Atmospheric oxygenation driven by unsteady growth of the continental sedimentary reservoir
Atmospheric oxygenation driven by unsteady growth of the continental sedimentary reservoir
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DOI：
10.1016/j.epsl.2016.12.012
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发表时间：
2017-02-15
影响因子：
5.3
通讯作者：
Peters, Shanan E.
中科院分区：
文献类型：
--
作者：
Husson, Jon M.;Peters, Shanan E.
在地球历史上，大气中的氧浓度一直在增加，从25亿年前的接近0，到现在的21%。大约23亿年前，Po(2)的最初上升需要氧合光合作用，但这一关键代谢途径的演变不足以将大气氧推向现代水平，直到大约20亿年后才得以维持。氧合光合作用的起源与地表环境中丰富的O-2之间的长期滞后对动物的进化有许多影响，但延迟的原因尚不清楚。这里我们表明，陆壳沉积的历史与大气氧浓度的历史是一致的。一个基于地壳净有机碳埋藏和氧化风化经验记录的正向模型预测，Po(2)有两次显著上升，被三个相对稳定的高原隔开，这种模式再现了主要的生物转变和基于代理的Po(2)记录。这些结果表明，地球表面环境的两阶段氧化作用，以及寒武纪爆发期间生命起源、后生动物的演化和随后的多样化之间的长期延迟，是由大陆积累和储存沉积有机碳的能力逐步转移造成的。因此，促进和抑制陆壳沉积物堆积的地球动力学机制对地球生命和环境的演化起到了一级控制作用。(C)2016爱思唯尔B.V.保留所有权利。
Atmospheric oxygen concentration has increased over Earth history, from similar to 0 before 2.5 billion years ago to its present-day concentration of 21%. The initial rise in pO(2) approximately 2.3 billion years ago required oxygenic photosynthesis, but the evolution of this key metabolic pathway was not sufficient to propel atmospheric oxygen to modern levels, which were not sustained until approximately two billion years later. The protracted lag between the origin of oxygenic photosynthesis and abundant O-2 in the surface environment has many implications for the evolution of animals, but the reasons for the delay remain unknown. Here we show that the history of sediment accumulation on continental crust covaries with the history of atmospheric oxygen concentration. A forward model based on the empirical record of net organic carbon burial and oxidative weathering of the crust predicts two significant rises in pO(2) separated by three comparatively stable plateaus, a pattern that reproduces major biological transitions and proxy-based pO(2) records. These results suggest that the two-phased oxygenation of Earth's surface environment, and the long delays between the origin of life, the evolution of metazoans, and their subsequent diversification during the Cambrian Explosion, was caused by step-wise shifts in the ability of the continents to accumulate and store sedimentary organic carbon. The geodynamic mechanisms that promote and inhibit sediment accumulation on continental crust have, therefore, exerted a first-order control on the evolution of Earth's life and environment. (C) 2016 Elsevier B.V. All rights reserved.