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1.
乌拉根铅锌矿床热卤水喷流沉积矿床,矿化分布于下第三系古新统乌拉根组第一、二岩性段,矿石结构构造兼有同生沉积及叠加改造特征,围岩蚀变为黄铁矿化、天青石化、石膏化及白云石化.矿石同位素研究表明成矿物质铅锌来自地壳深部或土地幔,硫主要来自海水硫酸盐的还原.成矿温度为64℃~193℃;成矿流体盐度7.22%~20.29%WtNaCl,成矿年龄45.4~54.0Ma.成矿作用经历了三个时期:1、热卤水喷流沉积成矿期;2、热卤水充填交代成矿期;3、表生氧化淋滤富集期.  相似文献   

2.
新疆乌恰县乌拉根新生代热卤水喷流沉积铅锌矿成因研究   总被引:18,自引:3,他引:18  
乌拉根铅锌矿床是新生代卤水喷流沉积矿床,矿化分布于下第三系古新统乌拉根组第一、二岩性段,矿石结构构造兼有同生沉积及叠加改造特征,围岩蚀变为黄铁矿化、天青石化、石膏化及白云石化。通过研究表明:成矿物质铅锌来自地壳深部或上地幔,硫主要来自海水硫酸盐的还原;成矿温度为64-193℃;成矿流体盐度7.22%-20.29%WtNaCl;成矿年龄45.4-54.0M。指出成矿作用经历了三个时期:a、热卤水喷流沉积成矿斯;b、热卤水喷溢叠加成矿期;c、表生氧化淋滤富集期。  相似文献   

3.
黄钢  宋玉财  庄亮亮  田力丹  吴畏  张滢 《矿床地质》2021,40(5):1100-1118
沉积岩容矿的天青石矿床是锶最主要的来源.文章对全球该类矿床的资料进行了系统梳理,对矿床的发育特征和成因进行了综述和探讨.研究显示:①该类矿床的产出与含石膏或硬石膏的蒸发盐密切相关,或赋存在碳酸盐岩-蒸发岩沉积建造中,或出现在蒸发岩底辟环境;②多数为后生成因,表现为富锶流体交代石膏或硬石膏,或富锶流体与富硫酸盐流体混合、充填开放空间;少数矿床为同生成因,天青石直接从蒸发环境的水体中沉淀出;③后生天青石矿床中的锶可以来自不同途径,包括盆地流体与富钙矿物相互作用萃取的锶、碳酸盐岩重结晶过程文石转变为方解石或硬石膏转变为石膏释放的锶;同生天青石矿床中的锶来自沉积水体本身,沉积源区岩石提供了锶;④天青石中的硫来源于围岩地层中的石膏或硬石膏,有些矿床中的硫来自发生过硫酸盐还原作用后的(溶解的)石膏/硬石膏,而在个别矿床中,还原硫氧化成硫酸盐提供了部分硫;⑤一些天青石矿床中出现有铅锌硫化物,两者可以有成因关系,也可以无成因关系;⑥少数天青石矿床中重晶石含量较高,与高Ba/Sr流体与富硫酸盐流体混合有关.天青石从低钡流体中结晶时,钡在流体中含量的震荡变化会导致SrSO4-BaSO4固溶体的形成,从而使天青石出现环带或出溶结构.  相似文献   

4.
沉积型天青石矿床的地质特征及其成因探讨   总被引:6,自引:0,他引:6  
沉积型天青石矿床和蒸发岩类 ,特别是石膏的沉积密切相关 ,含矿地层主要是纹层状叠层石或藻灰岩。天青石中硫、锶同位素值和海水硫、锶同位素值相近。在蒸发条件下海水浓缩到一定浓度时 ,产生天青石沉积 ,或是富锶的硫酸型晶间卤水和钙碳酸盐反应 ,形成交代型天青石。天青石主要分布于蒸发盐盆地的边缘部位 ,位于钙碳酸盐和钙硫酸盐沉积的过渡带  相似文献   

5.
中国西南部云南兰坪盆地因金顶Zn-Pn矿床和新发现的白秧坪超大型Cu-Co-Ag矿床而驰名。金顶矿床以白垩系和第三系陆相碎屑岩为主岩,拥有2亿吨矿石,平均品位Zn6.08%、Pb1.29%(1500万吨金属),是目前中国最大的Zn-Pb矿床,也是世界上形成时代最新且唯一产于陆相沉积岩容矿的超大型Zn-Pb矿床。不同于世界上人们公认的沉积岩容矿基本类型,即SST、MVT和Sedex型,金顶矿床也许代表了Zn-Pb矿床的一个新类型。通常认为兰坪盆地大规模成矿流体起源于盆地卤水,流体流动以重力驱动为主,压力体系接近静水压力。但基于矿田内水压破裂观察、流体包裹体研究和盆地流体动力学模拟,我们认为深部超压流体的注入对整个成矿系统起着重要作用。闪锌矿及相关脉石矿物(石英、天青石、方解石、石膏)中流体包裹体观测的均一温度主体在110~150℃,盐度(质量分数)在1.6%~18.0%NaCl;在时间上,大规模成矿主要阶段伴随着流体温度的不断升高和盐度的逐渐降低;在空间上,金顶矿区空间上从东到西,成矿流体温度明显降低,盐度系统性升高。富CO2流体包裹体揭示成矿流体曾高达(513~1364)×105Pa,大大高于静水压力。数值模拟表明,盆地沉积和压实产生的流体超压可以忽略,区域构造推覆也不足以产生如此高的流体压力。我们认为成矿流体超压很可能是幔源流体注入引起的;幔源含矿的相对高温低盐度流体沿导矿构造注入金顶穹隆构造-岩性圈闭并与其中富H2S的相对低温高盐度卤水混合是兰坪盆地大规模成矿的关键动力学过程。这个特殊的流体动力学过程和成矿系统,使兰坪盆地的成矿有别于世界其他沉积盆地已知的成矿作用。  相似文献   

6.
箭猪坡矿床是广西丹池成矿带南段五圩矿田中最大的Pb-Zn-Sb多金属矿床。矿床主要由早阶段特富大脉状闪锌矿-脆硫锑铅矿矿化和晚阶段脆硫锑铅矿-闪锌矿-碳酸盐-石英脉状矿化组成。本文分析了箭猪坡矿床两种不同矿化类型石英、闪锌矿中的流体包裹体特征、均一温度及盐度,探讨特富矿体形成的控制因素。两种矿化类型包裹体主要由含CO_2包裹体和水溶液包裹体组成。早阶段特富大脉状矿化流体包裹体均一温度为120~290℃,集中在220~290℃之间,盐度为3.6%~13.6%。晚阶段脉状矿化流体包裹体均一温度为150~350℃,集中在240~310℃之间,盐度为1.4%~12.0%。富CO_2成矿流体主要来自变质、有机质中低温热降解、有机质还原、岩浆出溶及夕卡岩化。箭猪坡矿化产于泥盆系破碎带中,晚于华南地区变质作用;矿床成矿温度(220~310℃)远大于有机物热降解释放大量CO_2的温度(约150℃);矿床深部发育Sn矿化,表明成矿流体具还原性,不太可能含有大量而区内非夕卡岩化岩浆热液矿床成矿热液只含有少量CO_2。因此,初步认为箭猪坡矿床富CO_2流体主要与深部夕卡岩化作用有关,成矿流体主要来源于岩浆热液。成矿流体含少量甲烷、沥青质等有机质,表明成矿过程有盆地卤水混入。早阶段特富矿体成矿流体在温度–盐度图上显示中高温中高盐度和低温低盐度流体混合特征,而晚阶段脉状矿化成矿流体温度–盐度分布较为分散,暗示晚阶段脉状矿化成矿过程主要经历了冷却降温,流体混合较弱。这表明成矿流体大规模混合是形成特富矿体的关键控制因素。依据富CO_2流体可能主要来源于深部夕卡岩化作用,初步推测五圩矿田深部有寻找夕卡岩型矿床良好前景。  相似文献   

7.
中国(天青石)锶矿床概述   总被引:8,自引:0,他引:8  
中国 (天青石 )锶矿资源丰富 ,矿床以大型、特大型单一 (天青石 )锶矿为主 ,构成我国目前主要的工业锶源。依据成矿作用和成矿地质特征 ,将我国 (天青石 )锶矿床划分为沉积型、岩浆 热液型、沉积 热卤水改造型和表生淋积型等四大类七个亚类。主要产于印支、燕山、喜马拉雅三个旋回之中 ,不同类型矿床分别与一定的大地构造环境、沉积岩相、岩浆岩、热液及热卤水等作用有关。中国四川东南部、柴达木盆地东北部、苏南、鄂东南、云南云龙 -维西一带、陕西黄龙铺及四川攀西等 7个地区具有良好的找矿前景  相似文献   

8.
川东是我国锶矿资源远景最大,质量最佳的成矿区。铝矿产于下三叠统嘉陵江组二、四段的灰岩-白云岩-天青石膏质藻层纹白云岩-石膏岩(或灰岩)韵律层中。天青石膏质藻层纹白云岩是含矿层。准同生阶段已有天青石沉积,局部富集形成矿源层。在后生阶段的热力、压力驱动下.四川盆地的热卤水(220~300℃)沿含矿层交代形成条纹条带状天青石矿层;第二期热卤水(150~220℃)在含矿层及其附近的碳酸盐岩裂隙中充填交代,形成四块状、脉状天青石;第三期热卤水(<150℃)沿断裂充填形成天青石、重晶石脉。一、二期热卤水成矿作用常相互叠加,形成工业矿床。川东褶皱带西部背料部位具良好的找矿前景。  相似文献   

9.
热水沉积岩相形成于裂谷盆地、洋中脊(有限洋盆)、弧—盆系统、陆缘盆地、陆内湖相盆地等不同的构造古地理单元内。按照成岩成矿方式—岩石组合—地球化学动力学分类原则,热水沉积岩相类型可划分为热水同生沉积岩相、热水准同生交代岩相、热水同生蚀变岩相、热水爆炸—液压致裂角砾岩相、热卤水准同生渗滤交代岩相与热流柱构造有关的热流体隐爆—液压致裂角砾岩相,包括不同成岩方式形成的17种构造岩相学类型,它们是建立构造岩相学独立填图单元的基础。热水流体系统的根部相→喷口相→中心相→过渡相→远端相,具有显著的构造岩相学分带和相体分布规律,但在现今陆内造山带中,它们多经历了碎裂岩相、糜棱岩相和热流体改造—叠加—再造成岩相,需进行构造岩相学变形史研究和构造岩相学变形筛分,才能有效恢复它们形成时的构造古地理,促进提升对深部隐伏构造岩相学探测与资源预测的准确性。  相似文献   

10.
厂坝一李家沟矿床为规模大、品位富、分布集中的层控型铅锌矿床。主要成矿作用发生在沉积—成岩阶段,矿带受裂谷海槽内次级同生断裂及伴生的沉积盆地控制。矿带内一组走向北东的同生断裂带及次级洼陷和隆起,控制着岩相带的发育和矿床规模。矿带内主要矿体赋存于碎屑岩向碳酸盐过渡的岩相带内,并受到后期变质热液、层间断裂的改造富集。 厂坝一李家沟铅锌矿床的同生断裂,是喷气沉积成矿阶段含矿热卤水的通道;属海底喷气一沉积受变质型矿床。  相似文献   

11.
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.  相似文献   

12.
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提  相似文献   

13.
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.  相似文献   

14.
本文介绍样品经四硼酸锂熔融制成玻璃小饼。采用Lachance模式和理论a系数来校正元素间的效应,由3080E型X-射线荧光谱仪和DF-350B数据处理系统完成硅酸盐中十三个项目的测定。  相似文献   

15.
本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。  相似文献   

16.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance.  相似文献   

17.
18.
岩石密度和超高压岩石折返速率   总被引:1,自引:3,他引:1  
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。  相似文献   

19.
《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).  相似文献   

20.
We have developed a set of four synthetic standards for the rare earth and high field strength elements designed for use in the determination of those elements in silicates. The base material is a glass nominally at the eutectic of the MgO-Al2O3-SiO2 ternary system. The nominal doping level was 2 wt% of the elements as oxides. To avoid problems associated with peak interference, the elements were doped in four separate glasses.  相似文献   

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