DOI: 10.1038/s41561-019-0492-6
论文题名: Great Oxidation and Lomagundi events linked by deep cycling and enhanced degassing of carbon
作者: Eguchi J. ; Seales J. ; Dasgupta R.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2020
卷: 13, 期: 1 起始页码: 71
结束页码: 76
语种: 英语
英文关键词: carbon cycle
; carbon flux
; carbon isotope
; degassing
; deposition
; isotopic ratio
; marine environment
; oxidation
; oxygen
; photosynthesis
英文摘要: For approximately the first 2 billion years of the Earth’s history, atmospheric oxygen levels were extremely low. It was not until at least half a billion years after the evolution of oxygenic photosynthesis, perhaps as early as 3 billion years ago, that oxygen rose to appreciable levels during the Great Oxidation Event. Shortly after, marine carbonates underwent a large positive spike in carbon isotope ratios known as the Lomagundi event. The mechanisms responsible for the Great Oxidation and Lomagundi events remain debated. Using a carbon–oxygen box model that tracks the Earth’s surface and interior carbon fluxes and reservoirs, while also tracking carbon isotopes and atmospheric oxygen levels, we demonstrate that about 2.5 billion years ago a tectonic transition that resulted in increased volcanic CO2 emissions could have led to increased deposition of both carbonates and organic carbon (organic C) via enhanced weathering and nutrient delivery to oceans. Increased burial of carbonates and organic C would have allowed the accumulation of atmospheric oxygen while also increasing the delivery of carbon to subduction zones. Coupled with preferential release of carbonates at arc volcanoes and deep recycling of organic C to ocean island volcanoes, we find that such a tectonic transition can simultaneously explain the Great Oxidation and Lomagundi events without any change in the fraction of carbon buried as organic C relative to carbonate, which is often invoked to explain carbon isotope excursions. © 2019, The Author(s), under exclusive licence to Springer Nature Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/169586
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX, United States; Department of Earth and Planetary Sciences, University of California, Riverside, CA, United States
Recommended Citation:
Eguchi J.,Seales J.,Dasgupta R.. Great Oxidation and Lomagundi events linked by deep cycling and enhanced degassing of carbon[J]. Nature Geoscience,2020-01-01,13(1)