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对部分矿体基建探矿前后矿体主要特征及资源储量对比,探讨矿体控制程度和控制网度问题。原勘探工作对矿体的控制程度很高,矿山生产探矿可适当放稀间距,减少工程量,降低生产成本。 相似文献
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普朗岩体外接触带,与热液活动密切相关,受构造裂隙控制,大脉状产出,可寻找大脉型矿体。而北部向深部寻找与斑岩有关的矿体;西南部则可寻找角岩化带矿体。 相似文献
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Dmitry M. Miljutin Maria A. MiljutinaPedro Martínez Arbizu Joëlle Galéron 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(8):885-897
We investigated nematode assemblages inhabiting the 26-year-old track created by experimental deep-sea mining of polymetallic nodules, and two adjacent, undisturbed sites, one with nodules and one without nodules. The aim was to compare density, assemblage structure, and diversity indices in order to assess the process of recovery of the nematode assemblage inhabiting the disturbed site. This experimental dredging was conducted in 1978 by the Ocean Minerals Company (USA) in the area of a French mining claim in the Clarion-Clipperton Fracture Zone (Tropical Eastern Pacific) at a depth of about 5000 m. The nematode assemblage had not returned its initial state 26 years after the experimental dredging: the total nematode density and biomass within the dredging track were significantly lower than outside the track; the biodiversity indices showed significantly lower nematode diversity within the track; and the structure of the nematode assemblage within the track differed significantly from those in the two undisturbed sites outside the track. However, there were no significant differences in the mean body volumes of adult nematodes and adult-juvenile ratios between the track and reference sites. Parameters such as the rate of sediment restoration (which depends on local hydrological conditions) and the degree and character of the disturbance appeared to be of considerable importance for the recovery rate of the deep-sea nematode assemblages and their ability to recolonize disturbed areas. The rates of recolonization and recovery may vary widely in different deep-sea regions. 相似文献
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马厂箐斑岩体与铜、钼、金等多金属矿成矿关系密切.斑岩体微量元素与稀土元素显示斑岩体物质来源具有壳幔混合特征. 相似文献
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Cd, Cu, Fe, Mn, Ni, Pb, Zn concentration in the organs (muscle, gonads, mantle, gills, digestive gland, kidney) of mussel Modiolus modiolus was studied. Mussels were collected from shelf upwelling sites of Kuril Is. Sea of Okhotsk (104 and 85 m) and, for comparison, coastal high contaminated and clean sites (Peter the Great Bay, Sea of Japan). It was found that mussels from shelf upwelling regions accumulated unusually high Cd concentration in studied organs, excepting digestive gland. Shelf mussels have evolved passive adaptation to elevated level of ambient heavy metals (distribution of heavy metal load between all organs, especially, muscle). In contrast, mussels from high contaminated sites have evolved active adaptation (strong regulation of metal concentration in the organs at the maximal permissible concentration due to increased kidney function). We supported that under natural condition, passive adaptation of aquatic organisms to increased ambient metal level have been evolved only under constant low-water temperature. 相似文献
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将中国地区划分为东西两部分详细地讨论了中国地区体波走时层析成像研究现状。总结了中国地区三维速度结构的一些特征:地震波速度存在明显的横向不均匀性,甚至在1100km左右深入还保留了这一特点,浅部层面地震波速度图像与地表已知的地质特征有较好的相关性,速度图像与地震活动性有一定的对应关系,岩石层厚度及地壳厚度的起伏状况等;最后分析了目前中国地区体波走时层析成像研究工作的特点并提出了一种可能的发展趋势。 相似文献
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