Sulfur Chemistry and Sulfate Reducing Bacteria of Archean Oceans

已发表的岩石样品硫同位素数据分析 为太古代沉积物的研究提供了一个新的模式 大气-海洋-生物圈系统：海洋， 大约38 - 32亿年前，已经富含硫酸盐， 硫酸盐浓度约为目前水平的1/3，为30- 比现代海洋高40 oC，并支持非常高的活动 硫酸盐还原菌的世界范围内;早太古代 大气中已经含有相当数量的游离氧。 拟议研究的目的是测试上述内容， 其他模式的太古代大气-海洋-生物圈， 研究硫碳铁化学和微观 硫、碳、氧同位素尺度变化 澳大利亚Warrawoona组沉积物的成分; Isua集团，格陵兰岛;和无花果树集团，南非，使用 最先进的稳定同位素比质谱仪 用激光烧蚀系统

Analyses of the published sulfur isotopic data on bulk rock samples of Archean sediments have led to a new model for the Archean atmosphere-ocean-biosphere system: the oceans, as far back as about 3.8-3.2 billion years ago, were already sulfate rich with a sulfate concentration of about 1/3 of the present level, were 30- 40 oC warmer than modern oceans, and supported a very high activity of sulfate reducing bacteria world wide; the early Archean atmosphere already contained appreciable amounts of free oxygen. The objective of the proposed research is to test the above and other models for the Archean atmosphere-ocean-biosphere by examining the sulfur-carbon-iron chemistry and the microscopic- scale variation in the sulfur, carbon and oxygen isotopic compositions of sediments from the Warrawoona Group, Australia; the Isua Group, Greenland; and the Fig Tree Group, South Africa, using a state-of-the-art stable isotope ratio mass spectrometer equipped with a laser ablation system.