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1.
P. Charusiri B. Charusiri W. Pongsapich R. Suwanwerakamtorn 《Natural Resources Research》1994,3(1):46-59
The study area is located in the Chiang Mai, Tak, and Mae Hong Son provinces of northern Thailand. Digitally enhanced Landsat TM5 and SPOT images and data on economic minerals deposits were used in the investigation. High-pass filtering and principal component analyses were determined to be the most appropriate enhancement methods.Space-borne image interpretation indicates two major faults: the north-trending Mae Hong Son and the northwest-trending Mae Ping. Both large-scale faults are inferred to be closely related to substantial, nearly parallel folds and thrusts. The four main sets of lineaments observed (north-south, northeast-southwest, northwest-southeast, and east-west) are considered to have an essential role in the occurrences of various mineral deposits. Mineral exploration has emphasized areas where several sets of lineaments cross-cut each other, since the possibility of finding concealed ore bodies or potential target areas is considered quite high. Some sets of lineaments probably control post-Triassic granitoid emplacements both directly and indirectly. Three major granitoid series are recognized in the study area: the Mae Lama (ca. 70 Ma), the Tae Song Yang (ca. 45 Ma), and the Mae Sariang (205–210 Ma) Granites. These peraluminous, S-type granites are closely related to tin, tungsten, and fluorite deposits. Fluorite, barite, manganese, and antimony deposits may be related to the northtrending lineaments. Stibnite deposits may be related to the northeast-trending lineaments. The tin/tungsten deposits are likely related to the east- and northwest-trending lineaments. Ovoid-shaped lineaments, found only at a few locations, are interpreted to indicate the granitoid emplacement and are thought to be important in the generation of concealed mineral deposits. We conclude that the existence of such lineaments is related to the post-Triassic abutment and collision of the Shan-Thai, Indochina, and Western Burma microcontinental blocks. 相似文献
2.
The quantitative probabilistic assessment of the undiscovered mineral resources of the 17.1-million-acre Tongass National Forest (the largest in the United States) and its adjacent lands is a nonaggregated, mineral-resource-tract-oriented assessment designed for land-planning purposes. As such, it includes the renewed use of gross-in-place values (GIPV's) in dollars of the estimated amounts of metal contained in the undiscovered resources as a measure for land-use planning.Southeastern Alaska is geologically complex and contains a wide variety of known mineral deposits, some of which have produced important amounts of metals during the past 100 years. Regional geological, economic geological, geochemical, geophysical, and mineral exploration history information for the region was integrated to define 124 tracts likely to contain undiscovered mineral resources. Some tracts were judged to contain more than one type of mineral deposit. Each type of deposit may contain one or more metallic elements of economic interest. For tracts where information was sufficient, the minimum number of as-yet-undiscovered deposits of each type was estimated at probability levels of 0.95, 0.90, 0.50, 0.10, and 0.05.The undiscovered mineral resources of the individual tracts were estimated using the U.S. Geological Survey's MARK3 mineral-resource endowment simulator; those estimates were used to calculate GIPV's for the individual tracts. Those GIPV's were aggregated to estimate the value of the undiscovered mineral resources of southeastern Alaska. The aggregated GIPV of the estimates is $40.9 billion.Analysis of this study indicates that (1) there is only a crude positive correlation between the size of individual tracts and their mean GIPV's: and (2) the number of mineral-deposit types in a tract does not dominate the GIPV's of the tracts, but the inferred presence of synorogenic-synvolcanic nickel-copper, porphyry copper skarn-related, iron skarn, and porphyry copper-molybdenum deposits does. The influence of this study on the U.S. Forest Service planning process is yet to be determined. 相似文献
3.
Estimates of numbers of undiscovered mineral deposits, fundamental to assessing mineral resources, are affected by map scale.
Where consistently defined deposits of a particular type are estimated, spatial and frequency distributions of deposits are
linked in that some frequency distributions can be generated by processes randomly in space whereas others are generated by
processes suggesting clustering in space. Possible spatial distributions of mineral deposits and their related frequency distributions
are affected by map scale and associated inclusions of non-permissive or covered geological settings. More generalized map
scales are more likely to cause inclusion of geologic settings that are not really permissive for the deposit type, or that
include unreported cover over permissive areas, resulting in the appearance of deposit clustering. Thus, overly generalized
map scales can cause deposits to appear clustered. We propose a model that captures the effects of map scale and the related
inclusion of non-permissive geologic settings on numbers of deposits estimates, the zero-inflated Poisson distribution. Effects
of map scale as represented by the zero-inflated Poisson distribution suggest that the appearance of deposit clustering should
diminish as mapping becomes more detailed because the number of inflated zeros would decrease with more detailed maps. Based
on observed worldwide relationships between map scale and areas permissive for deposit types, mapping at a scale with twice
the detail should cut permissive area size of a porphyry copper tract to 29% and a volcanic-hosted massive sulfide tract to
50% of their original sizes. Thus some direct benefits of mapping an area at a more detailed scale are indicated by significant
reductions in areas permissive for deposit types, increased deposit density and, as a consequence, reduced uncertainty in
the estimate of number of undiscovered deposits. Exploration enterprises benefit from reduced areas requiring detailed and
expensive exploration, and land-use planners benefit from reduced areas of concern. 相似文献
4.
5.
《Geomorphology》2007,83(1-2):67-81
In this study, Landsat 7 ETM+ data sets were used to study the geomorphology and mineralogy of different dune types in the eastern part of Abu Dhabi in United Arab Emirates. The extraction and mapping of the dominant mineral phase of the investigated sand dunes were carried out using image processing integrated with field techniques. Band ratios 6/4 and 5/7 were very useful for mineralogical distinction of (i) high mafic content areas (ratio 5/7), and (ii) carbonate and quartz content (ratio 6/4). The results of the present study show that these dunes are classified into several main classes based on composition. The first class is low dunes composed of a mixture of quartz and carbonate, the second class is carbonate-rich, the third quartz-rich and the fourth mafic mineral-rich. Morphologically, the dunes in the investigated area belong to two main types. The first is linear and is trending NE–SW. This type shows transitional change in mineralogy from carbonate-rich components to iron oxide-rich components. This mineral gradient was observed on Landsat images as spectral variations and color tones, and was confirmed from ground truth data. The second type is star dunes and appears in images as radially symmetrical to mound shape that characterize multidirectional wind systems. The results of this study show that multispectral data can be used to differentiate between different dune types and their associated mineralogy, and to reveal information on the dynamic processes shaping dunes, such as prevailing wind directions. 相似文献
6.
柴达木盆地天青石资源极为丰富,已发现有大风山、碱山、尖顶山等大型天青石矿床。通过元素分析、元素相关性分析、矿物组合分析等方法与手段,对柴达木盆地天青石矿区矿物特点及元素地球化学特征进行了研究。得到如下结论:大风山矿区以天青石—方解石—镁方解石矿物组合为主,矿物品位均值为59%;碱山矿区以天青石—文石矿物组合为主,矿物品位均值为39.6%;石膏、白云石在各矿区矿物均有分布,且含量较低。石膏与天青石成正相关关系,白云石的存在对天青石成矿来说是不利因素,铁白云石、文石和镁方解石的普遍存在可说明该区矿物成矿温度较高。Sr与S成正相关关系,证明Sr主要以天青石(硫酸锶)形式存在,锶与镁、钙成非线性关系,锶含量高则钙含量低,钙主要赋存在石膏中,而非方解石中。Sr/Ba比值、Sr/Cu比值分析表明该矿区经历过长期干旱的环境,Mg/Ca比值分析表明该区天青石成矿过程中微生物对其成矿作用起到了非常重要的作用。 相似文献
7.
In the southern part of Jewish Autonomous Oblast, large resources of iron ores and accompanying metals contained in them have
been assessed. As regards the resources of iron ores, it is one of the largest deposits in the Far East, and according to
the complex of satellite metals, it is similar to some deposits in China, while with respect to the value of the resources,
it refers to world class objects. 相似文献
8.
Liu Lushi Lu Jilong Tao Chunhui Liao Shili Chen Shengbo 《Natural Resources Research》2021,30(2):971-987
With the depletion of mineral resources on land, seafloor massive sulfide deposits have the potential to become as important for exploration, development and mining as those on land. However, it is difficult to investigate the ocean environment where seafloor massive sulfide deposits are located. Thus, improving prospecting efficiency by reducing the exploration search space through mineral prospectivity mapping (MPM) is desirable. MPM has been used in the exploration for seafloor deposits on regional scales, e.g., the Mid-Atlantic Ridge and Arctic Ridge. However, studies of MPM on ultraslow-spreading ridges on segment scales to aid exploration for seafloor massive sulfide have not been carried out to date. Here, data of water depth, geology and hydrothermal plume anomalies were analyzed and the weights-of-evidence method was used to study the metallogenic regularity and to predict the potential area for seafloor massive sulfide exploration in 48.7°–50.5° E segments on the ultraslow spreading Southwest Indian Ridge. Based on spatial analysis, 11 predictive maps were selected to establish a mineral potential model. Weight values indicate that the location of seafloor massive sulfide deposits is correlated mainly with mode-E faults and oceanic crust thickness in the study area, which correspond with documented ore-controlling factors on other studied ultraslow-spreading ridges. In addition, the detachment fault and ridge axis, which reflect the deep hydrothermal circulation channel and magmatic activities, also play an important role. Based on the posterior probability values, 3 level A, 2 level B and 2 level C areas were identified as targets for further study. The MPM results were helpful for narrowing the search space and have implications for investigating and evaluating seafloor massive sulfide resources in the study area and on other ultraslow-spreading ridges.
相似文献9.
de Quadros Telmo F. P. Koppe Jair C. Strieder Adelir J. Costa João Felipe C. L. 《Natural Resources Research》2003,12(1):57-65
A large number of mineral deposits are associated with hydrothermal processes, especially auriferous deposits. In such processes, studies on percolating fluids may indicate the presence of potash (K), among other elements. In this study, aerogammaspectrometric data-processing methodologies are evaluated, especially those methods based on the suppression of the primary contribution of potassium, the result of lithological and soil variations, and to environmental conditions. Resulting maps point out the contribution of hydrothermal K. This processing procedure was used because of the association of hydrothermal K and auriferous mineralizations according to the deposit model defined for the studied region. Intensity maps locate the areas with great influence of hydrothermal K. Data integration required to improve a change in the gammaspectrometric data processing in order to positively correlate hydrothermalised areas. Data integration could distinguish high and medium favorable targets for mineral exploration of lode-Au deposits in the studied region. 相似文献
10.
Characteristics of the mineral phase constituents of lacustrine deposits from the Fildes Peninsula of King George Island, Antarctica and their environmental implication 总被引：1，自引：0，他引：1 
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11.
The Random Forests (RF) algorithm is a machine learning method that has recently been demonstrated as a viable technique for data-driven predictive modeling of mineral prospectivity, and thus, it is instructive to further examine its usefulness in this particular field. A case study was carried out using data from Catanduanes Island (Philippines) to investigate further (a) if RF modeling can be used for data-driven modeling of mineral prospectivity in areas with few (i.e., <20) mineral occurrences and (b) if RF modeling can handle predictor variables with missing values. We found that RF modeling outperforms evidential belief (EB) modeling of prospectivity for hydrothermal Au–Cu deposits in Catanduanes Island, where 17 hydrothermal Au–Cu prospects are known to exist. Moreover, just like EB modeling, RF modeling allows analysis of the spatial relationships between known prospects and individual layers of predictor data. Furthermore, RF modeling can handle missing values in predictor data through an RF-based imputation technique whereas in EB modeling, missing values are simply represented by maximum uncertainty. Therefore, the RF algorithm is a potentially useful method for data-driven predictive modeling of mineral prospectivity in regions with few (i.e., <20) occurrences of mineral deposits of the type sought. However, further testing of the method in other regions with few mineral occurrences is warranted to fully determine its usefulness in data-driven predictive modeling of mineral prospectivity. 相似文献
12.
The Haji-Gak iron deposit of eastern Bamyan Province, eastern Afghanistan, was studied extensively and resource calculations
were made in the 1960s by Afghan and Russian geologists. Recalculation of the resource estimates verifies the original estimates
for categories A (in-place resources known in detail), B (in-place resources known in moderate detail), and C1 (in-place resources estimated on sparse data), totaling 110.8 Mt, or about 6% of the resources as being supportable for the
methods used in the 1960s. C2 (based on a loose exploration grid with little data) resources are based on one ore grade from one drill hole, and P2 (prognosis) resources are based on field observations, field measurements, and an ore grade derived from averaging grades
from three better sampled ore bodies. C2 and P2 resources are 1,659.1 Mt or about 94% of the total resources in the deposit. The vast P2 resources have not been drilled or sampled to confirm their extent or quality. The purpose of this article is to independently
evaluate the resources of the Haji-Gak iron deposit by using the available geologic and mineral resource information including
geologic maps and cross sections, sampling data, and the analog-estimating techniques of the 1960s to determine the size and
tenor of the deposit. 相似文献
13.
14.
V.F. Rodriguez-Galiano M. Chica-Olmo M. Chica-Rivas 《International journal of geographical information science》2014,28(7):1336-1354
Mineral exploration activities require robust predictive models that result in accurate mapping of the probability that mineral deposits can be found at a certain location. Random forest (RF) is a powerful machine data-driven predictive method that is unknown in mineral potential mapping. In this paper, performance of RF regression for the likelihood of gold deposits in the Rodalquilar mining district is explored. The RF model was developed using a comprehensive exploration GIS database composed of: gravimetric and magnetic survey, a lithogeochemical survey of 59 elements, lithology and fracture maps, a Landsat 5 Thematic Mapper image and gold occurrence locations. The results of this study indicate that the use of RF for the integration of large multisource data sets used in mineral exploration and for prediction of mineral deposit occurrences offers several advantages over existing methods. Key advantages of RF include: (1) the simplicity of parameter setting; (2) an internal unbiased estimate of the prediction error; (3) the ability to handle complex data of different statistical distributions, responding to nonlinear relationships between variables; (4) the capability to use categorical predictors; and (5) the capability to determine variable importance. Additionally, variables that RF identified as most important coincide with well-known geologic expectations. To validate and assess the effectiveness of the RF method, gold prospectivity maps are also prepared using the logistic regression (LR) method. Statistical measures of map quality indicate that the RF method performs better than LR, with mean square errors equal to 0.12 and 0.19, respectively. The efficiency of RF is also better, achieving an optimum success rate when half of the area predicted by LR is considered. 相似文献
15.
James C. Hower 《Natural Resources Research》1995,4(4):310-324
The mining of cannel coal was a small, but prestigious, component of the coal production of Kentucky in the 1800's and early 1900's. Cannel coal was retorted into liquid fuel, gasified as an enricher of municipal gas supplies, and distilled as a feedstock for the production of chemicals. Each peak in usage was subsequently tempered by a discovery of cheaper sources of liquid hydrocarbons.Four mining areas in Kentucky, three in eastern Kentucky and one in western Kentucky, will be discussed. The Breckenridge deposit in western Kentucky was developed as early as 1837 and came to prominence in the 1850's and, to a lesser extent, in the 1880's. The Johnson County deposits were developed in the 1880's and continued in production through the 1920's. The Bell County cannels were developed in the 1890's. Although highly praised for their quality, they had a brief mining history because of the limited extent of the reserves. The most prolific cannel field, Morgan County, was opened in 1901 and continued to be a large producer, albeit with some low-production years, through the 1950's, with minor production as late as 1987.The production of cannel, as with any mineral commodity, was at the mercy of market demands and available transportation. Cannel coal, more than banded bituminous coal, occurs in relatively limited areas, leading to the rapid exhaustion of commercial deposits as well as failed attempts to develop deposits that did not attain commercial size. 相似文献
16.
Thomas Poulet Juan Felipe Giraldo Erick Ramanaidou Agnieszka Piechocka Victor M. Calo 《Basin Research》2023,35(2):572-591
The Hamersley Basin in Western Australia is one of the world's largest iron ore-producing regions, hosting two types of ore in banded iron formations: the high-grade martite-microplaty haematite and the supergene martite-goethite ores. With the high-grade ores almost entirely mined in the last decade, the supergene ores have more recently become the dominant resource of interest. Consequently, understanding the genesis of these martite-goethite deposits is a critical step for exploration. Yet, although various models exist, there is still no consensus on how these mineral resources formed, complicating the prediction of resource volume and location. Here, we show that the paleo-stratigraphic permeability anisotropy (with higher permeability along strata than across) controls the supergene mimetic enrichment transport process and, subsequently, the mineralisation distribution. We introduce a flow model that implicitly represents strata with a potential function that orients the permeability tensor accurately. The numerical solver uses automatic mesh adaptivity to deliver robust solutions. By accurately reproducing the mineralisation patterns in specific deposits, we identify and quantify the paleo-water table level and permeability anisotropy ratio as the two main controlling parameters for the mineralisation distribution. These insights provide new timing constraints for the mineralisation and the physical process of iron enrichment, suggesting much more potential mineralisation volume in the paleo-reconstructed zones than previously anticipated. These flow models allow us to draw geological conclusions with few a priori assumptions required for the genetic model in which the transport component is dominant. The predictive power of this methodology will allow targeted drilling to narrow down the prospective areas and lower exploration costs. Furthermore, the methodology's generality applies to other commodities in sedimentary basins involving supergene processes and will improve our understanding of various genetic models. 相似文献
17.
Dennis P. Cox 《Natural Resources Research》1993,2(2):82-91
Quantitative mineral resource assessments used by the United States Geological Survey are based on deposit models. These assessments consist of three parts: (1) selecting appropriate deposit models and delineating on maps areas permissive for each type of deposit; (2) constructing a grade-tonnage model for each deposit model; and (3) estimating the number of undiscovered deposits of each type. In this article, I focus on the estimation of undiscovered deposits using two methods: the deposit density method and the target counting method.In the deposit density method, estimates are made by analogy with well-explored areas that are geologically similar to the study area and that contain a known density of deposits per unit area. The deposit density method is useful for regions where there is little or no data. This method was used to estimate undiscovered low-sulfide gold-quartz vein deposits in Venezuela.Estimates can also be made by counting targets such as mineral occurrences, geophysical or geochemical anomalies, or exploration plays and by assigning to each target a probability that it represents an undiscovered deposit that is a member of the grade-tonnage distribution. This method is useful in areas where detailed geological, geophysical, geochemical, and mineral occurrence data exist. Using this method, porphyry copper-gold deposits were estimated in Puerto Rico. 相似文献
18.
Sidnei Pires Rostirolla Paulo César Soares Hung Kiang Chang 《Natural Resources Research》1998,7(1):7-24
A methology to define favorable areas in petroleum and mineral exploration is applied, which consists in weighting the exploratory variables, in order to characterize their importance as exploration guides. The exploration data are spatially integrated in the selected area to establish the association between variables and deposits, and the relationships among distribution, topology, and indicator pattern of all variables. Two methods of statistical analysis were compared. The first one is the Weights of Evidence Modeling, a conditional probability approach (Agterberg, 1989a), and the second one is the Principal Components Analysis (Pan, 1993). In the conditional method, the favorability estimation is based on the probability of deposit and variable joint occurrence, with the weights being defined as natural logarithms of likelihood ratios. In the multivariate analysis, the cells which contain deposits are selected as control cells and the weights are determined by eigendecomposition, being represented by the coefficients of the eigenvector related to the system’s largest eigenvalue. The two techniques of weighting and complementary procedures were tested on two case studies: 1. Recôncavo Basin, Northeast Brazil (for Petroleum) and 2. Itaiacoca Formation of Ribeira Belt, Southeast Brazil (for Pb-Zn Mississippi Valley Type deposits). The applied methdology proved to be easy to use and of great assistance to predict the favorability in large areas, particularly in the initial phase of exploration programs. 相似文献
19.
J. R. Evans 《Natural Resources Research》1998,7(3):163-185
The Secretary of the Interior through appropriate staff can inquire into the validity of mining claims through the Act of
April 25, 1812 (R.S. 453; 43 USC 2). Validity examinations are also authorized by the Act of July 23, 1955 (USC 601), for
management over surface resources of mining claims located prior to the Act [Adams v. United States, 318 F2d 861 (9th Cir 1963).] Validity examinations are normally made in response to one of two circumstances: (1) to process
a mineral patent application; or (2) to resolve a conflict between the mining claim and some other use of the land. Federal
employees charged with the management of Federal lands have the right and authority to challenge the validity of mining claims
for any reason [Estate of Melvin E. Viles, 126 IBLA 162, 164 (1993).] A validity examination of an unpatented mining claim by a Federal Government minerals examiner
is to verify or refute a discovery on that claim. The mineral examiner makes a recommendation as to whether a claim is valid
or invalid. If a discovery cannot be verified within the limits of the claim, the examiner will normally recommend that the
government contest the claim. Concepts for making validity examinations on mining claims are here given. Many mineral deposits
are unique and it is important that the mineral examiner use their initiative and adopt whatever detailed procedures may be
required. 相似文献
20.
Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role of pesticides in human health. Humans can be exposed to pesticides via residential proximity to agricultural pesticide applications (drift). We present an improved geographic information system (GIS) and remote sensing method, the Landsat method, to estimate agricultural pesticide exposure through matching pesticide applications to crops classified from temporally concurrent Landsat satellite remote sensing images in California. The image classification method utilizes Normalized Difference Vegetation Index (NDVI) values in a combined maximum likelihood classification and per-field (using segments) approach. Pesticide exposure is estimated according to pesticide-treated crop fields intersecting 500 m buffers around geocoded locations (e.g., residences) in a GIS. Study results demonstrate that the Landsat method can improve GIS-based pesticide exposure estimation by matching more pesticide applications to crops (especially temporary crops) classified using temporally concurrent Landsat images compared to the standard method that relies on infrequently updated land use survey (LUS) crop data. The Landsat method can be used in epidemiologic studies to reconstruct past individual-level exposure to specific pesticides according to where individuals are located. 相似文献