气候变化领域集成服务门户(CCPortal): Triple oxygen isotope insight into terrestrial pyrite oxidation

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DOI	10.1073/pnas.1917518117
	Triple oxygen isotope insight into terrestrial pyrite oxidation
	Hemingway J.D.; Olson H.; Turchyn A.V.; Tipper E.T.; Bickle M.J.; Johnston D.T.
发表日期	2020
ISSN	0027-8424
起始页码	7650
结束页码	7657
卷号	117 期号:14
英文摘要	The mass-independent minor oxygen isotope compositions (∆0 17O) of atmospheric O2 and CO2 are primarily regulated by their relative partial pressures, pO2/pCO2. Pyrite oxidation during chemical weathering on land consumes O2 and generates sulfate that is carried to the ocean by rivers. The ∆0 17O values of marine sulfate deposits have thus been proposed to quantitatively track ancient atmospheric conditions. This proxy assumes direct O2 incorporation into terrestrial pyrite oxidation-derived sulfate, but a mechanistic understanding of pyrite oxidation-including oxygen sources-in weathering environments remains elusive. To address this issue, we present sulfate source estimates and ∆0 17O measurements from modern rivers transecting the Annapurna Himalaya, Nepal. Sulfate in high-elevation headwaters is quantitatively sourced by pyrite oxidation, but resulting ∆0 17O values imply no direct tropospheric O2 incorporation. Rather, our results necessitate incorporation of oxygen atoms from alternative, 17O-enriched sources such as reactive oxygen species. Sulfate ∆0 17O decreases significantly when moving into warm, low-elevation tributaries draining the same bedrock lithology. We interpret this to reflect overprinting of the pyrite oxidation-derived ∆0 17O anomaly by microbial sulfate reduction and reoxidation, consistent with previously described major sulfur and oxygen isotope relationships. The geologic application of sulfate ∆0 17O as a proxy for past pO2/pCO2 should consider both 1) alternative oxygen sources during pyrite oxidation and 2) secondary overprinting by microbial recycling. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Atmospheric O2; Chemical weathering; Himalayas; Sulfur cycle; ∆0 17O
语种	英语
scopus关键词	oxygen; pyrite; reactive oxygen metabolite; Article; atmosphere; chemical analysis; chemical reaction kinetics; concentration (parameter); geology; isotope analysis; Nepal; oxidation; precipitation; priority journal; river; seasonal variation; troposphere; weathering
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159026
作者单位	Hemingway, J.D., Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, United States; Olson, H., Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, United States; Turchyn, A.V., Department of Earth Sciences, Cambridge University, Cambridge, CB2 1TN, United Kingdom; Tipper, E.T., Department of Earth Sciences, Cambridge University, Cambridge, CB2 1TN, United Kingdom; Bickle, M.J., Department of Earth Sciences, Cambridge University, Cambridge, CB2 1TN, United Kingdom; Johnston, D.T., Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, United States
推荐引用方式 GB/T 7714	Hemingway J.D.,Olson H.,Turchyn A.V.,et al. Triple oxygen isotope insight into terrestrial pyrite oxidation[J],2020,117(14).
APA	Hemingway J.D.,Olson H.,Turchyn A.V.,Tipper E.T.,Bickle M.J.,&Johnston D.T..(2020).Triple oxygen isotope insight into terrestrial pyrite oxidation.Proceedings of the National Academy of Sciences of the United States of America,117(14).
MLA	Hemingway J.D.,et al."Triple oxygen isotope insight into terrestrial pyrite oxidation".Proceedings of the National Academy of Sciences of the United States of America 117.14(2020).