气候变化领域集成服务门户(CCPortal): Fingerprinting local controls on the Neoproterozoic carbon cycle with the isotopic record of Cryogenian carbonates in the Panamint Range, California

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DOI	10.1016/j.epsl.2021.116956
	Fingerprinting local controls on the Neoproterozoic carbon cycle with the isotopic record of Cryogenian carbonates in the Panamint Range, California
	Nelson L.L.; Ahm A.-S.C.; Macdonald F.A.; Higgins J.A.; Smith E.F.
发表日期	2021
ISSN	0012821X
卷号	566
英文摘要	Neoproterozoic carbon isotope excursions are commonly attributed to changes in the global fraction of organic carbon burial associated with climate instability and/or oxygenation. Here we show that carbonate sediment deposited during the ca. 661 – <651 Ma Cryogenian non-glacial interlude between the Sturtian and Marinoan glaciations exhibit lateral offsets in carbonate-carbon isotope values from coeval units by as much as 10‰. Within the Thorndike submember of the Cryogenian succession in the Panamint Range, California, USA, carbonate-carbon isotope values can be linked to a laterally discontinuous dolomitization front: limestones exhibit δ13Ccarb values of ∼+4 to +9‰, whereas values of stratigraphically equivalent dolostones are consistently lower, between ∼-4 and +4‰. Field observations and analyses of clasts from the overlying Marinoan glacial diamictite show that the offset in δ13Ccarb values resulted from pre- to syn-Marinoan dolomitization. Further, δ44/40Ca and δ26Mg data indicate that this isotopic variability resulted from sediment-buffered diagenesis. We propose that extremely positive δ13Ccarb values record local primary productivity within restricted platform surface waters and/or oxygenated pore fluids and negative values reflect anaerobic remineralization of organic carbon within sediment pore waters. In this scenario, neither the original calcite/aragonite nor subsequent dolomite precipitates of the Thorndike submember record δ13Ccarb values that are representative of global Cryogenian seawater, and instead they archive the evolution of local dissolved inorganic carbon pools. © 2021 Elsevier B.V.
关键词	carbon isotopes chemostratigraphy Cryogenian Death Valley diagenesis dolomitization
英文关键词	Calcite; Carbonation; Glacial geology; Lime; Organic carbon; Sedimentology; Sediments; $+13$/C; California; Carbon isotopes; Chemostratigraphy; Cryogenian; Death Valley; Dolomitization; Isotope values; Marinoan; Neoproterozoic; Isotopes; carbon cycle; carbon isotope; carbonate; chemostratigraphy; diagenesis; dolomitization; isotopic composition; Proterozoic; California; Death Valley; Panamint Valley; United States
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203237
作者单位	Department of Earth and Planetary Sciences, Johns Hopkins University, Olin Hall, Baltimore, MD 21218, United States; Department of Geosciences, Princeton University, Guyot Hall, Princeton, NJ 08544, United States; Department of Earth Science, University of California Santa Barbara, Webb Hall, Santa Barbara, CA 93106, United States
推荐引用方式 GB/T 7714	Nelson L.L.,Ahm A.-S.C.,Macdonald F.A.,et al. Fingerprinting local controls on the Neoproterozoic carbon cycle with the isotopic record of Cryogenian carbonates in the Panamint Range, California[J],2021,566.
APA	Nelson L.L.,Ahm A.-S.C.,Macdonald F.A.,Higgins J.A.,&Smith E.F..(2021).Fingerprinting local controls on the Neoproterozoic carbon cycle with the isotopic record of Cryogenian carbonates in the Panamint Range, California.Earth and Planetary Science Letters,566.
MLA	Nelson L.L.,et al."Fingerprinting local controls on the Neoproterozoic carbon cycle with the isotopic record of Cryogenian carbonates in the Panamint Range, California".Earth and Planetary Science Letters 566(2021).