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喀什凹陷中生代以来的构造事件对中-下侏罗统铀矿化的影响 总被引：2，自引：0，他引：2
喀什凹陷是我国西部重要的含铀区,自中生代以来主要发生过5次重大构造事件,对该地区中-下侏罗统铀矿成矿及保矿具有重要意义,即晚三叠世有利的构造背景,早-中侏罗世有利的构造-沉积环境形成的有利岩性-岩相建造,晚侏罗世构造掀斜与古层间氧化带及铀矿化的形成,白垩纪-古近纪的保矿作用及新近纪以来的构造破坏与局部层间氧化带的形成与叠加,从而很可能在中-下侏罗统中形成一定规模受层间氧化带控制的砂岩型铀矿床。指出主要找矿靶区为库孜贡苏断陷以西的南天山山前,同时还有托云盆地。 相似文献
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为了进一步拓展准噶尔盆地南缘的找矿空间,文章依据准噶尔盆地南缘头屯河地区的最新勘查进展,从中、新生代构造演化历史、蚀源区铀源条件、古气候环境及有利沉积建造、有利目标层位砂体及氧化带发育特征等方面系统分析了研究区砂岩型铀矿成矿条件。研究认为：北天山的富铀地质体和下白垩统清水河组底部砾岩层为该区铀成矿提供了丰富的铀源;形成于温暖潮湿气候的含煤碎屑岩建造,为铀成矿提供了良好的容矿空间;构造掀斜为含铀含氧水的渗入改造提供了构造条件,也为大规模的层间氧化带的发育提供了物质基础。最后提出在头屯河地区强构造变形区寻找第二成矿斜坡带的找矿新思路,将找矿方向从不利于保矿的山前褶皱冲断带转移至第一排构造带末端的单斜区,主要的找矿目标层位为中侏罗统头屯河组和下白垩统清水河组,找矿类型为古层间氧化带型叠加油气-潜水氧化型和潜水氧化型。 相似文献
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试论我国古层间氧化带砂岩型铀矿床成矿特点、成矿模式及找矿前景 总被引：10，自引：0，他引：10
文章将我国中新生代陆相盆地中发育的古层间氧化带砂岩型铀矿床分为地层超覆埋藏亚型、构造抬升破坏亚型、构造褶断保存亚型等3种亚型，文中主要讨论了这3种亚型古层间氧化带砂岩型铀矿床的成矿特点、成矿模式及找矿前景。作者认为，除近代层间氧化带砂岩型铀矿床以外，古层间氧化带砂岩型铀矿床在我国中新生代陆相盆地也有很大的找矿潜力。因此，需要从成矿理论上认真总结和不断充实，以推动我国砂岩型铀矿找矿工作不断向前发展。 相似文献
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层间氧化带是层间氧化带型砂岩铀矿床的重要找矿标志之一,弄清楚层间氧化带的成因对砂岩型铀矿找矿具有重要的意义。根据伊犁盆地蒙其古尔地区的构造特征和氧化带特征,对该地区的层间氧化带的成因做了分析。认为该地区的构造特征是层间氧化带形成的主要因素。 相似文献
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中国北西部东段中新生代盆地砂岩型铀矿找矿目标类型探讨 总被引：2，自引：0，他引：2
本文在综合分析中国北西部东段地质构造背景、中新生代盆地构造-沉积演化特征及砂岩型铀成矿条件的基础上，明确提出上三叠统、中下侏罗统、下白垩统、上新统为该区砂岩型铀矿找矿主要目的层；造山带山间盆地局部层间氧化带型、潜水氧化带型、潜水-层间氧化带过渡型、古层间氧化带型砂岩铀矿是主攻目标类型。进一步指出了主要目标类型的找矿有利地区。 相似文献
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古层间氧化作用是发育于盆地地质构造演化过程某一阶段的层间氧化作用,由此所形成并被保存的铀矿床被称为"古层间氧化带型铀矿床"。柴北缘地区中、下侏罗统含煤岩系的广泛发育,为古层间氧化带的发育及相应类型铀矿化的形成奠定了基础。早白垩世晚期—古近纪早期的强烈隆升剥蚀是层间氧化带及相应类型铀矿化的发育期。喜山期大规模逆冲推覆构造使原层间氧化带及相应成矿系统遭受强烈改造,保存并形成古层间氧化带和古层间氧化带型铀矿化。古层间氧化带型根据其改造、破坏或保存特点的不同,划分为褶-坳保存型、褶-断保存型和抬升破坏型3种改造亚型。褶-坳保存和褶-断保存2种亚型使得古层间氧化带砂岩型铀矿体能以盲矿形式有效保存,是今后重点找矿方向,如北大滩和冷湖石地26铀矿点。抬升破坏亚型使得古层间氧化带砂岩型铀矿体呈残留状或被剥蚀掉,找矿潜力不大。在总结不同改造亚型地质构造特点和找矿标志的基础上,建立了典型古层间氧化带砂岩型铀矿化成矿模式,并综合分析了其成矿特点。 相似文献
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正向构造对层间氧化带砂岩型铀矿成矿和定位的控制 总被引：1，自引：0，他引：1
正向构造指的是与铀矿带或铀矿床产出位置相关的背斜、隆起、上升断块等矿床地质构造。伊犁盆地南缘、吐哈盆地西南缘、酒东盆地东北缘等砂岩型铀矿成矿带的产出特征表明,层间氧化带砂岩型铀矿床、矿段和矿点总是选择性地就位于正向构造之中。其原因在于层间氧化带砂岩型铀矿的成矿机理所决定。即正向构造抬升了容矿层位,使其出露或接近地表,容易接受补给区含氧含铀水的渗入,造成主砂岩层的层间氧化,铀在主砂岩层中迁移,并在氧化还原界面还原成矿。因此,正向构造对氧化带砂岩型铀矿成矿和定位的作用应引起足够重视,它可以作为产铀盆地砂岩型铀矿带成矿远景区段识别和预测的一项重要判据。 相似文献
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通过对大庆油田丰富的地表油气化探、钻井资料分析研究,结合油藏放射性异常模型,提出了氡异常水平分布及特征值与油气藏深度的关系数学模型及参数计算方法。通过大庆油田杜29井区实际资料验证和平洋来27井区、来36井区试验应用,证实用地表油气化探特征值估算确定油气田埋藏深度的技术方法是可行、实用的。而这种解释结果结合地质解释分析,对指导油气田勘探部署,提高勘探效益都具有实际意义。 相似文献
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A preliminary test of biogeochemical exploration for locating uranium occurrences in the Marfa Basin, Texas, was conducted in 1978. Only 6 of 74 plant samples (mostly catclaw mimosa, Mimosa biuncifera) contained uranium in amounts above the detection limit (0.4 ppm in the ash) of the conventional fluorometric method. The samples were then analyzed using a Scintrex UA-3 uranium analyzer* - an instrument designed for direct analysis of uranium in water, and which can be conveniently used in a mobile field laboratory. The detection limit for uranium in plant ash (0.05 ppm) by this method is almost an order of magnitude lower than with the fluorometric conventional method. Only 1 of the 74 samples contained uranium below the detection limit of the new method. Accuracy and precision were determined to be satisfactory. Samples of plants growing on mineralized soils and nonmineralized soils show a 15-fold difference in uranium content; whereas the soils themselves (analyzed by delayed neutron activation analysis) show only a 4-fold difference. The method involves acid digestion of ashed tissue, extraction of uranium into ethyl acetate, destruction of the ethyl acetate, dissolution of the residue in 0.005% nitric acid, and measurement. 相似文献
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This paper describes a statistical analysis of reconnaissance exploration geochemical data for uranium. Three sets of data were analyzed, as they related to: (a) Charlotte-Winston-Salem and (b) Charlotte two-degree NTMS quadrangles of the south-eastern U.S.A. The coefficient of variation for uranium in each of the three sets of data was less than unity and hence no transformation of the original variable was needed. These data were subjected to correlogram analysis. A first-order Markovian model of the type: Y0
exp (-a |p|) was fit by the least-squares method to serial correlation coefficients of these data using the method proposed by Deming (1948). The model was tested by computing the variance-volume relationship for assumed individual blocks of unit length. The noise in the input (record) was eliminated by the application of an optimum bilateral exponential smoothing technique developed by Agterberg. A comparison of spectral density estimates obtained by a maximum entropy method employing Yule-Walker equations and the Burg algorithm was also made. The prediction error coefficients needed to determine the order of the autoregressive process and hence the spectral densities were determined in both cases for the three sets of data.On leave from National Geophysical Research Institute, Hyderabad-7, India. 相似文献
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本文在阐述了松辽盆地的区域地质构造特征，盆地北部区域铀源条件及含铀层位的基础上，论述了大庆油田北部铀矿化分布特点及铀矿化特征，并从沉积成岩作用，古水文地质，氧化-还原地球化学分带控矿的角度对该区铀矿化的成因进行了探讨。 相似文献
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Fundamental principles of thermoluminescence (TL) and the special role of TL in uranium exploration techniques are given in this paper with examples from Australia illustrating its application.TL can be used in two ways in uranium exploration. The first usage stems from the property of minerals capable of TL, to act as dosimeters accounting for charging of available traps by ionizing radiation. The second usage relates to ionizing radiation interfering with the crystal structure of the host mineral and thereby changing the capability for TL. Studies at the Beverley and Westmoreland uranium deposits utilize this second property.At Beverley a continuous drop in TL intensity is observed upon approaching the orebody with TL intensity at a minimum within the orebody. Recognition of ore type TL glow curves and sensitized (or marginal) TL glow curves within the area surrounding the orebody have enlarged the exploration target beyond that of the orebody and its associated radiometric halo.Traverses examining the variations in glow peak intensities, ratios and temperatures across the Junnagunna orebody at Westmoreland show that the glow peak intensity of the high-temperature glow peak increases, that of the low-temperature peak fluctuates though generally decreases, the high temperature/low-temperature glow peak ratio increases upon approaching the orebody. The high-temperature glow peak temperature is at a minimum within the orebody. Similar variations detected nearby may indicate further potential exploration sites.An example from an unmineralized area at Bremer River has indicated a lack of widespread radiation sensitization indicating the unsuitability of the area for economic uranium accumulation. 相似文献
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Mobility of uranium with ground water in near surface earth conditions and its association with sandstone formations of continental depositional environments require an increase in the understanding and application of depositional characteristics in exploration. This paper, therefore, summarizes significant relationships of uranium geochemistry in the supergene environments and depositional characteristics of fluvial, deltaic, and lacustrine environments and their influence on exploration that may aid in the expeditious search for sandstone-type uranium deposits throughout the world. 相似文献
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激光共聚焦扫描显微检测技术在大庆探区储层分析研究中的新进展 总被引：3，自引：0，他引：3
激光共聚焦扫描显微镜（Laser Confocal Scanning Microscope）分析技术是20世纪80年代末、90年代初兴起的一项新的光学显微测试方法，它具有普通光学显微镜和扫描电子显微镜不具备的很多优点，如样品制备十分简单、分层扫描和三维立体图像重建、清晰分辨有机和无机质等。我们将该技术应用到大庆探区的储层研究中，进行了储层孔隙和微裂缝的三维结构重建，对储层中原油形态进行了详细研究，其中原油形态观察对薄差水淹层的研究有重要意义，研究了裂缝中次生包裹体特征及形成期次，此外，该方法应用于微体古生物化石研究在大庆探区发现了以前本区未见的孢子化石种类。在原油乳化机理研究方面，首次应用共聚焦观察了乳化油的内部结构，通过动态分析可以确定其稳定性，这为乳化油乳化机理研究提供了科学可靠的依据。激光扫描共聚焦显微检测技术在大庆探区储层分析研究中取得了前所未有的效果。 相似文献
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综合评述了成像雷达技术的发展历史、技术优势及其在地质构造、岩性识别等地学应用领域的研究现状,指出成像雷达技术作为当前遥感对地观测前沿技术之一,在新时期铀矿地质勘查中发展前景广阔。 相似文献