现代洋底成矿作用及它对石化矿床研究的启示
MODERN SUBMARINE MINERALIZATION AND ITS ENLIGHTENMENT FOR THE STUDY OF LITHIFIED ORE DEPOSITS
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摘要: 洋底大规模热水环流系和富金属堆积的存在是近年来人类重大发现之一,它们沿快速扩展的东太平洋中脊分布。作为金属来源的新生玄武质洋壳、由地壳拉伸出现的裂隙系和驱动海水环流的热源是矿床生成的三个必要条件。但此类生成物能否存留下来还取决于洋流是否发育,陆源沉积的补给程度等其他因素。综合起来,像红海,加利福尼亚湾等裂陷早期的伸展小洋盆和弧后盆地对此类矿床的寻找最为有利。现代洋底热液成矿作用的发现对陆上石化矿床研究的启示在于,只要条件具备,陆壳范围内也可以出现类似的成矿作用,华南和秦岭中、晚泥盆世的层控矿床即其实例。Abstract: The existence of the large-scale submarine hydrothermal water circulation system and metal-rich accumulation is one of the recent important discoveries of the mankind. They are distributed along the rapidly developing Eastern Pacific mid-ocean ridge. The newly formed basaltic oceanic crust as the metal source, the fissure system produced by crustal extension and the heat source driving the seawater circulation are three necessary conditions for the formation of ore deposits. But whether this kind of product can be preserved also depends on ther factors such as the development of ocean currents and the amount supplement of terrigenous sediments. To sum up, early-stage small oceanic basin’s and back-ar basins such as the Red Sea, the California Gul and other taphrogenies are most favorable for looking for such kind of mineral deposit. The enlighement of the discovery of modern submarine hydrothermal mneralizaon f the study of subaerial lithified ore deposis is that so long as conditins are available similar mineralization may occur within the realm of continental crust. The examples are the Middle and Late Devonian stratabound deposits in South China and the Qinling Mountains.