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贵州低温汞锑矿床卤素元素地球化学特征及其找矿意义 总被引：1，自引：0，他引：1
本文对贵州万山汞矿,独山半坡锑矿卤素元素地球化学特征进行了较系统的研究,研究表明,Ｂｒ与Ｉ在矿区赋矿围岩,蚀变岩及矿石中都有不同程度的富集,从赋矿围岩→蚀变岩→矿石。其含量明显升高,而Ｆ,Ｃｌ主要富集于蚀变岩中,在隐伏矿体上部围岩中,Ｆ,Ｃｌ,Ｂｒ,Ｉ都有异常显示,这种卤素元素异常对寻找隐伏矿体具有指示意义。 相似文献
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贵州半坡锑矿床卤素元素地球化学研究 总被引：4，自引：1，他引：3
半坡锑矿矿石及近矿围岩中Ｂｒ与Ｉ含量很高,分别是地壳丰度值的数十倍至数百倍,这在热液矿床是十分罕见的,从远矿围岩→近矿围岩→矿石,Ｃｌ,Ｂｒ,Ｉ含量有规律地增高,而Ｆ主要富集在近矿蚀变围岩中,Ｆ,Ｃｌ,Ｂｒ,Ｉ在矿石与近矿蚀变岩中富集表明这些元素很可能能作为建筑该类隐优矿体的指示元素。 相似文献
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卡林型金矿指示元素研究 总被引：5，自引：2，他引：5
研究表明，卡林型金矿带中金矿及其共生的低温Ｈｇ、Ａｓ、Ｓｂ矿床中普遍含有较高的Ｔｌ、Ｆ、Ｃｌ、Ｉ和Ｂ，这些元素与金有明显的相关性，它们含量变化从远矿赋矿岩→近矿围岩→矿化岩→矿石明显呈依次递增趋势。根据矿床岩矿石中Ｔｌ、Ｆ、Ｃｌ、Ｉ和Ｂ的含量变化和分布特点及其与Ａｕ的相关性，尝试把富集系数和铊含量作为指示元素的应用指标。富集系数〉５、５￣０．５和０．５￣０．１分别为矿床，矿田和矿带标志；铊含量〉１ 相似文献
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热液型金矿床围岩蚀变过程中元素迁移规律—以张家口地区东坪,后 … 总被引：9，自引：2，他引：7
张家口的地区东坪、后沟、水晶屯金矿围岩蚀变发育,主要的蚀变类型有钾长石化、硅化、黄铁矿化、绿泥石化等。通过蚀变岩常量元素、微量元素的定量计算发现,三个金矿床围岩蚀变过程中元素迁移、富集有明显的规律,即常量元素（ＳｉＯ２、Ｋ２０、ＦｅＯ）,亲硫元素（成矿元素：Ａｕ、Ａｇ、Ａｓ、Ｓｂ、Ｂｉ、Ｐｂ、Ｚｎ）明显富集,其它亲铜亲铁元素（Ｃｒ、Ｃｏ、Ｎｉ、Ｃｕ）略有富集。蚀变热液是一种来自深部的携带亲硫元素富 相似文献
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银厂坡银矿床碳酸盐化蚀变作用与银的矿化富集在空间上紧密相伴,这种蚀变作用导致矿石与围岩中组分有明显差异。本文通过定量计算阐明组分之间的迁移方向;计算表明在银的原生富集过程中,常量组分的带入与带出最不明显;而微量组分Ａｇ和Ｃｕ、Ｐｂ、Ｚｎ、Ａｓ、Ｓｂ、Ｃｄ、Ｇｅ带入围岩明显。在银的次生富集过程表现为Ａｇ和Ｃｕ、Ｐｂ、Ｃｄ、Ｇａ、Ｇｅ、ＲＥＥ、ＡｌＯ３、Ｆｅ２Ｏ３、ＭｎＯ、Ｋ２Ｏ、Ｐ２Ｏ５的强烈带入,以Ａｌ２Ｏ３、Ｆｅ２Ｏ３、Ｋ２Ｏ、Ｐ２Ｏ５带入强度最大,这是由于ＣａＯ、ＭｇＯ被淋滤,体积亏损造成强烈带入的假象,而Ａｓ、Ｓｂ、Ｚｎ、Ｖ、Ｃｒ、Ｃｏ、Ｎｉ、ＣａＯ、ＭｇＯ为自围岩中带出组分,以ＣａＯ、ＭｇＯ带出强度最大。ＲＥＥ除原生富集的弱蚀变白岩→矿化白云岩表现为带出外,其余原富集过程均表现为带入围岩。造成组分发生迁 相似文献
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小柳沟铜钨矿赋存于长城系朱龙关群中，其中以赋存于云母角闪片岩，夕卡岩，夕卡岩化灰岩中的似层状矿化为主，矿体规模大，品位高，矿物成分复杂，围岩蚀变发育，其次为赋存于岩体接触带的夕卡岩型似层状，透镜状矿体，矿体规模较大，但品位低，矿石成分简单，围岩蚀变较发育，另外还有赋存于石英网脉带中的脉状矿体，矿体规模小，品位较低，矿石成分简单，围岩蚀变较发育。根据对矿区控矿条件及矿化富集规律的研究，今后该矿区找矿靶区为：小柳沟铜钨矿区西矿段西部及北部，北矿段及东矿段中的云母闪片岩，灰岩及Ⅰ，Ⅱ级重砂异常分布区，隐伏花岗岩体及地表花岗岩枝与围岩的接触带，石英网脉带脉。 相似文献
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狼娃山铁矿位于红石山蛇绿岩带南侧,矿体产于下石炭统白山组火山凝灰岩中,属火山岩型矿床。因前人对于该矿床的基础地质研究少之又少,因此对于矿床的勘探和进一步找矿带来了一定的难度。笔者从矿区的基础地质入手,通过对矿区围岩、蚀变岩和矿体的微量元素、稀土元素和S同位素的研究,探讨其矿床成因。结果表明,从围岩到蚀变岩,再到矿体,较之于地壳更加富集于地幔的微量元素(Sc、Co、Ni、Cu)均数倍乃至于数百倍的富集于矿石中,而相对富集于地壳的元素(Zr、Nb、Ta、Th)则更富集于围岩和蚀变岩。根据围岩、蚀变岩和矿体的稀土元素含量及其配分图,发现围岩和蚀变岩为右倾型,并具有明显负Eu异常,而矿石较特殊亏损轻稀土并具有显著的正Eu异常,S同位素结果显示"34S值的变化范围为+0.6‰~+3.4‰,平均值为+1.82‰。北山地区在早石炭世时曾发生大规模的岩浆事件,而同时期区域上为岛弧环境,综上结果表明,成矿物质来源于亏损上地幔部分熔融的含矿岩浆,在近地表侵入下石炭统白山组沉积成矿,据此可认为,狼娃山铁矿为火山岩型铁矿。 相似文献
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白秧坪铜钴多金属矿床产于下白垩统景星组陆相红色碎屑岩中，呈似层状、脉状分布于断裂带内，蚀变分带明显。研究表明：在原生矿石中钴主要赋存于独立矿物．辉砷钴矿中，同时钴可以类质同象赋存于砷黝铜矿及少量含钴黄铁矿中；在氧化矿石中，以钴华存在于矿石的表面。辉砷钴矿的成分和Co／Ni比值揭示钴的成矿作用与基性．超基性岩浆有关。矿床褪色蚀变岩、碳酸盐化蚀变岩矿石和正常岩石具有类似的稀土元素配分模式，即富集轻稀土而重稀土相对亏损、铈异常不明显而铕异常显著，但稀土元素总量、分异程度存在明显的差异。这可能与流体中带入稀土元素的方式、带入稀土的矿物类型和流体性质的差异等因素造成，反映成矿物质来源存在差异。相对正常岩石的微量元素含量，元素Cu、Co、As、Sb、Bi、Ag等在褪色蚀变岩、碳酸盐化蚀变岩和矿石中均相对富集，但在在褪色蚀变岩以亲石元素富集最明显，而在碳酸盐化蚀变岩和矿石中以显著富集亲硫元素(成矿元素)为主特征，表明在蚀变过程中，赋矿围岩本身没有为成矿作用提供主成矿元素，主成矿元素源自幔源的基性岩浆。由此认为钴的成矿作用可能主要与喜马拉雅期幔源的基性岩浆活动有关。 相似文献
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Tao He Mufei Li Zhaochu Hu Wen Zhang Haihong Chen Zaicong Wang Yongsheng Liu 《Geostandards and Geoanalytical Research》2023,47(1):155-168
The lack of analytical techniques for halogens in geological materials is mainly due to the loss of analytes during sample preparation. This study describes a rapid bulk rock digestion method (NH4F digestion) for determination of the abundances of Cl, Br and I in geological materials by SF-ICP-MS. During high temperature (200–240 °C) digestion, NH3 released from the decomposition of molten NH4F can effectively prevent the loss of halogens released from geological samples. Chlorine, Br and I were not lost during NH4F digestion at 220 °C for 0.25–6 h. The limits of quantitation for NH4F digestion were 2.8, 0.018 and 0.003 μg g-1 Cl, Br and I, respectively. Most results for halogens in geological reference materials by NH4F digestion were in agreement with their certified values, confirming that the high-performance rapid bulk rock NH4F digestion has sufficient digestion capability to extract Cl, Br and I from rocks, sediments and soils. In comparison, results obtained following acid digestion showed that HNO3 + HF digestion could effectively extract Br and I from soil and sediment samples, and that HNO3 acid digestion is only suitable to use for the determination of Br and I in soil samples. 相似文献
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Evidence for redistribution of Pt and Pd in the Acoje ultramafic rocks led to an investigation of the role of Cl, Br, F, I and C in Pt and Pd transport in hydrothermal solution. Anomalously high contents of 300–1000 ppm Cl, 3 ppm Br, up to 50 ppm F, 180–380 ppm I and 300–3300 ppm C are characteristic of the Acoje ultramafic rocks. The Cl and Br concentrations are restricted to serpentinized dunites and a positive correlation between Br and Cl indicate their common origin and their introduction during serpentinization. The ratios Br/Cl,F/Cl, and I/Cl correspond to those of sediments that contain seawater which suggests that Cl, Br and I were partly expelled from deep sea sediments during emplacement of the ophiolite. Fluorine could have been derived from mantle material.Carbon occurs in fluid inclusions in olivines as CO2, CO or CH4 and/or submicroscopic graphite. The high C content in serpentinized dunites suggests that C, at least in part, is also of serpentinization origin.Chlorine is mainly incorporated into Fe-rich serpentines and Ca-amphiboles. Very low F concentration in hydrous phases is common, except in serpentines from pyroxenes, pargasites and edenites. Brucite is finely dispersed in serpentines derived from olivines, indicating low CO2-activity during brucite formation and a pH of about 11.The presence of Pt and Pd tellurides, arsenides and bismuthides and the absence of selenides, in spite of elevated Se concentrations in bulk analyses of about 5 ppm, indicates that the stability conditions for selenide formation were not obtained during alteration. The formation of Pt and Pd halogen complexes, requiring highly oxidizing (fO2 > hematite-magnetite boundary (HM)) and acid environments is not favoured for Pt and Pd transport in Acoje ultramafics. An redistribution caused by the solubility reduction of Pt and Pd by Te, Bi and As and a precipitation of their intermetallic phases is proposed. No correlation between Cl and PGE-bearing rock units was observed, which indicates the minor role of halogens during redistribution of Pt and Pd in the Acoje ophiolite. 相似文献
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相山铀矿田成矿流体特征:来自微量、稀土元素地球化学证据 总被引：1，自引：1，他引：0
相山铀矿田的成矿流体性质和来源存在争议,为进一步探讨相山铀矿田成矿流体的性质和来源,本文对相山铀矿田西部的居隆庵铀矿床和北部的沙洲铀矿床中的新鲜围岩、蚀变围岩及矿石的微量、稀土元素含量及其变化进行了研究。结果显示:在含较多热液成因萤石的居隆庵铀矿床中,从新鲜围岩到蚀变围岩到矿石,Zr、Hf含量先降低再升高;而在含少量热液萤石的沙洲铀矿床中,新鲜围岩、蚀变围岩和矿石的Zr、Hf含量基本一致。鉴于富F流体易汲取岩石中的Zr、Hf,因此,这两个矿床中不同类型样品Zr、Hf含量的不同变化趋势,可能与居隆庵铀矿床的成矿流体富F、而沙洲铀矿床的成矿流体相对贫F有关。这两个铀矿床中矿石的稀土配分曲线与其各自的新鲜及蚀变围岩的稀土配分曲线形态相似但又存在差异,说明每个矿床的新鲜围岩、蚀变围岩和矿石之间的稀土元素既具有继承性、又受到不同性质的流体的影响。居隆庵铀矿床中矿石显示Eu负异常,可能主要是继承了围岩的Eu负异常;沙洲铀矿床中矿石Eu显示弱负异常至弱正异常的特征,可能与围岩中斜长石因热液蚀变作用而释放出的Eu的进入流体有关。基于新鲜围岩、蚀变围岩及矿石的U和REE研究,推断居隆庵铀矿床成矿流体中U和REE均以F的络合物形式迁移;但沙洲铀矿床中铀矿石品位较低,可能是与流体中相对贫F有关。 相似文献
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Halogen elements play an important role in the metallogenesis of metallic ore deposits and are involved in the whole process of remobilization, transport and precipitation of metallic elements. However, with the exception of fluorine, which, as a component of fluorite and mica minerals, can be occasionally concentrated in ores, Cl, Br and I are hard to enrich in the ores. Investigations have found that the halogen elements tend to diffuse toward country rocks with the development of hydrothermal alteration in the process of their involvement in metallogenesis, especially during the post-ore stage when extensive halogen diffusion halos over orebodies would be formed. Such halogen element diffusion halos over the Chadong As–Ag–Au deposit extend as widely as 200 m. The largest diffusion extent is for I and the diffusion halos of Br are most noticeable 50–130 m away from the orebodies. In areas of ore exposure and the strongly altered zone, the Cl, Br and I contents are close to those of the strata with a V-shaped distribution pattern in the periphery of the mining district. Comparatively speaking, in going away from the altered zone, the major metallic elements Au and Ag in the deposit tend to decrease suddenly to their normal contents in the strata. This variation feature of halogen elements can be used as geochemical indicators for exploring concealed orebodies at depth. In the Chadong ore deposit, halogen element anomalies can be used to predict concealed orebodies at the depth range of 0–200 m. 相似文献
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Hélène Balcone‐Boissard Agnès Michel Benoît Villemant 《Geostandards and Geoanalytical Research》2009,33(4):477-485
Concentrations of halogens (fluorine, chlorine, bromine and iodine) were determined in six geochemical reference materials (BHVO‐2, GS‐N, JG‐1, JR‐1, JB‐1b, JB‐2). Halogens were first extracted from powdered samples using a pyrohydrolysis technique, then hydrolysis solutions were analysed by ion chromatography for F and Cl and inductively coupled plasma‐mass spectrometry for Br and I. The detection limits in solutions were 100 μg l?1 for both F and Cl and 10 ng l?1 for Br and I. Considering the extraction procedure, performed on a maximum of 500 mg of sample and producing 100 ml of pyrohydrolysis solution, detection limits in rock samples were 20 mg kg?1 for F and Cl and 2 μg kg?1 for Br and I. The mean analytical errors on the studied composition ranges were estimated at 10 mg kg?1 for F and Cl, 100 μg kg?1 for Br and 25 μg kg?1 for I. The concentration values, based on repeated (generally > 10) sample analysis, were in good agreement generally with published values and narrowed the mean dispersion around mean values. Large dispersions are discussed in terms of samples heterogeneity and contaminations during sample preparation. Basaltic RMs were found to be more suitable for studies of halogen compositions than differentiated rock material, especially granites – the powders of which were heterogeneous in halogens at the 500 mg level. 相似文献
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Primary multiphase brine fluid inclusions in omphacite and garnet from low‐ to medium‐temperature eclogites have been analysed for Cl, Br, I, F, Li and SO4. Halogen contents and ratios provide information about trapped lower crustal fluids, even though the major element (Na, K, Ca) contents of inclusion fluids have been modified by fluid–mineral interactions and (step‐) daughter‐crystal formation after trapping. Halogens in the inclusion fluids were analysed with crush–leach techniques. Cl/Br and Cl/I mass ratios of eclogite fluids are in the range 31–395 and 5000–33 000, respectively. Most fluids have a Cl/Br ratio lower than modern seawater and a Cl/I ratio one order of magnitude lower than modern seawater. Fluids with the lowest Cl/Br and highest Cl/I ratios come from an eclogite that formed by hydration of granulite facies rocks, and may indicate that Br and I are fractionated into hydrous minerals. Reconstructions indicate that the inclusion fluids originally contained 500–4000 ppm Br, 1–14 ppm I and 33–438 ppm Li. Electron microprobe analyses of eclogite facies amphibole, biotite, phengite and apatite indicate that F and Cl fractionate most strongly between phengite (F/Cl mass ratio of 1469 ± 1048) and fluid (F/Cl mass ratio of 0.008), and the least between amphibole and fluid. The chemical evolution of Cl and Br in pore fluids during hydration reactions is in many ways analogous to Cl and Br in seawater during evaporation: the Cl/Br ratio remains constant until the aH2O value is sufficiently lowered for Cl to be removed from solution by incorporation into hydrous minerals. 相似文献
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东坪金矿床成矿过程中稀土元素活动性 总被引：8，自引：2，他引：6
尽管稀土元素常被认为是惰性元素,但在热液交代蚀变和化学风化作用过程中具有一定程度的活动性,河北省东坪与碱性岩有关的改进改造型热液金矿床成矿过程中,热液蚀变作用使近矿围岩ＬＲＥＥ／ＨＲＥＥ比值增大,并出现现铈正常异常;石英脉型金矿石的稀土元素分布模式呈出现明显的继承性,脉石矿物石英,钾长石的稀土元素组成相对富ＨＲＥＥ,且在脉石石英出现明显的铕正异常,研究结果表明在中,高温,近中性,较高氧逸度成矿流体 相似文献
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P. W. Uitterdijk Appel 《Mineralium Deposita》1994,29(4):341-352
Extensive scheelite-bearing calc-silicate zones with elevated contents of chromium, nickel, copper, zinc, yttrium and barium are found in Archaean supracrustal rocks of the Nuuk area, West Greenland. The calc-silicate zones are largely stratabound and occur in mafic and ultramafic metavolcanic rocks. The calc-silicates are interpreted as amphibolite facies metamorphosed alteration zones in komatiitic intrusive and extrusive rocks as well as in tholeiitic pillow lavas. The alteration which antedates the amphibolite facies metamorphism and the main deformation of the supracrustal rocks, presumably took place at the sea-floor or immediately below the sea-floor. The brines which caused the alteration were enriched in elements such as tungsten, boron, sulphur, iron, copper and zinc. The boron was precipitated as thin tourmalinites and the iron in massive to semi-massive sulphide bodies. The scheelite in the calc-silicates is mainly found as disseminated grains, as stringers and as veinlets. Rare veins up to 15 cm wide with massive scheelite are encountered. Channel sampling revealed grades up to 0.35% W over a width of 2.5 m. Highly anomalous bromine contents up to 418 ppm and equally anomalous chlorine/bromine ratios down to 3 have been found in scheelite-bearing calc-silicates. Somewhat similar anomalous bromine contents and Cl/Br ratios have been reported from serpentinites in the Outokumpu ore body, Finland. At Mount Isa, northern Australia and in the Antimony line in the Murchinson greenstone belt, southern Africa anomalous Cl/Br ratios have been observed. The possible role of bromine in the ore-forming processes is as yet poorly understood. 相似文献