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冰碛扇型砂金矿床特征及其成矿初探 总被引：1，自引：0，他引：1
成生于冰碛扇内，经一定的生物、物理化学成矿作用，以砂金形态分布而富集成矿的金矿称为冰碛扇型砂金矿床。它具有沿造山带一定标高范围成群、成带分布，深积物为近源且半胶结，砂金呈面状分布，并友粒金、块金为主，具胶状、包块状构造形态，分布极不均匀等特征。冰碛扇型砂金矿床的成矿作用与河成砂金矿床有体本质的区别。成矿作用模式是：造山带下地壳富含的活化金通过新构造运动活化的断裂运移地表，经地下流体物地表流体的迁移 相似文献
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应用砂金地质科研是以砂金成矿理论研究为基础,以砂金成矿予测为中心的一门实用目的很强的科研工作。它是普查前期的重要基础工作,担负着从找矿战略选区到提供靶区的一系列为找矿服务的予测评价任务。因此,它是砂金勘查系统工程中,不可缺少的重要环节。砂金成砂予测研究在我国是一较新的领域,在当前的砂金找矿热潮中,加 相似文献
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湖南益阳南郊古火山岩区位于雪峰隆起中段,与洞庭凹陷接壤部位.该区历来是湖南砂金特别是块金(狗头金)的重要产地.据史载公元一世纪时益阳山溪冲出一块重九斤八两,十一世纪时又冲出生金数百斤,其中一块重49斤.1983年6月14日,在本区北部地表以下3米左右的砾石层中,发现一块重2160.8克含金92%,纯金达1987.94克巨型金块.同年7月又在该地挖得一块重1511.49克,含金91.990%,纯金1360.57克的块金.现代细谷砂金、 相似文献
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大兴安岭漠河砂金富集区岩金找矿思路 总被引：6，自引：2，他引：4
大兴安岭漠河地区砂金极为丰富,充分研究区内的地质构造特征、砂金分布和富集规律、区域剥蚀深度等,利用砂金信息寻找岩金是区内岩金找矿工作的有效手段之一.利用砂金矿只能寻找剥蚀残留的那一部分岩金矿.对物源区剥蚀程度和探矿构造分析研究,是在砂金富集区内圈定岩金找矿靶区的关键.溶蚀系数可指示砂金是近或远原生源金矿.Pb同位素可指示成矿母岩,利用矿石、岩浆岩、地层和基底铅同位素全方位对比来判别铅同位素的来源是一种近年来国际上认同的办法,砂矿评价中利用铅同位素寻找母岩已获得成功.本区砂金Pb同位素特征值与源区极为相似,可做为砂金富集区寻找岩金的指示元素.本文旨在论述砂金富集区内砂金与岩金空间位置关系、成因上的联系及岩金成矿特点,为下一步岩金找矿工作提供思路和方法. 相似文献
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外生金包括砾岩金和松散砂金，是外能作用在地表开放条件下形成的。在地壳发展过程中，动力学成矿的时空演化是连续的，但主要集中在早、晚元古代及早、晚古生代和中生代，而大发展于新生代。依据演化规律和矿化环境，提出５个找矿有望的外生金成矿带。 相似文献
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辽南碧流河中上游砂金矿地质特征及成矿地质条件 总被引：1，自引：0，他引：1
辽南碧流河中上游砂金矿位于营口—宽甸台拱与复州台陷的交接部位。砂金主要赋存于碧流河及其支谷水系第四系全新统砂砾石层的底部,砂金矿体平行河谷呈层状分布;矿体埋藏浅,砂金粒度中粗,易采选;属冲洪积型谷底砂金矿。本区砂金主要来源于岩金矿和含金地层,成矿物质丰沛,成矿地质条件优越,是辽南砂金成矿的远景区。 相似文献
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黑龙江省是我国主要的砂金产区,北部呼玛河水系,砂金尤为集中,本文仅就大兴安岭北部地区砂金赋存规律及其与原生金矿的关系进行初步探讨.不到之处,望批评指正. 相似文献
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砂金富集规律可归纳为五条:(1)砂金比重大,体积小,一般下沉于砂砾层底部基岩之上,形成富矿带。(2)河流流速减缓处是砂金富集之场所,如河流内湾处;两河会流处;河谷由宽突变窄处;河谷由窄突变宽处。(3)河床起伏不平是砂金富集之主要条件。最理想的河床是软硬相间之岩层,如砂页岩互层,且走向横穿河谷,倾斜较陡,这样,便形成具有无数隔梁与隔槽的起伏不平的河床,砂金受阻,易于停积。(4)位于谷旁之古老河床沉积阶地是无水患的易采砂金矿床,不容忽视。(5)红黄杂色铁砂及石英碎屑常为砂金富集标志。 相似文献
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Z. S. Nikiforova B. B. Gerasimov E. G. Glushkova A. G. Kazhenkina 《Geology of Ore Deposits》2013,55(4):265-277
The data on typomorphism of placer gold and its localization in the eastern Siberian Platform have been integrated for the first time. The alluvial, pseudolode, and eolian morphology of gold determines the origin of placers, which is explained not only by hydrodynamic but also by eolian processes. The recent and older alluvial (Au-bearing reservoir rocks in the second case), as well as eolian (unconventional type), genetic types of placers are recognized in the given territory. Precambrian and Mesozoic stages of ore formation are distinguished by the set of typomorphic attributes of placer gold (chemical composition, microinclusions, internal structure, etc.). On the basis of distinguishing features of placer gold, Precambrian lode deposits of great depth spatially related to outcrops of the basement have been forecasted for the first time and classified into low-sulfide gold-quartz, Au-bearing banded iron formation, Au-Cu porphyry, and Au-PGE types. The inferred shallow-seated gold-silver and gold-sulfide-quartz disseminated deposits occur locally and are related to the Mesozoic tectonomagmatic reactivation. The elaborated methods and approaches to the study of placer gold typomorphism in the eastern Siberian Platform also could be helpful in providing insights into placer origin, and forecasting and prospecting gold deposits on the East European Platform, which is close to the Siberian Platform in geological evolution. 相似文献
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辽东半岛自晚白垩世以来,长期处于抬升剥蚀阶段,地形向准平原化,自晚更新世起发生多次海侵、海退作用,在黄海沿岸形成断续的滨海平原;数个滨海平原中以东沟滨海平原准平原化最好。其第四纪沉积物最全,厚度大,砂金成矿条件最好,对辽东半岛黄海沿岸砂金的供源条件、成矿环境的研究,并与国外特大型滨海砂金矿床的成矿地质条件对比认为,东沟滨海平原具有形成大型特大型滨海砂金矿床的成矿地质条件,此外,东沟平原从丘陵到浅海具有沟谷砂金、河床砂金、滨海砂金、浅海砂金的成矿条件,砂金潜在远景较大。 相似文献
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金仓砂金矿是吉林省延边地区著名的第四纪砂金矿床。其砂金含矿层中砾岩多呈棱角状,砂金粒度及形态沿河流流向分异现象不明显,砂金的连生矿物、伴生重砂矿物、成色、微量元素、稀土元素、铅及硫同位素、气液包裹体成分特征均可和矿区内原生金矿化对比。据此,初步从为金仓河砂金主要来源于金仓河谷中、上游底部基岩含金蚀变破碎带中的原生金。 相似文献
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BRYAN KRAPEZ 《Sedimentology》1985,32(2):223-234
Five local varieties of the Ventersdorp Contact placer at the East Driefontein Gold Mine, Carletonville, are distinguished by clast-type assemblage, reflecting discrete provenances. The placer further comprises six lithofacies which are not restricted to specific provenance-varieties. The six lithofacies are: massive, matrix-supported conglomerate (facies Gms): massive, or crudely bedded, clast-supported conglomerate (facies Gm); channel-based conglomerate (facies Gt); single clast layers (facies Glag); horizontally stratified sandstone (facies Sh); and trough cross-stratified sandstone (facies St). Facies Gms represents debris-flow deposits, whereas the other facies are stream deposits. Lithofacies and provenance-varieties are complexly interrelated in local environments, which are themselves complexly related to geomorphic elements of a degradation surface. The maximum thickness of the placer is 7 m. The placer was deposited on a hard, i.e. non-alluvial, bedrock surface, suggesting that it is a pediment mantle. It owes its preservation to a capping of conformably overlying basalts. Economic gold mineralization is present in all the conglomerate facies and all the provenance-varieties. Gold concentrations are high in gravel-bar deposits and channel fills but are not restricted to these environments. A major feature of gold concentration is its variability between provenance-controlled varieties. The gold concentration of a specific primary source is interpreted to be a major control on gold concentration in the final deposit. The origin of the placer as a pediment mantle, and its subsequent preservation by lava-flows, suggests that there was little potential for selective reworking of heavy minerals. Nevertheless, the Ventersdorp Contact placer on the Carletonville Goldfield is one of the richest gold placers in the Witwatersrand Basin. 相似文献
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浅谈冲积型砂金矿床成矿模式——以陕西月河砂金矿床为例 总被引：2，自引：0，他引：2
本文通过对砂金矿床形成过程的分析认为:在地壳局部下沉过程中,砂金在水等强应力作用下,与砾石、砂一起进入沉积盆地,形成砂金的中间储存体;随着地壳的间歇性上升,在蛇曲河流的作用下由于砂金与砾石的运动规律相仿,故和砾面一起被保留在河流冲刷面上的河床滞留砾石沉积中。当地壳多次间歇性上升后,使砂金中间储存体中分散的砂金集中富集在河床滞留砾石层中,从而形成砂金矿床。 相似文献
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我国砂金点多面广,很多江河水系都有砂金.为实现黄金生产发展的规划目标,当前加强砂金地质工作,对我国发展黄金生产建设具有重要现实意义. 相似文献