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共收集到现代海底热液沉积物的 1 2 6 4个硫同位素数据 ,结合我们对冲绳海槽Jade热液区和大西洋中脊TAG热液区中表层热液沉积物的硫同位素研究成果 ,对比分析了不同地质 -构造环境中海底热液沉积物的硫同位素组成特征及其硫源问题 .结果表明 :(1 )现代海底热液沉积物中硫化物的硫同位素组成集中分布在 1‰～9‰之间 ,均值为 4 5‰ (n =1 0 42 ) ,而硫酸盐矿物的硫同位素组成主要分布在 1 9‰～ 2 4‰之间 ,均值为 2 1 3‰ (n =2 1 7) ;(2 )无论在洋中脊还是在弧后盆地扩张中心 ,无沉积物覆盖热液活动区中热液沉积物与有沉积物覆盖热液活动区相比 ,其硫同位素组成的分布范围相对狭窄 ;(3)各热液活动区中硫化物硫同位素组成的不同 ,反映出各自硫源的差异性 .无沉积物覆盖洋中脊中热液成因硫化物的硫主要来自玄武岩 ,部分来自海水 ,是玄武岩和海水硫酸盐中硫不同比例混合的结果 ,而在弧后盆地和有沉积物覆盖的洋中脊 ,除了火山岩以外 ,沉积物和有机质均可能为热液硫化物的形成提供硫 ;(4)现代海底热液沉积物硫同位素组成的变化和硫源的不同可能归因于海底热液体系中流体物理化学性质的变化、岩浆演化和构造 -地质背景的不同 .
We collected a total of 1264 sulfur isotope data from modern seafloor hydrothermal sediments and compared the results of sulfur isotope studies on surface hydrothermal sediments in the TAG hydrothermal zone in the Jade hydrothermal zone and the mid-Atlantic ridge of the Okinawa Trough. The characteristics of sulfur isotope composition and sulfur source of hydrothermal sediments in different geological-tectonic environments are analyzed.The results show that: (1) Sulfur isotope compositions of sulfide in modern seafloor hydrothermal sediments are concentrated in the range of 1 ‰ to 9 ‰, with a mean of 45 ‰ (n = 1 0 42). The sulfur isotopic compositions of sulphate minerals are mainly distributed between 19 ‰ and 24 ‰, with an average of 2 1 3 ‰ (n = 2 1 7 ). (2) The distribution range of sulfur isotope composition of hydrothermal sediments in the non-sediment-covered hydrothermal activity area compared with the areas covered by sediments in both the mid-ocean ridge and the backarc basin, (3) The difference of sulfide sulfur isotope composition in each hydrothermal activity zone reflects the difference of their own sulfur sources.The sediments cover sulfur in the mid-ocean ridge of hydrothermal origin mainly from basalts and partly from Sea water is basaltic and seawater sulphate sulfur With the same proportion of mixed results, both sediments and organic matter may provide sulfur for hydrothermal sulfide formation in both the backarc basin and the mid-ocean ridges covered by sediments, except for volcanic rocks; (4) modern submarine hydrothermal sediments The variation of sulfur isotopic composition and sulfur source may be attributed to the change of physicochemical properties of fluid in seafloor hydrothermal system, and the difference of magmatic evolution and tectonic-geological background.