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区域化探样品元素测定几个问题的探讨 总被引：4，自引：0，他引：4
化探样品元素测定的要求,因任务的不同而异。区测与普查相比其要求不同。在普查(及详查)阶段,工作限定在较小的范围内,可能发现的矿种有限或可以预测,测定元素的数目也相应较少(约20种元素)．普查的测网较密,主要是圈出含量和衬度较高的异常内带,对灵敏度和准确度要求可以低些。区域化探主要是发现强度低、衬度低而范围大的区域地球化学异常,而且做为地球化学基础资料,是按分幅扫面,最后要拼缩成全国性的地球化学图。由于图幅间的对比拼接,要求较高的灵敏度和准确度。在区测中凡是能形成独立矿产的元素(包括稀有分散元素)以及有指示意义的伴生元素都要测定。区测化探不但用于找矿,目前日益为区域地质、自然区划、环境保护和农林畜牧的研究,提供重要的地球化学资料。目前测定的元素包括成岩特征元素在内已达39种。文中还探讨了在我国目前化验水平和能力的情况下,完成区测化探样品测定的方法和工作步骤。 相似文献
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本文以敞开式四酸溶样,电感耦合等离子体质谱测定了新疆、青海区调样品中的Co、Mo、W、Pb等元素,并把ICP-MS、ICP-AES和XRF三个大型仪器对新疆卡克-色帕巴衣地区样品的测定结果进行了比较,确定了区调样品元素分析方法的配套方案,并对溶样过程进行了一系列的优化,其方法检出限和精密度均符合DZ0130.4-2006及补充说明中1﹕5万化探样品标准要求。经国家标准物质验证,结果与标准值相符。优化的分析方法快速灵敏度高,能用于地球化学填图计划中分析测试任务, 同时也用于日常大规模多元素分析。 相似文献
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Interpolated geochemical maps contain problems of sample catchments and vacant sample areas. However, the resemblance of these
maps with regional geological maps implies that there are strong correlations between them. A conceptual model of the geological
units from multivariate chemical elements is constructed by decision tree technique. The reproducibility of the geological
map with the conceptual model is about 80% in the Chungbuk province map of Korea. Statistical uncertainties indicate that
rock units could be predicted reasonably well by decision tree if the geological map polygon is big enough. Misinterpreted
points are due to interpolation problems between samples from adjacent rock units and from different sample catchments. In
the Chungbuk example, the latter is less significant. The size of the map polygon is one of the most critical factors, and
a polygon size greater than 50 km2 is reliable for such analyses for the Chungbuk example. Combined lithologies in a single mapping unit are not critically
affected by decision tree prediction. 相似文献
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C. D'Ercole D. I. Groves C. M. Knox-Robinson 《Australian Journal of Earth Sciences》2013,60(5):913-927
Geographic Information Systems (GIS) provide an efficient vehicle for the generation of mineral prospectivity maps, which are products of the integration of large geological, geophysical and geochemical datasets that typify modern global‐scale mineral exploration. Conventionally, two contrasting approaches have been adopted, an empirical approach where there are numerous deposits of the type being sought in the analysed mature terrain, or a conceptual approach where there are insufficient known deposits for a statistically valid analysis. There are also a variety of potential methodologies for treatment of the data and their integration into a final prospectivity map. The Lennard Shelf represents the major Mississippi Valley‐type (MVT) province in Australia; however, there are only 13 deposits or major prospects known, making an empirical approach to prospectivity mapping impractical. Instead, a conceptual approach was adopted, where critical features that control the location of MVT deposits on the Lennard Shelf, as defined by widely accepted genetic models, were translated into features related to fluid pathways, depositional traps and fluid outflow zones, which can be mapped in a GIS and categorised as either regional or restricted diagnostic, or permissive criteria. All criteria were derived either directly from geological and structural data, or indirectly from geophysical and geochemical datasets. A fuzzy‐logic approach was adopted for the prospectivity analysis, where each interpreted critical feature of the conceptual model was assigned a weighting between 0 and 1 based on its inferred relative importance and reliability. The fuzzy‐logic method is able to cope with incomplete data, a common problem in regional‐scale exploration datasets. The data were best combined using the gamma operator to produce a fuzzy‐logic map for the prospectivity of MVT deposits on the southeastern Lennard Shelf. Five categories of prospectivity were defined. Importantly, from an exploration viewpoint, the two lowest prospectivity categories occupy ～90% and the highest two categories only 1.6% of the analysed area, yet eight of the 13 known MVT deposits lie in the latter and none in the former: i.e. all lie within ～10% of the area, despite the fact that deposit locations were not used directly in the analysis. The propectivity map also defines potentially mineralised areas in the central southeastern Lennard Shelf and the southern part of the Oscar Ranges, where there are currently no known deposits. Overall, the analysis demonstrates the power of fuzzy‐logic prospectivity mapping on a semi‐regional to regional scale, and emphasises the value of geological data, particularly accurate geological maps, in exploration for hydrothermal mineral deposits that formed late in the evolution of the terrain under exploration. 相似文献
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米纳毕戈塔斯地区（Mina Pirquitas）地处阿根廷西北部的安第斯山区,位于阿根廷西北部的新生代铜（金）及多金属成矿带内,是安第斯成矿带的组成部分。该区的岩性多样,火山岩、侵入岩发育,地质构造复杂,成矿地质条件优越,是阿根廷最主要的铜金等金属矿产资源的分布区。2010-2014年中国地质调查局与阿根廷地质调查局合作开展1：250 000地球化学示范研究,在米纳比戈塔斯地区采集了2470件水系沉积物和土壤样品,采样粒级为-10目~+60目,平均采样密度1.01个/4 km2。采用X射线荧光光谱法、等离子质谱法、原子荧光光谱法、发射光谱法、石墨炉原子吸收分光光度法和离子选择性电极法等分析了39种元素和氧化物,编制了单元素地球化学图和综合异常图,最终形成阿根廷北部米纳毕戈塔斯地区1：250 000地球化学集,包含有2 470件样品×39种元素（氧化物）的原始分析数据表格一个,地球化学图集一套（含有1张地质图、一张采样点位图和39张元素（氧化物）地球化学图）。新发现单元素地球化学异常487处,综合异常52处,并圈出了具进一步工作价值的找矿远景区。这些数据和图件对该区的找矿、基础地质研究和环境工程等具有重要参考利用价值。 相似文献
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近30年来我国地质分析重要成果评介 总被引：11，自引：1，他引：10
从地质标准物质体系的建立、X射线荧光分析成为岩矿全分析的主导方法、电感耦合等离子体光谱－质谱成为现代地质分析的支柱、化探配套方法的形成与发展、野外现场分析技术、贵金属元素分析、微区痕量分析及元素分布特征研究新技术、Re/Os同位素年代学方法及其应用、海洋地球化学分析方法体系及标准物质体系的形成等九个方面列举、评介了近30年来较重要的地质分析成果,说明成果产生的历史条件、意义与影响、成果的获得及给人的启示。最后就我国地质分析的当前热点及未来发展提出了看法。 相似文献
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该数据集依托中国地质调查局“山东莱州-招远地区金矿整装勘查区矿产调查与找矿预测”项目,在充分收集地质、物探、化探、遥感及矿产等资料基础上,开展毕郭幅矿产地质调查。项目共采集1 875件水系沉积物样品,采样粒级为-10～+80目,平均采样密度4.5个/km2。采用电感耦合等离子质谱法（ICP-MS）、原子荧光光谱法（AFS）、粉末发射光谱法（ES）和石墨炉原子吸收光谱法（GF-AAS）分析了16种元素,最终形成1：50 000山东毕郭幅地球化学数据集,数据集包含有1 875件样品×16种元素的原始分析数据表格一个,图集一套（含有1张矿产地质图、一张采样点位图和16张元素地球化学图）。区内共新发现单元素地球化学异常149处,综合异常10处,结合地质、矿产、物探、化探、遥感等信息并圈出金矿找矿靶区5处。 相似文献
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Empirical discriminant analysis classified multivariate data from 2174 geochemical reconnaissance samples from South Greenland, so that they were related to known geological units or characterized as outliers. Training sets, comprising 514 samples from 14 geologic units were selected in order to reflect only the background conditions of each geological unit. A smoothing parameter of 0.5 maximized correct classification of the training sets and extracted a reasonable number of outliers (289, 13% of the samples) representing geographically grouped anomalies. Plots of the geochemical samples classified into the geological units corresponded well to the geological map.Q-mode cluster analysis classified the 289 outliers into 30 groups with different element associations. All types of mineral occurrence known in South Greenland could be recognized amongst the clusters. For example, there were seven clusters which were characterized by samples with high U values and different associated elements each one related to a different type of U mineralization. Another cluster containing samples with high Zr, Nb, and Y values reflects recently discovered pyrochlore mineralization. Other clusters were explained on the basis of geological units which were too small to be mapped or included amongst the training sets.Empirical discriminant analysis successfully reduced the multivariate data to one map, which made it easier to evaluate the varying element levels over the different geological units. Incorrectly classified samples require follow-up in order to appraise the accuracy of the geological mapping. Classification of the outliers by cluster analysis assists both in identifying samples influenced by mineral occurrences and in predicting the type of mineralization to be expected, thereby substantially aiding in the selection of areas for mineral exploration. 相似文献
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Janet M. Hergt L. Paul Bédard Etienne Deloule Kathryn L. Linge Paul J. Sylvester Michael Wiedenbeck Jon D. Woodhead 《Geostandards and Geoanalytical Research》2005,29(1):5-52
The articles that comprise this critical review serve to draw attention to research papers published in specific fields of interest during 2003, provide critical comment on the relevance and importance of individual publications in these fields, and offer an overview of the comparative importance of advances in particular areas. In this way, these articles aim to assist experts in the field by keeping them informed of relevant recent publications, as well as providing an important resource for students or early career researchers who are embarking on studies in an area new to them. This year, five papers provide summaries of developments in bulk sample determinations employing (1) ICP-AES and ICP-MS (trace elements), (2) XRF and atomic absorption spectrometry and INAA, (3) isotope ratio measurements (TIMS, MC-ICP-MS, ICP-MS, ToF), as well as in situ measurements conducted using (4) secondary ion mass spectrometry and (5) laser ablation ICP-MS (trace element and isotope ratio determinations). 相似文献
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DUAN Jilin LIU Yanpeng ZHU Lixin MA Shengming GONG Qiuli Alla DOLGOPOLOVA Simone A. LUDWIG 《《地质学报》英文版》2023,97(4):1252-1267
Geochemical maps are of great value in mineral exploration. Integrated geochemical anomaly maps provide comprehensive information about mapping assemblages of element concentrations to possible types of mineralization/ore, but vary depending on expert’s knowledge and experience. This paper aims to test the capability of deep neural networks to delineate integrated anomaly based on a case study of the Zhaojikou Pb-Zn deposit, Southeast China. Three hundred fifty two samples were collected, and ea... 相似文献
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Recent Developments in Trace Element Analysis by ICP-AES and ICP-MS with Particular Reference to Geological and Environmental Samples 总被引：1，自引：1，他引：1
Kathryn L. Linge 《Geostandards and Geoanalytical Research》2005,29(1):7-22
This review describes recent developments in trace element analysis using inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). It aims to focus on the application of ICP techniques to geological and environmental samples. Therefore, fundamental studies in ICP-MS and ICP-AES instrumentation have largely been ignored. Whereas the majority of literature reviewed related to ICP-MS, indicating that ICP-MS is now the preferred technique for all geological analysis, there is still a steady development of ICP-AES to environmental applications. It is clear that true flexibility in elemental analysis can only be achieved by combining the advantages of both ICP-AES and ICP-MS. Two particular groups of elements (long-lived radionuclide and the platinum-group elements) stood out as warranting dedicated sections describing analytical developments these areas. 相似文献
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化探异常信息识别是化探数据分析最重要的任务之一, 也是化探数据在资源勘查领域受到广泛关注的最重要原因, 前人对化探异常信息识别做过大量研究, 这些研究中的大多数主要关注化探示踪元素的含量, 近而根据含量指标计算异常阈值, 而对示踪元素在空间中的分布特征关注较少。本文选择 1: 20万比例尺的克拉玛依幅为研究区, 根据区内金矿的矿床地球化学特征选择Ag、As、Au和Sb等4种元素为本区内金矿的示踪元素, 以地球化学元素分散晕形成理论为依据, 使用GIS技术和Matlab软件绘制研究区内4种金矿示踪元素的综合地球化学异常图。结果表明, 与传统阈值方法得到的化探异常图相比, 本文得到的化探异常图能够更好地指示研究区内已知金矿。 相似文献
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自区域化探全国扫面计划开始以来,区域化探数据在矿产勘查、环境、生态及农业等方面均发挥了很大作用,但对其在地质填图中的应用研究比较少。在中国南方花岗岩广泛分布的地区,化学风化强烈,风化层覆盖厚,植被发育,基岩裸露少,岩性识别和界线划分困难,严重影响了填图的速度和精度。通过对区域化探数据的处理分析,筛选特征指示元素编制地球化学图,发现对侵入岩体具明显指示的元素地球化学分区。通过野外实地验证,元素地球化学分区可以揭示不同期次侵入体的分布范围,利用元素地球化学分区可以有效提高强风化区地质填图的效率和精度。 相似文献
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1:5万矿产地质调查中通常会优先部署地球化学调查工作,采样密度一般大于8点/km2,并分析多达38项地球化学指标,其主要目的是发现"矿致异常",指导矿产勘查工作.而研究表明,区域地球化学数据是地表物质化学组成的直接反映,所以不仅包含了与成矿有关的异常信息,更包含了丰富的地质信息.在本次工作中应用中国西北干旱荒漠景观区1:5万地球化学调查数据成功识别了工作区地质体单元的分布.相比1:20万地质底图,通过clr-PCA分析提取出的1:5万地球化学数据信息展现了更多的细节:（1）地质体单元可以更为细致地划分为多个次级单元;（2）侵入体单元可以进行期次或岩相划分;（3）可为地质体单元的归属提供依据.本项研究结果成功指导了后续开展的1:5万地质调查工作,并对最终的1:5万地质图进行了验证,此外还提供了多处有利找矿线索. 相似文献
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Old geochemical datasets from the Paraná Shield of southern Brazil have been integrated into a new geochemical database and the results are presented as a series of multipurpose geochemical maps. Although the 24 datasets retrieved were analysed by three different laboratories, the maps produced correlate surprisingly well with bedrock geological features.The retrieval of old geochemical exploration data sets for the purpose of generating maps showing element depletions and enrichments is a powerful tool with a wide range of applications: trace elements such as Zn, Cu and Mo can significantly affect crop productivity; areas with high abundances of harmful elements such as As and F can be delineated in order to identify public health hazards; heavy metals such as Cd, Pb and Hg can be measured in order to better constrain knowledge of chemical background levels for environmental monitoring. The integration and manipulation of different data sets can however be complicated by the heterogeneity in sampling and analytical procedures. 相似文献
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U. Kramar 《Journal of Geochemical Exploration》1995,55(1-3)
In stream sediment and soil surveys, samples represent mixtures of components from different geological environments. Such mixed samples are misclassified when using conventional “hard” cluster methods. In fuzzy clustering, each sample is allowed to belong to several clusters. Similar to element concentrations, these cluster contributions can be displayed in contour maps (e.g. kriging maps). The amount of an element that is explained by the cluster contribution and element residuals can be calculated. The modified fuzzy clustering algorithm called “limited fuzzy clusters” used in this paper avoids negative residuals.Stream sediment data of Sierra de San Carlos, Tamaulipas, Mexico are used to demonstrate the possibilities of limited fuzzy clustering in geochemical exploration and mapping. From the different drainage systems, 681 stream sediment samples were taken and analyzed for 24 elements. A nineteen-element data set was used to calculate limited fuzzy clusters and element residuals. The contribution values for the clusters and element residuals are displayed in contour maps. All geological units were outlined by the cluster contributions. Extended anomalies are characterized by their own cluster. Small anomalies are clearly identified from the element residuals. 相似文献
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Determination of Trace Elements in the Quartz Reference Material UNS-SpS and in Natural Quartz Samples by ICP-MS 总被引：1，自引：0，他引：1
Thomas Monecke Gisela Bombach Werner Klemm Ulf Kempe Jens Götze Dieter Wolf 《Geostandards and Geoanalytical Research》2000,24(1):73-81
A procedure for the digestion and analysis of quartz samples was developed to measure trace element concentrations in natural quartz. The certified glass sand reference material UNS-SpS was chosen to assess the precision, accuracy and detection limit of the analytical method. Quartz was digested with HF/HNO3 in a closed glassy carbon vessel and analysed by means of quadrupole ICP-MS with external calibration. Analyte concentrations of the sand UNS-SpS were compared with certified and other values from the literature. The abundances of a number of elements (Pr, Gd, Ho and Er) in the reference material are reported here for the first time. The procedure was then applied to three quartz samples from different geological settings to show that trace element data by ICP-MS can distinguish the origin of the sample. 相似文献