共查询到18条相似文献，搜索用时 140 毫秒
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贵州水城-纳雍锰矿地质特征 总被引：3，自引：0，他引：3
水城-纳雍锰矿是106地质大队于本世纪初在水城一带发现的,皆属表生氧化锰矿床类,锰矿产于中二叠统茅口组第二段。氧化锰矿石仅分布在地表附近,沿倾斜一般向下延伸30-70m即全部变成原始锰矿胚层(含锰、微含锰的硅质灰岩、含硅质灰岩、含钙质硅质岩及石灰岩等)。研究表明,原始锰矿胚层是在茅口晚期黔中台沟相带内形成的富含锰质的热水沉积岩。流体包裹体测定,均一温度为105℃-178℃。锰矿胚层是表生氧化锰成矿的物质基础,本区锰矿是在适当的外因条件影响下,特别是水的作用下,通过矿胚层中杂质元素的淋失作用和锰质相对富集而形成的,是典型的锰帽型矿床。 相似文献
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与火山活动有关的热水沉积锰矿——以贵州二叠纪锰矿为例 总被引：9，自引：2，他引：7
贵州产于中二叠统茅口组第二段的锰矿、铁锰矿、含锰菱铁矿,均分布在茅口晚期黔中台沟内。东部遵义一带为碳酸盐锰矿床,西部宣威—水城一带主要为锰帽型次生氧化锰矿床。笔者目的在于探讨黔中台沟锰矿成矿条件,以期扩大找矿远景。研究表明,区内各类锰矿石和矿胚层岩石都是在热水中生成的,证据是：①有大量热水沉积的标志性矿物;②常量、微量元素及稀土元素均具有热水沉积的特征;③流体包裹体均一温度达90～275℃等。锰矿的形成可能与峨眉地幔柱演化的中晚期阶段密切相关。茅口期玄武岩的喷出活动,有利于黔中台沟内硅灰泥锰质组合的形成。东部遵义一带的锰矿,被严格限制在热水喷发形成的硅质角砾岩分布区内,结合其他特征等,说明该区锰矿形成可能与强烈的热水活动有关。 相似文献
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临沧锗矿含碳硅质灰岩的成因及其与锗成矿的关系 总被引：5，自引：1，他引：5
临沧锗矿是我国近年发现的具有独立开采价值且接近超大型规模的锗矿床，其富锗含煤段中存在薄层含碳硅质灰岩，深入研究含碳硅质灰岩的成因对于揭示锗矿床的成因具有重要的意义。通过对薄层含碳硅质灰岩岩石化学、微量元素、稀土元素和碳、氧同位素的系统研究，并与典型的陆相热水沉积物进行对比，得出以下初步认识：（1）含碳硅质灰岩属陆相热水沉积成因；（2）含碳硅质灰岩的微量元素和稀土元素可能主要来自基底的二云母花岗岩；（3）煤中锗主要由形成含碳硅质岩等热水沉积岩的热水带来。 相似文献
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四川庙子毒重石-钡解石-钡白云石型钡矿床的成因 总被引：10，自引：1，他引：9
庙子钡矿床是属于海底喷流热水沉积型毒重石 -钡解石 -钡白云石矿床。典型的海底喷流岩组合为毒重石岩 硅岩 硅质板岩 碳质板岩 灰岩 ,典型的海底喷流岩构造有角砾状、网脉状、气孔状、块状、层纹状、条带状等。钡矿石的主要组分为毒重石、钡解石、钡白云石。矿石的形成还与成岩早期有机质、细菌活动有着密切的关系。含矿岩系的岩石化学、微量元素、稀土元素地球化学特征表明硅岩、毒重石岩是在低能、缺氧、强还原条件下海底喷流热水沉积形成。钡矿形成环境为早寒武世麦地坪期扬子地台北部的陆棚边缘滞留盆地 相似文献
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凤县八卦庙特大型金矿热水沉积岩的地质地球化学特征 总被引：6，自引：0，他引：6
八卦庙特大型金矿的成因引人注目 ,作者提出含矿地层中存在的一套条带状岩石属于热水沉积成因。此套岩石顺层产出 ,主要由富石英纹层、富钠长石 -石英纹层和富铁碳酸盐纹层互层 ,构成纹层条带构造 ,具有沉积韵律和沉积旋回 ;地层走向上 ,条带状岩石渐变过渡为千枚岩或板岩 ,显示局部凹陷的热水沉积盆地特点 ;条带岩的化学成分、微量元素特征与秦岭泥盆系铅锌矿床中的硅质 -钠质 -铁碳酸质热水沉积岩非常相似 ,具有热水沉积特点。热水沉积岩与金矿化空间关系密切 ,说明八卦庙金矿属于热水沉积 (改造 )型金矿床。矿床成因类型的正确认识有利于指导区域找矿工作。 相似文献
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次生氧化锰矿一般是在热带或亚热带温暖潮湿气候条件下,含锰矿胚层中的锰矿物(如菱锰矿、蔷薇辉石、锰铝榴石等)在有利的构造条件和大气、水、生物等多种营力的综合作用下发生分解、氧化和锰的重新沉淀、富集而形成的(Var-entsov,1996;Ostwald,1988)。次生氧化锰矿 相似文献
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九子沟铜矿是凤县-太白铅锌多金属矿集区近年来发现的新矿床。矿化类型主要表现为硅质岩型、硅化灰岩型和石英-方解石脉型。矿体主要呈层状、似层状、透镜状与围岩整合产出,且多被后期顺层或切层含矿石英-方解石脉交代,形成富矿体。综合地质特征和地球化学特征,认为该矿床成因类型为喷流沉积-改造型铜矿。九子沟等铜矿床（点）与区域上的铅锌矿床构成了热水喷流沉积矿床的元素分带模式。这一发现,指示今后该地区可在热水喷流沉积矿床元素分带模式的基础上,结合区带内背斜控矿的地质特征开展找矿工作。 相似文献
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浅析贵州二叠系锰矿与峨眉山玄武岩之关系 总被引：2，自引：2，他引：2
贵州遵义-水城地区中二叠纪茅口组第二段顶部产出的原生碳酸锰和氧化锰矿床,为贵州二叠系锰矿主要矿床。贵州中西部有大量的峨眉山玄武岩分布。本文就贵州二叠系锰矿与峨眉山玄武岩之关系进行探讨。 相似文献
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为分析贵州遵义二叠纪锰矿的沉积环境,对谢家坝锰矿床进行常量元素、微量和稀土元素地球化学研究。研究认为：谢家坝锰矿赋存于茅口组顶部含锰岩系中,可分为下矿层豆状、角砾状菱锰矿、似层状菱锰矿,以及上矿层碎屑状、块状菱锰矿的二元结构矿石类型组合,可广泛代表遵义锰矿的矿石特征。谢家坝锰矿上下矿层之间主量元素和稀土元素含量差异较大,常量元素SiO2、TiO2、S、Fe2O3含量上矿层均大于下矿层,MnO、MgO与 Al2O3之间均呈负相关关系;上矿层Fe/Mn值较高,属高Fe低P型锰矿,而下矿层Fe/Mn值较低,属中低Fe低P型锰矿。上矿层稀土元素PAAS标准化配分后呈现较明显的重稀土亏损、弱的轻稀土富集、右倾配分的特征,具有弱的Ce正异常,类似海底铁锰结核稀土元素特征;下矿层呈现弱的中稀土富集,轻、重稀土亏损,弱的帽式分配特征,具明显的Ce负异常,类似典型深部海水沉积稀土元素特征。微量元素Th/U、Ni/Co、V/Cr、V/（V+Ni）、AU等沉积环境古氧相分析指标和稀土元素PAAS标准化配分模式指示,谢家坝锰矿下矿层是在贫氧-厌氧条件下Mn2+与CO32-直接形成菱锰矿,上矿层在常氧-贫氧环境下Mn3+、Mn4+以氧化物或氢氧化物形式沉淀。 相似文献
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鄂东北早元古代沉积变质锰矿是我国时代最古老的锰矿之一,是由早元古代锰质碳酸盐岩经区域变质作用而成,后又经风化富集形成工业矿床。由于特殊的地质构造背景和成矿作用的多阶段性,元素和矿物组合复杂,具有独特性。本文研究了各种组分的演变关系和元素集散因素,为锰质碳酸盐岩在高压绿片岩相区域动力变质及其后表生作用中的演变提供了一个实例。 相似文献
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XU Hai GAO Junbo YANG Ruidong DU Lijuan LIU Zhichen CHEN Jun FENG Kangning YANG Guanghai 《《地质学报》英文版》2020,94(1):90-102
The Zunyi manganese deposits, which formed during the Middle to Late Permian period and are located in northern Guizhou and adjacent areas, are the core area of a series of large-medium scale manganese enrichment minerogenesis in the southern margin and interior of the Yangtze platform, Southern China. This study reports the universal enrichment of rare earth elements(REEs) in Zunyi manganese deposits and examines the enrichment characteristics, metallogenic environment and genesis of REEs. The manganese ore bodies present stratiform or stratoid in shape, hosted in the silicon–mud–limestones of the Late Permian Maokou Formation. The manganese ores generally present lamellar, massive, banded and brecciated structures, and mainly consist of rhodochrosite, ropperite, tetalite, capillitite, as well as contains paragenetic gangue minerals including pyrite, chalcopyrite, rutile, barite, tuffaceous clay rock, etc. The manganese ores have higher ΣREE contents range from 158 to 1138.9 ppm(average 509.54 ppm). In addition, the ΣREE contents of tuffaceous clay rock in ore beds vary from 1032.2 to 1824.5 ppm(average 1396.42 ppm). The REEs from manganese deposits are characterized by La, Ce, Nd and Y enriched, and existing in the form of independent minerals(e.g., monazite and xenotime), indicating Zunyi manganese deposits enriched in light rare earth elements(LREE). The Ce_(anom) ratios(average-0.13) and lithofacies and paleogeography characteristics indicate that Zunyi manganese deposits were formed in a weak oxidation-reduction environment. The(La/Yb)_(ch), Y/Ho,(La/Nd)_N,(Dy/Yb)_N, Ce/Ce* and Eu/Eu* values of samples from the Zunyi manganese deposits are 5.53–56.92, 18–39, 1.42–3.15, 0.55–2.20, 0.21–1.76 and 0.48–0.86, respectively, indicating a hydrothermal origin for the manganese mineralization and REEs enrichment. The δ~(13) C_(V-PDB)(-0.54 to-18.1‰) and δ~(18) O_(SMOW)(21.6 to 26.0‰) characteristics of manganese ores reveal a mixed source of magmatic and organic matter. Moreover, the manganese ore, tuffaceous clay rock and Emeishan basalt have extremely similar REE fractionation characteristic, suggesting REEs enrichment and manganese mineralization have been mainly origin from hydrothermal fluids. 相似文献
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贵州西部中、上二叠统界线附近风化壳类型及成矿作用 总被引：4，自引：0，他引：4
贵州西部中、上二叠统界线附近普遍存在不整合面,在不整合面上往往发育厚度不等的风化壳。风化壳主要可归纳为三种类型:茅口组顶部的喀斯特漏斗、洼地中堆积的红粘土风化壳,锰质(铁质)风化壳,峨眉山玄武岩喷发间断面上或玄武岩顶部与龙潭组(宣威组)之间的的高铝高岭石风化壳。喀斯特侵蚀面上的红土风化壳是红土型金矿的赋存层位,峨眉山玄武岩喷发间断面上的高铝高岭石风化壳是铜矿、铝土矿赋存层位,喀斯特侵蚀面上的锰质(铁质)风化壳是锰矿、铁矿赋存层位,而玄武岩顶部与龙潭组(宣威组)之间的高岭石粘土风化壳是稀土、硫铁矿、铝土矿赋存层位。中、上二叠统界线附近风化壳对金、铜、铝土、硫铁、锰和稀土有明显的控制作用。 相似文献
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Datangpo-type sedimentary manganese deposits, which are located in northeastern Guizhou province and its adjacent areas, are Mn carbonate-type deposits hosted in black carbonaceous shale that represent a series of medium to large deposits containing a huge tonnage of reserves. PAAS-normalized rare earth element distribution patterns of manganese ores record “hat-shaped” REY (REE + Y) plots characterized by pronounced middle rare earth element enrichment, evident positive Ce anomalies, weak to strong positive Eu anomalies and negligible negative Y anomalies. These REY geochemical characteristics are different from those of country rocks and record the processes and features of sedimentation and diagenesis. Manganese was precipitated as Mn-oxyhydroxide particles in oxidized water columns with the sorption of a certain amount of rare earth elements, subsequently transforming from Mn-oxyhydroxides to rhodochrosite and redistributing REY in reducing alkaline pore-water during early diagenesis. A number of similarities can be observed through a comparison of Datangpo-type manganese ores and modern marine ferromanganese oxyhydroxide precipitates based on their rare earth elements. The precipitation of Datangpo-type manganese ores is similar to that of hydrogenetic crusts and nodules based on their positive Ce anomalies and relatively higher total REY concentrations. However, several differences also exist. Compared to hydrogenetic crusts and nodules, Datangpo-type manganese ores record smaller positive Ce anomalies, lower total REY concentrations, unobvious fractionation between Y and Ho, and weak to strong positive Eu anomalies. These were caused by quicker sedimentary rates in the oxic water columns of the shallower basin, after which pore water became strongly reducing and alkaline due to the degradation of organic matter in the early diagenetic stage. In addition, compared to typical deposits in the world, Datangpo-type manganese ores are similar to hydrogenetic deposits and different than hydrothermal deposits. All of these characteristics of manganese ores indicate that Datangpo-type manganese ores, the principal metallogenic factors of which include oxidation conditions during deposition and reducing conditions during early diagenetic stages, represent hydrogenetic deposits. 相似文献