| DOI: | 10.1038/s41561-020-0601-6
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| 论文题名: | A seawater-sulfate origin for early Earth’s volcanic sulfur |
| 作者: | Ohmoto H.
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| 刊名: | Nature Geoscience
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| ISSN: | 17520894
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| 出版年: | 2020
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| 卷: | 13, 期:8 | | 起始页码: | 576
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| 结束页码: | 583
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| 语种: | 英语
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| 英文关键词: | Archean
; data interpretation
; early Earth
; hydrothermal deposit
; isotopic composition
; isotopic fractionation
; photolysis
; pyrite
; reaction kinetics
; seawater
; sedimentary rock
; sulfate
; sulfur
; sulfur cycle
; tectonic structure
; thermodynamics
; troposphere
; volcanic rock
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| 英文摘要: | Mass-independent fractionation of sulfur isotopes (MIF-S)—as recorded primarily in pre-2.5 billion years ago (Ga) sedimentary rocks—has been interpreted as evidence of photolysis of volcanic SO2 in an anoxic troposphere. Here, I present thermodynamic and kinetic calculations, combined with data on the geology, mineralogy and chemical and isotopic compositions of modern and Archaean (3.8–2.5 Ga) aged volcanic samples from different tectonic settings, to examine early Earth’s sulfur cycle. Based partly on the similarities between submarine hydrothermal deposits and arc volcanic rocks in pyrite (FeS2) abundances and sulfur isotopic compositions (for example, the presence of both positive and negative δ34S values), I conclude that degassing of sulfur (mostly as SO2) into the atmosphere has been carried out primarily by subaerial eruptions of oxidized, arc-like magmas since at least 3.5 Ga. The generation of volcanic SO2 requires plate tectonics and the involvement of sulfate-rich seawater, which requires large exposed lands and an oxygenated atmosphere. I propose that the MIF-S signatures in sedimentary rocks were created by ultraviolet photochemical reactions between SO2 from explosive volcanic eruptions and O2 in the stratosphere, above an oxygen-rich troposphere, or by high-temperature reactions between organic compounds and sulfate in the oceans. © 2020, The Author(s), under exclusive licence to Springer Nature Limited. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/169655
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| Appears in Collections: | 气候变化与战略
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作者单位: | Department of Geosciences, The Pennsylvania State University, University Park, PA, United States
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| Recommended Citation: | |
Ohmoto H.. A seawater-sulfate origin for early Earth’s volcanic sulfur[J]. Nature Geoscience,2020-01-01,13(8)
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