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41.
在对世界著名的维特瓦特斯兰德矿床成因讨论中,存在着2种主要观点:热液交代说和砂积成因说。后者经过补充、修改演变为改造砂矿成因说。最近,加拿大地质学家Reimer和Mossman代表后一种观点撰文,概括了近年来争论的焦点,回答了热液成因论者的质疑。 相似文献
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Modeling multiscale heterogeneity and aquifer interconnectivity 总被引:2,自引:0,他引:2
A number of methods involving indicator geostatistics were combined in a methodology for characterizing and modeling multiscale heterogeneity. The methodology circumvents sources of bias common in data from borehole logs. We applied this methodology to the complex heterogeneity within a regional system of buried valley aquifers, which occurs in the western glaciated plains of North America and includes the Spiritwood Aquifer. The region is conceptualized as having a hierarchical organization with three facies assemblage types (large-scale heterogeneity) and two facies types within each assemblage (small-scale heterogeneity). We statistically characterized the sedimentary architecture at both scales, formulated indicator correlation models from those characterizations, and used the models to simulate the architecture in a multiscale realization. We focused on the interconnectivity of units creating higher-permeability pathways. Higher-permeability pathways span the realization even though the proportion of higher-permeability facies is less than the percolation threshold. Thus, geologic structures as represented in the indicator correlation models create interconnectivity above that which would occur if the higher-permeability facies were randomly placed. This amount of interconnection among higher-permeability facies within the multiscale realization is consistent with that suggested in prior hydraulic and geochemical studies of the regional system. 相似文献
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H- and K-band moderate-resolution and 4 μm high-resolution spectra have been obtained for FMM 362, a bright star in the Quintuplet Cluster near the Galactic center. The spectral features in these bands closely match those of the Pistol Star, a luminous blue variable and one of the most luminous stars known. The new spectra and previously obtained photometry imply a very high luminosity for FMM 362, L>/=106 L middle dot in circle, and a temperature of 10,000-13,000 K. Based on its luminosity, temperature, photometric variability, and similarities to the Pistol Star, we conclude that FMM 362 is a luminous blue variable. 相似文献
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地下水中砷元素的形成及其控制因素 总被引:3,自引:0,他引:3
研究了长江中下游地区和吉林省地区地下水中砷元素形成和主要控制因素及其分布规律。结果表明,地下水中砷主要以H_3ASO_3、H_2AsO_4~-、HA_3O_4~(2-)等形式存在。它的形成和分布与含水介质及其上覆土层的砷含量、地下水的酸碱度、地下水的迳流条件、氧化还原环境、有机物质及铁锰等有密切的关系。 相似文献
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为了调查浅部地层和确定雷达技术性能及其适用性,我们在四个测点上进行了地质雷达测量。所有测量均使用一套基本模拟记录系统和80MHz的单一天线,所有测点都有较好的地层控制,以利于评价雷达的效果,四个测点的介质成分和范围都有明显差别,在俄州西南部冰冻区的高地农场上的测点,富含粘土的土壤覆盖了较浅的基岩,雷达剖面上的一些土壤层位能够辨认出来,但仅到1.4m深,在俄西南部的砂砾采石场上绘制出超过4m深的不饱 相似文献
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