三道湾子金矿床矿石特征及金的赋存状态研究   总被引：4，自引：0，他引：4  

吕军 《地质与勘探》2009,45(4):395-401

三道湾子金矿是与大兴安岭燕山期火山活动有关的浅成中-低温热液金矿,矿石类型主要为石英脉型.矿石的结构为自形-半自形-它形粒状结构、碎裂结构、交代结构、包含结构.矿石的构造为致密块状构造、稀疏浸染状构造、角砾状构造、细脉状构造.矿体浅部金矿物以自然金、银金矿为主,呈裂隙金、粒间金、包裹金分布,金矿物以细粒为主,载金矿物主要为石英;深部富矿段金、银主要以碲化物形式存在,赋存于石英颗粒间或裂隙中.反映了成矿流体的阶段性及层次性.  相似文献   

瑶岭钨矿区寒武纪地层特征对寻找石英脉型黑 钨矿的指示意义   总被引：1，自引：0，他引：1  

李社宏 《地质与勘探》2009,45(4):358-366

瑶岭钨矿由北矿区、东矿区和白基寨矿区3个矿区组成,其中北矿区是主要生产矿区,以石英脉型黑钨矿为主.在对北矿区大比例尺填图过程中,我们发现矿区地表地层单一,主要为寒武纪沉积的变质砂岩和板岩.针时这种情况,我们采用土壤地球化学测量、物探磁法测量、钻探等工程方法对寒武纪地层进行研究,综合分析了矿区地质特征、地球物理磁法特征及地球化学特征在对矿脉水平分布、矿脉垂直分布、蚀变矿物因素、构造因素、热接触因素和成矿因素的外在表现,从而建立起矿区寒武纪地层对矿化的指示体系表,并指出瑶岭钨矿北区深部和东南部有很大的找矿潜力,是值得继续找矿的有利目标地段.  相似文献   

Petrographic and mineralogical study of hydrothermal alteration of the Rokko Granite at Hakusui-kyo and Horai-kyo along the Arima-Takatsuki Tectonic Line in western Japan     

Toru Shimizu  Mitsuo Manaka  Kohei Kazahaya  Hitoshi Tsukamoto 《Island Arc》2021,30(1):e12407

Field, hand specimen, and microscopic investigations alongside X-ray diffraction analyses revealed four types of hydrothermal alteration (Type-A, -B, -C, and -D) based on the mode of occurrence of altered rocks and alteration mineral assemblage at Hakusui-kyo and Horai-kyo along the Arima-Takatsuki Tectonic Line (ATTL) in western Japan. Type-A alteration locally occurred as gray alteration halos with sulfide minerals. Type-B and -C alterations were confined to fault gouge veins and occurred as greenish-gray veins and brown veins, respectively. Type-C alteration crosscut Type-B alteration. These alterations were associated with a number of granitic fragments including cohesive breccia and micrographic facies. Type-D alteration occurred locally in brown sediments. Different mineralogical features in the four alterations are summarized as (Type-A) illite; (Type-B) chlorite; (Type-C) limonite (Fe³⁺ hydroxides and goethite) and calcite; and (Type-D) limonite. We propose that the alterations can be broadly divided into Paleocene hydrothermal alteration (Type-A) and post-Late Miocene hydrothermal alteration (Type-B, -C, and -D): Type-A alteration occurred at approximately 200 °C during hydrothermal activity after a granitic intrusion in Late Cretaceous; Type-B, -C and -D alterations occurred under hydrothermal activity accompanying deep fluids with repeated ascents invoked by the seismicity of the ATTL after the Late Miocene. The fluids may have been the “Arima-type thermal waters” (i.e., mixtures of convective groundwater and Na-Ca-Cl-HCO₃-type fluids). Type-B alteration occurred in fractures at depths where the temperature was ≥150 °C. Type-C alteration overprinted Type-B alteration as a result of mixing of new deep fluids and descending oxidized meteoric water near the surface. Fe³⁺ hydroxides and calcite precipitated from the fluids due to the oxidation of Fe²⁺ and the degassing of CO₂, respectively, at ambient to near-boiling temperatures. When the ascending fluids gushed out from the fractures, they generated Type-D alteration at the surface under similar temperature conditions due to the oxidation of Fe²⁺.  相似文献   

蚌埠五河地区金矿床成矿物质来源及其年代学研究——以河口和荣渡金矿床为例     

杨治  邓宇峰  袁峰  李跃  林涛  张顺林  张家嘉 《岩石学报》2019,35(12):3875-3893

安徽省蚌埠五河地区河口和荣渡金矿床是华北地台东南缘蚌埠台隆和五河台坳邻接区域的两个金矿床。本文通过对比研究河口和荣渡金矿床的地质特征、流体包裹体地球化学、Re-Os同位素以及H-O-S同位素特征,来厘定其形成时代、探讨其成矿物质来源和成矿过程。河口及荣渡金矿床矿体主要呈细脉浸染状、脉状和网脉状赋存于古太古代西堌堆地层中,成矿过程可划分为4个阶段:(1)石英脉阶段(早阶段);(2)石英-黄铁矿阶段(早阶段);(3)石英-多金属硫化物阶段(中阶段);(4)碳酸盐阶段(晚阶段);其中,中阶段为金的主要矿化时期。河口和荣渡金矿床早阶段(石英脉和石英-黄铁矿阶段)的石英内发育富液两相包裹体(WL型)、富气两相包裹体(WG)以及少量的含子晶的气液固三相包裹体(S型),均一温度为322～412℃,盐度介于5. 56%～15. 67%NaCleqv之间,属于高温中低盐度流体体系;中阶段(石英-多金属硫化物脉阶段)石英内发育有富液两相包裹体(WL型)、富气两相包裹体(WG),均一温度为257～357℃,盐度介于3. 06%～7. 45%NaCleqv之间,属于中高温低盐度流体体系。从成矿早阶段到主成矿阶段流体的盐度和温度都发生了较大程度的降低,推测矿化过程可能是由流体温度和盐度的降低引起的。成矿阶段石英中流体水的δ~(18)O值介于5. 01‰～7. 90‰之间,δD_(V-SMOW)值介于-89‰～-65‰之间,表明两个矿床的成矿流体为主要为岩浆水。河口金矿床矿石中的黄铁矿δ~(34)S值介于3. 89‰～9. 65‰之间,荣渡金矿床方铅矿δ~(34)S值为0. 76‰,表明河口及荣渡金矿床δ~(34)S值具有岩浆硫的特征,后期由于岩浆去气作用或地层硫的参与使矿石中的δ~(34)S值升高。因此,这两个金矿床可能是与岩浆热液有关的热液石英脉型金矿床。对荣渡金矿床矿石的黄铁矿进行Re-Os同位素定年,确定金矿床形成于134±19Ma,结合前人对该地区所做的岩浆岩定年工作,推测荣渡金矿床的成矿可能与区内130Ma左右的岩浆活动密切相关。  相似文献   

大陆岩石圈伸展与斑岩铜矿成矿作用   总被引：1，自引：0，他引：1  

李晓峰  华仁民  马东升  徐净  张龙  齐有强  武丽艳  朱艺婷 《岩石学报》2019,35(1):76-88

华南地区自古生代以来一直属于陆内构造演化环境。华南陆内伸展型斑岩铜矿主要形成于早侏罗世、晚侏罗世和早白垩世3个时期,其中晚侏罗世成矿期与华南中生代大规模钨锡成矿作用的形成基本属于一个时期。这些斑岩型矿床的时空分布与同时期的俯冲带在时间上和空间上具有明显不协调的关系,且与俯冲有关的、后俯冲伸展背景以及陆陆碰撞有关的斑岩铜矿的线性分布特点明显不同,尤其是早白垩世斑岩铜矿的分布明显呈面状分布,与华南中生代地壳明显减薄的区域基本一致。虽然这3个时期的斑岩型铜矿在地球化学上显示出弧岩浆岩的特点,但是地质事实证明在这3个时期,华南岩石圈发生了明显的伸展作用,尽管每个时期华南不同地区岩石圈伸展的程度可能不同。因此,我们把华南这种类型的斑岩铜矿归称之为"陆内伸展型"斑岩铜矿。陆内伸展型斑岩铜矿的成矿机制可能是岩石圈伸展背景下软流圈上涌导致陆下岩石圈地幔或者下地壳被改造有关。  相似文献   

粤东塘唇石英脉型钨(锡)矿床地质特征、成矿时代及其找矿意义          下载免费PDF全文

卢友月  付建明  张国培  郑宗皓  李楠  程顺波  秦拯纬  马丽艳 《地球科学》2019,44(2):387-398

塘唇钨(锡)矿是近年来新发现的一个具有大型规模找矿潜力的石英脉型矿床.矿床产于粤东龙窝花岗闪长岩岩体西部外接触带,赋矿地层为下侏罗统金鸡组碎屑岩,该层位是南岭及邻区石英脉型钨锡矿的最新赋矿地层.在详细的野外地质调查基础上,对矿床含钨石英脉中的白云母进行⁴⁰Ar-³⁹Ar测年,获得白云母⁴⁰Ar-³⁹Ar坪年龄为150±1 Ma,等时线年龄为149±2 Ma(MSWD=1.20),它们在误差范围内一致,为南岭地区燕山早期大规模成岩成矿作用高峰期的产物.塘唇钨(锡)矿的发现,不仅拓宽了石英脉型钨锡矿的找矿视野,还有助于完善石英脉型钨锡矿成矿规律和成矿模式,对区域下一步找矿具有重要指导意义.  相似文献   

小秦岭Q9325、Q141、Q127号矿脉地质特征及深部找矿前景分析     

文月贵  王和平  黄娅娅 《陕西地质》2019,(1):16-22

Q9325、Q141、Q127号矿脉位于有利成矿构造部位和矿化富集区段,其深部具有良好的物理激电异常显示,推断三矿脉深部具有较好的找矿前景。  相似文献   

浙西下寒武统大陈岭组地震液化脉微量元素特征研究     

严兆彬  裴军令  郭福生  胡珺珺  刘礼洁 《地球学报》2019,40(1):236-248

地震液化脉是地震作用引起的软沉积变形的重要构造之一,前人对脉体形态学和动力学做了大量的研究工作,但对其成因的微观地球化学行为研究较少。笔者采取开化裴岭脚剖面2期地震事件沉积的3套地震液化脉层样品21块,分别对其脉体和含脉体围岩做了微量元素分析。结果显示,液化脉中Cs、Ba、Th、Zr、Hf、Cr、Rb、Nb等反映陆源性质元素明显高于含脉体围岩,而Sr、Y、Ni反映海相沉积特征元素则表现为含脉体围岩高于脉体。通过对V、Mo富集度和微量元素特征参数Sr/Ba、Th/U等的综合研究,发现液化脉体表现为氧化环境,含脉体围岩为还原环境,且脉体和围岩均具有淡水作用特点。研究认为,早寒武世大陈岭期白云质灰岩沉积过程中有蚀源区陆源碎屑物的补入;在地震突发振动力作用下,富含水的软沉积层液化泄水,因化学沉积物和碎屑沉积物性质的差异,塑性碳酸盐沉积物随水部分流失,使得单位体积内碳酸盐沉积含量低于围岩,导致脉体中更富陆源物质;地震事件沉积层属潮上带,特别是地震液化泄水后期至成岩期,含地震液化脉沉积层曾暴露地表,受后期陆源物的再补给及大气降水淋滤蚀变作用影响,表现为古气候和古盐度异常,为浙西大陈岭组浅水沉积提供了地球化学的证据。  相似文献   

Ore Genesis and Tectonic Significance of the Xiaojiashan Tungsten Deposit,Eastern Tianshan,Xinjiang, China: Evidence from Geology,Fluid Inclusions,and Stable Isotope Geochemistry     

Yunfei Zhou  Jiuhua Xu  Lihua Shan  Xihui Cheng  Yueping Deng  Wenhuan Feng  Lingxiao Qiao 《Resource Geology》2019,69(1):43-64

The Xiaojiashan tungsten deposit is located about 200 km northwest of Hami City, the Eastern Tianshan orogenic belt, Xinjiang, northwestern China, and is a quartz vein‐type tungsten deposit. Combined fluid inclusion microthermometry, host rock geochemistry, and H–O isotopic compositions are used to constrain the ore genesis and tectonic setting of the Xiaojiashan tungsten deposit. The orebodies occur in granite intrusions adjacent to the metamorphic crystal tuff, which consists of the second lithological section of the first Sub‐Formation of the Dananhu Formation (D₂d ₁²). Biotite granite is the most widely distributed intrusive bodies in the Xiaojiashan tungsten deposit. Altered diorite and metamorphic crystal tuff are the main surrounding rocks. The granite belongs to peraluminous A‐type granite with high potassic calc‐alkaline series, and all rocks show light Rare Earth Element (REE)‐enriched patterns. The trace element characters suggest that crystallization differentiation might even occur in the diagenetic process. The granite belongs to postcollisional extension granite, and the rocks formed in an extensional tectonic environment, which might result from magma activity in such an extensional tectonic environment. Tungsten‐bearing quartz veins are divided into gray quartz vein and white quartz veins. Based on petrography observation, fluid inclusions in both kinds of vein quartz are mainly aqueous inclusions. Microthermometry shows that gray quartz veins have 143–354°C of T_h, and white quartz veins have 154–312°C of T_h. The laser‐Raman test shows that CO₂ is found in fluid inclusions of the tungsten‐bearing quartz veins. Quadrupole mass spectrometry reveals that fluid inclusions contain major vapor‐phase contents of CO₂, H₂O. Meanwhile, fluid inclusions contain major liquid‐phase contents of Cl^?, Na⁺. It can be speculated that the ore‐forming fluid of the Xiaojiashan tungsten deposit is characterized by an H₂O–CO₂, low salinity, and H₂O–CO₂–NaCl system. The range of hydrogen and oxygen isotope compositions indicated that the ore‐forming fluids of the tungsten deposit were mainly magmatic water. The ore‐forming age of the Xiaojiashan deposit should to be ~227 Ma. During the ore‐forming process, the magmatic water had separated from magmatic intrusions, and the ore‐bearing complex was taken to a portion where tungsten‐bearing ores could be mineralized. The magmatic fluid was mixed by meteoric water in the late stage.  相似文献   

江西东坪石英脉型黑钨矿矿床地质特征、控矿因素及找矿标志     

杨细浩  胡文洁  钟起泓  朱昌杰  万欢  胡正华 《吉林大学学报(地球科学版)》2019,49(5):1301-1316

东坪钨矿床是近年在赣北地区新发现的首个超大型石英脉型黑钨矿矿床,位于长江中下游成矿带幕阜山地区东坪-香炉山钨矿找矿远景区东部。矿床赋矿层位为新元古代双桥山群安乐林组浅变质岩系,北东向断裂及其两侧的次级裂隙为区内主要控矿构造、容矿构造,隐伏的燕山晚期黑云母二长花岗岩为成矿岩体,与区内钨多金属成矿关系密切的为石英脉状硅化;两个矿带的钨矿体均产于成矿岩体外接触带,呈现了石英脉型黑钨矿矿床典型的"五层楼"分带特征,矿石工业类型主要为黑钨矿矿石;明确了构造和岩浆岩等主要控矿因素;总结出地表微细裂隙云英岩化-黄铁矿化蚀变带、含硫化物石英细脉带、石英脉、重砂及地球化学异常为区内主要找矿标志。  相似文献