Johnston David T, Wing Boswell A, Farquhar James, Kaufman Alan J, Strauss Harald, Lyons Timothy W, Kah Linda C, Canfield Donald E
Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20742, USA.
Science. 2005 Dec 2;310(5753):1477-9. doi: 10.1126/science.1117824.
The environmental expression of sulfur compound disproportionation has been placed between 640 and 1050 million years ago (Ma) and linked to increases in atmospheric oxygen. These arguments have their basis in temporal changes in the magnitude of 34S/32S fractionations between sulfate and sulfide. Here, we present a Proterozoic seawater sulfate isotope record that includes the less abundant sulfur isotope 33S. These measurements imply that sulfur compound disproportionation was an active part of the sulfur cycle by 1300 Ma and that progressive Earth surface oxygenation may have characterized the Mesoproterozoic.
硫化合物歧化作用的环境表现被认为发生在6.4亿至10.5亿年前,并与大气中氧气的增加有关。这些观点基于硫酸盐和硫化物之间34S/32S分馏程度的时间变化。在此,我们展示了一条元古代海水硫酸盐同位素记录,其中包括含量较少的硫同位素33S。这些测量结果表明,到13亿年前硫化合物歧化作用就是硫循环的一个活跃部分,且地球表面的渐进氧化作用可能是中元古代的特征。