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本文在野外调查和大量钻孔资料基础上,运用重砂、地球化学、古地磁、扫描电镜等测试手段以及沉积与地貌之间的相关方法,对研究区第四纪沉积物成因类型、地层、地层年代、沉积模式和发育过程作了详细研究。 相似文献
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基于东北地区多目标区域地球化学调查获得的海量土壤地球化学数据,利用BP神经网络模型,在土壤地球化学性质与油气田空间位置之间建立模型,构造最优的油气资源预测模型. 以土壤54项地球化学指标以及XY坐标值共同作为模型输入层,以样本是否在油气田内(1代表油气田内,0代表油气田外)作为模型输出层,基于随机抽取的油气田内和油气田外各500个土壤样本数据进行模型训练. 结果显示,多次训练后识别准确率保持在90%左右,说明该模型分类效果较好,可用于油气资源预测. 利用该模型获得了松嫩平原11 291个土壤样本的含油气概率,并绘制了油气资源预测图. 研究表明,神经网络对于解决复杂的非线性地质问题可以发挥重要作用. 相似文献
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第四纪沉积地球化学是研究第四纪时期化学元素及其同位素在地壳中的分布与演化规律的科学。它着重研究元素及其同位素在不同成因类型的第四纪沉积物中分市、分配、迁移和富集的规律。距今2—3Ma以来的第四纪是地球历史的最新篇章。第四纪沉积物作为第四纪地质过程在特定的地质环境中所形成的产物,留下了许多自然环境变迁的遗迹,含有它们形 相似文献
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根据第四纪地质的有关理论和研究方法,结合长期的工作实践,对贵州第四纪地质研究中存在的问题进行了探讨。如在第四纪沉积研究中,有些资料不去研究沉积物的成因类型,仅凭个别“冰碛石”并把冲积物定为冰碛物;在研究方法上不采用综合方法确定其顺序、成因类型与时代,仅凭某一种方法下结论。 相似文献
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关于第四纪埋藏沉积物成因类型的研究,常规的方法是利用钻井取芯资料进行综合分析和对比,所得结论往往是定性的。由于钻井取芯的费用十分昂贵,且第四纪松散沉积物的收获率一般比较低,所以这种方法的广泛应用受到了很大的限制。本文介绍了一种利用测井资料进行沉积相分析的思路和方法。由于地球物理测井具有快速、经济等特点,因此该方法在第四纪沉积的研究中具有较好的应用前景。另外,随着计算机的广泛使用,人工智能技术的迅速发展为测井相分析的定量化和自动化提供了实现的途径。 相似文献
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新疆哈拉奇地区地球化学分区特征及地质意义 总被引：1，自引：0，他引：1
水系沉积物测量是勘查地球化学一种重要方法。随着勘查地球化学的深入发展,有关地球化学异常圈定的方法已成为人们关注的焦点。采用R型因子分析方法,对哈拉奇地区水系沉积物测量所取得的数据进行统计处理,提取了具有代表性的5种因子组合类型,同时以因子得分为综合指标,绘制了因子得分等值线图并制作了元素组合分区图。通过综合分析,地球化学分区图反映了不同地段中以相应的元素组合类型为主的地球化学异常及地质成因信息,同时与主要控矿因素的空间分布比较一致,为研究区地质找矿提供新方向。 相似文献
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估算水系沉积物的地球化学背景值和识别其异常对人为污染判别与环境风险评估非常重要。采集并分析了珠江58件水系沉积物样品,经分析检验,Al、Fe和Sc被选作参考元素,并对比了确定地球化学背景及识别异常值的方法。其中,基于最小截断二乘法的回归分析是定义地球化学背景的有效方法,它是一种对异常值不敏感的稳健统计方法,而基于局部富集因子的箱线图和回归诊断图更适用于识别异常值。珠江不同河段重金属污染存在差异,北江和河网区主要受As、Cd、Cu、Pb和Zn污染,东江主要受Cu、Cr和Ni污染,而西江几乎不存在重金属污染。水系沉积物的主要污染类型是点源污染,主要污染来源是采矿和电镀等相关的工业活动。 相似文献
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沈树荣 《水文地质工程地质》1957,(9)
在水文地质和工程地质工作中,都时常遇到第四纪的沉积物。对第四纪沉积物进行分类时,一般都采用“成因分类”。但是成因分类的原则究竟是什么,应该分出那些“成因类型”,却至今尚无定论。而且有的分得比较笼统,象鲁萨诺夫在其报告中列举的(注1),和目前一般在第四纪地质图上所采用的(注2),都只有一个等级,十几种类型。有的则分得系统比较复 相似文献
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岩性识别是对地层认识及储层参数求解的基础,受沉积环境复杂性和非均质性影响,传统岩性识别方法已不能满足实际生产需要。针对传统识别方法容错能力差、自动化程度低和解释精度低的问题,通过应用神经网络自主学习预测分析手段,对比分析当下几种流行的岩性识别方法,选出更为适合现场实用的方法应用到随钻测井系统中。经研究发现,在预测方法及测井曲线相同的情况下,获得标准层段训练样本越多,准确率越高。通过对比得出结果:PNN概率神经网络方法在生产应用中效果更佳、识别准确率高、训练识别用时最短,在获取较少测井资料信息时,仍能保持较高的识别水平。 相似文献
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Forty-two substrate sediment samples and three cores procured from the shelf region between Chennai and Cuddalore were analyzed to understand the spatial and vertical sediment distribution. Samples subjected to grain size, bulk and clay mineralogical analyses, REE and trace element geochemistry yielded interesting results about the sediment characteristics with respect to the modern day environment. The present study revealed that the study area is characterized by high energy environment marked by predominant composition of medium sand. Results confirmed the evidence of more illite than kaolinite, smectite, and chlorite in the clay mineral assemblage indicating a terrigenous source. Geochemical data also revealed that the enrichment of light rare earth elements (LREE) in the sediments is due to continental source of Precambrian times. High feldspar content in the sediments which is emphasized by bulk mineralogical data displayed positive Eu anomaly. By using the paleoredox index, the area of interest is considered to have undergone no major changes in its depositional settings. 相似文献
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Biomarker Compounds as Indicators of Paleoenvironments 总被引：2，自引：0，他引：2
In an attempt to assess the paleoenvironments of terrestrial sediments,some twenty-two representa-tive Chinese non-marine sediment samples were studied using the molecular organic geochemistry method.The sediment samples stuied include oilshale,shale,mudstone and glauber salt from Tertiary to Cretaceous in age.Judging from geological/geochemical data and paleosalinity data,the samples studied are of lacustrine sedimentary origin and can be divided into three different types:fresh water,brackish and saline/hypersaline lake sediments.The aliphatic fractions were separated from the extracts of the samples and analysed by means of GC and GC/MS instruments,giving a number of parameters such as relative abundances of alkanes and cycloalkanes as shown in the mass chromatograms. 相似文献
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中国沙漠物源研究:回顾与展望 总被引：1，自引：0，他引：1
沙漠物源研究不仅在风沙地貌学上有重大的理论和实践意义,而且对联结大气粉尘排放、黄土堆积、气候系统和海洋生物地球化学循环也有重要价值。在简要回顾中国沙漠研究的基础上,梳理了中国沙漠物源研究的理论、方法和主要成果,结合国际上沉积物物源分析的趋向,指出目前世界沙漠物源的研究都是基于沉积物组份属性统计的反演模型,这种研究范式在数据获取、处理与解释方面存在缺陷,如沉积物的取样设计与测试分析、未消除"粒级依赖"对沉积物组份影响、数据未进行对数变换、忽视Dickinson图解应用的前提条件等。提出今后中国沙漠物源研究的方向:①采用正确统一的取样设计和分析方法对各沙漠的沉积物组份属性进行系统研究,建立中国沙漠沉积物组份的属性数据库;②选择若干典型沙漠,利用其周边山地详尽的地质构造、母岩和气候数据,定量构建沉积物生成的正演模型,模拟源区生成沉积物的数量、成分和结构,并用建成的沉积物组份属性数据验证和校正;③定量评估河流冲积物、冲积-湖积物、洪积-冲积物和基岩风化的残积、坡积物对中国各沙漠物源的贡献率与迁移路径,研究中国各沙漠中细颗粒物质的形成机制,对比中国沙漠与低纬度沙漠物源的形成机制;④定量研究历史和地质时间尺度沙漠-黄土-深海沉积物物源的内在联系及其驱动因素,建立陆地-大气-海洋物质循环的机理模型。 相似文献
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Petrophysical properties have played an important and definitive role in the study of oil and gas reservoirs, necessitating that diverse kinds of information are used to infer these properties. In this study, the seismic data related to the Hendijan oil field were utilised, along with the available logs of 7 wells of this field, in order to use the extracted relationships between seismic attributes and the values of the shale volume in the wells to estimate the shale volume in wells intervals. After the overall survey of data, a seismic line was selected and seismic inversion methods (model-based, band limited and sparse spike inversion) were applied to it. Amongst all of these techniques, the model-based method presented the better results. By using seismic attributes and artificial neural networks, the shale volume was then estimated using three types of neural networks, namely the probabilistic neural network (PNN), multi-layer feed-forward network (MLFN) and radial basic function network (RBFN). 相似文献
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《Applied Geochemistry》2003,18(2):283-309
International agreements (e.g. OSPAR) on the release of hazardous substances into the marine environment and environmental assessments of shelf seas require that concentrations and bioavailability of metals from anthropogenic sources can be distinguished from those originating as a result of natural geological processes. The development of a methodology for distinguishing between anthropogenic and natural sources of metals entering the Irish Sea through river inputs is described. The geochemistry of stream, river and estuarine sediments has been used to identify background geochemical signatures, related to geology, and modifications to these signatures by anthropogenic activities. The British Geological Survey (BGS) geochemical database, based on stream sediments from 1 to 2 km2 catchments, was used to derive the background signatures. Where mining activity was present, the impact on the signature was estimated by comparison with the geochemistry of sediments from a geologically similar, but mining free, area. River sediment samples taken upstream and downstream of major towns were used respectively to test the validity of using stream sediments to estimate the chemistry of the major river sediment and to provide an indication of the anthropogenic impact related to urban and industrial development. The geochemistry of estuarine sediments from surface samples and cores was then compared with river and offshore sediment chemistry to assess the importance of riverine inputs to the Irish Sea. Studies were undertaken in the Solway, Ribble, Wyre and Mersey estuaries. The results verify that catchment averages of stream sediments and major river samples have comparable chemistry where anthropogenic influences are small. Major urban and industrial (including mining) development causes easily recognised departures from the natural multi-element geochemical signature in river sediment samples downstream of the development and enhanced metal levels are observed in sediments from estuaries with industrial catchments. Stream sediment chemistry coupled with limited river and estuarine sampling provides a cost-effective means of identifying anthropogenic metal inputs to the marine environment. Investigations of field and laboratory protocols to characterise biological impact (bioaccumulation) of metals in sediments of the Irish Sea and its estuaries show that useful assessments can be made by a combination of surveys with bioindicator species such as clams Scrobicularia plana, selective sediment measurements that mimic the ‘biologically available’ fractions, and laboratory (mesocosm) studies. 相似文献
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沉积物的形成受到多种地质因素的综合控制。通过粒度分析可判别沉积物的成因类型,推断其形成的沉积环境,解释环境演变;而沉积物的粒度组分除了受到原岩的控制外,还受到机械沉积作用的影响难以准确预测。运用人工神经网络对稳定湖相沉积物和风沉积物的粒度参数进行研究,将沉积物的4个粒度参数作为网络模型的输入变量,在对168个浙闽沿海迎风岸风成老红砂样品和282个苏贝淖湖滨湖泊沉积物样品所对应的粒度参数进行数据样本训练之后,获得了基于BP神经网络的稳定湖相和风沉积物预测模型。然后利用448个大树摆鱼湖相沉积物粒度参数样本和100个兰州榆中黄土风沉积物粒度参数样本作为测试样本对该模型进行了测试和验证,结果显示模型的可靠性较好,能够对沉积物的形成环境做出正确的判断。 相似文献
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Comparison of Synchrotron Radiation X-Ray Fluorescence with Conventional Techniques for the Analysis of Sedimentary Samples 总被引：3，自引：0，他引：3
Michael A. Phedorin Vladislav A. Bobrov Evgeny P. Chebykin Evgeny L. Goldberg Michael S. Melgunov Svetlana V. Filippova Konstantin V. Zolotarev 《Geostandards and Geoanalytical Research》2000,24(2):205-216
A comparison is made of elemental analyses of sediment samples (lake bottom sediments and sediments from the petroliferous Bazhenovka Formation) by five competitive methods (synchrotron radiation X-ray fluorescence (SR-XRF), INAA, ICP-MS, AAS and traditional XRF). The object of this study was to identify the most suitable analytical techniques for applications in sedimentary geochemistry. Advantages and shortcomings of the five techniques were considered with respect to applications related to studies of palaeo-climate changes recorded in sedimentary cores from Lake Baikal and the geochemical stratigraphy of the Bazhenovka Formation, which is rich in organic material. We have concluded that SR-XRF was the best technique for producing extensive analytical data series, from the point of view of its speed, ease of application, cost, non-destructive nature and sensitivity, which allowed for the simultaneous determination of more than twenty elements of geochemical interest in small samples of sediments. An additional benefit of the method was demonstrated when used for the independent certification of geological reference materials. International reference samples BIL-1 and SDO-1 were certified by means of this method without use of reference materials. Analyses were based on the physics of the theory of energy transport. 相似文献
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Fingerprinting technique provides an essential means for estimating source contributions of watershed sediments, in which a single group of “optimum composite fingerprints” has been widely used in the literature to estimate sediment provenance. This type of methods is not restricted by the scale or process of sediment transportation so that similar procedures can be applied in sediment provenance research for aeolian depositions. However, recent studies found no direct link (positive relationship) between the ability of the tracer group to discriminate sources and its rigor in estimating source contributions after optimization. Here, we introduced a recently developed multiple composite fingerprinting method with additional screening based on analytical solutions, and further reviewed its verification in watersheds at different scales. It turned out that compared to Monte Carlo optimization method, a reasonable estimation can be achieved using the mean of the maximum number of composite fingerprints that given analytical solution to the mixing model, but the computational cost can be reduced significantly. The reliability of this new method was also tested in source contribution estimating of aeolian sediments, and the provenance quantification of reservoir sediment in an arid region experiencing both wind and water sediments. 相似文献