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11.
四川省白玉县呷村银多金属矿床是中国著名的VHMS矿床之一,前人曾进行过详细的矿床模型研究。对于矿床下部脉状矿体大致呈层状平行于上部块状矿体的地质现象,前人曾提出"层状矿席+层控网脉状矿带"等模式。文章通过对呷村矿床地质特征的详细研究后认为,呷村矿床在印支期形成之后,遭受到燕山期弧-陆碰撞造山的强烈改造,导致矿区地层直立并倒转,并在能干性弱的流纹质火山岩中普遍发生层内韧性剪切变形,使原先近于垂直层状矿体和喷气沉积岩的下-中部脉状-网脉状矿体被构造置换为紧闭褶皱状、无根褶皱状、透镜体状,并近于平行于上部层状矿体。构造恢复表明,下-中部脉状-网脉状矿体原始三维形态为不整合的筒状或漏斗状,与上部层状矿体组成典型的"下筒上层"的"双层结构"。根据脉状-网脉状矿体和层状矿体的空间展布特征,在构造恢复的基础上重新建立了呷村VHMS矿床的双通道夹卤水池的矿床模型。该模型对矿区外围找矿有一定的指导意义。 相似文献
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Xiomara Cazañas Pura Alfonso Joan Carles Melgarejo Joaquín Antonio Proenza Anthony Edward Fallick 《Mineralium Deposita》2008,43(7):805-824
The El Cobre deposit is located in eastern Cuba within the volcanosedimentary sequence of the Sierra Maestra Paleogene arc.
The deposit is hosted by tholeiitic basalts, andesites and tuffs and comprises thick stratiform barite and anhydrite bodies,
three stratabound disseminated up to massive sulphide bodies produced by silicification and sulphidation of limestones or
sulphates, an anhydrite stockwork and a siliceous stockwork, grading downwards to quartz veins. Sulphides are mainly pyrite,
chalcopyrite and sphalerite; gold occurs in the stratabound ores. Fluid inclusions measured in sphalerite, quartz, anhydrite
and calcite show salinities between 2.3 and 5.7 wt% NaCl eq. and homogenisation temperatures between 177 and 300°C. Sulphides
from the stratabound mineralisation display δ
34S values of 0‰ to +6.0‰, whilst those from the feeder zone lie between −1.4‰ and +7.3‰. Sulphides show an intra-grain sulphur
isotope zonation of about 2‰; usually, δ
34S values increase towards the rims. Sulphate sulphur has δ
34S in the range of +17‰ to +21‰, except two samples with values of +5.9‰ and +7.7‰. Sulphur isotope data indicate that the
thermochemical reduction of sulphate from a hydrothermal fluid of seawater origin was the main source of sulphide sulphur
and that most of the sulphates precipitated by heating of seawater. The structure of the deposit, mineralogy, fluid inclusion
and isotope data suggest that the deposit formed from seawater-derived fluids with probably minor supply of magmatic fluids. 相似文献
13.
Seismic imaging and potential field modelling to delineate structures hosting VHMS deposits in the Skellefte Ore District, northern Sweden 总被引:1,自引:0,他引:1
A. Malehmir A. Tryggvason C. Juhlin J. Rodriguez-Tablante P. Weihed 《Tectonophysics》2006,426(3-4):319-334
The Skellefte District in northern Sweden is a roughly 150 by 50 km2 large early Proterozoic massive sulphide belt. Based on high-resolution reflection seismic data along two parallel seismic profiles, potential field modeling has been carried out and two geologic cross sections have been constructed that are consistent with the available geophysical data as well as surface geologic observations. The combined modelling suggests that the Kristineberg deposit occurs on the northern limb of a regional E–W striking syncline. The interpretations help to identify new prospective areas, both down-plunge from known ores, and on the ore-bearing horizon on the southern limb of the syncline. The new results suggest that the post-orogenic Revsund granites can be divided into two major types of intrusives, those which are intruded as domes/stokes with a maximum present day thickness of about 3–3.5 km and those which are intruded as thin sheets, with a maximum thickness of a few hundred meters. The margins of the intrusions are generally inclined inwards, suggesting that the current erosion level is near the middle, or toward the base, of the granites. The contact between the Skellefte volcanic rocks and the Bothnian Basin has been interpreted as a thrust fault. We also suggest that crustal thickening predates the Skellefte volcanism and that the interpreted Bothnian Basin rocks are either a structural basement or a separate terrane to the Skellefte volcanism. Diffraction patterns in the reflection seismic data can be interpreted as originating from either a mafic–ultramafic intrusion or a mineralization zone, similar to observations elsewhere in the world. The results obtained in this study have greatly improved our understanding of the tectonostratigraphic framework and architecture of the poly-deformed c. 1.9 Ga Skellefte VHMS belt and is a key step towards building a 3D geological model in the area. 相似文献
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新疆克兰盆地红墩铅锌矿床与铁木尔特铅锌矿床的对比研究 总被引:8,自引:0,他引:8
虽然红墩铅锌矿床与铁木尔特铅锌矿床均产于新疆阿尔泰山南缘中部的克兰裂谷盆地,且二者的矿体产状与地层走向一致,具有明显的纹层状构造,但是在某些主要地质特征上,二者却存在显著的差异.例如,前者赋存于中泥盆统阿勒泰镇组的沉积碎屑岩,与海相基性火山岩有关,表现为锌多铅少,不含铜,且闪锌矿为含铁较少的低温闪锌矿;而后者却赋存于下泥盆统康布铁堡组的火山碎屑-碳酸盐岩中,与海相酸性火山岩有关,表现为铅多锌少,富含铜,且闪锌矿为含铁较多的高温闪锌矿.综合对比研究表明,红墩铅锌矿床属于SEDEX型铅锌矿床,而铁木尔特铅锌矿床则属于VHMS型铅锌矿床. 相似文献
16.
哈萨克斯坦阿尔泰巨型成矿带的地质特征和成矿模型 总被引:15,自引:2,他引:15
概要介绍了哈萨克斯坦阿尔泰巨型成矿带的构造背景、地质特征、成矿规律、典型矿床特征及成矿模型。矿山阿尔泰是世界上著名的海相火山岩型块状硫化物(VHMS)铜—铅—锌多金属矿富集区,已发现十几个大型和超大型矿床。VHMS型矿床形成于泥盆纪裂谷发育阶段,赋存于玄武岩—流纹岩双峰式火山岩和陆源碎屑沉积岩中。与成矿有关的火山岩主要为中泥盆世吉维特期(380~370Ma),部分为早泥盆世和晚泥盆世。泥盆纪之后的大陆边缘俯冲、碰撞、岩浆热液活动,对裂谷阶段形成的VHMS型矿床进行不同程度的叠加改造。在早二叠世形成了与花岗岩有关的钨、锡,铌、钽、锂等稀有金属矿化。 相似文献
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Post-collisional crustal extension setting and VHMS mineralization in the Jinshajiang orogenic belt, southwestern China 总被引:2,自引:0,他引:2
Hou Zengqian Wang Liquan Khin Zaw Mo Xuanxue Wang Mingjie Li Dingmou Pan Guitang 《Ore Geology Reviews》2003,22(3-4):177-199
The Jinshajiang orogenic belt (JOB) of southwestern China, located along the eastern margin of the Himalayan–Tibetan orogen, includes a collage of continental blocks joined by Paleozoic ophiolitic sutures and Permian volcanic arcs. Three major tectonic stages are recognized based on the volcanic–sedimentary sequence and geochemistry of volcanic rocks in the belt. Westward subduction of the Paleozoic Jinshajiang oceanic plate at the end of Permian resulted in the formation of the Chubarong–Dongzhulin intra-oceanic arc and Jamda–Weixi volcanic arc on the eastern margin of the Changdu continental block. Collision between the volcanic arcs and the Yangtze continent block during Early–Middle Triassic caused the closing of the Jinshajiang oceanic basin and the eruption of high-Si and -Al potassic rhyolitic rocks along the Permian volcanic arc. Slab breakoff or mountain-root delamination under this orogenic belt led to post-collisional crustal extension at the end of the Triassic, forming a series of rift basins on this continental margin arc. Significant potential for VHMS deposits occurs in the submarine volcanic districts of the JOB. Mesozoic VHMS deposits occur in the post-collisional extension environment and cluster in the Late Triassic rift basins. 相似文献
19.
四川呷村VHMS矿床:从矿石化学分析到地球化学模型 总被引:7,自引:2,他引:7
中国四川呷村矿床是一个典型的含金富银多金属VHMS矿床,其主要成矿金属元素Cu,Zn,Pb,Ag,Au丰度型式均呈非正态分布,多由两重或多重母体构成,揭示矿床经历了两次以上的成矿作用过程。成矿金属元素总体上集中于块状矿带,但贱金属Cu,Zn,Pb没有明显的下部富Cu Zn、上部富Pb Zn的分带,贵金属Ag、Au没有显示明显的层位优选性。矿床构造恢复和化学结构图像显示,金属元素的空间分布和富集机制严格受海底凹陷盆地的基底张性断裂和热水喷口位置控制。至少有4条近SN走向的盆地基底断裂带构成海底下部热水流体的迁移-排泄通道和网脉状成矿带的容矿空间;近EW向断裂与4条SN向断裂的交汇部位,成为上排泄的热水流体在海底的主要喷口,控制了金属元素在海底凹地的空间分布。分别处于凹陷盆地东缘和西缘的热水喷口,因正地形地貌形态而形成山丘堆式矿体(mound-syle),而处于凹陷盆地中心的热水喷口则积聚大量热水流体,构成卤水池,淀积席状块状矿体(sheet-style)。 相似文献
20.
地质与地球物理方法的综合找矿预测是以成矿模式和地球物理理论为基础,将矿床(地质体)成矿理论、地球物理、地球化学、遥感等信息进行综合分析的工作方法(张宝林,2004;廖桂香,2007)。矿床的形成经历了特定的成矿条件和成矿过程,并赋存于一定的地质环境中,地球物理信息是对地质体的空间分布特征的反映,不包含成矿的直接信息,因此,在成矿预测与找矿过程中,要以地质成矿理论为基础,充分挖掘地球物理、地球化学等的综合数据,尽可能地排除干扰,提取有利信息(申萍等,2011;陈思宇,2014)。本文以刘家坪VMS型铜锌矿床为例,介绍综合地质-地球物理方法在多金属硫化物矿床中的应用,建立了VMS型矿床综合找矿模式,为其他地区的找矿工作提供一定的理论与实践依据。 相似文献