Evolution of the precambrian earth system through progressive oxidation of surface environments

前寒武纪地球系统通过表面环境的渐进氧化而演化

• 批准号: 342384-2007
• 负责人: Bekker, Andrey
• 金额: $ 1.72万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=482481
• 关键词: Evolution; precambrian; earth; system; through

The redox states of the atmosphere and ocean changed dramatically in the Precambrian. The rise of atmospheric oxygen has been constrained, based on geological and geochemical evidence, to have occurred between ca. 2.45 and 2.32 Ga, during the assembly of the first supercontinent and a series of ca. 2.48-2.42 Ga mantle plume breakouts. This sequence of events led to several perturbations in Earth's surface environment, including global glaciations followed by extreme greenhouse conditions, carbon isotope excursions in seawater composition, the rise of seawater sulfate content, and changes in the ocean redox state. Since these events affected surface environments globally, they have implications not only for the understanding the history and stability of the Earth System, but also for correlation between Paleoproterozoic basins that otherwise lack high precision geochronologic constraints.

在前寒武纪，大气和海洋的氧化还原状态发生了巨大的变化。 根据地质学和地球化学证据，大气中氧气的上升被限制在大约200万年之间。2.45和2.32Ga，在第一超大陆的组装和一系列的ca. 2.48-2.42 Ga地幔柱爆发。 这一系列事件导致了地球表面环境的几次扰动，包括全球冰川随后的极端温室条件，海水成分的碳同位素偏移，海水硫酸盐含量的上升以及海洋氧化还原状态的变化。由于这些事件影响了全球的地表环境，它们不仅对理解地球系统的历史和稳定性具有重要意义，而且对缺乏高精度地质年代学约束的古元古代盆地之间的对比也具有重要意义。