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1.
四川宁南跑马铅锌矿床的成矿时代及其地质意义   总被引:11,自引:1,他引:10       下载免费PDF全文
四川省宁南县跑马铅锌矿床是产于下寒武统麦地坪段白云岩中的层控矿床,主要受层间破碎带控制,有两个含矿层。该矿床是沉积改造型铅锌矿床,Pb+Zn的品位6%~9%,富矿可达30%以上。笔者利用TIMS测试技术获得闪锌矿的Rb-Sr同位素年龄值,结果表明跑马铅锌矿化等时线年龄为(200.1±4.0)Ma,属印支晚期—燕山早期。由于该矿床与云南会泽铅锌矿年龄相近,推断为同一构造-岩浆活动的产物。  相似文献   

2.
香格里拉县磨莫亚铅锌矿体呈脉状或透镜状,产于北西向构造破碎带中,矿体近矿围岩为上三叠统图姆沟组(T_3t)砂岩、板岩与安山岩,该矿为中低温热液铅锌矿床。矿区Pb、Zn化探异常套合较好,规模大、强度高,显示出该区有极好找矿潜力。  相似文献   

3.
辽宁青城子铅锌矿田成矿机理研究   总被引:1,自引:0,他引:1       下载免费PDF全文
青城子铅锌矿开采历史悠久,是我国北方重要的铅锌矿产地之一.矿田由榛子沟、甸南、南山、本山、喜鹊沟等十几个中小型矿床组成.1983~1984年,笔者对矿田进行了矿床地质方面的研究.本文在野外及室内工作的基础上,着重对该矿的成矿机理进行探讨. 区域及矿床地质概况青城子铅锌矿田在大地构造位置上,处于中朝准地台辽东地盾的营口-宽甸古隆起.矿区内出露的地  相似文献   

4.
滇东北火德红铅锌矿床地球化学特征与成矿机制分析   总被引:1,自引:0,他引:1  
文章通过研究滇东北火德红铅锌矿床岩石地球化学和S、Pb同位素地球化学特征,分析其成矿金属和成矿流体来源,进而对其成矿机制进行探讨。围岩主量与微量元素分析结果表明,火德红铅锌矿床为后生热液矿床,铅锌等成矿金属物质随热液进入赋矿围岩,结合围岩蚀变特征判断,其应属中_低温热液成因;闪锌矿与黄铁矿的δ34S主要分布在-17‰~-11.4‰,其S源极可能来自生物成因硫酸盐还原,与川滇黔地区铅锌矿的S同位素来源(总体来自海水硫酸盐热化学还原)有着明显的不同;矿石硫化物的Pb同位素比值变化范围较窄,均为正常Pb;Pb同位素主要来自于上地壳,有少量岩浆物质混入。上述特征表明火德红铅锌矿床为构造和岩性共同控制的后生热液型矿床,其成矿机制与典型MVT型铅锌矿相似。  相似文献   

5.
浙江遂昌治岭头筒状铅锌矿体地质特征及成因   总被引:1,自引:0,他引:1  
通过矿床地质特征、同位素和稀土地球化学特征的研究,认为浙江遂昌治岭头直筒状铅锌矿体为隐爆角砾岩型的铅锌矿,受直筒状的隐爆角砾岩控制,主矿元素Pb的平均品位自下而上逐渐升高,而Zn的平均品位则相反,具有下部Zn,上部Pb、Zn的分带性;直筒状铅锌矿的黄铁矿δ34S平均值为6.78‰,铅同位素:206Pb/204Pb平均值为17.986、207Pb/204Pb平均值为15.596、208Pb/204Pb平均值为38.893,δEu值0.53,稀土演化曲线与变质岩和上侏罗统火山岩相似;铅、硫同位素以及稀土地球化学特征表明,成矿物质来源较单一,与燕山期壳源重熔型花岗岩型火山活动有关,从矿石组合来看,表明了热液富含Mn,且含较丰富的S、F及碳酸根等阴离子,成矿为相对封闭的还原环境,成矿时代介于148.2±0.5~104.8±0.8Ma之间。  相似文献   

6.
四川大梁子铅锌矿床单颗粒闪锌矿铷-锶测年及地质意义   总被引:22,自引:1,他引:21  
大梁子铅锌矿床位于扬子地台西南缘、甘洛-小江深大断裂带西缘,是中国川滇黔地区重要的大型铅锌矿床之一,其金属储量为 180 万吨(Pb Zn),平均品位为11.45%.铅锌矿体产于灯影组顶部,严格受近南北向断层控制.本文首次采用超低本底单颗粒闪锌矿 Rb-Sr 同位素测年方法,测得大梁子铅锌矿床成矿年龄为(366.3±7.7)Ma,代表了矿床的主成矿阶段年龄.通过地球动力背景探讨,认为该矿床的形成可能与晚加里东期扬子地台西缘构造活动有关.锶同位素初始比值测试结果表明大梁子铅锌矿床成矿物质来源可能主要源自围岩碳酸盐岩或基底地层.  相似文献   

7.
纳雍水东铅锌矿床共圈定7处铅锌矿体,矿体严格受断裂控制,呈透镜脉状产出。铅锌矿体平均厚度为1.50m,平均品位Zn9.06%,Pb1.05%。估算锌铅金属资源(332+333)总量分别为7.91万t和0.92万t,为小型矿床规模。通过在区内多年的勘查工作,并结合区内的地球化学异常特征,系统地分析了铅锌矿床的矿床地质特征、矿体形态以及矿石特征,并论述了矿床成因及Pb-Zn-Ag-Cd找矿前景。  相似文献   

8.
辽东青城子矿集区由青城子铅锌矿床和其外围的金银矿床组成,是中国北方重要铅锌金银矿产地之一.矿集区内铅锌金银矿分布严格受含矿建造控制,铅锌矿主要赋存于辽河群大石桥岩组第3岩段中下部,而金银矿主要赋存于大石桥岩组第3岩段上部和盖县岩组下部.在成矿时代上,铅锌矿主要形成于古元古代-中生代,矿床成因属于沉积变质-岩浆热液改造型,而金银矿床形成受中生代岩浆-构造作用控制.铅锌矿床与其外围的金银矿床相伴而生,且两者具有一定的成生联系.  相似文献   

9.
<正>青城子铅锌矿开采历史悠久,明朝嘉靖年间民间开采银矿,上世纪初开始开采铅锌矿,到1939年日本人在青城子开采铅锌矿已达一定规模。但大规模、正规的找矿勘查和采矿工作是建国后,先后发现榛子沟、喜鹊沟、南山、本山、甸南等15处铅锌矿床,铅锌矿脉200余条,形成一个累计铅锌金属量150万吨的大型矿山。  相似文献   

10.
祁东留书塘铅锌矿地质特征及资源远景预测   总被引:1,自引:0,他引:1  
矿床赋存于中泥盆统棋子桥组碳酸盐岩中,受总体呈近SN走向的F1挤压破碎带控制。矿体呈脉状、透镜状,走向长4 500 m,宽1~5 m,平均品位(×10-2):Zn 5.91、Pb 0.22、Ag 126.95 g/t,富矿体Pb+Zn最高达24.83×10-2、Ag 506.02 g/t。围岩蚀变有硅化、重晶石化等,铁帽可视为直接找矿标志。资源量预测表明,经过进一步勘查,可望找到一个Pb+Zn达 n×102 万t、Ag n×103 t的铅锌多金属脉状充填矿床。  相似文献   

11.
张建明  程培生  李壮 《江苏地质》2023,47(3):249-258
西湾铅锌矿床位于长江中下游成矿带中段庐枞矿集区北部、NE与近EW向基底断裂交会处,成矿条件优越。通过对矿区地质、矿化蚀变、矿体特征及矿石特征等进行分析,认为西湾铅锌矿的主要赋矿围岩为中三叠统周冲村组灰岩角砾岩,控矿构造为基底褶皱隆起带、基底断裂及其次级断裂,构造破碎带和“硅钙面”对铅锌矿体的控制明显。NE向断裂为导矿构造,其次级断裂及其形成的破碎带和“硅钙面”为容矿构造。根据赋矿围岩、控矿构造及铅锌矿赋存特征,认为西湾铅锌矿床的控矿因素为地层和构造,该矿床为受地层岩性和构造控制的热液充填型铅锌矿床。  相似文献   

12.
李南生 《福建地质》2007,26(1):27-33
闽清牛路坑铅锌矿床地处闽东中生代火山岩成矿带上[1],产于晚侏罗世中酸性-酸性火山岩中,成矿与断裂构造及火山活动密切相关。矿区内已发现4个矿体,呈不规则似层状、脉状、透镜状,受南北向和北北东向2组断裂控制。通过对矿床地质、控矿条件、矿体规模及形态的特征分析,初步研究认为,该矿床应属裂隙带充填交代中-低温热液型铅锌矿床。  相似文献   

13.
新疆和田火烧云铅锌矿的发现,标志着我国铅锌找矿在西昆仑甜水海地区取得了重大突破,区内目前已发现铅锌矿床(点)29处,其中铅锌矿中型矿床7个、大型矿床2个、超大型矿床1个。通过收集整理区内最新的矿产地质勘查成果资料,对该区带内铅锌矿的成矿特征、找矿前景进行系统分析与总结,将区内铅锌矿床划分为密西西比河谷型(MVT)和沉积喷流型(SEDEX) 2个大类和4个具体类型,认为它们的成矿过程分别与区域大地构造演化、区域断裂活动及同沉积断层-喷流沉积活动密切相关,在矿体形态、矿石矿物、矿石结构构造等矿化特征及成矿模式方面均有明显差异。火烧云式是受中侏罗统龙山组上段灰岩-白云岩沉积层位控制的沉积喷流型铅锌矿,化石山式是受中侏罗统龙山组铁锰质沉积层位控制的沉积喷流型铅锌矿,多宝山式是受断裂构造控制的碳酸盐岩建造中的MVT型铅锌矿,元宝岭式是受北东向左行张扭性断裂控制的碎屑岩建造中的MVT型铅锌矿。  相似文献   

14.
棋盘石铅锌多金属矿属于矽卡岩型多金属矿。通过对该矿床地质特征的分析后认为,矿体严格受岩体、碳酸盐岩及构造的控制,矿石类型为矽卡岩型硫化铅锌矿石;围岩蚀变以黄铁矿化、矽卡岩化、绿泥石化、碳酸盐化为特征;岩体与碳酸盐岩接触带为该矿床的重要的找矿方向。  相似文献   

15.
新疆托克赛铅锌矿床位于伊犁-伊赛克湖微板块赛里木地块,矿体赋存于下元古界温泉群碳酸盐岩中,含矿层延伸稳定,矿体呈层状顺层产出,矿石主要呈条带状、纹层状构造,矿石矿物组合简单,分析认为其成因类型属碳酸盐岩容矿的沉积-变质型铅锌矿床。矿区处于1∶20万水系沉积物及金属量测量异常区内,1∶5万水系沉积物测量在矿区内圈出了Pb-Zn-Ag综合异常,主成矿元素Pb、Zn异常面积大,强度高,套合较好,与地表铅锌矿化体对应极好。激电扫面圈出的中低电阻、高极化率异常反映了地表及浅部铅锌矿化体分布范围,瞬变电磁测量高磁变率异常可以较好地指示中深部富矿体的存在。在综合分析矿床成矿地质条件、地球化学、地球物理异常特征的基础上,初步建立了矿床的地质-地球化学-地球物理综合找矿模型。  相似文献   

16.
代启勇 《贵州地质》2015,32(3):190-195
通过对赫章县白腊厂观音山铅锌矿床地层、构造及矿体特征的分析,从构造、含矿岩性、物源等方面对该矿床进行了控矿条件进行研究。矿床主要受北西向和北北东向两组构造控制,该构造既为含矿热液的导矿构造,也为该区铅锌矿体的容矿构造。矿体主要产于碳酸盐岩地层中,层控特征明显。成矿物质可能主要来源于地层,但有深部地壳或地幔硫的混合。综合研究表明,该矿床属于层控矿床,北西向和北北东向两组构造以及旁侧小褶皱分布区域可能为成矿远景区。  相似文献   

17.
In the 1990s, some median-large gold deposits have been discovered in several lead-zinc metalloge-netic belts (e.g. the Qinling lead-zinc metallogenetic belt, Shanxi Province and Gansu Province and the Qingchengzi lead-zinc ore field, Liaoning Province) in China. Gold deposits and lead-zinc deposits spatially co-exist in the same tectonic setting; lead-zinc orebodies are commonly located below gold ore bodies. The host rocks of lead-zinc ore-bodies are conformably overlain by those of gold ore bodies. The age of gold mineralization is obviously younger than that of lead-zinc mineralization. Preliminary geochemical research has demonstrated the following: lead-zinc mineralization took place in a marine sedimentary-exhalative system, which had the characteristics of a high fluid/rock ratio, a high salinity and a high halide activity; meanwhile, most of gold was transported into the low-temperature hydrothermal plume and primarily enriched in sediments. During later (magmatism-) metamorphism-tectonism, gol  相似文献   

18.
Zinkgruvan, a major stratiform Zn-Pb-Ag deposit in the Paleoproterozoic Bergslagen region, south-central Sweden, was overprinted by polyphase ductile deformation and high-grade metamorphism (including partial melting of the host succession) during the 1.9–1.8 Ga Svecokarelian orogeny. This complex history of post-ore modification has made classification of the deposit difficult. General consensus exists on a syngenetic-exhalative origin, yet the deposit has been variably classified as a volcanogenic massive sulfide (VMS) deposit, a sediment-hosted Zn (SEDEX) deposit, and a Broken Hill-type (BHT) deposit. Since 2010, stratabound, cobaltiferous and nickeliferous Cu ore, comprising schlieren and impregnations of Cu, Co and Ni sulfide minerals in dolomitic marble, is mined from the stratigraphic footwall to the stratiform Zn-Pb-Ag ore. This ore type has not been fully integrated into any of the existing genetic models. Based on a combination of 1) widespread hematite-staining and oxidizing conditions (Fe2O3 > FeO) in the stratigraphic footwall, 2) presence of graphite and reducing conditions (Fe2O3 < FeO) in the ore horizon and hangingwall and 3) intense K-feldspar alteration and lack of feldspar-destructive alteration in the stratigraphic footwall, we suggest that both the stratiform Zn-Pb-Ag and the dolomite-hosted Cu ore can be attributed to the ascent and discharge of an oxidized, saline brine at near neutral pH. Interaction of this brine with organic matter below the seafloor, especially within limestone, formed stratabound, disseminated Cu ore, and exhalation of the brine into a reduced environment on the sea floor produced a brine pool from which the regionally extensive (>5 km) Zn-Pb-Ag ore was precipitated.Both ore types are characterized by significant spread in δ34S, with the sulfur in the Cu ore and associate marble-hosted Zn mineralization on average being somewhat heavier (δ34S = −4.7 to +10.5‰, average 3.9‰) than that in the stratiform Zn-Pb-Ag ore (δ34S = −6 to +17‰, average 2.0‰). The ranges in δ34S are significantly larger than those observed in syn-volcanic massive sulfide deposits in Bergslagen, for which simple magmatic/volcanic sulfur sources have been invoked. Mixing of magmatic-volcanic sulfur leached from underlying volcanic rocks and sulfur sourced from abiotic or bacterial sulfate reduction in a mixing zone at the seafloor could explain the range observed at Zinkgruvan.A distinct discontinuity in the stratigraphy, at which key stratigraphic units stop abruptly, is interpreted as a syn-sedimentary fault. Metal zonation in the stratiform ore (decreasing Zn/Pb from distal to proximal) and the spatial distribution of Cu mineralization in underlying dolomitic marble suggest that this fault was a major feeder to the mineralization. Our interpretation of ore-forming fluid composition and a dominant redox trap rather than a pH and/or temperature trap differs from most VMS models, with Selwyn-type SEDEX models, and most BHT models. Zinkgruvan has similarities to both McArthur-type SEDEX deposits and sediment-hosted Cu deposits in terms of the inferred ore fluid chemistry, yet the basinal setting has more similarities to BHT and felsic-bimodal VMS districts. We speculate that besides an oxidized footwall stratigraphy, regionally extensive banded iron formations and limestone horizons in the Bergslagen stratigraphy may have aided in buffering ore-forming brines to oxidized, near-neutral conditions. In terms of fluid chemistry, Zinkgruvan could comprise one of the oldest known manifestations of Zn and Cu ore-forming systems involving oxidized near-neutral brines following oxygenation of the Earth’s atmosphere.  相似文献   

19.
五伦铅锌矿床位于扬子陆块东南缘之江南(雪峰)造山带北西侧,是湘西北铅锌矿带内新近发现的热液脉型矿床.铅锌矿床产于万民岗背斜轴部,矿体沿NE向比铁溪-陈家河断裂旁侧派生的NW向断裂呈陡倾脉状产出,直接容矿围岩为奥陶系下统桐梓组和红花园组.对该矿床主成矿期的闪锌矿进行Rb-Sr等时线法定年,获得成矿年龄为238.9±4.5 Ma(MSWD=1.8),(87Sr/86Sr)i值为0.710 86±0.000 16,指示其主成矿期为中三叠世晚期.结合已有的成矿年代学资料,通过地球动力学背景探讨,结果表明湘西北地区至少存在两期铅锌成矿作用,分别对应于加里东期构造运动后伸展作用和印支早期华南陆块汇聚碰撞形成的局部伸展作用.五伦铅锌矿床的成矿物质应主要来源于含矿层之下成矿元素高含量的南华纪-寒武纪早期地层中的碎屑岩系,其较高的(87Sr/86Sr)i值指示成矿过程中陆壳影响较为明显.   相似文献   

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