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1.
The Zhongtiao Mountain is located in the southern part of the North China Craton. The area experienced multi-stage tectono-magmatic events during the Precambrian, including Neoarchean-Early Paleoproterozoic (2550–2350 Ma) crustal growth, Paleoproterozoic (2350–1850 Ma) rifting–subduction–accretion–collision, and Early Mesoproterozoic (1800–1750 Ma) extension. The geological events contributed to a major copper mineral system in the region. Here we evaluate the processes of the mineral system, such as the source of metals, migration pathways, the formation of trap zones, and the deposition of metal in an attempt to establish a mineral accumulation evaluation model for regional ore prospecting. A three-step process has been proposed in this study as follows. (i) Determining the spatial and temporal distribution of the essential elements and processes of the mineral system to understand the most critical ore-controlling factors. (ii) Translating the ore-forming processes into mappable features and quantitative extraction of the information on mineralization using Geographic Information System (GIS) technology to establish a mineral accumulation evaluation model. They were treated as evidence layers for weight-of-evidence (WofE) analysis. (iii) Utilizing the weighted values of the evidence layers to create a posterior probability map. Based on the posterior probabilities, four mineral accumulation horizons were finally delineated for the Zhongtiao Mountain, which are considered to provide important guidelines for further ore exploration and study. 相似文献
2.
Controls on mineral deposit occurrence inferred from analysis of their spatial pattern and spatial association with geological features 总被引：4，自引：0，他引：4
In this paper, point pattern analysis, fractal analysis and Fry analysis were employed to study the spatial pattern of known occurrences of mineral deposits of the type sought, whereas distance distribution method was applied to study the spatial associations between various geological features and known occurrences of mineral deposits of the type sought. In the Aroroy district (Philippines), the results of the applications of these spatial analytical techniques support a conceptual model of district-scale mechanism of geologic controls on low-sulphidation epithermal Au mineralization, which involves a more-or-less regular mesh of interlinked zones of extension faults/fractures at and/or around intersections of NNW- and NW-trending strike-slip faults/fractures. Integration of spatial evidential data layers representing these structural controls and surficial geochemical anomalies, via knowledge-guided application of data-driven evidential belief functions, results in delineation of prospective areas occupying about 25% of the district, in which there is about 70% likelihood of undiscovered occurrences of low-sulphidation epithermal Au deposits. 相似文献
3.
证据权模型作为一种数据综合方法已被广泛应用于矿产资源定量预测与评价。在模糊证据权基础上,发展了基于地质单元思想的矢量证据图层构建和数据综合方法,并通过实例作具体阐述：它以矿点缓冲区图层作为训练图层,以各证据变量图层在空间上的叠置所形成的唯一地质单元作为评价对象,统一计算各个证据变量的证据权重,进而基于地质单元进行证据综合和后验概率成图。与基于栅格（或规则格网）的模型不同,基于矢量证据权模型以具有明确地质内涵的地质单元（而非规则网格单元）为预测单元,易于解释,并且消除了边界误差;相比基于规则格网划分所得到的成矿单元,以矿床（点）缓冲区作为训练对象,提高了已知矿点的代表性。实例表明：若预测单元大小为初始栅格大小整数倍,各缓冲等级平均面积计算误差为0.26%,否则面积平均误差达到6%;即使在预测单元大小为初始栅格大小整数倍情况下,矿点平均计算误差也达到4.78%。因此,基于地质单元思想的证据权预测单元划分方法在精度上优于基于栅格或规则格网方法。 相似文献
4.
流体地质填图是一种全新的地质调查及找矿方法。本次研究选择云南巍山－永平矿集区进行流体地质填图试验，研究了矿集区的控矿地质要素、各种主要的矿床（点）特征、成矿流体子系统及流域、流体的盐度与均一温度、流体的气液相成分、微量元素含量、稳定同位素特征及成矿流体的浓集中心。得到的流体地质图基本反映了本区成矿流体的性质与状态，反映了两个成矿流体子系统的基本特征，圈字了2个成矿流体子系统的流域范围及7个成矿流体浓集中心。这些浓集中心与已知矿化点分布、化探异常及有利的地质条件基本吻合，成为该区进一步找矿预测的重要依据之一。本项目的实践表明，流体地质填图不失为一种有效的找矿手段。 相似文献
5.
The Zhuxi deposit is the largest copper-tungsten polymetallic deposit in the world and is in Jiangxi Province in South China. The ore body is characterized by hydrothermal-vein deposits of copper, lead, and zinc minerals at shallow levels, skarn deposits of tungsten and copper minerals at middle levels, and altered-granite-hosted copper and tungsten minerals at depth. Such metallogenic systems are typically intrusion-related. The intrusive granites related to the Zhuxi polymetallic deposit have been dated at 152.9 Ma to 146.9 Ma. The intrusions provided the thermal energy and the source material for the ore mineralization. Skarns mineralization, the main type of ore mineralization, developed in the contact zone of Carboniferous-Permian formations with the granites. Nappe structures changed the dip of the ore bodies from steep in the top part to gentle in the bottom. NE-trending faults provided the fluid pathways and controlled the geological framework and distribution of ore deposits on a regional scale. In this study, recognition exploration criteria were analyzed based on a mineral deposit model and the geological setting. Extraction of favorable geological information and GIS-based data-integration methods were used for mineral-prospectivity mapping of Zhuxi-type polymetallic deposits. Buffering analysis was employed to extract structural information (e.g. faults) and lithologic or stratigraphic information (e.g. granites or geologic units). The singularity method and spatially weighted principal component analysis were used to enhance and delineate geochemical anomalies. The derivative norm was utilized to extract magnetic-gradient anomalies associated with intrusive granites. Student t-test of weights-of-evidence (WofE) proved to be an effective way to optimize threshold values for binarization of variables as evidence layers by evaluating the spatial correlation between known deposits and geological variables. The posterior probabilities of WofE gave a relative estimation of mineralization potential. Areas delineated by high posterior probability had much higher potentiality for the discovery of new deposits where had none had been found yet. 相似文献
6.
Although major crustal lineaments may play an important role in mineralisation, the relationship between lineaments and mineral deposits can be quite cryptic, and structural controls may vary as a function of scale along lineaments. Major lineaments alone may be of limited use for detailed target generation. The Cloncurry Lineament in the Eastern part of the Mount Isa Inlier is a crustal scale structure defined by potential field-derived ‘worms’. Weights-of-evidence quantifies the association between mineral occurrences and this lineament. Autocorrelation is used to recognise structural controls on mineralisation at different scales, by progressively limiting the lengths of the vectors between mineral occurrence points in the autocorrelation plot. The weights-of-evidence analysis shows that Au, Au–Cu, Cu–Au and Cu deposits have a positive spatial correlation to the Cloncurry Lineament, which suggests it that acted as a primary crustal scale control on the localisation of Cu and Au through focussing mineralisation systems on a broad scale. However, autocorrelation defines a variety of local structural controls, which can be interpreted as shear zones, variably oriented fault sets, en echelon fault arrays, and potentially the orientation of bedding and/or iron formations which localise fluid flow and mineral deposition at finer scales. The results suggest that major lineaments defined by geophysical contrasts can be used in conjunction with techniques of spatial analysis for targeting structurally controlled mineralisation in areas under thin cover adjacent to mineralised terrains such as the Mt Isa Inlier. 相似文献
7.
四川省会理-会东矿集区是我国著名的铜资源基地。近年来,随着找矿勘查工作的深入,又提交了多处大中型铜矿床,表明该地区仍具有较大的找矿潜力。本文基于获取的地质、化探和物探数据,应用随机森林(Random Forest,RF)方法,在研究区开展"拉拉式"铜矿成矿潜力预测,取得了较好的效果:随机森林模型预测的平均袋外误差率为6. 25%,受试者工作特征曲线(Receiver Operating Characteristic Curve,ROC)的AUC值为0. 938。利用偏依赖图(Partial Dependence Plot,PDP)分析解释了预测变量与已知矿床(点)的响应关系,按平均精度下降法排序预测要素的重要性,对"拉拉式"矿床的找矿预测工作具有重要意义的前4个变量依次为:Cu元素含量,中-晚元古代(超)基性岩体临近度,Ni元素含量和PC2因子得分。从成矿地质条件角度分析,河口群地层无疑是"拉拉式"铜矿的重要找矿预测要素,但在随机森林模型中的重要性排序相对靠后。究其原因,一方面是与其它连续数值型预测要素不同,河口群地层是二值(0～1)变量;另外,河口群地层的分布范围受覆盖层的影响较大。根据随机森林模型生成的拉拉地区成矿有利度信息,圈定了6处找矿远景区。红铜山-落凼-红泥坡-姜驿高成矿有利度区带呈北北东向展布,主体上与研究区内重要的地质-地球化学-地球物理预测要素异常空间分布一致;其中蒿枝坝-落凼-红泥坡-姑鲁迷找矿远景区是本区已探明铜矿的主要分布区,其内还有进一步勘探的潜力;同时,该异常区呈半环形态,结合地质勘探揭示的变质火山岩厚度分布,及其西部受一组后期北北东向走滑断裂限制的特点,显示出古火山活动中心在西部,并可能存在被切割分离的另一半环异常,这为该地区后续地质研究和铜矿勘查指明了方向。 相似文献
8.
BassamFAIBassam 《中国地质大学学报(英文版)》2003,14(3):283-292
Gengma region, Sanjiang district is known to have some large-scale gold deposits. GIS predictive model for hydroghermal gold potential was carried out in this region using weights of evidence modeling technique. Datasets used include large-scale hydroghermal gold deposit records, geological, geophysical and remote sensing imagery. Based on the geological and mineral characteristics of areas with known gold occurrences in Sanjiang, several geological features were thought to be indicative of areas with potential for the occurrence of hydroghtermal gold deposits. Indicative features were extracted from geoexploration datasets for use as input in the predictive model. The features include host rock lithology, geologic structures, wallrock alteration and associated (volcanic-plutonic) igneous rocks. To determine which of the indicative geological features are important spatial predictors of area with potential for gold deposits, spatial analysis was done through the modeling method. The input maps were buffered and the optimum distance of spatial association for each geological feature was determined by calculating the contrast and studentized contrast. Five feature maps were converted to binary predictor patterns and used as evidential layers for predictive modeling. The binary patterns were integrated in two combinations, each of which consists of four patterns in order to avoid over prediction due to the effect of duplicate features in the two structural evidences. The two produced potential maps define almost similar favorable zones. Areas of intersections between these zones in the two potential maps placed the highest predictive favorable zones in the region. 相似文献
9.
哈图地区地处西准噶尔达尔布特断裂带上盘,有利的构造及热动力条件导致该区形成许多金矿床、矿(化)点。文章以多种遥感数据为主导,在哈图地区开展矿产勘查工作。首先利用HSI编码的ETM+图像,增强、解译识别区内断裂;然后利用ASTER数据及光谱匹配滤波法提取矿化蚀变信息;重点部位采用Quickbird高分辨率数据解译小岩体和石英脉;并将多种结果进行综合分析。结果表明,HSI编码的ETM+图像可以有效解译出区内主断裂和次级断裂,并在安奇断裂和达尔布特断裂间解译出了宝贝断裂;蚀变信息结果与已知矿床、矿(化)点吻合较好,沿宝贝断裂带提取出了一条白云母、高岭土、绿泥石蚀变带;利用Quickbird高分辨率数据解译出了2个中酸性小岩体和数条石英脉,通过对小岩体和石英脉进行野外检查,发现了铜矿化点及微弱金矿化点多处,为后续的找矿提供了方向。 相似文献
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A new type of model, referred to as a geology-exploration endowment model, is proposed in this paper. These models differ from conventional ones in that they simultaneously estimate discoverable mineral resources and endowment by extracting and utilizing geoscience information from both geological features and exploration factors. Geological measurements describe mineral endowment, while exploration variables describe the completeness of exploration, and together, they explain discoverable resources. Without incorporation of exploration factors to geological-endowment models, the estimation of endowment is generally biased. This paper presents two variations of such hybrid nonlinear models: Poisson-logistic (PL) and exponential-logistic (EL) for estimation of number of mineral deposits or prospects based upon the Arps and Roberts' discovery process model and assumptions of endowment distributions. The PL model is obtained by assuming that endowment follows a Poisson distribution and that the probability of mineral occurrences ( 1) is a logistic function with geological arguments. The EL model is derived similarly, except that endowment is assumed to be exponentially distributed. The PL model is demonstrated on both a synthetic example and a case study of epithermal gold-silver vein deposits in the Walker Lake quadrangle of Nevada and California. A map containing the estimated numbers of gold-silver mineral occurrences potentially discoverable in the Walker Lake quadrangle is produced. The parameter estimates for the PL model based on the Levenberg-Marquardt iterative algorithm are validated by using several statistical measures, such as theT-statistic, Box's bias, and goodness of fit. Both a synthetic example and a case study suggest that the Box's bias measure is useful for validation of the nonlinear estimates. 相似文献
12.
证据权方法是目前最常用的信息综合方法之一,广泛应用于矿产资源定量预测与评价.然而,它要求变量间相互独立,地质上很难满足这一条件.如何削弱条件不独立对证据权预测结果的影响,已成为当前数学地球科学研究的热点.解决该问题的途径之一是对传统证据权模型进行校正,比如采取加权的方法对原证据权模型计算的证据权重进行修正,以便消除非条件独立性的影响.对近期提出的多种加权证据权模型进行了系统的对比研究,基于同样的应用实例和实验方案,对不同方法的应用效果进行了比较,结果表明,各种加权证据权模型均可不同程度地削弱证据图层条件不独立性的影响,其中,基于逻辑回归的加权证据权模型优于其他加权方法. 相似文献
13.
I. V. Gordienko D. V. Gorokhovsky O. K. Smirnova V. S. Lantseva R. A. Badmatsyrenova D. A. Orsoev 《Geology of Ore Deposits》2018,60(1):1-32
Based on complex structural, rheological, and metallogenic studies, taking into account the results of earlier subject-specific, prospecting, mapping, and exploration works, it has been established that the geological structure of the district was caused by the ensimatic evolution of the Vendian–Early Paleozoic Dzhida island-arc system, in which oceanic and island-arc complexes served as a melanocratic basement for Late Paleozoic–Mesozoic active within-plate (riftogenic) processes, which gave rise to the formation of ore deposits and occurrences of strategic mineral commodities (Mo, W, Au, Pt, Ag, and rare elements, including REE). Mantle plumes and flows of deep-seated transmagmatic solutions (ore-forming fluids) played a critical role in these processes, the significance of which increases in upper crustal swarms of dikes and fault systems. The forecasts and development prospects of the Dzhida ore district envisage the expansion of geological prospecting and exploration, scientific research, and technological testing of ore for insight into strategic mineral commodities, as well as reanimation of mining within the areas of the Dzhida’s large territorial and industrial complex (TIC) in eastern Siberia. 相似文献
14.
岭壳铜(银-金)矿床赋存于白垩纪岭壳村组流纹质角砾凝灰熔岩和早白垩世花岗闪长岩中.目前已发现11条铜(银-金)矿(化)体,矿体的产出严格受断裂破碎带控制,与成矿关系密切的围岩蚀变呈现出自东(20线)向西的钾化→绢云母化→强高岭石化、绿泥石化蚀变分带,矿化相应呈现从铜(金)向铜(银)的过渡.根据其对称性的蚀变分带,应加强20线以东的地质找矿;根据成矿元素分形和统计研究发现,Au,Ag矿化具有专属性,即在流纹质凝灰熔岩中寻找Cu,Ag矿,而在花岗闪长岩中以寻找Cu,Au矿为主. 相似文献
15.
安徽庐枞铁铜整装勘查区成矿远景预测中遥感技术的应用 总被引：1，自引：0，他引：1
安徽庐枞铁铜整装勘查区为国家首批整装勘查区之一,以往地质找矿成果显著,本文利用遥感技术,通过线、环构造解译和蚀变信息提取,并综合考虑区域内的地质特征和成矿地质条件,开展遥感成矿预测,划分了四个成矿远景区。 相似文献
16.
《Chemie der Erde / Geochemistry》2021,81(4):125803
Central Alborz Metallogenic Belt is a major mineral province of northern Iran placed at the northern margin of the Arabia-Eurasia collision zone. This study aimed to at recognition the affiliation between reverse/thrust faults and Pb-Zn carbonate-hosted mineral deposition using fractal modeling. Thrusting is the major mechanism of faulting in this region in terms of length, frequency and density. The carbonate-hosted Pb and Zn occurrence/deposit were classified using the concentration-number fractal method. All faults then are categorized based on fault density, and concentration-area fractal methods are utilized for the thrust faults. According to our analysis, main fault density zones are situated at the central and western parts of the Alborz Mountains. Relationship among the major fault density zones and the Pb-Zn carbonate-hosted occurrences/deposits using logratio matrix reveals that there is a proper connection between reverse/thrust faults and the Zn-Pb carbonate-hosted occurrences/deposits. Moreover, the results were controlled by four ore deposits/prospects in this region which shows high-grade ores directly relate to faults especially reverse/thrust faults based on their distribution. This research indicates that this method can be used for other various ore deposit types that have been distributed by faulting. 相似文献
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为了研究宁芜北段火山岩盆的矿产资源潜力及空间分布,本文以Landsat8中分辨率遥感数据及Pleiades1高分辨率遥感数据为数据源,综合运用目视解译法和多种遥感图像增强技术,结合区域成矿地质背景,对研究区进行了遥感影像解译,提取了与预测矿种密切相关的线、环、色、带、块遥感五要素。通过分析遥感五要素矿产地质特征与矿产点分布关系表明,研究区内的铁铜硫金矿床及星罗棋布的矿点大部分位于构造岩浆成矿亚带中,受区内北东向、东西向、北西向及其它断裂纵横交叉形成的断裂网格及火山机构控制,大多分布在数条断裂带交汇位置,另有一些分布在断裂带与环形构造的交汇处附近。基于主要的矿点受区内断裂网格及火山机构控制,遥感图像的综合地质信息特征与找矿目标紧密相联,说明了基于遥感图像的综合信息可以作为找矿预测的标志。 相似文献
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