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1.
通过对松辽盆地东南部区域地质资料综合分析及铀资源区域钻探评价,基本查明了目的层泉头组、姚家组、四方台组岩相古地理、岩性与砂体特征。通过对目的层岩石形成的地球化学环境研究,识别和划分了原生地球化学类型和后生蚀变作用类型,原生地球化学类型有原生氧化和原生还原类型,后生蚀变作用类型有油气、煤层气还原作用和后生氧化作用类型。对比研究了原生地球化学类型及后生蚀变作用类型岩石、矿物及化学成分特征,提出了油气、煤层气还原后生蚀变作用识别标志。认为原生含炭质砂岩铀有强烈的沉积预富集,油气、煤层气还原作用中有铀的叠加富集。  相似文献   

2.
松辽盆地东南部油气、煤层气后生蚀变硫同位素特征   总被引:1,自引:0,他引:1  
对松辽盆地东南部上白垩统泉头组、姚家组和嫩江组岩石中黄铁矿及硫同位素特征研究表明,泉头组、姚家组中后生还原褪色作用形成的灰色、灰绿色砂岩中的黄铁矿及硫同位素均显示出了深部来源的油气、煤层气有机流体作用成分特征。该区原生沉积成岩岩石及黄铁矿中硫同位素的δ^34SV-CDT为正值,油气、煤层气有机流体还原作用岩石及黄铁矿中δ^34SV-CDT为负值。油气、煤层气还原作用不仅使杂色、紫红色原生氧化砂岩还原为灰色、灰绿色还原性砂岩,还使岩石还原容量大大增强,而且油气、煤层气在有机流体与岩石的相互作用过程中有铀的叠加富集,岩石铀含量普遍增加,局部可形成铀异常、铀矿化。首次在门达地区姚家组含矿砂岩中发现网脉状水云母化,显示铀成矿具有低温热液蚀变特征,铀矿化与低温热流体作用有关。  相似文献   

3.
巴音塔拉盆地砂岩型铀矿化主要产于呼和地段下白垩统赛汉组(K1bs)下段辫状河沉积砂体中。其铀矿化的形成受盆地盖层结构与古气候特征和辫状河沉积砂体发育状况以及沉积构造的控制。通过对含矿主岩岩性特征、铀矿化特征的分析研究,认为早期为潜水氧化成矿作用;晚期为油气还原改造成矿作用,即来自周围富铀蚀源区的含铀含氧地下水与沿断裂上升的油气还原改造成矿。  相似文献   

4.
伊犁盆地油气与地浸砂岩型铀矿成矿关系研究   总被引:7,自引:0,他引:7  
伊犁盆地南缘中、下侏罗统水西沟群产有数个可地浸的砂岩型铀矿床。前人对这些铀矿床的成因认识基本上都是层间氧化带成因观点,但对铀矿化的富集机理研究不够深入,普遍认为铀成矿富集机理是含矿层沉积时堆积的有机质及沉积成岩阶段形成的硫化物对层间渗入氧化水中铀的还原吸附作用。油气包裹体及其气相色谱特征研究表明,盆地至少发育过一期石油和一期天然气运移、聚集过程;铀矿床含矿砂岩中的油气来源于深部二叠纪或更老地层的较成熟的烃源层。油气一方面消耗了含矿含水层中的大量氧气,造就了含矿层较强的还原环境;另一方面也参与了铀成矿过程的氧化还原反应,加速了铀还原、沉淀、富集成矿的速度。结合盆地断裂构造研究,本文推断深部油气主要沿近EW向东曼里塔勒迪深大断裂和NWW—SEE向霍城托开深大断裂向上运移,造成断裂附近形成较强的还原障,进而控制了盆地砂岩型铀矿床(点)的空间分布。  相似文献   

5.
松辽盆地钱家店砂岩型铀矿床自勘查以来不断获得重大发现,已成为超大型铀矿床。该区矿床地质特征、成矿特点有过不少报道,但就其含矿建造的详细岩石学特征(蚀源区母岩)及有利的成矿条件等还需要随着研究程度的加深不断完善。铀矿的成矿作用包括导致铀元素集中形成铀矿的各种地质作用,其中,铀含量高且容易析出铀的源岩是铀成矿的物质基础,后期的氧化—还原、矿化蚀变是铀矿形成的关键。作者主要利用微观实验分析的方法,通过对钱家店砂岩型铀矿床赋矿岩石岩石学特征的详细分析,提出了矿层岩性主要为中—细粒长石岩屑砂岩、细粒长石岩屑砂岩和含泥砾砂岩和砂砾岩等,并且石英和长石总量与岩屑含量相近,岩屑主要以流纹岩、流纹质凝灰岩为主,次为粗面岩、正长细晶岩、花岗岩、花岗斑岩、安山岩、硅质岩和泥岩等。后生蚀变碳酸盐化、高岭石化较为普遍,局部强烈,其次黄铁矿化、氧化铁化,偶见重晶石化。常见深部油气渗入在赋矿层中出现油渍、油斑、溢散晕圈,共生黄铁矿莓球群及微细粒黄铁矿聚晶。铀的存在形式为铀矿物(沥青油矿、铀石)和吸附状态。分析了多成因—多阶段成矿模式,即沉积预富集阶段—层间渗入成矿阶段—油气改造富集成矿阶段—油气还原护矿阶段。  相似文献   

6.
地下水中铀的油气化探意义及其应用   总被引:2,自引:1,他引:2  
经过20多年的实验研究,逐渐认识了地下水中铀的油气化探意义和特性,从而掌握了它对油气的指标意义,并在油气化探中得到了应用。油田水和深层地下水由于处在还原和弱还原环境中,铀的浓度分异效应不显著;潜水处于氧化环境中,铀的浓度分异效应显著,储集着与油气有关的信息。文章阐述了油气藏上方潜水中铀的异常特征,接着论述了铀指标的特性,即稳定性、直观性和单一性。最后以松辽中央拗陷南部和东濮凹陷为例,介绍了应用实例。  相似文献   

7.
中国北方砂岩型铀矿成矿作用与油气关系研究   总被引:2,自引:1,他引:1       下载免费PDF全文
油气与砂岩型铀矿的相互作用关系日益受到地质、特别是铀矿地质学者的重视,单个能源矿产的成矿理论已日趋成熟,但相互作用关系研究却十分薄弱,是亟需探究和解决的关键科学问题之一。本文通过中国北方典型砂岩型铀矿与油气时空分布特征分析、镜下微观分析、化学计算,表明油气主要通过吸附作用、还原作用、供铀作用和保铀作用促使铀的富集成矿。其中,油气的裂解产物沥青、有机酸层对铀有强烈的吸附作用;油气的还原作用主要是通过强还原气体(H_2、CH_4、CO、H_2S等)将高价、活化的铀离子还原成四价、稳定的铀矿物;油气与硫酸根离子相互作用生成的有机酸能够通过酸溶、萃取和金属-有机络合作用将途经围岩的部分铀富集并在成矿部位释放,从而叠加改造铀成矿作用,增加铀的来源;油气逸出的强还原气体H_2、CO能使地层产生酸化,形成高岭土化,从而使氧化带呈弱碱性、成矿带呈弱酸性特征。砂岩型铀成矿作用与油气的关系对砂岩型铀矿含矿目的层的厘定、铀矿床定位、补充完善砂岩型铀成矿理论、"烟囱效应"指导找油气等具有重要启示意义。  相似文献   

8.
内蒙古巴彦塔拉盆地砂岩型铀矿化的蚀变特征   总被引:1,自引:0,他引:1  
巴彦塔拉盆地砂岩型铀矿床产于下白垩统赛汉塔拉组下段辫状河流相砂岩中。本文通过对含矿主岩沉积特征、矿化和矿床蚀变特征的分析研究 ,认为早期为潜水氧化蚀变成矿 ;晚期为层间氧化 油气还原蚀变成矿 ,即来自蚀源区和天窗补给的含铀、含氧地下水遇沿断裂 (F2 1)上升的含H2 S的油气还原叠加改造成矿  相似文献   

9.
松辽盆地钱家店砂岩型铀矿床自勘查以来不断获得重大发现,已成为超大型铀矿床。该区矿床地质特征、成矿特点有过不少报道,但就其含矿建造的详细岩石学特征(蚀源区母岩)及有利的成矿条件等还需要随着研究程度的加深不断完善。铀矿的成矿作用包括导致铀元素集中形成铀矿的各种地质作用,其中,铀含量高且容易析出铀的源岩是铀成矿的物质基础,后期的氧化—还原、矿化蚀变是铀矿形成的关键。作者主要利用微观实验分析的方法,通过对钱家店砂岩型铀矿床赋矿岩石岩石学特征的详细分析,提出了矿层岩性主要为中—细粒长石岩屑砂岩、细粒长石岩屑砂岩和含泥砾砂岩和砂砾岩等,并且石英和长石总量与岩屑含量相近,岩屑主要以流纹岩、流纹质凝灰岩为主,次为粗面岩、正长细晶岩、花岗岩、花岗斑岩、安山岩、硅质岩和泥岩等。后生蚀变碳酸盐化、高岭石化较为普遍,局部强烈,其次黄铁矿化、氧化铁化,偶见重晶石化。常见深部油气渗入在赋矿层中出现油渍、油斑、溢散晕圈,共生黄铁矿莓球群及微细粒黄铁矿聚晶。铀的存在形式为铀矿物(沥青油矿、铀石)和吸附状态。分析了多成因—多阶段成矿模式,即沉积预富集阶段—层间渗入成矿阶段—油气改造富集成矿阶段—油气还原护矿阶段。  相似文献   

10.
本文分析了二连盆地巴赛齐赛汉组含铀古河谷的钻孔、地震、测井等资料,对其进行了沉积特征及地层划分。结果显示,古河谷内赛汉组下段主要发育三角洲-湖沼沉积,可划分为两层。赛汉组上段主要为冲积扇-河流沉积,可划分为4层,不同地段顶部遭受了不同程度的剥蚀。古河谷内铀矿化主要位于赛汉组上段第一、第二层辫状河砂体中。古河谷铀成矿流体动力学研究表明,古河谷内铀成矿作用方式主要为:(1)砂体本身还原介质及深部油气还原的氧化还原成矿;(2)不同盐度含铀含氧流体混合卸载成矿。通过地层划分对比及铀成矿流体动力学研究,合理解释了古河谷内砂岩型铀矿床分布的原因及关系。  相似文献   

11.
Data reported by laboratories contributing to the GeoPT proficiency testing programme for geochemical laboratories over the period from 2001 to 2011 have been assessed to identify the elements and concentration ranges over which analytical performance can be considered satisfactory. Criteria developed in the paper indicated that performance in the content determination of the elements/constituents SiO2, Al2O3, MnO, Cs, Dy, Er, Eu, Ga, Hf, Ho, Lu, Nd, Pr, Sm, Sr, Tb, Tl, Tm, U, Y, Yb and Zn was satisfactory over the full concentration range assessed. The elements/constituents TiO2, Fe2O3(T), MgO, CaO, Na2O, K2O, P2O5, Ba, Be, Cd, Ce, Co, Gd, La, Li, Nb, Rb, Sb, Sc, Sn, Ta, Th, V and Zr showed some degradation in performance at lower concentration levels (approaching the detection limit of some techniques). Performance in determining LOI, As, Bi, Cr, Cu, Ge, Mo, Ni, Pb and W was in general unsatisfactory over the full concentration range assessed. Other elements (especially Fe(II)O, H2O+, CO2, Ag, Au, B, Br, Cl, F, Hg, I, In, Ir, N, Os, Pd, Pt, Re, Rh, S, Se, Te) could not be evaluated as they were not routinely reported by laboratories participating in the GeoPT programme, often because they are present in silicate rocks at sufficiently low concentrations to require a pre‐concentration stage. Some suggestions are made for the causes of unsatisfactory performance, but further progress will require a detailed assessment of the methods used by participating laboratories, which will form the subject of a further paper.  相似文献   

12.
The diabolical and supernatural folklore traditions of geology are examined systematically for the first time. The following have all been suggested explanations for fossil remains: Devil's footprints, bones, toenails, fingers, thumbs, buttons, money and ninepins; Hobgoblin's claws; Fairy's fingers, heads, faces, hearts, beads, causeways, saltcellars, bottles, weights, money and loaves; elf arrows; witches’ beads and tongues. Twinned staurolite crystals have been called Fairy crosses.  相似文献   

13.
The Ilgin lignite field can be subdivided into the Haramiköy and Kurugöl areas which are separated by an area of basement and a fault. The lignite-bearing sequence consists mainly of fluvial and lacustrine Neogene deposits. The Ilgin lignite, averaging 8 m (up to 25 m) thick, is blackish brown and dark brown in colour. The lignite contains abundant brown wood, plant remains and white gastropod shells. Samples have an average of 38.9% moisture on an as-received basis and a mean of 3.9% total sulphur on an air-dried basis. Geochemical analysis, using an ICP-MS, was undertaken. Thirteen lignite core samples from three boreholes drilled in the Kurugöl area were ashed at 750°C. The average trace element contents of the lignite show a higher concentration of U (average 43 ppm) when compared to the range for most coals in the world, while the others (Ti, P, Sc, Be, Mn, Co, Cu, Zn, Ga, As, Rb, Sr, Zr, Nb, Mo, Cs, Ba, Y, Ta, W, Tl, Pb, Bi, Th, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu) agree with the global ranges. The Ilgin lignite is identified as of Middle Miocene (Middle Serravallian) age and occurs within lacustrine sediments deposited under subtropical climatic conditions.  相似文献   

14.
时国  喻美艺  罗茂  田景春 《沉积学报》2009,27(3):427-434
贵阳花溪下三叠统大冶组中富产遗迹化石,产出18个遗迹属:Beaconichnus,Circulichnis,Cosmorhaphe,Dendrohaphe,Glockerichnus,Gyrochorte,Gordia,Maeandropolydora,Micatuba,Mammillichnis,Megagrapton,Planolites,Palaeophycus,Phycodes,Phycosiphon,Rhizocorallium,Thalassinoides和Undichna。自下而上可识别出三个遗迹组构,分别为Phycodes、Phycosiphon Mammillichnis和Thalassinoidess遗迹组构。根据遗迹化石各属种分布,大冶组自下而上出现四个遗迹相:Cruziana遗迹相、Zoophycoss遗迹相、Nereites遗迹相和Cruziana遗迹相。结合遗迹组构,对大冶组的沉积环境进行了讨论,Phycodes组构属于Cruziana相,指示浅水环境;Phycosiphon Mammillichnis组构属于Zoophycos遗迹相—Nereites遗迹相,代表台缘下斜坡半深海低能环境;Thalassinoides组构属于Cruziana相,指示早三叠世印度期末的浅水高能环境。  相似文献   

15.
Abstract: Ilmenite, hematite, garnet, monazite, zircon, rutile, magnetite, sillimanite, pyroxene and amphibole from the beach sands of Ekakula, Gahiramatha coast, Orissa, India are reported here for the first time. Their total concentration varies from 26. 4 to 100%. Ilmenite, monazite and zircon are between 100 and 300 um in size and are well rounded in shape. Ilmenite-hematite intergrowth is common. Ilmenite has 50. 02–54. 73% TiO2, 42. 42–46. 90% FeO (total Fe) and small amounts of Al, Mn, Mg, Ca, Ba, Si, V, Cr, and Zn. The bulk samples contain 10. 63–41. 42 % TiO2, 6. 15–26. 07 % FeO, 5. 86–16. 75 % Fe2O3, 7. 41–61. 74 % SiO2, 1. 39–12. 83% A12O3, 0. 32–4. 97% CaO, 0. 53–4. 24% P2O5, 0. 17–3. 27% MgO, 0. 15–2. 97% Na2O, 0. 07–2. 34% K2O, and 0. 05–0. 71% V2O5 together with appreciable amounts of La, Ce, Pr, Nd, Sm, Eu, Y, U, Th, Zr, and trace amounts of Pb, Zn, Cu, Ni, Co, and Cr. Khondalite, charnockite, calc-silicate granulite, leptynite, migmatite, gneiss, basic granulite and pegmatite of the Eastern Ghats appear to be the major source for the above heavy mineral assemblages. The samples are amenable to gravity and magnetic methods of beneficiation.  相似文献   

16.
Concentrations of some heavy metals and trace elements such as Cr,Ga,Ni,Zn,Mo,Cu, Pb,Yb,Y,Nb,Ti,Sr,Ba,Mn,Sc,Co,V,Zr,Fe,Al,W,Se,Bi,Sb,As,Cd in recent mollusk shells and factors affecting their distribution and deposits collected from various depths in the southern and southwestern parts of the Marmara Sea are investigated.The distribution of the elements in the shells is categorized into four groups.Of these,concentrations of 12 elements(As,Bi,Cd,Co,Ga,Mo,Nb, Sb,Se,Sc,W and Yb)are below zero [(0.053-0.79)×10~(-6)];concentrations of seven elements(Cr,Ni, Pb,V,Y,Zr and Cu)are(1.0-6.0)×10~(-6);concentrations of four elements(Ti,Mn,Ba and Zn)are 10- 20×10~(-6);and concentrations of five elements(Si,Al,Fe,Mg and Sr)are(47.44-268.11)×10~(-6).The taxonomic characteristics of the 29 elements were studied separately in mollusk shells such as Chamalea gallina(Linné),Pitar-rudis(Poll),Nassarius reticulatus(Linné),Venerupis senescens (Coocconi),Mytilus galloprovincialis(Lamarck),Mytilaster lineatus(Gemelin in Linné)and Chlamys glabra.It was found that,in mollusk taxonomy,the elements have unique values.In other words, element concentrations in various mollusk shells depend mainly on the taxonomic characteristics of mollusks.In various bionomic environments different element distributions of the same species are attributed to the different geochemical characters of the each environment.Data obtained in this study indicate that the organisms are the most active and deterministic factors of the environment.  相似文献   

17.
Selenium and heavy metals content in some Mediterranean soils   总被引:1,自引:0,他引:1  
The study of metal contents in industrial, agricultural or/and polluted soils compared with natural or unpolluted soils is currently necessary to obtain reference values and to assess soil contamination. Nonetheless, very few works published appear in international journals on elements like Se, Li and Sr in Spanish soils. This study determines the total levels of Se, Li, Sr, As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn, Fe, Mn and Ba in 14 natural (unpolluted) soils (Gypsisols, Leptosols, Arenosols and Acrisols), 14 agricultural soils (Anthrosols, Fluvisols and Luvisols), and 4 industrial–urban affected-surface soil horizons (Anthrosols and Fluvisols) of Eastern Spain. The geochemical baseline concentrations (GBC) and reference values (RV) have been established, and the relationships among elements and also between soil properties and elemental concentrations have been analysed. The RV obtained in this study were (mg kg−1): Se 2.68, Li 115, Sr 298, Cd 0.97, Co 35, Cr 217, Cu 46, Ni 50, Pb 137, V 120, Zn 246, Fe 124,472, Mn 2691, and Ba 743. The RV for Se and Li were used as a preliminary approach to assess soil contamination in Spanish soils. The results confirm human impact on Sr, As, Cd, Cr, Cu, Ni, Pb and Zn soil concentrations, but evidence no deviation from natural Se, Li, Co, V, Fe, Mn and Ba concentrations. The results obtained from the statistical analysis reveal significant correlations between some elements and clay and soil organic matter (SOM) contents, indicating that metal concentrations are controlled by soil composition. One particularly interesting finding is the high correlation coefficients obtained between SOM and Se, Cd, Cr, V, Fe, and Mn, and between clay and Cd, Zn, V, Fe and Mn. Once again, these facts confirm the role of SOM and clay minerals in soil functions and that soil is an ecosystem element responsible for maintaining environmental quality.  相似文献   

18.
Eleven synthetic silicate and phosphate glasses were prepared to serve as reference materials for in situ microanalysis of clinopyroxenes, apatite and titanite, and other phosphate and titanite phases. Analytical results using different micro-analytical techniques showed that the glass fragments were homogeneous in major and trace elements down to the micrometre scale. Trace element determinations using inductively coupled plasma-mass spectrometry (ICP-MS), multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS), laser-ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) and secondary ionisation mass spectrometry (SIMS) showed good agreement for most elements (Li, Be, B, Cs, Rb, Ba, Sr, Ga, Pb, U, Th, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Er, Tm, Yb, Lu, Zr, Hf, Ta, Nb) studied and provide provisional recommended values.  相似文献   

19.
 The geochemical and mineralogical characteristics of bulk samples and various size fractions of sulfide-bearing fine-grained sediments in the Petalax area, western Finland, were studied with ICP-AES (aqua regia digestion and "total" digestion) and X-ray diffraction. The sediments, which are dominated by particles <0.06 mm (clay and silt size), are composed of phyllosilicates (micas, kaolinite, chlorite, vermiculite), quartz, feldspars, amphiboles, organic matter, and secondary S minerals. The chemical analyses show that Na, Ca, and Sr are enriched in the silt and sand fractions, that Zr is enriched in the silt fraction, and that the concentrations of all other studied metals (Al, Ba, Co, Cr, Cu, Fe, K, La, Mg, Mn, Nb, Ni, Sc, Th, Ti, V, Y, and Zn) increase from the sand to the clay fraction. Sodium, Ca, and Sr occur largely in poorly dissolved feldspars, which explains the distribution of these metals in the sediments. The increase in the concentrations of most metals in the clay fraction is interpreted to be the result mainly of an increase in phyllosilicates in this size fraction. A geochemical comparison between the sulfide-bearing fine-grained sediments and glacial till shows that the former are enriched in several potentially toxic metals. It is therefore argued that the hydrological and ecological problems associated with the sulfide-bearing sediments are related not only to the production of acidity in oxidized layers, but also to mobilization and dispersion of toxic metals. Strategies to minimize damage of freshwater systems in areas covered with sulfide-bearing fine-grained sediments are suggested. Received: 20 February 1997 · Accepted: 25 August 1997  相似文献   

20.
This study presents the concentrations and modes of occurrence of trace elements in 81 coal samples from the Çan basin of northwestern Turkey. The concentration of trace elements in coal were determined by inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry. Additionally, traditional coal parameters were studied by proximate, ultimate, X-ray diffraction, and petrographic analyses. Twenty trace elements, including As, B, Ba, Be, Cd, Cu, Co, F, Hg, Mo, Ni, Pb, Sb, Se Sn, Th, Tl, U, V, and Zn, receive much attention due to their related environmental and human health concerns. The Çan coals investigated in this study are lignite to sub-bituminous coal, with a broad range of ash yields and sulphur contents. The trace element concentrations show variety within the coal seams in the basin, and the affinities vary among locations. The concentrations of B, Ba, Be, Cd, Cu, Co, F, Hg, Mo, Ni, Pb, Sb, Se, Sn, Tl, and Zn in Çan coals are within the Swaine's worldwide concentration range, with the exception of As, Th, U, and V. On the other hand, compared with world coals, the Çan basin coals have higher contents of As, B, Cu, Co, Mo, Pb, Th, U, V, and Zn. Based on statistical analyses, most of the trace elements, except for U, show an affinity to ash yield. Elements including As, Cd, Hg, Se, Cu, Mo, Ni, and Zn, show a possible association with pyrite; however, the elements Se, B, and Mo can be have both organic and inorganic associations.  相似文献   

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