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DOI	10.1016/j.palaeo.2020.109966
	Manganese-rich deposits in the Mesoproterozoic Gaoyuzhuang Formation (ca. 1.58 Ga); North China Platform: Genesis and paleoenvironmental implications
	Fang H.; Tang D.; Shi X.; Lechte M.; Shang M.; Zhou X.; Yu W.
发表日期	2020
ISSN	0031-0182
卷号	559
英文摘要	The redox state of the surface ocean–atmosphere system has long been considered to have been remarkably stable during the mid-Proterozoic (ca. 1800–800 Ma); however, there is a growing body of evidence that supports dynamic redox fluctuations during this time. Sedimentary Mn enrichment in the ca. 1.58 Ga Gaoyuzhuang Formation (North China) may represent an important archive of mid-Proterozoic paleoenvironmental conditions. We present a sedimentological and geochemical study of the Mn-rich carbonate succession in the Gaoyuzhuang Formation in order to further elucidate the genesis and paleoredox implications of this Mn-rich deposit. We suggest that the Mn-rich interval was deposited in deep subtidal environments close to storm wave-base. Manganese occurs either as millimeter-sized Mn-oxide (pyrolusite) nodules or as Mn-rich dolomite, which features moderately positive I/(Ca+Mg) values (0.5–1.7 μmol/mol) and Ce anomalies (1.1–1.2). In contrast, the underlying and overlying carbonates that lack Mn-oxides were deposited in a shallow subtidal environment above fair-weather wave-base. They have relatively low I/(Ca+Mg) values (<0.5 μmol/mol) and negligible Ce anomalies (average Ce/Ce* = 1.05 ± 0.05). Thus, we suggest that during the deposition of the highly Mn-enriched strata shallow seawaters were sufficiently oxygenated to drive active redox cycling of Mn, and that this interval was bracketed by less-oxygenated shallow marine conditions. Given the widespread distribution of the Mn-rich deposits across the North China platform, we argue that the Mn-rich deposits may have recorded a basin-scale, pulsed oxygenation. The association of this interval with enigmatic macrofossils in the overlying strata of the upper Gaoyuzhuang Formation warrants further investigation of the potential link between pulsed episodes of oxygenation and evolutionary advances in the early Mesoproterozoic. © 2020 Elsevier B.V.
英文关键词	Eukaryote; Manganese cycling; Oxygenation; Precambrian; Redox
语种	英语
scopus关键词	calcium; concentration (composition); manganese; oxygenation; paleoenvironment; Proterozoic; subtidal environment; succession; China; North China Block; Eukaryota
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150332
作者单位	State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing, 100083, China; School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing, 100083, China; Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing, 100083, China; Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montréal, QC H3A 0E8, Canada; Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100029, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan, 430074, China
推荐引用方式 GB/T 7714	Fang H.,Tang D.,Shi X.,et al. Manganese-rich deposits in the Mesoproterozoic Gaoyuzhuang Formation (ca. 1.58 Ga); North China Platform: Genesis and paleoenvironmental implications[J],2020,559.
APA	Fang H..,Tang D..,Shi X..,Lechte M..,Shang M..,...&Yu W..(2020).Manganese-rich deposits in the Mesoproterozoic Gaoyuzhuang Formation (ca. 1.58 Ga); North China Platform: Genesis and paleoenvironmental implications.Palaeogeography, Palaeoclimatology, Palaeoecology,559.
MLA	Fang H.,et al."Manganese-rich deposits in the Mesoproterozoic Gaoyuzhuang Formation (ca. 1.58 Ga); North China Platform: Genesis and paleoenvironmental implications".Palaeogeography, Palaeoclimatology, Palaeoecology 559(2020).