Formation of supercontinents linked to increases in atmospheric oxygen
Formation of supercontinents linked to increases in atmospheric oxygen
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DOI：
10.1038/ngeo259
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发表时间：
2008-08-01
影响因子：
18.3
通讯作者：
Allen, Charlotte M.
中科院分区：
文献类型：
--
作者：
Campbell, Ian H.;Allen, Charlotte M.
地球大气中的氧气浓度从太古时代可以忽略不计的水平上升到今天的21%左右。这种增加被认为是分六个步骤发生的，分别是2.65亿年前、2.45亿年前、1.8亿年前、6亿年前、3亿年前和4亿年前，第七次可能发生在12亿年前。在这里，我们表明这些步骤的时间与地球陆地块合并成超级大陆有关。我们认为形成超级大陆所需的大陆-大陆碰撞产生了超级山脉。在我们的假设中，这些超级山脉被迅速侵蚀，并向海洋释放了大量的营养物质，如铁和磷，导致藻类和蓝藻的爆发，因此光合作用和光合作用产生的O-2显著增加。在这些时期，增强的沉积作用促进了大部分有机碳和黄铁矿的埋藏，从而阻止了它们与游离氧的反应，导致大气中氧气的持续增加。
Atmospheric oxygen concentrations in the Earth's atmosphere rose from negligible levels in the Archaean Era to about 21% in the present day. This increase is thought to have occurred in six steps, 2.65, 2.45, 1.8, 0.6, 0.3 and 0.04 billion years ago, with a possible seventh event identified at 1.2 billion years ago. Here we show that the timing of these steps correlates with the amalgamation of Earth's land masses into supercontinents. We suggest that the continent-continent collisions required to form supercontinents produced supermountains. In our scenario, these supermountains eroded quickly and released large amounts of nutrients such as iron and phosphorus into the oceans, leading to an explosion of algae and cyanobacteria, and thus a marked increase in photosynthesis, and the photosynthetic production of O-2. Enhanced sedimentation during these periods promoted the burial of a high fraction of organic carbon and pyrite, thus preventing their reaction with free oxygen, and leading to sustained increases in atmospheric oxygen.