The sulphur isotopic evolution of Neoarchean and Paleoproterozoic seawater - clues for reconstructing Earth's oxygenation and sulphur metabolism

新太古代和古元古代海水的硫同位素演化——重建地球氧合和硫代谢的线索

• 批准号: 31620366
• 负责人: Professor Dr. Harald Strauß
• 金额: --
• 依托单位: Institut für Geologie und Paläontologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/31620366?language=en
• 关键词: sulphur; isotopic; evolution; Neoarchean; Paleoproterozoic

It is commonly accepted that Earth s atmosphere and ocean have experienced a substantial increase in oxygen abundance in the early Paleoproterozoic (the Great Oxidation Event - G.O.E.). It has further been demonstrated that changes in atmospheric composition and the timing of this G.O.E. can be constrained by multiple sulphur isotope measurements (32S, 33S, 34S, 36S), recording mass independent sulphur isotope fractionation. Among other aspects, the increase in atmospheric oxygen must have been paralleled by an increase in oceanic sulphate abundance. This in turn should have stimulated microbial sulphur metabolism. The sulphur isotopic composition of seawater sulphate provides an excellent proxy for changes within the global sulphur cycle. Specifically, microbial turnover of oceanic sulphate, a process associated with substantial isotope fractionation, is recorded by an increase in (34SSO4 In the absence of respective data, a temporal record for the sulphur isotopic composition of seawater sulphate through the Neoarchean-Paleoproterozoic transition will be obtained. For this, trace sulphate in carbonates from the respective South African succession will be studied.

人们普遍认为，地球大气层和海洋在古元古代早期经历了氧丰度的大幅增加（大氧化事件 - G.O.E.）。进一步证明，大气成分的变化和 G.O.E. 发生的时间。可以通过多个硫同位素测量（32S、33S、34S、36S）来限制，记录与质量无关的硫同位素分馏。除其他方面外，大气中氧气的增加必定与海洋硫酸盐丰度的增加同时发生。这反过来又刺激了微生物的硫代谢。海水硫酸盐的硫同位素组成为全球硫循环的变化提供了极好的替代指标。具体来说，海洋硫酸盐的微生物周转是一个与大量同位素分馏相关的过程，通过 (34SSO4) 的增加来记录。在缺乏相应数据的情况下，通过新太古代-古元古代过渡时期海水硫酸盐硫同位素组成的时间记录将是为此，将对南非各系列碳酸盐中的微量硫酸盐进行研究。