共查询到20条相似文献，搜索用时 125 毫秒
1.
A. K. Chaturvedi M. Sridhar R. Murlidharan K. Shrivastava R. Pavan Guru 《Journal of the Geological Society of India》2014,84(4):385-396
Surface exploration techniques have been key contributors in discovering mineral deposits over the past three decades. However, in the last decade there has been a growing emphasis on integrating remote sensing, geological, geophysical and geochemical exploration techniques to compliment them in identifying concealed deposits. Successful integrated exploration requires putting mappable petrophysical property contrasts in terms of geological and geochemical process that could be associated with different mineralisation environment. The Precambrian Gangpur basin comprising volcanic free sedimentary sequence is considered as a potential geological setting for hosting uranium mineralisation. The Gangpur basin with metasediments of low to medium metamorphic grade classified as the Gangpur Group are known for hosting manganese, limestone and lead-zinc deposits. Uranium mineralization is reported in limonitic carbonaceous phyllite and sheared quartzite of Kumarmunda Formation at Jhamankele-Bhalulata areas. Several uranium anomalies have been associated with gossan at Kaedarpani, Jamdra and in ferruginised laterite at Badekachar, Jarmal, Jhagarpur, Kadorpani, Karamabahal, Tetelkela & Kumtinunda. In the present study geological, geophysical and remote sensing data sets are processed and integrated with other available data to delineate target zones for uranium exploration. Even though direct detection of uranium mineralisation remains unresolved in exploration strategy, instead it is becoming increasingly instructive to focus on mapping suitable depositional environments. The enhanced satellite imagery is interpreted in terms of thematic layers viz. trend lines, lineaments, faults and geological contacts. The aeromagnetic data is processed and interpreted thematic layers of magnetic breaks and linears from total magnetic intensity (TMI), the reduced to pole (RTP), tilt derivative and amplitude of analytical signal grid images. The radiometric data is processed based on their broad lithology and radio-elemental distribution maps viz. count maps, ratio maps, ternary (%K-eTh-eU) and eU/K ? eU/eTh ? eU images are generated to aid in mapping uranium favourability zones. The favourability image zones with high eU/K, eU/eTh and eU counts zones are classified into class based on statistics and anomalous high zones are picked up as uranium favourable locales. The thematic layers of geological contacts, lineaments and faults interpreted from satellite imagery, magnetic linears interpreted from aeromagnetic data and uranium favourability zone extracted from Airborne Gamma Ray Spectrometric (AGRS) data are overlaid. Based on spatial association of favourable features few locals are delineated for uranium exploration. 相似文献
2.
Renguang ZUO 《Resource Geology》2011,61(3):296-303
An exploration targeting model for Gangdese porphyry copper deposit in Tibet, China, is constructed based on (i) the age of porphyry intrusions within Gangdese magmatic arc; (ii) the regional‐scale normal E–W, N–S and N–E striking faults; and (iii) comprehensive anomalously high concentrations of Cu‐Mo‐Au‐Ag‐Pb‐Zn. These targeting elements are derived from geological map and geochemical dataset, and are integrated by weights of evidence with the aid of geographic information system (GIS). The resulting prospectivity for porphyry copper deposits delineated by posterior probability demonstrates that the target areas extend along the Yaluzangbujiang River and contain the two large deposits, Qulong and Chongjiang, located in the eastern and central part of the Gangdese belt, respectively. These results indicate that the proposed exploration targeting model is a potential tool to map regional‐scale mineral prospectivity. The target areas with high values of favorability, especially where high concentrations of Cu‐Mo‐Au‐Ag‐Pb‐Zn are present, are the potential areas for finding undiscovered porphyry copper deposits. 相似文献
3.
Mineral exploration programs commonly use a combination of geological, geophysical and remotely sensed data to detect sets of optimal conditions for potential ore deposits. Prospectivity mapping techniques can integrate and analyse these digital geological data sets to produce maps that identify where optimal conditions converge. Three prospectivity mapping techniques – weights of evidence, fuzzy logic and a combination of these two methods – were applied to a 32,000 km2 study area within the southeastern Arizona porphyry Cu district and then assessed based on their ability to identify new and existing areas of high mineral prospectivity. Validity testing revealed that the fuzzy logic method using membership values based on an exploration model identified known Cu deposits considerably better than those that relied solely on weights of evidence, and slightly better than those that used a combination of weights of evidence and fuzzy logic. This led to the selection of the prospectivity map created using the fuzzy logic method with membership values based on an exploration model. Three case study areas were identified that comprise many critical geological and geophysical characteristics favourable to hosting porphyry Cu mineralisation, but not associated with known mining or exploration activity. Detailed analysis of each case study has been performed to promote these areas as potential targets and to demonstrate the ability of prospectivity modelling techniques as useful tools in mineral exploration programs. 相似文献
4.
西藏冈底斯多金属成矿带斑岩铜矿定位预测与资源潜力评价 总被引：3，自引：1，他引：2
自1999年开展地质大调查以来,冈底斯成矿带斑岩铜矿研究取得了重大进展.本文在全面收集冈底斯成矿带地质、矿产和物化探资料基础上,建立了本区GIS平台上的资源预测评价系统.采用数理统计分析,确定了冈底斯成矿带斑岩铜矿定位预测的定量化标志35个,认为对斑岩铜矿预测影响比较重要的地质变量(因素权重>0.2)为花岗岩体(不限时代)、Cu、Mo、W、Au、Ag、Bi化探异常、Cu-Mo、Cu-Mo-Au、Cu-Au-Ag组合化探异常、矿床规模、重力场中低负异常场等.在此基础上,开展了工作区斑岩铜矿的定位预测,圈定了斑岩铜矿成矿远景区33处,计算结果与实际矿产分布和地质理论分析相吻合.采用面金属量法对冈底斯成矿带斑岩铜矿的资源潜力进行了估算,结果表明,冈底斯地区仍具有良好的斑岩铜矿找矿远景,1 000 m以浅的潜在铜资源量可达1亿吨以上.其中,驱龙-甲马-拉抗俄、松多雄、白容-冲江、松多握、吉如、达布、汤不拉、龙卡朗、崩不弄金矿、洞嘎、雄村、麦热-仁钦则、蒙哑啊东北、吹败子、岗达、沙让-亚贵拉、青龙-龙马拉、冲木达、洛麦南、拉屋找矿潜力较大. 相似文献
5.
Lineament extraction and analysis is one of the routine work in mapping medium and large areas using remote sensing data, most of which are satellite images. Landsat Enhanced Thematic Mapper （ETM） of 945×1 232 pixels subscene acquired on 21 March 2000 covering the northwestern part of Yunnan Province has been digitally processed using ER Mapper software. This article aims to produce lineament density map that predicts favorable zones for hydrothermal mineral occurrences and quantify spatial associations between the known hydrothermal mineral deposits. In the process of lineament extraction a number of image processing techniques were applied. The extracted lineaments were imported into MapGIS software and a suitable grid of 100 m×100 m was chosen. The Kriging method was used to create the lineament density map of the area. The results show that remote sensing data could be useful to extract the lineaments in the area. These lineaments are closely correlated with the faults obtained through other geological investigation methods. On comparing with field data the lineament-density map identifies two important high prospective zones, where large-scale deposits are already existing. In addition the map highlights unrecognized target areas that require follow up investigation. 相似文献
6.
The central Iranian volcanic-sedimentary belt in Kerman province of Iran that is located within the Urumieh-Dokhtar magmatic arc zone is chosen to integrate diverse evidential layers for mineral potential mapping. The studied area has high potential of mineral occurrences especially porphyry copper, and the prepared potential maps aim to outline new prospect zones for further investigation. Two evidential layers including the downward continued map and the analytic signal of filtered magnetic data are generated to be used as geophysical plausible traces of porphyry copper occurrences. The low values of the resistivity layer acquired from airborne frequency domain electromagnetic data are also used as an electrical criterion in this study. Four remote sensing evidential layers including argillic, phyllic, propylitic, and hydroxyl alterations are extracted from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images in order to map the altered areas associated with porphyry copper deposits. The Enhanced Thematic Mapper Plus (ETM+) images are used as well to prepare iron oxide layer. Since potassic alteration is generally the mainstay of copper ore mineralization, the airborne potassium radiometry data is used to explore both phyllic and potassic alteration. Finally, the geochemical layers of Cu/B/Pb/Zn elements and the main geochemical component responsible for ore mineralization extracted from principal component analysis are included in the integration process to prepare final potential maps. The conventional and the extended version of VIKOR method (as a well-known algorithm in multi-criteria decision making problems) produced two mineral potential maps, and the results were compared with the ones acquired from prevalent methods of the index overlay and fuzzy logic operators of sum and gamma. The final mineral potential maps based upon desired geo-data set indicate adequately matching of high potential zones with previous working and active mines of copper deposits. 相似文献
7.
中蒙边境及邻区斑岩型铜矿床地质特征及成因 总被引：56，自引：3，他引：56
依据金属矿床围岩岩性组合和成矿作用特征，将中蒙边境及邻区分布的斑岩铜矿床(点)划分为3种类型：①加里东期经典型斑岩铜矿床(点)；②海西期经典型和火山岩型斑岩铜矿床；③燕山期深成岩型和火山岩型斑岩铜矿床。在较详细剖析各类金属矿床(点)基本地质特征的基础上，划分了9个矿化集中区，并讨论了区域地壳演化与金属成矿作用的关系。研究结果表明，尽管研究区内的金属矿床(点)成矿作用分别发生在加里东期、海西期和燕山期，但是大规模成矿作用发生的时问与海西期板块构造活动的高峰期相吻合，是地壳特定演化阶段构造一岩浆活动的产物。 相似文献
8.
基于模糊逻辑的中甸岛弧斑岩型铜矿定位预测 总被引：7，自引：2，他引：7
文章选择中甸岛弧地区中比例尺地表填图所圈定的侵入岩及火山岩、航磁解译构造格架及汇水盆地沉积物多元素异常作为斑岩型铜矿定位预测的主要方法,总结提出了该区斑岩型铜矿的定位预测准则,并根据该准则在GIS平台上基于模糊逻辑模型进行了模糊成员权重赋值和模糊推理网络构建。通过模糊推理计算得到该区不同高度、不同方向航磁解译构造的交汇部位以及不同元素的组合异常特征,最终确定了该区可以发现斑岩型铜矿的模糊概率分布图。该区主要矿床如普朗、红山和雪鸡坪等均处于高模糊概率分布区,经野外检查验证发现普上和地苏嘎两处斑岩铜矿矿化新区。 相似文献
9.
《China Geology》2022,5(4):614-625
Landsat 8 Oli, ASTER, and Sentinel 2A satellite images processing was used to map geological formations, lineaments and hydrothermal alteration minerals in the Aouli inlier, as a case study to illustrate the application of digital images processing and Geographic Information System (GIS) in geological mapping and mining prospecting. Principal Component Analysis (PCA) applied to the Landsat images allowed good lithological discrimination and contributed to the updating of available geological maps. The Automatic lineament extraction from Sentinel images revealed the main tectonic structures affecting Aouli inlier. The ratio bands (b5+b7)/b6 and the false color composite (b4/b6, b2/b1, b3/b2) allowed the hydrothermal alteration minerals mapping from Aster images. Combined with available geological data and field observations, the satellite derived data were integrated and analyzed in a GIS software to establish mining prospecting guides. The results showed that the anomaly zones are intimately linked to NNE –SSW and NW –SE oriented faults and to highly fractured areas developing argillic and Fe rich alterations. Verified via field survey, this approach was successfully applied to the Aouli inlier to rapidly target potential areas to be explored in the tactical phase. This provides a model for future prospecting efforts for similar mineral deposits in other areas.©2022 China Geology Editorial Office. 相似文献
10.
A Sugeno-type fuzzy inference system is implemented in the framework of an adaptive neural network to map Cu–Au prospectivity of the Urumieh–Dokhtar magmatic arc (UDMA) in central Iran. We use the hybrid “Adaptive Neuro Fuzzy Inference System” (ANFIS; Jang, 1993) algorithm to optimize the fuzzy membership values of input predictor maps and the parameters of the output consequent functions using the spatial distribution of known mineral deposits. Generic genetic models of porphyry copper–gold and iron oxide copper–gold (IOCG) deposits are used in conjunction with deposit models of the Dalli porphyry copper–gold deposit, Aftabru IOCG prospect and other less important Cu–Au deposits within the study area to identify recognition criteria for exploration targeting of Cu–Au deposits. The recognition criteria are represented in the form of GIS predictor layers (spatial proxies) by processing available exploration data sets, which include geology, stream sediment geochemistry, airborne magnetics and multi-spectral remote sensing data. An ANFIS is trained using 30% of the 61 known Cu–Au deposits, prospects and occurrences in the area. In a parallel analysis, an exclusively expert-knowledge-driven fuzzy model was implemented using the same input predictor maps. Although the neuro-fuzzy analysis maps the high potential areas slightly better than the fuzzy model, the well-known mineralized areas and several unknown potential areas are mapped by both models. In the fuzzy analysis, the moderate and high favorable areas cover about 16% of the study area, which predict 77% of the known copper–gold occurrences. By comparison, in the neuro-fuzzy approach the moderate and high favorable areas cover about 17% of the study area, which predict 82% of the copper–gold occurrences. 相似文献
11.
南秦岭柞山地区铜矿成矿类型、成矿规律及找矿预测 总被引：2，自引：0，他引：2
[摘 要]南秦岭柞山地区位于陕西省东南部,其西起柞水县,东到山阳县,面积约3000km2。其地处南秦岭海西-印支褶皱带东段,主体夹持于商丹缝合带与凤镇-山阳大断裂之间。作者总结了区域成矿地质背景,对热卤水喷流沉积型铜(银铅)矿、沉积-改造层控型铜矿、热液脉型铜(镍)矿、矽卡岩型铜(铁)矿、震裂岩型铜矿、斑岩型铜(钼、金)矿等6 种铜矿成矿类型的特征进行了探讨,在此基础上阐述了柞山地区铜矿的成矿规律,指出热水喷流型铜矿、斑岩型铜矿、沉积-改造层控型铜矿最具找矿潜力。目前已知的矿床(点)均受具导浆、导热、导流、导矿功能的区域性凤镇-山阳大断裂控制,并沿其两侧展布。未来一段时期,柞山地区铜矿找矿主攻类型为热水喷流型铜矿、斑岩型铜矿、沉积-改造层控型铜矿。找矿靶区首推柞水县银洞子矿床深部、山阳县池沟铜矿点、柞水县冷水沟铜矿点,次为柞水县张家坪铜矿点、山阳县色河铺铜矿点。通过进一步勘查有望取得铜矿找矿的重大突破。 相似文献
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13.
文章首次对蒙甘新相邻(北山)地区各类金、铜和铜—镍矿床(点)地质特征、成因类型和空间分布特点进行了系统总结，论证了金、铜和铜—镍成矿作用与古生代岩浆活动的关系，对区域地壳演化过程中金、铜和铜—镍成矿的动力学机制进行了深入讨论。研究结果表明，该区的金矿床(点)大体可划分为变质岩型、火山岩型、斑岩型和深成侵入岩型；铜矿床(点)有斑岩型、夕卡岩型和铜—镍硫化物型。金和铜矿床(点)大都沿古板块汇聚带分布，与海西期火成岩具密切的时空分布关系，它们是古板块对接碰撞期和碰撞期后大规模构造—岩浆活动的产物。 相似文献
14.
Re-Os Dating of the Pulang Porphyry Copper Deposit in Zhongdian,NW Yunnan, and Its Geological Significance 总被引：1，自引：0，他引：1
ZENG Pusheng HOU Zengqian WANG Haiping QU Wenjun MENG Yifeng YANG Zhusen LI Wenchang Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing National Research Center of Geoanalysis Chinese Academy of Geological Sciences Beijing Yunnan Institute of Geological Survey Kunming Yunnan 《《地质学报》英文版》2004,78(2):604-609
The Pulang porphyry copper deposit is located in the Zhongdian island arc belt, NW Yunnan, in the central part of the Sanjiang area, SW China, belonging to the southern segment of the Yidun island arc belt on the western margin of the Yangtze Platform. In the Yidun island arc, there occur well-known "Gacun-style" massive sulfide deposits in the northern segment and plenty of porphyry copper deposits in the southern segment, of which the Pulang porphyry copper deposit is one of the representatives. Like the Yulong porphyry copper deposit, this porphyry copper deposit is also one of the most important porphyry copper deposits in the eastern Qinghai-Tibet Plateau. But it is different from other porphyry copper deposits in the eastern Qinghai-Tibet Plateau (e.g. those in the Gangdise porphyry copper belt and Yulong porphyry copper belt) in that it formed in the Indosinian period, while others in the Himalayan period. Because of its particularity among the porphyry copper deposits of China, this porphyry copp 相似文献
15.
The relationship between major structural lineaments and locations of ore deposits in Iran has been investigated using geospatial data. In the course of lineament extraction, satellite images, aeromagnetic data, digital elevation model (DEM) and structural maps were processed and the lineaments and large-scale faults were identified. The extracted lineaments, based on subjective assessment, from each dataset were imported into GIS software and the “lineament map of Iran” was prepared by data integration. The analysis for selecting significant lineament was mainly based on fault correlated lineament and lineament with field map fractures, which was sets as benchmarks for compiling a final output map. Four major regional lineament trends of N–S, E–W, NW–SE and NE–SW were identified in the data of all images, which are corresponded to the structural zones and the major fault systems of Iran. The mineral deposits (active and abandoned) and mineral indications database compiled are based on the published maps, papers, reports and the ore deposits data files of Geological Survey of Iran. Integrating the output of these two datasets by GIS software resulted in the “Combined Map of Lineaments and Gold, Copper, Lead, Zinc and Iron Deposits of Iran”. The number and distance of ore deposits toward the lineaments were processed by the counting and cumulative methods in the GIS software's. Approximately, over 90% of the ore deposits of Iran are located in the central part of the lineaments (15 km on each side) which are concordant with a definition of large lineament. About 50% of these mineral deposits are closer than 5 km to the lineaments. There are significant correlations between lineament density and intersections with ore deposits occurrences. The observed associations at this scale are informative in establishing exploration strategy and decreasing exploration risks for detailed work on ore deposit scale. 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
18.
This paper presents a review of the available information on the significant porphyry, epithermal, and orogenic gold districts in Argentina, including the tectonic, geological, and structural settings of large deposits or deposits that have been exploited in the past. Based on this review of the geology and mineralization, targeting models are developed for epithermal and orogenic gold systems, in order to produce GIS-based prospectivity models. Using publically available digital geoscience data, weights of evidence and fuzzy logic prospectivity maps were generated for epithermal and orogenic gold mineralization in Argentina. The results of the prospectivity mapping highlight existing gold deposits within known mineralized districts throughout Argentina, as well as other highly prospective areas with no known deposits within these districts. Additionally, areas within Argentina that have no known gold mineralization (based on publically available information) were highlighted as being highly prospective based on the models used. 相似文献
19.
中国大陆斑岩铜矿资源潜力定量评价 总被引：1，自引：0，他引：1
应用美国"三部式"资源评价方法原理,对中国大陆斑岩铜矿成矿地质背景、时空分布规律、矿床模型等方面研究,圈出46个远景区;以中国1999年金属储量数据库和区划矿产地数据为基础,建立了铜矿数据库共984个,分不同类型进行品位吨位的研究,以此为基础构造出数字找矿模型和开发出矿产资源定量评价模型程序,并计算了每个远景区的概率资源量,为评估中国斑岩铜矿资源潜力提供了参照。 相似文献