Kump Lee R, Barley Mark E
NASA Astrobiology Institute and Department of Geosciences, Pennsylvania State University, 535 Deike Building, University Park, Pennsylvania 16802, USA.
Nature. 2007 Aug 30;448(7157):1033-6. doi: 10.1038/nature06058.
The hypothesis that the establishment of a permanently oxygenated atmosphere at the Archaean-Proterozoic transition (approximately 2.5 billion years ago) occurred when oxygen-producing cyanobacteria evolved is contradicted by biomarker evidence for their presence in rocks 200 million years older. To sustain vanishingly low oxygen levels despite near-modern rates of oxygen production from approximately 2.7-2.5 billion years ago thus requires that oxygen sinks must have been much larger than they are now. Here we propose that the rise of atmospheric oxygen occurred because the predominant sink for oxygen in the Archaean era-enhanced submarine volcanism-was abruptly and permanently diminished during the Archaean-Proterozoic transition. Observations are consistent with the corollary that subaerial volcanism only became widespread after a major tectonic episode of continental stabilization at the beginning of the Proterozoic. Submarine volcanoes are more reducing than subaerial volcanoes, so a shift from predominantly submarine to a mix of subaerial and submarine volcanism more similar to that observed today would have reduced the overall sink for oxygen and led to the rise of atmospheric oxygen.
关于在太古代-元古代过渡时期（约25亿年前），当产氧蓝细菌进化时出现了永久氧化大气的假说，与2亿年更古老岩石中存在蓝细菌的生物标志物证据相矛盾。因此，尽管从大约27亿年前到25亿年前氧气产生速率接近现代水平，但要维持极低的氧气水平，就需要氧气汇比现在大得多。我们在此提出，大气氧气的增加是因为太古代时期氧气的主要汇——增强的海底火山活动——在太古代-元古代过渡时期突然且永久地减少了。观察结果与这样一个推论一致，即陆地火山活动直到元古代初期大陆稳定的一次重大构造事件之后才广泛出现。海底火山比陆地火山更具还原性，所以从主要是海底火山活动转变为类似于今天观察到的陆地和海底火山活动的混合，会减少氧气的总体汇，并导致大气氧气增加。
