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吉林省珲春市杨金沟白钨矿床地质特征及成因机制探讨 总被引:1,自引:0,他引:1
杨金沟白钨矿床产于下古生界五道沟群地层中的石英脉及附近的蚀变岩中。矿化类型为石英脉—蚀变岩型,矿体受断裂带及北北西—北北东向层间构造控制,矿床成因为层控与岩浆热液复合型。 相似文献
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《International Geology Review》2012,54(7):882-893
The Yangjingou gold deposit in Jilin Province lies 11 km south of the large-scale Xiaoxinancha gold–copper deposit. Yangjingou orebodies are structurally controlled fault- or fracture-related auriferous quartz veins. This type of mineralization is significantly different from that of the Xiaoxinancha porphyry gold–copper deposit, and has mineral assemblages and fluid inclusion compositions typical of orogenic gold deposits. We suggest that the Yangjingou deposit is the first orogenic gold deposit discovered in the Yanbian area, even in all of NE China. Here, we present new isotopic dating and trace element analysis of the ore-hosting monzogranite and auriferous quartz veins within the deposit, in order to determine the age and tectonic setting of metallogenesis, and the geological conditions controlling gold mineralization. LA-ICP-MS U–Pb dating of zircons separated from the monzogranite yielded an age of 262.3 ± 1.3 Ma, indicating intrusion during the late Permian. Hydrothermal muscovite from auriferous quartz veins yielded a 40Ar/39Ar plateau age of 241.57 ± 1.2 Ma, indicating that gold mineralization occurred at 241 Ma. Trace element and REE compositions of the monzogranite and auriferous quartz veins are both indicative of the formation from a region of the upper mantle that previously underwent crustal contamination. Geochronological analysis indicates that the diagenesis and mineralization resulting in the Yangjingou gold deposit occurred during the late Permian–Early Triassic. The tectonic evolution of the region and comparison of this deposit with other mineralizing events indicate that the orebody formed during orogenesis associated with collision between the North China and Siberian cratons. 相似文献
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甘肃白石头沟石墨矿位于阿尔金南缘敦煌地块,赋存于前寒武纪敦煌岩群大理岩和石英片岩之中,目前圈定矿体33条,主要矿体2条。作为研究白石头沟石墨矿理想地层的敦煌岩群,是一套以变质碎屑沉积岩和变质基性岩为主的变质岩浆杂岩。本文从矿床角度出发,立足于区域地质勘查资料,结合前人研究成果,在对白石头沟石墨矿成矿地质背景、矿床及矿体特征、组合样化学分析、矿石矿物赋存状态及特征研究的基础上,对矿床的成因进行初步探讨并归纳区域找矿标志。研究表明,白石头沟石墨矿可分为大理岩型和石英片岩型两种类型,是古元古代经历区域动力热液变质作用而形成的沉积变质型矿床,成矿物质主要来源于变质碎屑沉积岩类的原岩(海相陆源碎屑岩和碳酸盐岩)本身,成矿环境为古老活动大陆边缘。找矿标志具有特定层位、岩性、矿化及物探特征。 相似文献
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小秦岭成矿带是我国重要的贵金属成矿带之一,区域成矿地质背景和成矿条件显示了该区良好的资源潜力。金矿受地层、构造和岩浆岩控制,具有“三位一体”的成矿模式。成矿过程复杂,太古宙太华群为成矿提供了物质基础,区域变质作用使金发生初次富集;早期自北而南的挤压形成规模巨大的推覆构造为含金石英脉的生成提供了有利空间;燕山期构造-岩浆活动对金的活化、迁移、富集起主导作用。金成矿温度属中低温热液矿床,围岩蚀变简单,成矿具有多阶段、多成因等复合型特征。矿床成因为动热再造多元热液型。通过对该区综合研究工作的不断深入,初步显示开展小秦岭地区深部找矿工作具有重要的现实意义。 相似文献
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延边东部五道沟脉型白钨矿矿床地质特征及流体包裹体 总被引:1,自引:0,他引:1
延边东部五道沟矿床内的钨矿体主要呈平行脉状赋存于华力西晚期蚀变花岗闪长岩中,与相邻的杨金沟大型钨矿相比,具有矿脉数量少、单脉厚度大和品位高的特点;矿石中金属矿物以白钨矿为主,呈团块状、粗粒浸染状、细脉状产于石英脉及碎裂蚀变围岩中,具有热液脉型矿床的矿化特征。主成矿阶段形成的粗粒白钨矿及石英颗粒中主要发育气液两相包裹体,白钨矿颗粒中尚含少量的含CO2三相包裹体。石英中气液两相包裹体均一温度主要介于171.2~268.0℃,热液盐度(w(NaCl))为0.70%~10.74%;白钨矿中气液两相包裹体的均一温度变化范围为209.6~253.3℃,热液盐度为1.39%~8.67%;白钨矿中2个含CO2三相包裹体完全均一温度分别为287.2℃和294.7℃。结合单个包裹体气相组分分析,认为五道沟白钨矿矿床的成矿流体为中温、低盐度的NaCl-H2O-CO2体系,并含一定数量的N2等气体。该矿床与杨金沟大型钨矿综合对比表明:两矿床具有相似的成矿地质背景和控矿条件,围岩蚀变、矿石矿物组成、矿石组构及白钨矿赋存状态等矿化特征基本相同,不同赋矿围岩中含矿构造性质不同应是两矿区钨矿体形态、产状和规模差异的主控因素。 相似文献
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为查明新疆东昆仑地区早古生代铜镍矿和早中生代金矿的成矿规律和成矿背景,采用“找矿发现-规律总结-新区发现”工作技术方法,在新疆若羌县阿确墩地区开展了1:5万红土岭等四幅矿产地质调查工作,取得的新进展及主要成果为: ①查明研究区内吐特卡—红土岭一带出露的基性—超基性岩体具有镁铁—超镁铁质岩的特征,是早泥盆世早期裂解环境下亏损地幔与岩石圈地幔共同作用的产物,而非原定的“蛇绿岩残片”; ②首次在研究区内的金水口岩群白沙河岩组中新发现退变质榴闪岩,呈透镜状产出于片麻岩中,获得的两组变质年龄与东昆仑已报道的榴辉岩、榴闪岩等高压变质岩石的高压变质年龄(450~430 Ma)和退变质作用时代(420~405 Ma)相接近,暗示了东昆仑早古生代存在规模巨大(大于1 000 km)的高压变质岩带,对探讨东昆仑造山带早古生代构造演化具有重要意义; ③通过1:5万化探综合异常查证,新发现金、铜镍等6处矿(化)点,其中以玉古萨依铜镍矿化点和豹子沟金矿点最具找矿潜力; ④在系统总结研究区含矿层位、成矿地质背景、成矿时代及成矿规律的基础上,划分了2个成矿远景区,圈定2个找矿靶区,并对优势矿产资源潜力进行了初步分析。 相似文献
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本文简要地介绍了矿区的成矿地质背景及主要矿床的地质特征,重点阐述了控矿因素,分析了区内下古生界五道沟群变质岩系、华力西晚期至燕山期侵入岩以及主要断裂构造与成矿作用的关系。通过对大东南岔金铜矿床控矿条件进行分析、评价,为区内及外围找矿提供依据。 相似文献
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吉林省珲春杨金沟白钨矿区地质特征及找矿方向 总被引:1,自引:0,他引:1
杨金沟矿区白钨矿体产于下古生界五道沟群地层与印支期二长花岗岩内外接触带中。矿化类型为花岗岩中的白钨矿—石英脉和斜长角闪片岩、云母石英片岩、红柱石片岩中的白钨矿—石英脉。矿体受南北向、北西向断裂及裂隙构造控制,矿床成因为岩浆热液—层控与岩浆热液复合型。 相似文献
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The Xiaotongjiapuzi gold deposit occurs in a Palaeoproterozoic rift accretionary terrane in eastern Liaoning and is hosted by a carbonate formation of the Dashiqiao Formation, Liaohe Group. The metamorphic grade of the host rock is low amphibolite-high greenschist facies. Gold, which is mainly invisible, is distributed in pyrite and arsenopyrite. The grains of Au-bearing sulphide minerals are fine, ranging from 0.0 n to 1 mm. The wall-rock alterations are characterized by low-temperature silification, hydro-sericitization, sericitization and carbonatization. The homogenization temperatures of the fluid inclusions in quartz closely associated with gold mineralization range from 140 to 240° C. The metallogenic age represented by the Ar-Ar isotopic age of sericite is 167 Ma. Comparisons and studies show that the Xiaotongjiapuzi gold deposit can be classified as the submicron-sized disseminated deposit (analogous to the Carlin-type) hosted in metamorphic rocks. 相似文献
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西藏班公湖- 怒江成矿带商旭金矿成矿时代探讨及其地质意义 总被引:2,自引:0,他引:2
造山型金矿在世界范围内具有重要的经济价值和找矿潜力,也是西藏班公湖 怒江铜多金属资源基地的主攻矿床类型之一。班公湖 怒江成矿带是近十年来识别和建立的我国最重要的斑岩 浅成低温热液 矽卡岩型铜金成矿带。商旭金矿位于班公湖 怒江缝合带中段,是该成矿带上首例造山型金矿床。矿体产于中 下侏罗统木嘎岗日群沉积岩,由石英脉、碳酸盐+石英脉和蚀变岩构成,呈透镜状、块状、条带状、鞍状、浸染状、角砾状等产出,受北西西向的区域断裂构造控制。热液蚀变发育碳酸盐化、白云母化、绿泥石化和硫化物蚀变等。矿物学研究和含矿脉体特征表明,早期热液活动发育于挤压应力环境,后期挤压应力逐渐消失,对应了变形晚期的构造环境。含金石英流体包裹体的Rb- Sr同位素测试获取的等时线年龄为135. 6±2. 7Ma,87Sr/86 Sr平均初始比值为0. 713,预示成矿作用发生于早白垩世,成矿物质主要来自地壳。综合研究认为,商旭金矿形成于早白垩世初班公湖 怒江缝合带中段的闭合期,地块间挤压应力致使木嘎岗日群发生构造变形,在挤压变形晚期构造环境发生转换的过程,围岩中应力释放促成了区域的金矿化。对比研究显示,商旭金矿化与世界大型、超大型造山型金矿在矿床地质、热液蚀变特征、成矿流体性质、成矿构造环境、动力学背景等方面具有相似性,进一步表明班 怒带具备寻找造山型金矿的潜力。 相似文献
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北秦岭构造带广泛发育与古生代洋壳俯冲和碰撞造山有关的岩浆活动以及与造山过程有关的变质作用,但古生代热液脉型矿床在北秦岭构造带少见报道。银洞沟银金多金属矿为北秦岭构造带东部的一处中型热液脉型矿床,本文通过对该矿床赋矿围岩和含矿石英脉中锆石开展LA- MC- ICP- MS U- Pb测年和锆石成因研究,确定了矿床的形成时代,并探讨了矿床的成矿动力学背景。结果表明赋矿围岩黑云母二长花岗岩的形成时代为431. 4±2. 1 Ma,含矿石英脉中锆石结晶年龄为419. 4±5. 9 Ma,石英脉中锆石的岩相学、锆石中矿物和流体包裹体及锆石微量元素研究表明419. 4 Ma代表矿床的形成时代。结合前人的研究结果,确定银洞沟银金多金属矿为形成于晚志留世的造山型矿床,成矿作用与碰撞期后~420 Ma的变质作用密切相关,成矿流体来源于地层的变质脱水,成矿物质主要来源于秦岭岩群和二郎坪群。 相似文献
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CAO Ye LI Shengrong XIONG Xianxiao LI Zhenzhen LIU Xiaobin YAO Meijuan ZHANG Huafeng 《《地质学报》英文版》2012,86(5):1211-1224
The Shihu gold deposit, situated in the Taihang Mesozoic orogen of the North China Craton (NCC), is hosted by ductile-brittle faults within Archean metamorphic core complex. The deposit is characterized by gold-bearing quartz-polymetallic sulfides veins. The Mapeng granitoids stock and intermediate-basic dikes intruded the metamorphic basement rocks, and are spatially related to gold mineralization. Detailed laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) U-Pb zircon ages of the granitic rocks, dykes and mineralized quartz veins in the studied area reveal its magmatic and mineralized history. The mineralized quartz veins contain inherited zircons with ages of about 2.55 Ga and 1.84 Ga, probably coming from the basement. These two Precambrian events are coeval with those in other parts of the NCC. The Mapeng granitoid stock, the largest intrusion in the area, was emplaced at ca. 130 Ma, and is coeval with magmatic zircon populations from diorites and quartz diorite pophyrites in the same region. The ca. 130 Ma magmatism and gold mineralization were most likely related to an underplating event that took place in the Taihang orogen at Late Mesozoic. The timing of gold mineralization with respect to felsic magmatism in the area is similar to those observed in other major gold-producing provinces in the NCC. This episode is simultaneous with those in the eastern margin of NCC, indicative of a widespread late Yanshanian metallogenic event that was a response to the Early Cretaceous lithosphere in the eastern NCC, in which the mesothermal gold deposits were formed from similar tectono-magmatic environments. 相似文献