青海赵卡隆铁铜多金属矿床地质特征及找矿前景

青海赵卡隆铁铜多金属矿床处于三江成矿带北西段德钦晚三叠世裂谷带中.该区沉积境复杂多样,构造变质变形强烈,岩浆侵入活动频繁,造山带成矿系统发育,具有良好的找矿前景.     

青海省赵卡隆铁多金属矿成矿特征及矿床成因

青海赵卡隆铁多金属矿床处于三江成矿带北西段,矿体赋存于上三叠统巴塘群上部碎屑岩组、安山岩的上下盘,严格受地层控制,呈层状、似层状和透镜状顺层展布,矿体与围岩无明显界限,呈渐变过渡关系。初步研究认为矿床属火山喷流沉积—改造型铁多金属矿床。     

青海西部祁漫塔格地区矽卡岩铁铜多金属矿床的矽卡岩类型和矿物学特征

青海西部祁漫塔格地区矽卡岩型铁铜多金属矿床分布广泛,主要发育两类矽卡岩,即钙矽卡岩和锰质矽卡岩,少数矿区还有镁矽卡岩.钙矽卡岩的组成矿物主要有透辉石、钙铁辉石、钙铝-钙铁系列石榴石、绿帘石、阳起石和方柱石,常伴随Fe、Cu、Mo矿化,构成钙矽卡岩型铁多金属矿床或铜(钼)矿床,而锰质矽卡岩主要由锰钙铁辉石组成,含少量锰三...     

新疆彩虹铜多金属矿床地质特征及成因探讨

彩虹铜多金属矿床位于库米什-彩华沟-依格尔达坂多金属成矿带内,具多期成矿特征.早期的火山-沉积成矿作用形成了层状含铜黄铁矿层.第2期热液成矿作用形成了脉状、块状、团块状的铜(铅锌)矿化,氧、氧同位素及流体包裹体研究均显示,在该期矿化过程中,有岩浆流体的参与,结合钨异常及时间证据,认为该期矿化与忠宝岩体的侵入有关,且受N...     

甘肃省小柳沟铜钨多金属矿床地质特征及成因探讨

小柳沟铜钨多金属矿床赋存于长城系朱龙关群下岩组段及上岩组中下岩段,容矿岩石为碳酸盐岩及火山岩,该矿床是以Ｗ为主的超大型多金属矿床。矿体受岩性,断裂及隐伏岩体的接触带控制,根据矿石矿物石英包裹体测得的均一温度,成矿流体的盐度,成矿流体的密度,成矿压力,ｐＨ值,δ＾１８Ｏ,δ＾１８Ｏ,（Ｈ２Ｏ）,Ｄ（Ｈ２）的特征,表明成矿溶液既不是纯岩浆水,也下是海水,而是大气地表水与地层中的建造水或重熔花岗岩岩浆水     

新疆博罗科努成矿带东段矽卡岩型铁铜多金属矿床:地质特征、成矿背景与找矿潜力

新疆西天山博罗科努成矿带东段近年来找矿成果丰硕,相继发现了可克萨拉-艾木斯呆依、哈勒尕提-木祖克、色勒特果勒和肯登高尔4个矽卡岩型多金属矿床,其成矿岩体分别为呼斯特、大瓦布拉克、埃姆劲和纳林果勒岩体。在矿区系统地质调查的基础上,本文对4个成矿岩体开展了岩石地球化学研究,分析了矿床的成矿背景、控矿因素和找矿潜力。研究表明,本区矽卡岩矿床的成矿岩体具有高硅、低镁、准铝-弱过铝质、富碱且富钾的特征,呼斯特和大瓦布拉克岩体形成于北天山洋向南部伊犁地块俯冲背景,埃姆劲和纳林果勒岩体形成于碰撞造山环境;成矿受"中酸性侵入岩-钙质地层-接触带及捕虏体构造"三位一体联合控制。综合分析研究认为,区域上岩体与呼独克达坂组(O3h)和东图津河组(C2dt)钙质地层的接触带、可克萨拉-艾木斯呆依矿区外围的灰岩捕虏体、肯登高尔矿区深部隐伏的花岗闪长岩与东图津河组(C2dt)地层接触带具有较大的找矿潜力。     

内蒙古白乃庙铜多金属矿床地质特征及成因讨论

白乃庙铜多金属矿床产于遭受了韧性变形的白乃庙群变质火山岩和花岗闪长斑岩中,矿床的地质-地球化学特征表明,除了赋矿围岩不同外,南、北两矿带中的其他地质特征基本一致,成矿流体具有深源特点,韧性剪切对成矿有叠加改造作用,连续发生的斑岩成矿作用和韧性剪切成矿作用产生于加里东期.矿床为复因多位的铜(钼)多金属矿床.     

青海阿尔金采石沟金-铜多金属矿床地质特征及成因分析

阿尔金采石沟金-铜多金属矿是受火山机构控制的火山一次火山岩型矿床，产于火山一次火山岩岩体周边环状、放射状断裂构造中，矿体形态以脉状为主。地表及浅部以金矿化为主，而深部则以含金的铜多金属矿床为主，具有大型金及铜多金属的找矿潜力。文章就采石沟金矿地质特征及成因作初步探讨。     

大井铜-锡多金属矿床地质特征及其成因

通过对大井铜-锡多金属矿床成矿地质环境、矿床地质特征以及对岩（矿）石同位素、稀土元素、成矿温度等地球化学和成矿物理化学环境的研究,认为,大井铜-锡多金属矿床为一典型的岩浆热液充填型矿床。与成矿有关的隐伏岩体受深部隐伏的深大断裂控制,可能与黄岗梁矽卡型铁-锡矿床同属一构造岩浆成矿带上不同成矿环境下形成的矿床。并认为,在该成矿带上及大井矿区深部仍有较大的找矿潜力。     

三江北段查涌铜多金属矿床成矿流体特征——流体包裹体及氢氧同位素证据

在矿床地质特征研究和成矿阶段划分的基础上,选取三江成矿带北段查涌铜多金属矿床主成矿热液期的矿石样品,进行了流体包裹体显微测温和氢氧同位素测试。流体包裹体研究结果表明,矿物中包裹体以富液相为主,均一温度为320~360℃,盐度w(NaCl,eq)=3%~5%,显示岩浆热液矿床的流体特征;氢氧同位素测试结果显示,δD=-110.0×10~(-3)~-95.5×10~(-3),平均-104.4×10~(-3),δ(~(18)O_(V-SMOW))=-2.2×10~(-3)~2.5×10~(-3),平均-0.6×10~(-3),表明其主成矿期的成矿流体以岩浆水为主,并伴有少量大气降水的加入。     

Genesis of the Zhaokalong Fe-Cu Polymetallic Deposit at Yushu, China:Evidence from Ore Geochemistry and Fluid Inclusions

The ore types of the Zhaokalong Fe-Cu deposit are divided into two categories: sulfide-type and oxide-type. The sulfide-type ore include siderite ore, galena-sphalerite ore and chalcopyrite ore, whereas the oxide-type ore include magnetite ore and hematite ore. The ore textures and structures indicate that the Zhaokalong deposit is of the sedimentary-exhalative mineralization type. Geochemical analyses show that the two ore types have a high As, Sb, Mn, Co and Ni content. The REE patterns reveal an enrichment of the LREE compared to the HREE. Isotopic analysis of siderite ore reveal that the δ13CPDB ranges from 2.01 to 3.34 (‰) whereas the δ18O SMOW ranges from 6.96 to 18.95 (‰). The fluid inclusion microthermometry results indicate that homogenization temperatures of fluid inclusions in quartz range from 131 to 181℃, with salinity values of 1.06 to 8.04 wt% NaCl eq. The mineralizing fluid therefore belongs to the low temperature - low salinity system, with a mineralizing solution of a CO2-Ca2+(Na+, K+)-SO42-(F-, Cl-)-H2O system. The geochemical results and fluid inclusion data provide additional evidence that the Zhaokalong deposit is a sedex-type deposit that experienced two stages of mineralization. The sulfide mineralization probably occurred first, during the sedimentary exhalative process, as exhibited by the abundance of marine materials associated with the sulfide ores, indicating a higher temperature and relatively deoxidized oceanic depositional environment. After the main exhalative stage, hydrothermal activity was superimposed to the sulfide mineralization. The later stage oxide mineralization occurred in a low temperature and relatively oxidized environment, in which magmatic fluid circulation was dominant.     

Geochemistry of the Batang Group in the Zhaokalong Area,Yushu, Qinghai: Implications for the Late Triassic Tectonism in the Northern Sanjiang Region,China

The Batang Group in the Zhaokalong area not only hosts an important Fe-Cu polymetallic deposit but also reveal important insights for the Late Triassic tectonism in the northern Sanjiang region. In order to delineate the tectonic setting and evolutionary process of the paleo arc-basin system, geochemical studies on the Batang Group strata have been carried out. The results suggest that andesite in the Zhaokalong area mainly belongs to the tholeiite series and is characterized by obvious fractionation of LREE and HREE, enrichment in LILE and depletion in HFSE, and a distinctly elevated δ~(34)SCDT average of 10.5‰. The sandstone is classified as lithic sandstone, which is also characterized by obvious fractionation of LREE and HREE, as well as weak negative Ce and Eu anomalies. The limestone displays positive Eu anomalies, with δ~(13)CPDB ranging from-1.3‰ to 4.4‰ and δ~(18) OSMOW ranging from 14.6‰ to 22.5‰. These results indicate that the andesite has a dual signature of both arc andesite and rift volcanic rocks, whereas the sandstone may be formed in an active continental margin, and the limestone could be deposited in a weak oxidizing shallow sea. The sandstone in the Zhaokalong area represents sedimentation in a platform slope facies, corresponding to the main stage of the Jinshajing oceanic basin subduction during the middle period of Late Triassic. The continental arc volcanic activity resulted from subsequent strengthened subduction, forming the andesite in the North Qiangtang backarc basin. Afterwards, the limestone was formed after the cessation of magmatic activity. The information gleaned from the Batang Group strata helped constrain the evolution of the paleo-Jomda island arc and Jinshajiang oceanic subduction in the Late Triassic.     

Geology and Geochemistry of the Shizitou Molybdenum Deposit,Jiangxi Province: Implications for Geodynamic Setting and Metallogenesis

The Shizitou molybdenum(Mo) deposit in Yongping, Jiangxi, is an important, recently discovered deposit in the eastern section of the Qin–Hang metallogenic belt. The Mo deposit is located in the outer contact zone between the porphyritic biotite granite and the Neoproterozoic migmatite, and present in the deep central part of the intrusion. Re–Os dating and S and Pb isotopic analysis have been conducted to assess the metallogenesis of the Shizitou Mo deposit. S, Pb and Re isotopes show that the ore–forming materials were derived from the porphyritic biotite granitic magma, which originated from the mixing of mantle and crust. Re–Os dating of molybdenite from the ores gives a model age from 156.9±2.2 to 158.5±2.4 Ma, with a weighted mean age of 158±1 Ma and an isochron age of 158.0±2.5 Ma. Geological and geochemical characteristics of the ore deposit and the related granitoids indicate that the Shizitou deposit is a Climax–type Mo deposit. Based on previous studies of the Qin–Hang metallogenic belt, two metallogenic events are believed to have occurred during 172–145 Ma and 137–132 Ma. These two metallogenic periods are consistent with the timing of two metallogenic peaks during the middle to late Jurassic and the Cretaceous in South China. These events represent responses to the partial back–arc extension associated with the subduction of the Izanagi plate beneath the Eurasian continent and the rapid northeastward movement of the subducting Izanagi plate.     

青海锡铁山铅锌矿床类型刍议

锡铁山铅锌矿床是我国大型块状硫化物矿床之一。该矿床类型认识长期存在争议,目前已有越来越多学者将其视为SEDEX型矿床。本文在近年来块状硫化物矿床成矿构造背景研究进展归纳整理的基础上,结合柴达木盆地北缘早古生代区域地质研究进展,提出锡铁山矿床的成矿构造环境不是以往认为的陆内裂谷,而是活动大陆边缘弧后/间盆地裂谷。鉴于成矿构造环境变化,锡铁山矿床类型也应作出相应调整,由原来的SEDEX型矿床改为VSHMS型矿床。这样做可以达到三个方面的目的:其一,有利于解决现存的成矿构造背景认识与区域地质认识不一致的矛盾;其二,有利于保障本区目前和未来大规模展开的区域成矿研究及找矿勘查评价建立在正确的成矿背景认识前提之下;其三,将矿床类型划分与成矿构造背景相结合,进而用矿床类型揭示构造背景,体现了矿床研究为地球系统科学服务的宗旨。     

青海五龙沟金矿矿床成因及成矿模式探讨

五龙沟金矿是青海省东昆仑成矿带最具找矿潜力的矿床,分析和研究五龙沟地区金矿床成因、成矿模式对于确定该区成矿类型及进一步找矿工作具有重要的指导和借鉴意义。通过收集五龙沟地区金矿床成矿大地构造背景、区域地层、岩性、构造、岩浆岩等方面的资料,首先对区内红旗沟-深水潭、百吨沟、岩金沟典型金矿床特征进行了描述;然后从地层、岩浆岩、构造3个方面对控矿因素和矿床成因进行了系统的分析,认为五龙沟金矿床经历了长期及多期次的成矿阶段,复杂的构造演化使金矿床的形成与地层、岩浆岩、构造关系密切。在分析控矿因素和矿床成因的基础上,建立了金矿床成矿模式,揭示了成矿地质因素,直观地反映了五龙沟地区金矿床具有多来源、多成因、多阶段矿化的变化和发展过程。     

陕西凤县八卦庙超大型金矿床成矿地质特征及成矿作用

本文通过Ar-Ar同位素计时、稳定同位素示踪、石英位错观察、差异应力计算和热水沉积岩研究等,探讨了八卦庙超大型金矿床的成矿作用和成矿机制。NW向无根揉皱石英脉含Au 0.5×10~(-6)～4×10~(-6),矿化元素组合为Au+Cu+Pb+Zn,Ar-Ar坪年龄232.58±1.59Ma;NE向石英脉含An大于4×10~(-6),可达37.2×10~(-6),Au为主,Ar-Ar年龄为131.91±0.98Ma。研究表明:①泥盆纪热水沉积岩为金矿床的形成提供了矿源,成矿热液水以岩浆水为主,从矿质富集到成矿至少经历了印支期挤压推覆、韧性剪切→印支晚期—燕山期岩浆热液作用;②印支晚期和燕山早期(即韧性构造变形向脆性变形的转换期)是本区金矿成矿的高峰期;③多期成矿作用叠加、多次脉动式构造活动的“应力泵”作用是该超大型金矿床成矿的主因。     

甘肃礼县李坝大型金矿床成矿地质特征及成因

文章以成矿地质条件、矿床地质特征为基础，通过Ar—Ar年龄测定、稳定同位素测试和地层含金性分析等，研究了李坝金矿床的成因。研究表明，李坝金矿床与中川花岗岩在时间、空间和成因上关系密切。含金石英脉Ar—Ar法、Rb-Sr法和Pb—Pb法年龄为210～171．6Ma，与中川岩体年龄(177～229Ma)吻合。包裹体水的δD-74‰～-83‰，δ^18O水9．51‰～11．72‰，成矿流体水为岩浆水和大气降水的混合水。花岗岩提供了部分成矿物质来源，含矿热液通过F1导矿构造进入F3、F12等容矿断裂破碎带沉淀成矿。     

青海省苦海汞矿床形成条件及成因探讨

苦海汞矿床是位于东昆仑造山带南带东段上的大型含金汞矿床。围岩为一套滨海-浅海相富含碳质碳酸盐（石英砂岩）建造。矿体受地层和构造联合控制,一般产在褶皱的层间剥离裂隙、构造裂隙及节理中,或产于褶皱翼部的断裂破碎带内。矿床成矿流体以建造水和大气降水为主,并可能有岩浆热液的加入。成矿流体盐度（w(NaCl)）为1.90%～5.70%,密度为0.78～0.97 g/cm³;流体包裹体均一温度为118.8～291.6 ℃;成矿压力约43.24 MPa,成矿深度为4.56 km。研究表明,该区下二叠统含碳地层提供了主要的成矿物质,晚三叠世受构造造山作用及相应的岩浆侵入所驱动的热液流体活化了矿质,并迁移至褶皱带层间剥离裂隙等部位沉淀成矿。总体上,该矿床为一受构造和地层联合控制的中偏低温热液矿床,相当于造山型金矿系列的浅成矿床。