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加利福尼亚州旧金山地区的122个侏罗纪-白垩纪岩石样品,以及日本西南部四万十地区24个白垩纪岩石样品的分析结果表明,与枕状玄武岩伴生的燧石及伴生岩石富含可能来源于热液活动的Fe和Mn。旧金山地区岩石中陆源质的、玄武岩质的、热液和生物成因的端员组分的分析结果表明,热液喷溢使岩石样品富集Fe和Mn,并对硅质岩石的形成起了重要作用。热液组分和元素如Fe、Mn、Ni、Zn、Y和Pb的TiO_2标准化值的垂向变化表明有这种可能性,即旧金山地区层状燧石都是在某些活动洋中脊上或附近的热液场中经过30Ma以上的时间沉积而成的,是加到北美大陆上的洋壳残块。另一方面,根据区域产状扣热液元素的TiO_2标准化值的垂向变化来判断,旧金山地区岩石相是在半深海环境中(如边缘盆地和弧内盆地中)沉积的。
122 Jurassic-Cretaceous rock samples in San Francisco, California, and 24 Cretaceous rock samples from 40,000 in southwestern Japan show that the chert associated with pillow-basalt basalts may be derived from hydrothermal fluids Active Fe and Mn. The analysis of terrestrial, basaltic, hydrothermal and biogenic endmember components in the rocks of the San Francisco area shows that hydrothermal spurting enriches rock samples with Fe and Mn and is important for the formation of siliceous rocks effect. The vertical variation of the normalized values of TiO 2 for hydrothermal constituents and elements such as Fe, Mn, Ni, Zn, Y and Pb suggests the possibility that the stratiform flint in the San Francisco area is on some active mid-ocean ridges or Near the hydrothermal field after 30Ma deposited over time, is added to the North American continent on the oceanic crust. On the other hand, judging from the vertical variation of normalized TiO 2 values of buckling hydrothermal elements in the area, the lithofacies in the San Francisco area were deposited in semi-deep sea environments, such as marginal and intracurrent basins.