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1.
内蒙古东珺银铅锌矿床是大兴安岭东乌旗—兴安成矿带内新发现的脉状银铅锌矿。通过分析该矿床地质特征、矿体特征及控矿因素,总结了其矿化富集规律,初步探讨了矿床成因。该矿床赋存于中侏罗统塔木兰沟组构造裂隙中,NW向构造是矿区的主要控矿构造;成矿与晚侏罗世—早白垩世火山和次火山热液活动密切相关,属火山-次火山热液型矿床。  相似文献   

2.
内蒙古油房西银多金属矿床地质特征及成因探讨   总被引:2,自引:0,他引:2  
论述了油房西银多金属矿床的矿体、火山-潜火山岩等地质特征,探讨了矿床成因,初步认为脉状银铅锌矿体受NW向断裂构造和火山构造控制,层状铜钼矿体受隐伏花岗斑岩体制约,矿床属晚侏罗世末-早白垩世初形成的火山、潜火山—斑岩型系列组合矿床。  相似文献   

3.
复兴屯银铅锌矿床位于大兴安岭南段中生代宝石火山沉积盆地内,是内蒙古近年来地质找矿的一大突破。文章通过分析复兴屯区域地质背景及矿床地质特征,详细介绍了地球物理及地球化学在该矿床找矿过程中的应用,最后总结了矿床的找矿标志。复兴屯银铅锌矿体产于晚侏罗世—早白垩世陆相火山碎屑岩内,其形态、规模、产状受火山机构-网格状断裂构造体系控制,呈“拱形”产出。矿床以独立银矿体、银铅锌共生矿体为主,其次为锌矿体、铅矿体、锌铅矿体,均为隐伏矿体。矿体形态为似层状、透镜状,主要矿化蚀变有叶腊石化、绿泥石化、高岭土化、碳酸盐化、菱锰矿化、闪锌矿化、方铅矿、黄铁矿化,局部见黄铜矿化。该矿床推断Ag金属资源量5258 t,平均品位198.21 g/t;Zn金属推断资源量17.6万t,平均品位1.61%;Pb金属推断资源量3.3万t,平均品位1.36%,达超大型规模。文章初步总结出复兴屯矿床找矿标志:晚侏罗世—早白垩世陆相火山碎屑岩、网格状断裂构造体系、破火山口和火山盆地、矿化蚀变(铁锰碳酸盐化、硅化、叶腊石化、黄铁矿化、铅锌矿化)、平面及垂向Ag-Pb-Zn-CuAu元素异常组合、环状平稳负磁异常和低阻高极化激电异...  相似文献   

4.
粤东宝山银(锑)矿床地质特征和成因   总被引:10,自引:2,他引:10  
粤东宝山大型银(锑)矿床产于早侏罗世火山-沉积地层中,银、硫(锑)化物矿体呈脉状,沿下侏罗统金鸡组上段碳质页岩和粉砂岩的层间断裂中分布。矿床深部具青磐岩化蚀变,中部以黄铁矿化、硅化、碳酸盐化主,上部以硅化为特征。矿区自西向东锑矿化减弱,银矿化增强,在垂直方向上,60m标高之上为锑矿化富集带,0m标高以下为银矿化富集带,研究表明,区域早侏罗世火山-沉积地层可能是矿源层,矿床是与燕山中一晚期火山-次火  相似文献   

5.
广东梅县嵩溪宝山银锑矿床成因探讨   总被引:2,自引:0,他引:2  
宝山矿床位于白渡-嵩溪东西向断裂南例,矿体呈脉状于下侏罗统,受北北东和东西向断裂构造控制,穿切的最新岩石是安山玄武岩,本文拟据矿床地质及矿物包裹体特征和硫,氢,氧,碳稳定同位素组成,阐明该银锑床床为燕山晚期早阶段形成的,由火山热液提供热 及要矿质来源的中一低温热液矿床。  相似文献   

6.
嵩溪银(锑)矿床形成于下侏罗统金鸡组,呈脉状穿层产出,具脉状、角砾状构造,矿石含大量硫盐矿物.成矿物质在剖面上具分带现象,上部富Sb、As;中部富Ag、Au、Pb、Zn;下部富Mo、Cu.包裹体均-温度介于130~340℃之间.围岩蚀变包括硅化、黄铁矿化、碳酸盐化、绢云母化及青磐岩化.硫、氧同住素和成矿年龄显示,成矿作用与下部早白垩世石英斑岩有关,嵩溪银(锑)矿床为与陆相次火山岩有关的浅成低温热液矿床.  相似文献   

7.
刘丛强 《矿床地质》1987,6(4):53-61
银洞沟铅锌-银矿床产于—火山穹窿核部。矿床的矿化过程先后由银矿化期和铅锌矿化期组成。前者分三个矿化阶段,后者分两个矿化阶段。矿床地质特征表明,矿床形成和火山穹窿核部的流纹质次火山侵入岩具有密切成因联系。本文较全面、系统地论述了该矿床的微量元素、同位素(Pb、H、O、S、C)、流体包裹体地球化学特征、矿床形成的化学热力学条件。在此基础上,从火山作用和成矿作用的地质背景、时代和相互关系,成矿物质来源,成矿物理化学条件及成矿机理三个方面探讨了矿床成因。作者认为本矿床形成于13亿年左右,成矿物质来自上地幔或下部地壳的次火山中—低温热液。  相似文献   

8.
本文总结了陕西秦岭中泥盆统铅锌矿床的类型及成矿地质特征。通过对矿床形成地质条件、成矿主要元素及Zn/Pb值、矿物标型特征、同位素地质特征等研究,证明本区中泥盆统铅锌矿床属层控沉积—改造成因。  相似文献   

9.
比利亚谷铅锌银矿位于海拉尔—根河中生代火山盆地北西缘地区。该矿床赋存于上侏罗统满克头鄂博组酸性火山岩中,受北西向断裂构造控制,主矿体呈脉状产出。赋矿围岩流纹质火山角砾熔岩LA-ICP-MS锆石U-Pb测年结果表明,其成岩时代为(159.2±1.8)Ma,并依据赋矿围岩与成矿的关系推测成矿时代为晚侏罗世。矿床赋矿围岩流纹质火山角砾熔岩和流纹岩的主量元素具有富硅(68.31%~77.18%)、富钾(3.39%~4.28%)、低钠(0.14%~0.18%)、高铝(11.74%~14.93%)的特征,属高钾钙碱性系列;岩石REE总量较低(93.65×10~(-6)98.94×10~(-6)),以轻稀土相对富集、轻稀土和重稀土分异明显、弱的Ce负异常和Eu负异常为特征;结合岩石具有亏损Sr、高度富集轻稀土等特征认为火山岩产于板内,与其有关的岩浆可能来源于上地幔,并混染了壳源物质。综合本次研究和区域构造演化特征,初步认为矿床形成于鄂霍次克板块剪刀式闭合时期的拉张伸展环境。  相似文献   

10.
索家沟银铅锌矿床位于华北陆块北缘阴山隆起东部。银铅锌矿体主要赋存于玄武岩覆盖层下北西向断裂构造带及燕山晚期酸性岩体上侵形成的张裂隙内。据现有钻探工程初步估算银金属量为1 404 t (大型);铅+锌28万t (中型)。在分析索家沟银铅锌矿成矿地质背景、矿体地质特征及物探异常特征的基础上,提出了该矿与燕山期酸性火山--侵入活动有关,属中低温热液脉状充填型银铅锌矿床,并进一步指出了找矿标志。  相似文献   

11.
砂西银铅锌矿床产于燕山晚期黑云母二长花岗岩俸外接触带上,矿体赋存于上三叠统图姆沟组变质砂岩、板岩中的北北西向顺层破碎带内.矿石矿物以铅锌硫化物为主,主成矿元素银铅逛锌的资源量达大型以上规模,属中低温热液型富银铅锌矿床。矿床本身及其外围均具有很大的找矿潜力。  相似文献   

12.
为了评价内蒙古靠山屯勘查区银铅多金属矿床找矿前景,对该勘查区进行了地质、航磁激电和化探综合找矿信息的提取。结果表明,靠山屯银铅多金属矿床是以银为主,伴生有铅和锌的中型矿床,产于早白垩世钾长花岗岩和晚侏罗世凝灰岩内。蚀变和矿化特征显示该矿床成因类型为中温热液脉型。上侏罗统玛尼吐组火山岩富含Pb、Ag等成矿元素,是有利的容矿围岩,产于火山岩和岩体接触带附近的断裂构造是有利的控矿构造,绢英岩化和硅化是近矿的围岩蚀变。成矿后区内存在差异性抬升,中部和北东部矿化以方铅矿和共伴生银矿物为主,矿床保存条件好,如Ⅱ和Ⅲ号蚀变带。南西部以闪锌矿(含黄铜矿)为主,矿床剥蚀较大,如Ⅰ号蚀变带,中高极化、低阻或中高阻、低-中高磁异常的物探异常总体为矿致异常的特征。Pb、Zn、Ag异常套合好,Pb和Ag异常面积大,强度高的异常KHt4-11分布区矿床保存条件较好,找矿前景较好。Zn异常面积大,外侧的Pb和Ag异常面积小的异常KHt1 KHt3分布区矿床剥蚀较大,找矿前景较差。  相似文献   

13.
矿床产于哈拉胜火山穹隆中,成矿与火山-岩浆作用关系密切.钻探和高磁资料显示,火山基底为额尔古纳河组,穹隆核部为次火山岩体,盖层塔木兰沟组和满克头鄂博组火山-沉积岩为容矿围岩.共圈定的11条矿体分布于穹隆东北部,受近南北向张性断裂-裂隙控制,产状较陡.4条主矿体长500~1400 m,平均厚度1~3 m,延深一般500~900 m.自岩体至围岩化探异常元素组合依次为Bi(-Pb-Ag-As-Mo)→Ag-Pb-Mo-Cu→Pb-Zn-As→Ag-Pb-Zn-Sb→Ag-Pb-Zn-Sb;矿化元素组合依次为Cu(-Mo-Pb-Zn)→Pb-Zn-Ag→Pb-Ag;围岩蚀变由岩体内部向外依次为硅化-钾化-石英绢云母化→夕卡岩化→玉髓化-绿帘石化-绿泥石化-碳酸盐化.3件岩浆岩锆石U-Pb年龄为161~142 Ma,结合区域典型矿床研究成果,认为矿床成岩成矿于晚侏罗世—早白垩世,成矿年龄为142 Ma.  相似文献   

14.
为进一步探讨楠木树铅锌矿床的成矿物质来源,文章对矿床中的25件岩矿石样品进行了系统的微量元素分析,并对矿床中不同阶段的热液脉石矿物进行了包裹体测温和氢、氧同位素测试。结果表明,Pb、Zn等成矿元素在郭家坝组地层中明显富集,而基底变质岩中Pb、Zn元素的丰度明显低于地壳岩石圈丰度;与成矿元素密切相关的元素Ag、Cd、Ge、In在寒武系郭家坝组地层中富集,在基底岩石中亏损;矿石中Ag、Cd、Ge、In等元素的含量明显高于未矿化的围岩。元素迁移分析表明流体运移过程中成矿热液萃取了Zn、Pb及其密切相关的Ag、Cd、Ge、In等组分,使Zn、Pb等成矿组分进一步富集。氢、氧同位素组成显示,与铅锌矿密切相关的石英样品落入变质水范围内,且靠近有机水范围,晚期方解石样品向雨水线漂移,表明早期成矿流体可能来自于深部的盆地卤水,在向上运移的过程中流经富含有机质的地层或有有机流体的加入,晚期有大气降水和海水的加入。  相似文献   

15.
Qingdong Zeng    Jianming Liu    Zuolun Zhang    Changshun Jia    Changming Yu    Jie Ye    Hongtao Liu 《Resource Geology》2009,59(2):170-180
The Baiyinnuoer deposit (32.74 Mt ore with grades of 5.44% Zn, 2.02% Pb and 31.36 g t?1 Ag), the largest Zn‐Pb‐Ag deposit in northern China, is hosted by crystalline limestone and slate of the Early Permian Huanggangliang Formation. Detailed cross‐section mapping indicates stratigraphic and fold structural controls on the mineralization. The Zn‐Pb‐Ag mineralization is hosted predominantly by skarn, which occurs as bedding‐parallel lens that pinch out at the margins of the main economic zone. Three skarn stages are identified at the deposit: (i) garnet‐clinopyroxene; (ii) sulfides; and (iii) carbonate‐epidote. Lead isotopic compositions were determined for galena and sphalerite of the ores, whole rock samples of the Yanshanian granite and granodiorite, Permian marble and tuff, and Jurassic volcanic and subvolcanic rocks in and around the Baiyinnuoer area in order to discuss the sources of ore‐forming materials and the relationship between the ore formation and these whole rocks. Galena and sphalerite of the Baiyinnuoer ore have uniform isotopic ratios (206Pb/204Pb, 18.267–18.369; 207Pb/204Pb, 15.506–15.624; 208Pb/204Pb, 38.078–38.394) consistent with the granite and granodiorite (206Pb/204Pb, 18.252–18.346; 207Pb/204Pb, 15.504–15.560; 208Pb/204Pb, 38.141–38.320), whereas the ratios for Jurassic volcanic and subvolcanic rocks are variable and radiogenic (206Pb/204Pb, 18.468–18.614; 207Pb/204Pb, 15.521–15.557; 208Pb/204Pb, 38.304–38.375). These results indicate that the mineralization was not related to the Jurassic volcanism, but to the Yanshanian magmatism. The Permian strata may have a slight contribution to the mineralization. All features show that the Baiyinnuoer deposit is related to the Yanshanian granitic magmatism, and can be classified as a zinc‐lead‐silver skarn deposit.  相似文献   

16.
The Nanmushu Zn‐Pb deposit, hosted by the Neoproterozoic Dengying Formation dolostone, is located in the eastern part of the Micangshan tectonic belt at the northern margin of the Yangtze Craton, China. This study involves a systematic field investigation, detailed mineralogical study, and Rb‐Sr and Pb isotopic analyses of the deposit. The results of Rb‐Sr isotopic dating of coexisting sphalerite and galena yield an isochron age of 486.7 ± 3.1 Ma, indicating the deposit was formed during the Late Cambrian to Early Ordovician. This mineralization age is interpreted to be related to the timing of destruction of the paleo‐oil reservoir in the Micangshan tectonic belt. All initial 87Sr/86Sr ratios of sphalerite and galena (0.70955–0.71212) fall into the range of the Mesoproterozoic Huodiya Group basement rocks (0.70877–0.71997) and Dengying Formation sandstone (0.70927–0.71282), which are significantly higher than those of Cambrian Guojiaba Formation limestone (0.70750–0.70980), Cambrian Guojiaba Formation carbonaceous slate (0.70766–0.71012), and Neoproterozoic Dengying Formation dolostone (0.70835–0.70876). Such Sr isotope signatures suggest that the ore strontium was mainly derived from a mixed source, and both of the Huodiya Group basement rocks and Dengying Formation sandstone were involved in ore formation. Both sphalerite and galena are characterized by an upper‐crustal source of lead (206Pb/204Pb = 17.849–18.022, 207Pb/204Pb = 15.604–15.809, and 208Pb/204Pb = 37.735–38.402), and their Pb isotopes are higher than, but partly overlap with, those of the Huodiya Group basement rocks, but differ from those of the Guojiaba and Dengying Formations. This suggests that the lead also originated from a mixed source, and the Huodiya Group basement rocks played a significant role. The Sr and Pb isotopic results suggest that the Huodiya Group basement rocks were one of the most important sources of metallogenic material. The geological and geochemical characteristics show that the Nanmushu Zn‐Pb deposit is similar to typical Mississippi Valley type, and the fluid mixing may be a reasonable metallogenic mechanism for Nanmushu Zn‐Pb deposit.  相似文献   

17.
矿床含矿岩系下石炭统依柳组(C1y)火山岩系形成于陆内裂谷构造环境,具有大陆碱性玄武岩特征。岩系中成矿元素铅、锌(特别是铅)背景值较高,为区内银铅锌多金属矿重要矿源层;岩系因子分析表征:Cu、Pb、Zn、As、Sb、Sn、Ag、Au等元素与Cu、Bi、Sn、Mo、Se、W等元素均代表不同期次成矿作用和主要成矿元素组合,对指导区带成矿环境与成矿作用具有一定理论意义。  相似文献   

18.
The Yinshan deposit in the Jiangnan tectonic belt in South China consists of Pb‐Zn‐Ag and Cu‐Au ore bodies. This deposit contains approximately 83 Mt of the Cu‐Au ores at 0.52% Cu and 0.8 g/t Au, and 84 Mt of the Pb‐Zn‐Ag ores at 1.25% Pb, 1.02% Zn and 33.3 g/t Ag. It is hosted by low‐grade metamorphosed sedimentary rocks and mafic volcanic rocks of the lower Mesoproterozoic Shuangqiaoshan Group, and continental volcanic rocks of the Jurassic Erhuling Group and dacitic subvolcanic rocks. The ore bodies mainly consist of veinlets of sulfide minerals and sulfide‐disseminated rocks, which are divided into Cu‐Au and Pb‐Zn‐Ag ore bodies. The Cu‐Au ore bodies occur in the area close to a dacite porphyry stock (No. 3 stock), whereas Pb‐Zn‐Ag bodies occur in areas distal from the No. 3 stock. Muscovite is the main alteration mineral associated with the Cu‐Au ore bodies, and muscovite and chlorite are associated with the Pb‐Zn‐Ag ores. A zircon sensitive high‐resolution ion microprobe U‐Pb age from the No. 3 dacite stock suggests it was emplaced in Early Jurassic. Three 40Ar‐39Ar incremental‐heating mineral ages from muscovite, which are related to Cu‐Au and Pb‐Zn‐Ag mineralization, yielded 179–175 Ma. These muscovite ages indicate that Cu‐Au mineralization occurred at 178.2±1.4 Ma (2σ), and Pb‐Zn‐Ag mineralization at 175.4±1.2 Ma (2σ) and 175.3±1.1 Ma (2σ), which supports a restricted period for the mineralization. The Early Jurassic ages for the mineralization at Yinshan are similar to that of the porphyry Cu mineralization at Dexing in Jiangnan tectonic belt, and suggest that the polymetallic mineralization occurred in a regional transcompressional tectonic regime.  相似文献   

19.
五道沟金矿位于太平岭金-铜多金属成矿带,矿体呈脉状赋存于下二叠统双桥子组碳质板岩中,并严格受NE向断裂控制。根据野外观察和岩相学研究,将五道沟金矿成矿划分为早期石英阶段、石英-黄铁矿阶段、石英-碳酸盐阶段3个阶段,其中石英-黄铁矿阶段为主要成矿阶段。石英流体包裹体显微测温和拉曼光谱分析表明,金成矿期流体为中低温、低盐度的含CO2流体。氢氧同位素分析表明,成矿流体是岩浆水和大气降水的混合流体。黄铁矿微量元素特征表明矿区内黄铁矿为岩浆热液成因;矿石硫同位素数据显示其具有岩浆硫和地层硫的混合特征。铅同位素组成图上,矿石铅、围岩铅和岩浆岩铅三者呈线性关系,具有同源特征,矿石中207Pb/204Pb和208Pb/204Pb值明显高于围岩的相应值,暗示了矿石铅为围岩铅淋滤产物。矿石同位素特征表明双桥子组碳质板岩应为金矿矿源层。综合矿床地质特征、流体包裹体和H-O-S-Pb同位素分析,认为五道沟金矿为造山型金矿。  相似文献   

20.
The Jebel Ressas Pb–Zn deposits in North‐Eastern Tunisia occur mainly as open‐space fillings (lodes, tectonic breccia cements) in bioclastic limestones of the Upper Jurassic Ressas Formation and along the contact of this formation with Triassic rocks. The galena–sphalerite association and their alteration products (cerussite, hemimorphite, hydrozincite) are set within a calcite gangue. The Triassic rocks exhibit enrichments in trace metals, namely Pb, Co and Cd enrichment in clays and Pb, Zn, Cd, Co and Cr enrichment in carbonates, suggesting that the Triassic rocks have interacted with the ore‐bearing fluids associated with the Jebel Ressas Pb–Zn deposits. The δ18O content of calcite associated with the Pb–Zn mineralization suggests that it is likely to have precipitated from a fluid that was in equilibrium with the Triassic dolostones. The δ34S values in galenas from the Pb–Zn deposits range from ?1.5 to +11.4‰, with an average of 5.9‰ and standard deviation of 3.9‰. These data imply mixing of thermochemically‐reduced heavy sulfur carried in geothermal‐ and fault‐stress‐driven deep‐seated source fluid with bacterially‐reduced light sulfur carried in topography‐driven meteoric fluid. Lead isotope ratios in galenas from the Pb–Zn deposits are homogenous and indicate a single upper crustal source of base‐metals for these deposits. Synthesis of the geochemical data with geological data suggests that the base‐metal mineralization at Jebel Ressas was formed during the Serravallian–Tortonian (or Middle–Late Miocene) Alpine compressional tectonics.  相似文献   

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