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本文在论述秦岭地区浊积岩的分布与特征的基础上,以拉尔玛金矿、中川岩体外接触带金矿、双王金矿、二台子金矿等为例,讨论了该区浊积岩型金矿的分布和特征,总结了金矿的成矿条件。认为,浊流沉积特别是双层沉积作用是成矿的基础,形成金的富集层,而多期的岩浆-构造活动和强烈蚀变作用是金等成矿元素活化,富集的重要条件。金矿最主要的是含金黄铁矿石英脉的贯入。浊积岩类泥质岩和碳酸盐岩往往形成过渡性岩石,对成矿十分有利。 相似文献
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笔者应用岩石学、构造学、矿床学、地球化学等手段和方法研究了该区金矿床的特点和形成条件,结果表明青龙河金矿的容矿岩石是一套成分以火山(碎屑)岩岩屑为主的浊积岩,其含金量高达2.87g/t,且金主要与硫化物共生,浊积岩是金的矿源层。矿区内有细脉浸染型和含金石英脉型矿床。金矿的形成受浊流作用、火山作用和后生热液作用的控制。 相似文献
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黔西南和黔东南是贵州的两个主要产金地区,大部分金矿都产于浊积岩中。但黔西南的金矿主要是含金蚀变岩型(或称卡林型、微细浸染型),以不可见金为主;黔东南的金矿却是含金石英脉型,以明金为主。这两种金矿都产在造山带,赋矿围岩是浊积岩,区内岩浆侵入作用不显著,成矿受背斜与断裂控制,成矿温度不高,矿石物质成分基本一致。研究表明,产生不同类型矿化的原因主要在于:黔东南地区的容矿岩石是浅变质的硅质碎屑岩,碳酸盐矿物很少;而黔西南地区是未变质的富钙硅质碎屑岩,碳酸盐矿物多。前者形成石英脉型金矿床,后者形成蚀变岩型金矿床。 相似文献
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滇黔桂区中三叠世安尼期浊积岩微相划分与金矿关系 总被引：2，自引：0，他引：2
对滇黔桂区中三叠世安尼期浊积岩微相的划分,认为区内浊流有3处发源地,形成了3个浊积扇,每一扇中又由中心相、过渡相及末梢相组成,从各微相分布特征和含金性分析,认为浊积岩的过渡相与卡林型金矿密切,并提出了找矿方向. 相似文献
5.
广西金牙金矿床百逢组沉积特征及其与金矿的关系 总被引：2，自引：2，他引：2
广西金牙金矿产于中三叠统百逢组中 ,矿区的百逢组为一套陆源碎屑浊积岩 ,既有阵发性高密度浊流引起的浊积扇体系 ,又有稳定低密度浊流引起的鲍马序列。百逢组下段为浊积扇体系 ,中段及上段为鲍马序列 ,一般不全 ,其中d、e段最发育 ,其次为c、b段。金矿化出现在砂泥混积的百逢组中段。矿体位于鲍马序列段 ,尤其是de和cde组合段 ,岩石为富含有机质的泥质与粉砂的混积岩 ,属远端浊积岩。其中 ,钙质泥岩和粉砂质泥岩是最有利的矿化围岩。主要载金矿物毒砂和黄铁矿呈自形晶出现。矿体的有机碳含量高于相邻围岩的有机碳含量 ,与运移烃类的叠加有关。金品位随有机碳含量的增加而增加 ,有机质也是有用的金的载体。富含有机质的浊积岩是浊积岩型金矿床形成的有利条件。 相似文献
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贵州东南部浊积岩中金矿的地质特征和成因 总被引：12，自引：0，他引：12
文章首次明确提出黔东南天柱县、锦屏县、黎平县以及相邻的湖南省靖县、会同县、洪江县存在浊积岩型金矿。研究发现,这些金矿均产在加里东皱褶带中,它们产于背斜的轴部,向两翼延伸,形成平行于地层的石英脉;另一种石英脉则充填于褶皱和剪切作用形成的剪切带或断裂带中。这些褶皱和断裂均呈北东方向。黔东南地区的浊积岩型金矿,均赋存于前震旦系下江群浊积岩中,产在板岩、凝灰岩或者在板岩和砂岩交界处。石英脉中金的富集与黄铁矿、毒砂、闪锌矿、方铅矿等密切相关。细脉比宽脉更富集金,断裂交叉处更富含金。石英脉两侧(尤其是顺层石英脉)的蚀变很弱,主要为硅化和绿泥石化。应用RB_SR方法测得石英脉的年龄为370～450Ma,成矿时代应在加里东期或期后。黔东南浊积岩金矿在品位(多数可见明金)、储量和产量方面均很有前景,研究它们具有十分重要的学术价值和经济意义。 相似文献
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辽宁青城子矿田浊积岩型金银多金属矿床 总被引：3，自引：0，他引：3
辽宁东部赋存大面积的浊积岩,在浊积岩建造中产有铅锌矿床。近年来在青城子地区除发现铅锌矿床之外还发现了大型的金、银矿床。本文对典型的浊积岩型金、银金属矿床进行了初步研究,概述了浊积岩型矿床的成因,认为辽宁东部原辽河群是浊积岩型矿床产出的有利场所,在浊积岩发育区进行找矿将能取得较大的突破。 相似文献
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明代学者陈献章说过:"学贵有疑". 读完《贵州地质》2007年1期,"浊积岩型金矿简介"一文以后,脑海中充满疑问.首先感到"简介"一文的结构比较特别.按常理,写完前4节,已完成"简介"任务,第5节似属多余. 相似文献
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浊流及相关重力流沉积研究综述 总被引：44，自引：2，他引：42
本文首先介绍了浊流及相关重力流的有关概念,并对浊流沉积研究历史进行了简要回顾,概括了当前浊流沉积的研究现状;随后,总结了浊积岩的沉积特征并对其成因进行了扼要解释;最后,对浊流及相关重力流沉积研究中两个有争议的问题－浊积相的划分和浊积相模式的建立进行了探讨。 相似文献
11.
John Berge 《Ore Geology Reviews》2011,39(1-2):91-100
The Paleoproterozoic gold deposits of the Ashanti gold belt, Ghana, occur mainly as auriferous quartz veins in graphitic shears proximal to contacts between deformed and metamorphosed turbidites and tholeiitic volcanics (alternately block-faulted Tarkwaian sediments). They are suggested in this article to belong to that class of gold deposits recognized as ‘turbidite-hosted’. Hence, evidence from previous investigations of turbidite-hosted and turbidite-associated gold deposits occurring in circumstances roughly similar to the Ashanti deposits are used, where relevant, to produce an updated genetic model for the latter.Given the relatively significant amounts of graphite associated with the major Ashanti deposits, the role of non-carbonate carbon is assessed in the light of conclusions reached by work on other turbidite-hosted and turbidite-associated gold belts. Conclusions as to the origins of mineralizing fluids and temporary repositories of gold (auriferous interflow sediments) reached by work on these other belts are also analysed.A concept of the tectonic development of the Ashanti belt-Kumasi basin area, introduced in this article, is deemed to be critical to the origin of the Ashanti gold deposits. It encompasses the role of non-carbonate carbon, turbidites, and the primary sources and secondary repositories of Au and As in the genesis of the major Ashanti gold deposits. It examines the significance of the intimate relationship between calc alkaline volcanism and the basin sediments, the occurrences of felsic metasandstones in transition-zone sediments, and TTG granitic material and fragments of chemical sediments in turbidites: all of which are incompatible with one or the other of existing concepts of tectonic development in the area. 相似文献
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太古宙绿岩建造中与韧性剪切带有关的动力变质热液金矿床(排山楼式),早-中元古代变质碎屑岩建造中的浊积岩金矿床(猎岭式或白云式)和与显生宙交代-深熔花岗岩类有关的钾质蚀变岩型金矿床(东坪-后沟式)是华北地台北缘近几年发现和探明的具有巨大资源潜力的新类型金矿床。区域潜在含金性和适宜的活化营力是这些矿床形成的基本条件。通过矿源层(岩)中成矿物质的二次活化再成矿是它们的主要成矿机制。稳定同位素研究成果可为此提供证据。 相似文献
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为了探讨离子晶体晶形与介质环境的关系,文章引入两个重要概念——离子生长机制与分子生长机制,并以黄铁矿和萤石为例,探讨了在不同介质条件下,两种生长机制对晶体形态的影响。 相似文献
14.
Pb isotope fingerprinting of mesothermal gold deposits from central Victoria, Australia: implications for ore genesis 总被引：2，自引：0，他引：2
New Pb isotope data from three major mesothermal lode gold deposits (Ballarat West, Tarnagulla, Maldon) in central Victoria
support a model whereby the metals derived from a large reservoir with a long residence time in the crust below the Palaeozoic
Lachlan Fold Belt. The Pb isotopic ratios of least radiogenic samples from these deposits are in close agreement with published
Pb signatures for turbidite-hosted gold deposits, and for Devonian granites, elsewhere in the Lachlan Fold Belt. Despite their
spatial distribution and variations in the geological setting, the Pb signatures point to the extraction and transport of
metals from a crustal source area by long-lasting, large-scale hydrothermal systems, resulting in the prominent homogenisation
of Pb isotopic ratios. The enduring interaction between large hydrothermal systems and an extensive crustal source reservoir
were a vital pre-requisite in the formation of the Victorian gold province. In this regard, the prospectivity of Victoria
is analogous to world-class ore provinces elsewhere, such as the Archaean Yilgarn Block in Western Australia.
Received: 10 February 1998 / Accepted: 28 April 1998 相似文献
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关于剪应力和剪应变的思考 总被引：1，自引：0，他引：1
对力学中广泛应用的剪应力互等定理提出了质颖，认为该定理并不能广泛成立。根据内力分析的基本原理，运用截面法分析了该定理成立的条件和适用的范围。回顾了现有剪应变概念的主要描述形式，在讨论和分析其内涵的不确定性的基础上，对剪应变的概念作了修正。 相似文献
16.
The NW—SE trending segments of the California coastline from Point Arena to Point Conception (500 km) and from Los Angeles to San Diego (200 km) generally parallel major right-lateral strike-slip fault systems. Minor vertical crustal movements associated with the dominant horizontal displacements along these fault systems are recorded in local sedimentary basins and slightly deformed marine terraces. Typical maximum uplift rates during Late Quaternary time are about 0.3 m/ka, based on U-series ages of corals and amino-acid age estimates of fossil mollusks from the lowest emergent terraces.In contrast, the E–W-trending segments of the California coastline between Point Conception and Los Angeles (200 km) parallel predominantly northward-dipping thrust and high-angle reverse faults of the western Transverse Ranges. Along this coast, marine terraces display significantly greater vertical deformation. Amino-acid age estimates of mollusks from elevated marine terraces along the Ventura—Santa Barbara coast imply anomalously high uplift rates of between 1 and 6 m/ka over the past 40 to 100 ka. The deduced rate of terrace uplift decreases from Ventura to Los Angeles, conforming with a similar trend observed by others in contemporary geodetic data.The more rapid rates of terrace uplift in the western Transverse Ranges reflect N—S crustal shortening that is probably a local accommodation of the dominant right-lateral shear strain along coastal California. 相似文献
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The Late Proterozoic Conception Group, exposed on the Avalon Peninsula in Newfoundland, Canada, is a 4 km thick turbidite succession containing a conformable 300 m thick sequence of diamictites (the Gaskiers Formation) near the base. Massive and crudely-stratified diamictites form beds up to 25 m thick which have a tabular geometry with slightly erosive basal contacts and are interbedded with mudstones and fine-grained, thin-bedded turbidites. These diamictites are interpreted as submarine debris flow deposits. Disrupted diamictites form strongly deformed units that contain large, complexly folded rafts of mudstone and turbidite facies. These diamictite units are interpreted as submarine slumps. Diamictites contain glacially-striated and faceted clasts; clasts and matrix are predominantly of volcanic provenance. One outcrop shows interbedded volcanic agglomerate and diamictite, and volcanic bombs can also be identified. The interbedding of diamictites with turbidites and the stratigraphic context provided by the thick sequences of turbidites below (Mall Bay Formation) and above (Drook Formation) indicate a deep marine slope setting of diamictite deposition. Diamictite facies record remobilization and downslope transfer of large volumes of unstable volcanic and glacial debris initially deposited in a shallower water marginal marine zone. The regional tectonic framework suggests the Conception Group accumulated in a deep, southward-opening ensialic rift basin with active but waning volcanic centres to the north. The Gaskiers Formation may be representative of other Late Precambrian glacially-influenced diamictite sequences that were deposited around the North Atlantic region and in Europe. These deep marine diamictite sequences characterized by debris flows, turbidites, and slump deposits, can be contrasted with more extensive shallow marine shelf diamictite sequences found in association with dolomites and tidally influenced shallow water facies in other basinal settings. 相似文献
18.
紫木凼金矿床载金矿物及金的赋存状态 总被引：2，自引：0，他引：2
紫木凼金矿床主要载金矿物为含砷黄铁矿和毒砂,氧化矿石中,金呈显微粒状自然金－显微金嵌布于褐铁矿,石英水云母,方解石的颗粒间或孔隙中,原生矿石中,金主要呈次显微粒自然金－次显微金包裹体,其次是类质同像形式赋存在含砷黄铁矿和毒砂矿物中。 相似文献
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中国卡林型金矿床金矿物的一般特征 总被引：6，自引：0，他引：6
卡林型金矿的金矿物主要为Ａｕ－Ａｇ系列的自然金和含银自然金，金的成色高。在构造活动强烈的秦岭地区，金矿物形态复杂多样，以显微金为主，明金可见，而在其他构造活动微弱地区金矿物多呈圆形－椭圆形，以次显微金为主，金矿物成色与成矿地质条件密切相关。 相似文献