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最近几年对深成岩进行了许多岩石和地球化学方面的工作,尤其在法国是如此,这些研究结果导致我们重新考虑铀在花岗岩类中的分布机理。在法国产有两种铀矿化,一种是发育在中央地块西部和阿摩坎地块中与酸性花岗岩类(浅色花岗岩)伴生并产于花岗岩内部的矿化,另一种是和浅色花岗岩无联系的中央地块东部类型的矿化。与浅色花岗岩共生的铀矿化产于遭受巴罗式变质的硅铝壳增厚带之中。由于不含钍的晶质铀矿微晶体的出现,铀的地球化学本底有明显的增加,而矿脉严格地产于浅色花岗岩中。与此相反,在中央地块东部,被不太厚的泥盆-迪南盖层不整合复盖的前海西基底中,看不出晶质铀矿和哪一种花岗岩有更密切的关系,这里的晶质铀矿一般含钍多,矿脉更多的是受基底和盖层联合控制。在较厚的硅铝壳中,“富铀”花岗岩的概念依然是有效的。在厚硅铝壳中,来自深熔作用的矿液和沉淀出脉状矿化的矿液之间有一定关系。相反,这种概念在正常厚度的硅铝壳中就没有用了。在正常厚度硅铝壳中,地球化学本底预先增高和脉状矿化这两种现象之间好象没有关系,或关系不大。最后我们把这种概念推广到变质程度不同于前者的地区,并以纳米比亚的罗辛矿床和美国的斯波坎矿床为例。
In recent years, many petrological and geochemical work has been done on deep plutons, especially in France, and these findings led us to reconsider the distribution of uranium in granite classes. There are two types of uranium mineralization in France, one is mineralization associated with acidic granites (light-colored granites) and produced in the interior of granite in the western central block and the Amokan block, and the other is Light-colored granite is associated with the eastern type of mineralization of the Central Massif. The uranium mineralization symbiotic with the light-colored granite is in the thickening zone of the Si-Al shell subjected to Barlow metamorphism. Due to the appearance of thorium-free crystalline uranium microcrystals, there is a clear increase in the background of uranium geochemistry and the veins are strictly produced in light-colored granites. In contrast, in the former Hercynian basement in the eastern part of the Central Massif that was not covered by a thicker Devonian-Devonian caprock, there is no closer correlation between the crystalline uranium and which granite , Where the crystalline uranium generally contain more thorium, veins more by the joint control of the substrate and the cover. The concept of “uranium rich” granite remains effective in thicker Si-Al shells. In thick-Si aluminum casings, there is a relationship between the mineral deposits from the deep melting and the precipitated mineralized ore fluids. On the contrary, this concept is of no use in the normal thickness of the aluminum-silicon shell. In the normal thickness of the Si-Al shell, there appears to be no relationship between the two phenomena of pre-elevation of geochemical background and vein mineralization, or not. Finally, we extend this notion to areas that differ from the former in terms of metamorphism, taking the Rohingin deposit in Namibia and the Spokane deposit in the United States as an example.