气候变化领域集成服务门户(CCPortal): In situ S-isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling

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DOI	10.1111/gbi.12393
	In situ S-isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling
	Nabhan S.; Marin-Carbonne J.; Mason P.R.D.; Heubeck C.
发表日期	2020
ISSN	14724677
起始页码	426
结束页码	444
卷号	18 期号:4
英文摘要	Sulfate minerals are rare in the Archean rock record and largely restricted to the occurrence of barite (BaSO4). The origin of this barite remains controversially debated. The mass-independent fractionation of sulfur isotopes in these and other Archean sedimentary rocks suggests that photolysis of volcanic aerosols in an oxygen-poor atmosphere played an important role in their formation. Here, we report on the multiple sulfur isotopic composition of sedimentary anhydrite in the ca. 3.22 Ga Moodies Group of the Barberton Greenstone Belt, southern Africa. Anhydrite occurs, together with barite and pyrite, in regionally traceable beds that formed in fluvial settings. Variable abundances of barite versus anhydrite reflect changes in sulfate enrichment by evaporitic concentration across orders of magnitude in an arid, nearshore terrestrial environment, periodically replenished by influxes of seawater. The multiple S-isotope compositions of anhydrite and pyrite are consistent with microbial sulfate reduction. S-isotope signatures in barite suggest an additional oxidative sulfate source probably derived from continental weathering of sulfide possibly enhanced by microbial sulfur oxidation. Although depositional environments of Moodies sulfate minerals differ strongly from marine barite deposits, their sulfur isotopic composition is similar and most likely reflects a primary isotopic signature. The data indicate that a constant input of small portions of oxidized sulfur from the continents into the ocean may have contributed to the observed long-term increase in Δ33Ssulfate values through the Paleoarchean. © 2020 John Wiley & Sons Ltd
关键词	anhydrite barite concentration (composition)isotopic composition oxidation photolysis seawater sedimentary rock sulfate sulfide sulfur cycle sulfur isotope Barberton Greenstone Belt
语种	英语
来源机构	Geobiology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/133178
推荐引用方式 GB/T 7714	Nabhan S.,Marin-Carbonne J.,Mason P.R.D.,et al. In situ S-isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling[J]. Geobiology,2020,18(4).
APA	Nabhan S.,Marin-Carbonne J.,Mason P.R.D.,&Heubeck C..(2020).In situ S-isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling.,18(4).
MLA	Nabhan S.,et al."In situ S-isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling".18.4(2020).