共查询到20条相似文献，搜索用时 546 毫秒
1.
REE示踪沉积物物源研究进展 总被引：101，自引：0，他引：101
ＲＥＥ作为一种重要的沉积物物源示踪剂运用很广。在介绍了ＲＥＥ性质的基础上，对海水、河水、沉积岩、河流及边缘海沉积物中的ＲＥＥ元素丰度与配分模式特征进行了深入综述，概述了影响和控制ＲＥＥ丰度、模式及分馏特征的主要因素；论述了ＲＥＥ的物泊示踪意义以及在国内外应用情况与存在问题：源岩风化对ＲＥＥ分馏的影响；颗粒运及沉积时水动力分选对ＲＥＥ分馏可能造成的影响，即不同粒级中的ＲＥＥ不同的丰度与配分模式和碎屑 相似文献
2.
集中分布于南非金伯利岩和橄榄岩中的石榴石显示出ＲＥＥ正常型和正统曲线型两配分模式。这两种模式被解释为富集ＨＲＥＥ的熔体或流体对古老地幔石榴石交代的结果。在本文的模式中，交代作用的进行与石榴石－流体的分配系数ＫＤＳ的变化相一致，即ＫＤＳ随着ＬＲＥＥ、ＭＲＥＥ到ＨＲＥＥ的富集系数增大而增，这样将ＲＥＥ分成三组。 相似文献
3.
汉诺坝玄武岩中地幔岩捕掳体REE和Sr,Nd同位素地球化学 总被引：20，自引：3，他引：20
本文报道汉诺坝玄武岩中地幔岩捕掳体的ＲＥＥ丰度和Ｓｒ、Ｎｄ同位素组成。不同岩石类型的ＲＥＥ配分模式和同位素组成反映地幔部分熔融程度和交代作用过程。二辉橄榄岩亏损轻稀土，是原始地幔经不同程度部分熔融的残留体。方辉橄榄岩具Ｕ型ＲＥＥ配分模式，是强烈亏损的地幔岩被熔体非化学平衡交代的结果。二辉岩脉状体富轻、中稀土，它同与脉状体接触的二辉橄榄岩可达化学平衡或近于化学平衡，而二辉岩脉状体的形成与玄武岩岩浆无成因关系。据对二辉岩脉状体和不含脉状体橄榄岩的Ｓｍ－Ｎｄ同位素定年，这种脉状体形成于３００Ｍａ左右。 相似文献
4.
华北西缘太原组火山事件沉积的发现及太原组地层对比 总被引：11，自引：0，他引：11
摘要：作者主要依据镜下岩矿特征,辅以岩石的野外产状与分布特点,并参考ＲＥＥ配分模式特征,首次发现华北西缘太原组存在３个火山事件层。根据火山事件沉积并结合最大海侵事件层对华北西缘太原组进行了区域对比． 相似文献
5.
川西呷村超大黑矿型矿床成矿流体烯土元素组成 总被引：20，自引：5，他引：15
本文用ＩＣＰ－ＭＳ首次测定了呷村银多金属黑矿型矿床矿石流体包裹体中的稀土元素含量,研究表明,主成矿期流体稀土元素配分模式均为轻稀土富集,Ｅｕ具明显正异常,通过初步对比,本区主成矿期流体与东太平洋脊、大西洋脊等现代高温酸性地热系统热液具有相似的稀土模式,反映了它们物化条件的相似性;但前者∑ＰＥＥ高于后者,且两者Ｅｕ／Ｅｕ＾＊值不同,经过分析,本区成矿流体Ｅｕ正异常主要为Ｔ、ｐＨ、ｆｏ２控制,另外,围 相似文献
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7.
沉积物微量元素示踪地壳成分和环境及其演化的最新进展：环境对沉积… 总被引：6，自引：0，他引：6
本文提出环境是影响微量元素配分的重要因素，并列举了不同侧面的一系列证据或表现。为查明环境影响沉积物元素成分的机理，引进了先进的软硬酸碱（ＳＨＡＢ）理论；通过严格的逻辑推导，建立了氧化还原模式。作为模式的验证，介绍了华北克拉通南缘的实际研究结果，从而有力地证明了氧化还原模式的科学性和环境影响沉积物化学成分的重要性。与此同时，根据华北克拉通南缘沉积物ＲＥＥ型式的演化，推论２３００Ｍａ时发生了全球地质环 相似文献
8.
关于热水沉积物稀土配分模式的讨论 总被引：5，自引：0，他引：5
海底热水沉积物的稀土配分模式取决于流体的密度和流方式,低密度热流体的沉积物稀配合模式类似于海水模式,高密度热流体的沉积物没有固定的稀土配分模式,在判别热水沉积物时不宜单独使用稀土配分模式。 相似文献
9.
扬子东南大陆边缘晚前寒武纪古海洋演化的稀土元素记录 总被引：10，自引：1，他引：9
本文采用中子活化方法分析了晚震旦～早寒武纪１９件样品的稀土元素组成,发现硅质岩石ＲＥＥ配分形式有着复杂的变化,初步可以划分为五种类型,包括“台地型”、“红海型”、“海水型”及两种特殊的配分形式。剖面上Ｃｅ异常由小到大的演变反映了古海洋底层水由缺氧环境向氧化条件的逐渐转化。正Ｅｕ异常的出现代表了热水沉积事件的存在。 相似文献
10.
煤系高岭岩的地球化学判别标志 总被引：7，自引：0，他引：7
本文主要研究了煤系高岭岩的微量、稀土、氧同位素地球化学特征。根据高岭岩产出层序、岩石学、矿物学、地球化学特征的研究，将煤系高岭岩分为两类：（１）铝土质高岭岩，微量元素含量、稀土总量，氧同位素值高，稀土配分模式与典型北美页岩相似，Ｅｕ负异常，反映其源岩为风化壳化学风化作用产物。（２）夹矸高岭岩，微量元素含量，稀土总量，氧同位素值低，稀土配分模式部分与典型北美页岩相似，反映其源岩与铝土质高岭岩类似；部 相似文献
11.
Li Shengrong 《中国地质大学学报(英文版)》1999,10(1):2
ＩＮＴＲＯＤＵＣＴＩＯＮＬｏｗｅｒＣａｍｂｒｉａｎｂｌａｃｋｒｏｃｋｓｅｒｉｅｓｅｘｉｓｔｓｂｒｏａｄｌｙｉｎｍｏｒｅｔｈａｎ１０ｐｒｏｖｉｎｃｅｓｉｎＳｏｕｔｈＣｈｉｎａ（Ｃｈｅｎｅｔａｌ．,１９９０）．Ｔｈｅｂｏｔｏｍｏｆｔｈｅｓｅｒｉｅｓｓｐｏ... 相似文献
12.
S. G. Kovalev V. N. Puchkov S. I. Vysotsky S. S. Kovalev 《Doklady Earth Sciences》2016,471(2):1247-1252
The noble metal (PGE and Au) geochemical specialization of igneous rocks of the Bashkir meganticlinorium and adjacent areas of the East European Platform is characterized for the first time. The identical plots of normalized PGE and Au concentrations of igneous rocks in these regions indicate similar conditions and mechanisms of the formation of the noble metal geochemical specialization during the emplacement of magmatic bodies. It is established that a specific feature of noble metal geochemical specialization (the “rhodium anomaly”) in magmatic complexes of the Bashkir meganticlinorium and eastern areas of the East European Platform is determined by the concentrations of noble metals in sulfide minerals (pentlandite); i.e., it is “primary” in origin. 相似文献
13.
The relationship between noble metal mineralization and carbonaceous rocks (black shales and brown coals) is considered. We have confirmed the previous conclusions of multistage syn- and epimetamorphic formation of gold-bearing deposits in black shales and syn- and epigenetic accumulation of noble metals in brown coals. The gold and PGE in the brown coals of the Verkhnii Amur region and Primorye were presumably derived by disintegration of adjacent ore sources in the Cenozoic. Addition studies and sampling are required at the coal and graphite objects of the Russian Far East to solve this problem. 相似文献
14.
黑色岩系是多种有用元素的重要载体,Cu、Pb、Zn、Ni、Mo、V、U、Au、Ag、稀有和稀土元素在黑色岩系中异常富集,某些黑色岩系的贵金属(铂族元素、Au、Ag)也异常富集,其含量甚至部分超过了基性和超基性岩,这类黑色页岩矿床中铂族元素(PGEs)的赋存状态至今尚未有一个确切的定论。本文采集了湖南张家界属寒武系牛蹄塘组黑色页岩中Mo-Ni矿层作为研究样品,通过化学分析表明矿石中含Pt 531×10~(-9),Pd 514×10~(-9),Os 185×10~(-9),PGEs合量为1259.43×10~(-9),Au 332×10~(-9),Ag 12.2×10~(-6),已富集成矿。进一步利用重砂分级、化学分析、X射线衍射、扫描电镜及能谱技术研究了贵金属元素赋存状态,结果表明:①Ag:主要以独立矿物形式存在,少量以类质同象形式赋存在其他矿物中。独立矿物有砷铜银矿、硫锑铜银矿、硫锑铅银矿、锑银矿、硫银锡矿、硫砷银铅矿、银黄锡矿、辉银矿、锑-银-锡互化物;类质同象主要是银黝铜矿-银砷黝铜矿、含银方铅矿和含银砷铜矿等。②Au:未发现独立矿物,黄铁矿是重要载金矿物。③PGEs:未见独立矿物,在不同重砂分级样品中没有富集,具分散性,推测铂族矿物很可能是以纳米形式存在,建议今后研究选矿工艺时,可考虑从制取纳米材料的思路进行应用研究。本文Ag-Sn-Sb互化物的发现为研究黑色岩系多元素富集成因机制提供了重要物证。 相似文献
15.
A. A. Cherepanov 《Russian Journal of Pacific Geology》2008,2(2):110-121
The distribution and speciation of gold and platinum in ash-cinder wastes of the thermal power plants of Khabarovsk krai and Primorye are considered in terms of the research methods and the results obtained. The Au and PGE contents attain 2 g/t and higher, being 0.8–1.5 g/t on average. The ash of brown coal from the Pavlovka, Khurmuli, and some other fields is characterized by elevated PGE contents. The causes of discrepancies in the analytical determination of noble metals in coaly and carbonaceous rocks are considered. Accumulation of noble metals in coal is caused largely by their sorption on carbonaceous matter. The content of noble metals in ash-cinder wastes depends on their grade in the burnt coal. The latter, in turn, depends on the metallogenic characteristics of the coalfield. Gold and platinum are of economic importance, and a special technology for their recovery should to be worked out. 相似文献
16.
对太平洋CL、CM海山调查时获取9个富钴结壳样品,采用化学处理及ICP-MS法进行分析。对贵金属元素含量分布特征、富集因子、标准化模式以及来源进行探讨和研究。结果表明：海山结壳中贵金属元素Ag、Au、Ru、Rh、Pd、Pt等的平均含量分别为： 1.05×10-6、2.3×10-6、15.6×10-9、22.3×10-9、2.39×10-9和432×10-9。与结核、洋壳及陆地矿石的Pd/（Pt+Pd）、Pt/（Pt+Pd）和Pd/Pt等贵金属元素的比值相比,大洋富钴结壳的 Pd/（Pt+Pd） 比值最低,为0.006;其次是结核,为0.06;洋壳为0.08;陆地矿石的Pd/（Pt+Pd）比值较大,为0.35～0.65。结壳的Pt/（Pt+Pd）比值最高,为0.99;其次是结核,为0.95;洋壳为0.93;陆地矿石的Pt/（Pt+Pd）比值相对较低,为0.33～0.65。统计分析显示了不同区域、不同环境中贵金属元素的特征参数变化,并且说明富钴结壳中富铂、金、钌、铑,而贫钯。贵金属元素标准化显示,海山富钴结壳均存在着Pt、Au正异常和Pd的负异常,其中Au异常幅度与结核的Au异常一致。 相似文献
17.
Results of the study of noble metal specialization of Lower and Middle Riphean terrigenous rocks in the Bashkir Anticlinorium (South Urals) are reported. The study revealed their genetic differences in the relatively unaltered, i.e., “background” terrigenous rocks in type sections of the Burzyan and Yurmatau groups and in sedimentary rocks of the same stratigraphic levels from tectonic zones subjected to local dynamothermal metamorphism of the greenschist facies and intruded by mafic rocks. It has been established that Ru serves as a geochemical marker of the impact of magmatic processes on sedimentary rocks and the redistribution of noble metals during metamorphism and local metasomatism. A generalized model is proposed for the formation of noble metal geochemical specialization of Lower and Middle Riphean terrigenous rocks in the South Urals. 相似文献
18.
V. V. Seredin 《Geology of Ore Deposits》2007,49(1):1-30
Original data and a survey of the literature indicate that Au and Au-PGE mineralization are abundant in coal measures. Anomalous contents of noble metals have been established in basins with various types of basement, composed of granite, volcanic rocks, schist, and limestone. These basins are located in Au-and PGE-bearing ore districts, as well as at a considerable distance from known ore deposits and occurrences. Ore formation in coal-bearing basins may occur during sedimentation, peat accumulation, and diagenesis of organic matter or may be epigenetic. Noble metals are supplied to sedimentary basins as minerals that are transported by water and air and as ion species migrating along with surface and subsurface in-and exfiltration solutions of various chemical and genetic types. Ore mineralization concentrates in coal seams and host sedimentary beds of various grain size, including conglomerate, sand, and clay, as well as in zones of hydrothermal alteration superimposed on basement rocks and the sedimentary cover. The mode of occurrence of noble metals in coal basins is diverse as well (noble metal minerals, isomorphic admixtures in sulfides, and organic compounds). The data presented allow coal-bearing basins to be regarded as promising for economic noble metal mineralization fit for recovery as by-products in the course of coal mining. 相似文献
19.
A. I. Khanchuk L. P. Plyusnina V. P. Molchanov E. I. Medvedev 《Russian Journal of Pacific Geology》2007,1(1):61-70
Carbon-rich metamorphic rocks of Riphean age in the northern part of the Khanka terrane were first analyzed for concentrations of noble metals (Au, Ag, Pt, Pd, Ir, Os, and Ru). According to the data of various physicochemical analytical techniques, the Au and Pt concentrations broadly vary: from 0.01 to 52 ppm for Pt and from 0.1 to 30 ppm for Au. Various techniques of sampling and analysis variably affect the losses of these metals because of difficulties in the decomposition of metal-carbon chemical bonds. The carbon isotopic composition (13C from ?8.5 to ?8.7‰) of the graphitized amphibolite-facies rocks widespread in the core of the Ruzhino paleodiapir suggest that their carbon is of mantle provenance. The Early Cambrian metaterrigenous rocks metamorphosed to the greenschist facies have 13C from ?19.9 to ?26.6‰, which testifies to its organic origin. The elevated concentrations of noble metals in these rocks suggest that the sources of carbon and metals were polygenetic and that the ore-forming system evolved over a long time span. 相似文献
20.
Noble Metal Concentrations in Shoshonitic Lamprophyres: Analysis of the Weekend Dykes, Eastern Shore, Nova Scotia, Canada 总被引：2，自引：0，他引：2
Devonian, spessartite dykes, known as the Weekend dykes, onthe Eastern Shore of Nova Scotia contain panidiomorphic texturesand mineral (amphibole, clinopyroxene, and biotite) compositionstypical of shoshonitic lamprophyres. The major element and traceelement geochemistry of the Weekend dykes is also representativeof shoshonitic lamprophyres with high large ion lithophile elementconcentrations (LILE, e.g., Rb, K, and Ba) relative to the lightrare earth elements (LREE, e.g., La) and very low Nb and Ti.Only Ta concentrations are uncharacteristically high relativeto Nb and Ti. The dykes are variably evolved but many samplesshow primitive compositions with high mgnumber [>0.70, wheremg-number=Mg/(Mg+09total Fe) atomic] high MgO and Ni concentrations(>10 wt.% and 150 ppm, respectively), and low heavy REE concentrations.All noble metal concentrations (Au, Pd, Pt, Rh, Ru, and Ir)tend to be lower in evolved samples than in primitive rocks,suggesting that evolved magmas were efficiently scavenged byimmiscible sulphide globules and that shoshonitic lamprophyreplutons may hold economic promise for the platinum-group elements(PGE). Noble metal abundances in even the most primitive rocksare low compared with many basaltic rocks excepting mid-oceanridge basalt (MORB). This makes doubtful the idea that Megumagroup mesothermal gold deposits, which are spatially and temporallyassociated with the dykes, derived their gold from the lamprophyres.Models that explain PGE concentrations and Pd/Ir ratios in awide variety of mafic rocks suggest that the low noble metalabundances probably reflect metal retention in mantle sulphides,olivine, and PGE alloys at low percentages of melting. However,noble metal abundances are higher than expected if the oceanicslab was involved in the melting process or if the source regionresembled that for most MORB, which appears to have low PGE.Mantle metasomatism represents an unlikely explanation for thePGE abundances, which are equivalent to those expected in alkalinehot-spot magmas. The high PGE abundances of hot-spot magmas(compared with MORB) may be related to the incorporation ofcore materials in deep mantle plumes. Presumably the hot-spotlikemantle became part of the subcontinental lithospheric mantlebefore the subduction and transpressional event that producedthe shoshonitic magmas. 相似文献