东秦岭上宫金矿流体成矿作用:矿物学研究   总被引：6，自引：2，他引：6  

李晶  陈衍景  李强之  唐国军 《矿物岩石》2004,24(3):28-35

通过对上宫金矿矿物学资料的研究，确定其成矿过程具有3阶段演化特征。早阶段以粗粒乳白色石英脉为标志，矿物破碎、变形明显，金和杂质成分含量低，形成于挤压构造背景下静岩压力的变质流体。中阶段发育细粒多金属硫化物-碲化物-自然元素组合，呈微细网脉浸染于共轭节理或裂隙，没有遭受变形，金和杂质成分含量高，自然金与其他矿物属共沉淀关系，由变质流体沸腾导致，而流体沸腾则由造山过程的地壳快速隆升剥蚀引起。晚阶段发育具梳状构造的石英-碳酸盐网脉，含金性较低，由静水压力的大气降水热液在伸展构造背景下贯入张性裂隙形成。矿床地质地球化学特征与造山型金矿一致，成矿过程同步于陆陆碰撞造山作用，属于典型的断控脉状造山型金矿，成因适合于CMF模式。  相似文献   

华南大规模低温成矿的主要科学问题   总被引：9，自引：7，他引：2  

胡瑞忠  付山岭  肖加飞 《岩石学报》2016,32(11):3239-3251

大面积低温成矿是全球独特的重要成矿事件。华南地区扬子地块西南部面积约50万平方千米的广大范围,低温矿床广泛发育,包括卡林型金矿床、MVT型Pb-Zn矿床和脉型锑、汞、砷等矿床,构成华南低温成矿域。该成矿域由川滇黔接壤区的Pb-Zn、右江盆地Au-Sb-As-Hg和湘中盆地Sb-Au等三个矿集区组成。其中的矿床主要赋存于沉积岩中,受断裂构造控制,形成于100~250℃的低温条件下。以往的研究取得了重要进展,但成矿时代、成矿动力学背景、成矿物质基础和成矿过程等关键科学问题一直悬而未决。近年的研究表明,这些矿床可能形成于200~230Ma(印支期)和130~160Ma(燕山期)两个时期,除川滇黔Pb-Zn矿集区由盆地卤水演化成矿外,其余两个矿集区的形成可能均受印支期和燕山期的深部岩浆活动驱动,尽管成矿流体中的水主要是大气成因地下水。本专题报道了近年来这些方面的最新研究进展,包括20篇文章,主要涉及这些低温矿床的地质地球化学特征、成矿时代、矿床成因和成矿动力学背景等。  相似文献   

小兴安岭霍吉河钼矿床成矿过程——透岩浆成矿作用     

王泉  刘东舟  郭鸿斌 《地质与资源》2018,27(3):243-250

传统上将小兴安岭霍吉河钼矿床归类为斑岩型钼矿.通过对矿区地质特征的研究,即矿区无斑岩体、矿体围绕隐爆角砾岩呈环状出露、石英细脉-网脉状和浸染状矿石结构、成矿年龄明显晚于赋矿围岩形成时间等,认为该矿床是透岩浆成矿作用的结果.早中生代伊春-延寿花岗岩岩基带上相伴的大型-超大型钼矿是典型的透岩浆成矿作用的产物,是岩基后成矿作用.  相似文献   

Genesis and Metallogenic Process of the Lujing Uranium Deposit,Southwest Jiangxi Province,China: Constraints of Micropetrography and S–C–O Isotopes     

《Resource Geology》2018,68(3):303-325

The Lujing uranium deposit, located in the southeastern part of the Nanling metallogenic province, is one of the representative granite‐related hydrothermal uranium deposits in South China. Basic geology, geochemistry, and geochronology of the deposit have been extensively studied. However, there is still a chronic lack of systematic research on the genesis and metallogenic process of the deposit. Thus, we recently carried out an electron microprobe and stable isotopic analysis. The main research results and progresses are as follows: Uranium minerals in this deposit include coffinite, pitchblende, and uranothorite, and small amounts of uranium exist in accessory minerals in the form of isomorphism. Coffinite, which occurs predominantly as the pseudomorphs after pitchblende, also occurs as a primary mineral and is locally formed from the remobilization of uranium from adjacent uranium‐bearing minerals. The mineralizing fluid was originally composed of a magmatic fluid generated by late Yanshanian magmatism. The high As content of pyrite in ores may reflect the addition of meteoric water, or the formation water (or both), to the magmatic hydrothermal system. The δ³⁴S values vary from −14.4‰ to 13.9‰ (mean δ³⁴S = −3.9‰), showing a range that is similar to nearby Cambrian metamorphic strata and Indosinian granites, indicating that these host rocks represent the source of sulfur; however, the possibility of a mantle source cannot be completely ruled out. According to our new isotopic data and recent Pb isotopic data, we conclude that the uranium in ores was derived by leaching dominantly from the uranium‐rich host rocks, especially the Cambrian metamorphic strata. The δ¹³C_PDB values (−8.75‰ to 1.40‰; mean δ¹³C_PDB = −5.41‰) and δ¹⁸O_SMOW values (5.45–18.62‰; mean δ¹⁸O = 13.02‰) of reddish calcite from the ore‐forming stage suggest that the CO₂ in the mineralizing fluids was derived predominantly from the mantle, with a small component contributed by marine carbonates. Based on these new data and previous research results, this paper proposes that uranium metallogenesis in the Lujing deposit is closely associated with mafic magmatism resulting from crustal extension during the Cretaceous to Paleogene in South China.  相似文献   

Jurassic and Cretaceous (Yanshannian) tectonics,magmatism and metallogenesis in South China: preface     

Xiaoyong Yang  Weidong Sun 《International Geology Review》2018,60(11-14):1321-1325

ABSTRACT

South China is famous for its poly-metal deposits, with more than 50% of global W and Sb reserves, 20% of global Sn reserves, as well as abundant Cu-Mo-Pb-Zn-Au-Ag, Ta, Nb, REE and U deposits. This special issue consists of 21 papers, reporting recent progress on Yanshannian tectonic evolution, magmatism and ore deposits in South China, aiming at better understandings on the Mesozoic large-scale magmatism and mineralization events.  相似文献   

菲律宾迪纳加特岛30^#矿权区红土型镍矿床地质特征及成矿作用探讨          下载免费PDF全文

江胜国  王志刚  曹健 《地质找矿论丛》2018,33(2):299-305

30~#矿权区位于菲律宾迪纳加特岛北部,区内发育有红土型镍矿床。本次勘查圈定4处矿(化)体,其中以Ⅰ、Ⅱ、Ⅲ矿(化)体的矿化范围较大,厚度变化系数为45%~50%(相对稳定),经济价值较高。红土型镍矿体平面上呈地毯状展布于地表,厚度受地形控制,富镍矿体分布于矿权区东部的5、6、11、12小区;剖面上从地表向深部矿体为铁质红土层、松散红土层及高岭土化蛇纹石化橄榄岩层。30~#矿权区红土镍矿矿床的形成经历了从普通矿到富矿两个阶段,红土镍矿石属于酸性矿石。  相似文献   

论宁夏金场子渗流热卤水-表生改造型金矿床的矿源     

徐国风 《地球科学》1988,(2)

稳定同位素、岩石微量元素(金)和地质特征研究的结果,表明金场子金矿床的成矿物质来源系上地壳源,并且金、银、铅、铜等金属和硫、硒、砷、氯、氟、碳等来源于石炭纪和泥盆纪沉积岩。成矿流体是大气水和沉积地层水的混合溶液。金矿化与地热流体渗流热卤水成矿作用和表生风化成矿作用有关。  相似文献   

煎茶岭镍矿床成矿作用特征     

陈民扬  庞春勇  肖孟华 《地球学报》1994,15(Z1):138-144

煎岭镍矿与同类矿床相比,具有特殊的地质、地球化学物征，是一种特殊类型镍矿。本矿床流体包裹体同位素特征，表现出成矿体为岩浆与地层两端元混合趋势，成矿流体分属于Mg2+-Ca2+-Na+-F-(Cl-)型。根据 Pb、Sr、O、H、C 同位素及 REE资料，作者认为该镍矿的形成与后期酸性岩浆活动有密切关系，后期岩浆活动为成矿提供热力与热液，使成矿元素活化迁移、富集。本文最后提出了初步的成矿模式。  相似文献   

对“康滇地轴”轴成矿环境的初步探讨     

罗一月 《铀矿地质》1990,(4)

本文是根据“康滇地轴”的地壳演化历史和铀的地球化学特性来探讨“康滇地轴”的铀成矿环境,认为“康滇地轴”既有有利于铀成矿的地质环境和条件,又有不利的因素,因此,应加强基础地质研究,以各种成矿理论为指导选择有利地段,对“康滇地轴”进行第2轮找矿。  相似文献   

安徽铜陵地区含金硫化物矿床成矿作用     

戴瑞榕 《大地构造与成矿学》1991,15(1):23-30

铜陵地区位于华中地洼区,苏鄂地洼系。具工业价值的金矿床多赋存于地洼期次一级构造以及它们的交汇处,这是本区构造控矿的特点。近矿围岩以地台型碳酸盐岩为主,矿体明显受地层层位控制。与矿化有关的侵入岩,主要形成于地洼期(燕山早、中期)。岩体形成后叠加了成矿热液的多次活动。金的成矿作用及金矿床的形成,通常与含金丰度相对较高的地台构造层有密切的成因联系,它们提供了重要的物质来源,可认为是矿源层(Source beds)。本区各主要矿床是以地洼型岩浆期后热液作用为主的多因复成层控含金硫化物矿床。  相似文献