Conditional Indicator Simulation: Application to a Saskatchewan uranium deposit   总被引：11，自引：0，他引：11  

A. G. Journel  E. H. Isaaks 《Mathematical Geology》1984,16(7):685-718

Mineral deposits frequently exhibit a mixture of rock types in which each type can be identified by a characteristic metal concentration. Such a mixture can be correctly simulated by first reproducing the spatial and geometric configuration of the various rock types in the deposit. Then the grades for each rock type can be jointly simulated and filled in according to their specific coregionalization characteristics. The method of Conditional Indicator Simulation and an uranium—arsenic joint simulation are presented with a detailed, step-by-step application to the Midwest deposit, a high grade uranium deposit in northern Saskatchewan.  相似文献   

Indicator favorability theory for mineral potential mapping     

Guocheng Pan 《Natural Resources Research》1993,2(4):292-311

Favorability methods produce a unique measure for mineral potential mapping and quantitative estimation of mineral resources. Indicator favorability theory is developed in this study to account for spatial (auto and cross) correlations of regionalized geological, geochemical, and geophysical fields based on the indicator concept. Target and explanatory indicators are introduced to describe, respectively, direct and indirect evidence of the mineralization of interest. Mineralization is represented by a combination () of a set of target indicators. Indicator favorability theory estimates a regionalized favorability function in two stages: (1) estimate a linear combination of target indicators by maximizing var() and (2) estimate favorability functionF by minimizing estimation variance var[F–]. The model is established on the basis of a conceptual model of target. The favorability estimates can be justified by correlation analysis and cross validation in control areas. The indicator favorability theory is demonstrated on a case study for gold-silver mineral potential mapping based on geophysical, structural, and geochemical fields.  相似文献   

湘中地区微细粒浸染型金矿的找矿标志   总被引：1，自引：0，他引：1  

陈强春 《湖南地质》1998,17(2):100-104

本文总结了湘中地区微细粒浸染型金矿的地层岩性、构造、岩浆岩、成矿系列与地球化学等方面的找矿标志,这无疑对今后的找矿工作具有指导意义。  相似文献   

Evaluation of the resources of a slate deposit using indicator kriging     

F.G. Bastante  J. Taboada  L.R. Alejano  C. Ordez 《Engineering Geology》2005,81(4):191-418

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Identification of Cu and Ni indicator plants from mineralised locations in Botswana     

Bonang B.M. Nkoane  Gerald M. Sawula  Grethe Wibetoe  Walter Lund 《Journal of Geochemical Exploration》2005,86(3):130-142

Plant species that accumulate high levels of metals in proportion to the metal content in the soil are of considerable interest in biogeochemical and biogeobotanical prospecting. This study was aimed at investigating copper and nickel accumulation in the plants Helichrysum candolleanum and Blepharis diversispina, to assess their potential use as mineral indicators in biogeochemical prospecting. Soils and plants were collected from copper–nickel mineralised areas in Botswana. Analyses of the soils and the respective plant parts (roots, stem, leaves and flowers) were carried out using ultrasonic slurry sampling electrothermal atomic absorption spectrometry (ETAAS), which allowed rapid determination of copper and nickel in small amounts of the samples.The metal concentration in the soil was in the range ≈ 40 μg/g–4% (w/w) for Cu and ≈ 60 μg/g–0.3% (w/w) for Ni. The concentration ranges of the elements in the plant parts were ≈ 6 μg/g–0.2% Cu and ≈ 3–210 μg/g Ni. At high soil metal content (greater than 2.5% (w/w) Cu and 0.1% (w/w) Ni), high levels of both nickel and copper were found in the shoots (leaves and flowers) of H. candolleanum. Concentrations as high as 0.2% (w/w) Cu were found in the leaves and flowers of H. candolleanum, indicating hyperaccumulation for this plant. For B. diversispina, the metal concentrations did not exceed 100 μg/g for any plant part, for both metals. Both plant species tolerate high concentrations of metals and should therefore be categorized as metallophytes. In order to evaluate metal translocation from the soil to the shoots, metal leaf transfer coefficients (ratio of metal concentration in the leaf to metal concentration in the soil) were calculated. Our data suggest that the two plant species have different metal uptake and transport mechanisms, which needs to be investigated further. The present work also suggests that H. candolleanum may be used as a copper/nickel indicator plant in biogeochemical or biogeobotanical prospecting.  相似文献   

Improvement of the sediment ecosystem following diversion of an intertidal sewage outfall at the Fraser river estuary,Canada, with emphasis on Corophium salmonis (Amphipoda)     

Arvai JL  Levings CD  Harrison PJ  Neill WE 《Marine pollution bulletin》2002,44(6):511-519

Primary treated sewage effluent from the city of Vancouver, Canada was deposited directly onto the intertidal ecosystem of Sturgeon bank, Fraser river estuary between 1962 and 1988. In response to the degraded sediment conditions an azoic zone developed near the discharge outfall. Effluent discharges into the intertidal zone were almost completely stopped in 1988 with the construction of a submerged outfall. Our studies, conducted between 1994 and 1996, showed considerable improvement in the environment of the mudflat ecosystem, including increased dissolved oxygen, decreased sediment chlorophyll, decreased organic material in the sediment, reduced heavy metals in surficial sediment and increased grain size. The amphipod Corophium salmonis, important in the food web for juvenile salmon and other fish species, recolonized the previously azoic location. At reference stations, C. salmonis density was similar to that observed in previous surveys two decades earlier. Our data strongly suggest that improvement or sediment conditions near the former sewage outfall was a major factor enabling colonization by C. salmonis.  相似文献   

油气田上方某些化探新指标与油气埋深的关系之研究（二）   总被引：3，自引：0，他引：3  

贾国相  姚锦琪 《矿产与地质》2001,15(3):185-191

试验研究了油气田上方壤中某些气元素，Ba及铁，铜等元素与油气藏的关系，结果显示这些元素对油气藏有明显的指示作用，可作为指标油气藏的存在及埋深的新指标。  相似文献   

Halogen elements as indicator of deep-seated orebodies in the Chadong As–Ag–Au deposit, western Guangdong, China     

Qian Zhang  Shuxun Shao  Jiayong Pan  Zhihao Liu 《Ore Geology Reviews》2001,18(3-4)

Halogen elements play an important role in the metallogenesis of metallic ore deposits and are involved in the whole process of remobilization, transport and precipitation of metallic elements. However, with the exception of fluorine, which, as a component of fluorite and mica minerals, can be occasionally concentrated in ores, Cl, Br and I are hard to enrich in the ores. Investigations have found that the halogen elements tend to diffuse toward country rocks with the development of hydrothermal alteration in the process of their involvement in metallogenesis, especially during the post-ore stage when extensive halogen diffusion halos over orebodies would be formed. Such halogen element diffusion halos over the Chadong As–Ag–Au deposit extend as widely as 200 m. The largest diffusion extent is for I and the diffusion halos of Br are most noticeable 50–130 m away from the orebodies. In areas of ore exposure and the strongly altered zone, the Cl, Br and I contents are close to those of the strata with a V-shaped distribution pattern in the periphery of the mining district. Comparatively speaking, in going away from the altered zone, the major metallic elements Au and Ag in the deposit tend to decrease suddenly to their normal contents in the strata. This variation feature of halogen elements can be used as geochemical indicators for exploring concealed orebodies at depth. In the Chadong ore deposit, halogen element anomalies can be used to predict concealed orebodies at the depth range of 0–200 m.  相似文献   

ENSO事件指数与指标研究   总被引：101，自引：4，他引：97  

李晓燕  翟盘茂 《气象学报》2000,58(1):102-109

根据 1 951～ 1 996年完整可靠的海面温度 ( SST)和南方涛动指数 ( SOI)资料 ,以中、东太平洋 SST异常变化为指标 ,定义了 ENSO事件 ,并在此基础上提出了以 ENSO事件过程海温距平累积值为指标的强度指数。此外 ,还定义了 ENSO事件的海 -气综合强度指数 ,并对 ENSO事件的长度、强度及爆发类型等进行了分类。  相似文献   

山东省可持续发展指标体系初步研究^*   总被引：152，自引：7，他引：152  

毛汉英 《地理研究》1996,15(4):16-23

山东省作为我国沿海地区经济发展较快的省区之一,无论从自然条件、经济发展的区域差异,还是从当前发展中所面临的人口、资源及环境问题,在全国均具有较强的代表性与典型性,可作为研究中国可持续发展的一个“缩影”.本文探讨了建立可持续发展指标体系的基本原则、山东省实施跨世纪可持续发展战略的主要思路,在此基础上提出了指标体系的基本框架及实际应用。  相似文献