainly formed during 143-128 Ma, coinciding with the authors'geological observations and previous hypothesis. This ore formation is coeval with theregional-tectonic transition from collisional compression to extension, strongly showing that thedecompression-geothermal increase regime during compression-to-extension transition is the mostconducive geodynamic environment to orogenic-type gold mineralization.

Metallogenic Age of Dapinggou Gold Deposit in Northern Altun Area, Northwestern China

Studying the metallogenic age of Dapinggou gold deposit may provide important material not only for the study of metallization and the further prospecting of gold deposits but also for research into tectonic evolution in the Altun area. In this study, we used Rb-Sr isotopic dating method of fluid inclusion in the Au-bearing quartz, combining field investigation, REE, sulfur isotopes, lead isotopes, strontium isotopes and hydrogen-oxygen isotope, to determine the metallogenic age of the Dapinggou gold deposit. The only newly-discovered medium-sized gold deposit in the northern Altun area, Dapinggou gold deposit, is controlled by a ductile shear zone. It is characterized by mainly altered mylonite-types with a little K-feldspar quartz vein-types. Data from REE, sulfur isotopes, lead isotopes and strontium isotopes show that the source materials of the deposit were derived mainly from the metamorphic rocks. The data from the inclusion and hydrogen-oxygen isotope indicate that the ore-forming fluid came mainly from dynamic metamorphic water and partly from remelting magmatic water, with a little influence from meteoric water. The density of the ore-forming fluid is 0. 791 - 0. 971g/cm^3 and it contains 2.36 %-5.5 % salinity, The gold deposit was formed at 1.61-2.68 km below the surface at a temperature of 198--290 ℃ and a pressure of （420-700） × 10^5 Pa. The isotopic age from the Rb-Sr isochron of fluid inclusion in quartz is 487 Ma, which indicates that the mineralization occurred in the early Caledonian epoch. The study on the metallogenic age of Dapinggou gold deposit may provide important material not only for the study of metallization and the further prospecting of gold deposits but also for research into tectonic evolution in the Altun area.

Characteristics of Ore-Forming Fluids of Gold Deposits in Daqingshan District,Inner Mongolia,China

<Abstract>Locatedinthemid-westoflimerMongolia.Daqingshandistricthasmanygolddepositsoccurringalongaeast-weststrikingductileshearzonewithinagreelt,whichismainlycomposedoftheArcheanWulashangroup.Thehydrothermalmineralizationcanbedividedintofourstages:(1)pyrite-quartz,(2)quartz-Pyrite,(3)polymetallicsulfidesand(4)carbonates-quartz.Themajormetalylicmineralsintheoreofgold-bearingveinsarenativegold,electrum,pyrite,chalcopyriteandgalena,buttheganguemineralsaremainlyquartz,secondarilysericite,ankeriteandexcite.Prinipalalterationpatternsinthegolddepositsaresericithation,silicification,pyritizationcarbonatizationandchlorization.Aninvestigationonfluindinclusionsshowsthattheore-formingfluidswerelowinsalinitieandhighinCO2content,MeasuredδDoffluidinclusionsinquartzfromtheoreveinsrangesfrom-65‰to-104‰,butδ18Oquartzfrom10.0‰to12.8‰.Thesedatashowthatthewaterinhydrothermalfluidprecipitatingtheorebodiescouldhavebeenmainlymagmaticwaterandmetamorphicwaterbutlocalmeteoricwatermighttakepartinthelatemineralization.δ13Cfromfl

Ore-forming and Exploration Models of the Baguamiao Gold Deposit,Shaanxi Province

The Baguamiao superlarge gold deposit in Shaanxi Province is one of the typical cases in China that are hosted by sedimentary rocks. Explorers and researchers have discussed the gold mineralization enrichment conditions by studying sulphur, oxygen, carbon, silicon stable isotopes and mineralizing fluid features of the Baguamiao gold deposit and proposed a hydrothermal sedimentation-magmatic reconstructing gold mineralization model featuring multi-sources of ore-forming materials and multistage mineralizations. In addition, prospecting for “Baguamiao-type” gold deposits was started in the Fengtai Basin and a great number of important prospecting targets such as Tonglinggou, Simaoling, Guoansi and Dachaigou were discovered.

Interpretation of remote sensing of geological structures and prediction of gold mineralization in Mohe area and its adjacent region

The authors took the ETM+ multi-spectra data as the data information and correlation coefficient for each band and carried out their information volume statistics.According to certain criteria,the authors also determined the optimum band-combined image.The image clarity is improved by various enhancements and fusions method.Based on remote sensing geological interpretation in detail,the relationship between remote sensing geological characters and gold mine were analyzed systemically.Using all kinds of remote sensing structure information,combining other research data,the authors determined mainly ore-controlling ore structure.Several prospective areas of gold ores were determined and furthermore significant finding mine target areas was confirmed.

Measurement of Metallogenic Depth and Deep Second Enrichment Belt Forecasting in Jiaodong Gold Deposit

The depth is important for ore finding in Jiaodong gold deposit. However, many geologists are still discussing how to confirm the depth for the tectonic and metallogenesis formation. The authors of this paper propose a new method-the correction of metallogenic depth via its structure to calculate the depth. This method, based on the crust rock in a solid stress state, emphasizes the elastic pattern rather than the static fluid pattern. In addition, this method is more appropriate to the actual situation in the crust than the method of weight/special weight. The authors of this paper illustrating, with the Jiaodong gold deposit as an example, the metallogenic depth correction via structure conclude that the depth of the most deposits, lower than 4-6 km, is often 2.5 km. Therefore, the authors suggest that there exists a second enrichment belt and that ore resources are more potential at the belt of Jiaodong area. These results have been demonstrated by years of exploration.

胶东金矿与中生代区域性花岗岩关系及成矿预测和找矿方向

胶东地区是世界著名的金矿资源基地,截至2023年6月已累计探明金矿资源量已达5757余吨。与金矿成矿密切的中生代花岗岩分布广泛,岩石类型多样,也是山东省最发育、最典型的地区。本文对胶东地区金矿与中生代区域性花岗岩空间展布、形成时代和形成环境等关系进行了分析研究。区域性广泛分布的中生代花岗岩为晚侏罗世玲珑期(166~146 Ma)、早白垩世早期郭家岭期(135~123 Ma)、早白垩世晚期伟德山期(123~110 Ma)和崂山期(118~108 Ma),研究认为区域性岩浆事件一般持续10 Ma左右,而重熔型花岗岩一般持续20 Ma,反映了由基底岩石熔融到侵入结晶的2个阶段,它有一个由基底固体岩石熔融的过程,大致也需要10 Ma,既固体岩石熔融10 Ma,熔浆活动上侵结晶10 Ma。玲珑期重熔型花岗岩是扬子板块和华北板块碰撞的期后产物,郭家岭期岩浆事件代表了中国东部中生代构造体制转换的开始,伟德山期岩浆事件代表了构造体制转换的高峰期,崂山期岩浆事件代表了构造体制转换的结束期。86.8%的金矿赋存在玲珑期花岗岩中,6.9%的金矿赋存于郭家岭期花岗岩中,玲珑期花岗岩和郭家岭期花岗岩Au元素背景值明显高于伟德山期花岗岩和崂山期花岗岩。矿石硫与玲珑期花岗岩、郭家岭期花岗岩范围相近,特别是与玲珑期花岗岩大范围重叠,具有岩浆热液硫同位素变化小的特点,说明矿石硫主要源为玲珑期花岗岩、郭家岭期花岗岩。矿石铅主要为再活化的下地壳铅,即前寒武纪结晶基底铅,有幔源铅加入。金矿成矿年龄有162~146 Ma、133~120 Ma、120~115 Ma、112~105 Ma共4个区间范围,与胶东地区四期区域性花岗岩形成时间对应,成矿年龄一般晚于成岩年龄3~5 Ma。根据胶东金矿及多金属矿与岩浆热液事件对应关系,划分为玲珑金成矿期、郭家岭金成矿期、伟德山金及多金属成矿期和崂山多金属成矿期。胶东地区金矿主要是新太古代变质地层和古元古代底部片岩层位经过重熔作用金元素活化、迁移、富集和郭家岭期岩浆作用成矿。基于以上成矿作用认识,根据地球化学块体理论,对胶东金矿潜力进行了估算,胶东地区3000 m以浅金矿潜力约为1.8万t,同时对胶西北深部金矿进行了系统预测,预测3000 m以浅金资源量3997 t,5000 m以浅7497 t。通过地质综合研究,栖霞地区中新太古代变质岩下部有隐伏玲珑期花岗岩,根据金矿主要赋存在玲珑期花岗岩中的空间展布,S、Pb等同位素以及玲珑期花岗岩是金矿成矿直接围岩或母岩的认识,该地区变质岩中发育众多的石英脉型中小型金矿和矿(化)点,可能是浅部或顶部矿体的表现,认为该地区具有良好的成矿背景和潜力,是胶东地区今后金矿找矿的重要地区和方向。并建议在该地区部署地震和大功率激电剖面及地质科研钻探,查清一系列NE向断裂和地质结构,为金矿找矿提供科学依据。

Research on the Application of Electromagnetic Method in the Exploration of Altered Rock-type Gold Deposits in the East Kunlun Metallogenic Belt

Introduction The East Kunlun Orogenic Belt is located in the northeastern part of the Qinghai–Tibet Plateau(Li et al.,2007),stretching from the East Kunlun to the Elashan area in an east–west direction(Guo et al.,2018).It is an important part of the Central Orogenic Belt(Xiong et al.,2023).It is considered one of the important gold mineralization regions in the Tethys tectonic domain(Norbu et al.,2023)and an essential potential base for mineral resources in China.Wulonggou and Gouli gold mines have been discovered successively,earning the reputation of the"Golden Belt of Qinghai Province"(Feng et al.,2004;He et al.,2023).

辽东半岛内生金矿床基本特征、成矿作用与资源潜力

辽东半岛是华北克拉通重要组成部分,中生代发生强烈的构造、岩浆活动和金矿成矿作用,其内部产有不同规模的金矿床,并具有明显的地域特色.通过系统总结辽东半岛金矿床的空间分布、赋矿围岩、控矿构造类型、矿化蚀变等基本特征和成矿作用,分析金矿的资源潜力.根据金矿床的空间分布,划分4个金矿集区,即:猫岭、白云-青城子、五龙-四道沟和新房金矿集区.猫岭和白云-青城子矿集区赋矿围岩为古元古代沉积变质岩系,矿化类型分为蚀变岩型和石英脉型,矿体主要受低角度层间断裂控制;五龙-四道沟矿集区赋矿围岩分别为中侏罗世片麻状黑云母花岗岩和古元古代沉积变质岩系,矿化类型以石英脉型为主,蚀变岩型次之,矿体受高角度断裂和低角度层间断裂控制;新房矿集区赋矿围岩为太古宙片麻岩和新元古界青白口系变质砂岩、变粒岩和大理岩,矿化类型为石英脉型和蚀变岩型,矿体多呈脉状受变质核杂岩剥离断层下盘发育的韧-脆性次级断裂和上部新元古界青白口系盖层构造裂隙控制.年代学研究表明,金矿成矿时代可分为晚三叠世(约220 Ma)、早侏罗世(约190 Ma)和早白垩世(约120 Ma).流体包裹体研究显示,流体不混溶是金矿成矿的主要机制;氢-氧同位素显示,成矿流体主要来自岩浆水,后期有大气降水加入;氦-氩同位素数据揭示,成矿流体主要来自壳源,少量来自幔源;硫-铅-锶同位素显示,成矿物质主要来自中生代岩浆.同时,赋矿地层起到不可或缺的作用.矿床地质特征及同位素数据显示,辽东半岛金矿为与岩浆热液有关的金矿床.结合区域构造大地构造演化,认为,辽东半岛晚三叠世金矿形成与扬子板块向华北板块深俯冲背景有关,早侏罗世金矿形成与古太平洋板块向欧亚板块俯冲挤压构造背景有关,早白垩世金矿形成于古太平洋板块向欧亚板块俯冲折返伸展环境.结合典型矿床地质特征、区域地球化学和地球物理特征,圈定找矿靶区23处,预测3000 m以浅金资源量2414.56 t.

胶东大尹格庄金矿碳酸盐矿物的特征、物源及其在金成矿过程中的作用

胶东金矿的成因研究一直是矿床学研究的热点,其中金的物质来源与活化、沉淀机制是最受关注的问题之一。大尹格庄金矿位于胶西北地区的招平断裂带中段,是区内典型的超大型破碎蚀变岩型金矿,以存在大量碳酸盐脉而有别于区内其他金矿床,这些热液成因的碳酸盐脉对该矿区Au成矿具有重要作用,因而是破解胶东巨量Au物质来源和成矿机制的良好对象。本研究通过细致的岩相学观察,发现大尹格庄金矿中的碳酸盐矿物主要包括菱铁矿和方解石,以脉状、浸染状存在于黄铁绢英岩型矿石中,其中部分菱铁矿与黄铁矿等金属硫化物共生,其他菱铁矿则与石英共生,方解石则呈浸染状和脉状两种形式产出,菱铁矿和方解石均为热液型碳酸盐矿物。扫描电子显微镜研究表明,在菱铁矿和方解石中均发现有金矿物的存在。Au含量分析结果表明,菱铁矿和方解石是大尹格庄金矿的重要载金矿物,形成于成矿作用的主要阶段。碳酸盐矿物原位微区稀土元素数据也显示出热液型碳酸盐矿物的特征;同位素地球化学数据显示大尹格庄金矿中碳酸盐矿物与胶东地区前寒武纪变质基底中的大理岩明显不同。C-O同位素分析显示,大尹格庄金矿中菱铁矿的δ^(13)CPDB为-5.12‰~-4.82‰,δ^(18)OSMOW为12.13‰~12.80‰,具有明显的幔源特征;而方解石δ^(13)CPDB为-0.64‰,δ^(18)OSMOW为6.21‰,显示出幔源流体在上升过程中受到了一定程度的围岩的影响。金矿中菱铁矿显示轻稀土相对亏损,重稀土相对富集,有轻微的负Eu异常,(87Sr/86Sr)i为0.709842~0.710087,εNd(t)为-18.5~-17.1;方解石的(87Sr/86Sr)i为0.710861,εNd(t)为-12.7,指示形成碳酸盐矿物的CO_(2)流体可能来自于幔源的基性岩浆。结合胶东以及整个华北克拉通中生代地质演化,本文认为胶东巨量金可能来自于富集的岩石圈地幔,成矿物质随这些幔源基性岩浆的活动沿断层等壳内软弱面向上运移,而CO_(2)流体在这个过程中起到了促进作用,并随含金流体最终运移至地壳浅部发生金成矿作用。

胶东大尹格庄金矿床后疃矿区深部矿体定位预测

后疃矿区位于大尹格庄金矿床主矿区外围,属于深边部找矿区段。采用多元信息找矿策略,通过构造地球化学法-伽玛能谱法-多极化电磁测深技术组合,开展后疃矿区深边部成矿预测。完成地表构造地球化学与伽玛能谱测量面积12 km^(2),结合因子分析,厘定后疃矿区构造地球化学找矿标志为Au-Ag-As-Sb组合异常。同时,采用MPMT-18多极化电磁测深系统,完成了L108测线—L136及L80测线多极化电磁测深和异常反演,确定了后疃矿区深部招平断裂的位置。根据构造地球化学测量、伽玛能谱测量与大地电磁测深的异常特征、分布与关联性,结合钻探工程验证的有利程度,共圈定找矿靶区8处。其中,A-1、B-1、B-3、C-2和C-3找矿靶区经钻探工程验证并见矿。

高精度磁测在柴达木盆地北缘三角顶金矿床找矿中的应用

三角顶金矿床位于柴北缘结合带滩间山岩浆弧,是区域造山型金矿成矿事件响应的产物;研究区主要出露寒武系—奥陶系滩间山群火山岩组,岩性主要为玄武岩、硅质岩等;岩浆活动强烈,主要为晚泥盆世花岗闪长岩、二长花岗岩等,岩体中发育辉绿岩脉、石英脉等;基性—酸性岩中磁性由强变弱,其中辉长岩、二长花岗岩磁化率最高分别为8815.6×10^(-6)×4π·SI、5992.4×10^(-6)×4π·SI,可能由磁铁矿化、黄铁矿化引起强磁化率;磁异常呈锯齿状不规则跳跃,强度中等,梯度变化大,幅值为-733~820 nT;高精度磁法测量对与金矿成矿关系密切的断裂构造、破碎蚀变带等地质体有较好的分辨效果,经高精度磁法探测出局部异常呈串珠状分布,沿异常轴部存在断裂构造。经部分工程验证,在区内圈定构造蚀变带12条、金矿体7条、金矿化体40余条,M18-2异常与区内化探异常、深部工程验证等找矿信息相吻合,为区内进一步金矿找矿方向提供了依据。

宁夏海原西华山地区金矿床地质地球化学特征及成因分析

宁夏海原西华山金矿区位于秦岭—祁连—昆仑造山带之祁连构造成矿带,在该矿区已发现马场和柳沟2个金矿床。区内含矿地层为长城系海原群变质地层,矿脉受断裂带控制,矿石类型主要为蚀变煌斑岩型、石英脉型和蚀变岩型。为了查明西华山金矿区矿床成因类型和成矿过程,对马场和柳沟2个金矿床开展了野外地质调查、流体包裹体显微测温和H-O-S同位素地球化学研究工作。研究表明:马场和柳沟金矿床石英流体包裹体均一温度范围分别为140.1~382.6℃和203.2~353.9℃,集中在250~260℃和270~280℃;盐度[w(NaCleq)]分别为2.57%~10.72%和5.28%~12.08%,集中在6%~7%和7%~8%;成矿期成矿流体δD值分别为-86.5‰~-87.2‰和-90.2‰~-91.6‰,δ^(18)O值分别为7.4‰~8.7‰和8.7‰~10.0‰;2个矿区矿石黄铁矿中δ^(34)S分布范围为-1.00‰~0.27‰。综合研究认为,区内金矿成矿流体属于中低温、中低盐度的流体,主要来源于岩浆水;硫也主要源于岩浆,有少量可能源于围岩地层;区内金矿床属于与晚古生代中酸性岩浆活动有关的中低温低盐度岩浆热液型金矿。

胶东水旺庄超大型金矿床构造叠加晕特征及深部找矿预测

胶东是我国最重要的金成矿区,水旺庄金矿床是招平断裂带上近年来探获最大的深部特大型金矿床,首次采用构造叠加晕方法开展深部成矿预测意义重大。本文通过收集整理前人地质资料,结合野外地质调查工作,对水旺庄金矿床开展钻孔化探数据测试分析。研究表明:矿体中共同元素组合是:Au、As、Sb、Ag、Cu、Pb、Zn、Bi、W;特征元素组合是:As、Ag、Cu,其中Au为主要成矿元素,Cu为主要的伴生元素。以26勘探线为主要研究对象,运用构造叠加晕理论分析可知前缘晕特征指示元素为As、Sb、Hg;近矿晕特征指示元素为Au、Ag、Cu、Pb、Zn;尾晕特征指示元素为Bi、Mo、W。建立了水旺庄金矿床构造叠加晕理想模式,进行了深部矿体预测圈定预测靶区3个。