Oxygenation of Ediacaran Ocean recorded by iron isotopes

doi:10.1016/j.gca.2014.05.029

	Oxygenation of Ediacaran Ocean recorded by iron isotopes
	Fan, Haifeng 1; Zhu, Xiangkun ; Wen, Hanjie 1; Yan, Bin ; Li, Jin ; Feng, Lianjun 2
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2014
卷号	140 页码:80-94
ISSN号	0016-7037
DOI	10.1016/j.gca.2014.05.029
英文摘要	The increase in atmospheric oxygen during the late Neoproterozoic Era (ca. 800-542 Ma) may have stimulated the oxygenation of the deep oceans and the evolution of macroscopic multicellular organisms. However, the mechanism and magnitude of Neoproterozoic oxygenation remain uncertain. We present Fe isotopes, Fe species and other geochemical data for two sections of the Doushantuo Formation (ca. 635-551 Ma) deposited after the Nantuo glacial episode in the Yangtze Gorge area, South China. It is highlighted that highly positive delta Fe-56 values reflect a lower oxidation rate of Fe(II)(aq) under ferruginous conditions, and in turn near zero delta Fe-56 values indicate oxidizing conditions. Our study suggests that during the deposition of the bottom of Member II of the Doushantuo Formation the shallow seawater was oxic, but the deep water was characterized by ferruginous conditions, which is consistent with a redox chemical stratification model. Subsequent anoxic conditions under shallow seawater, represented by positive delta Fe-56 and negative delta C-13(carb) excursions, should be ascribed to the upwelling of Fe(II)(aq) and dissolved organic carbon (DOC)-rich anoxic deep seawater. The oxidation of Fe (II)(aq) and DOC-rich anoxic deep seawater upon mixing with oxic shallow water provides an innovative explanation for the well-known negative delta C-13(carb) excursions (ENC2) and positive delta Fe-56 excursions in the middle of Doushantuo Formation. Meanwhile, the upwelling Fe (II)(aq)- and DOC-rich anoxic deep seawater could increase photosynthetic activity. The balance between oxygen consumption and production was most important criteria for the oxygenation of Early Ediacaran Ocean and diversity of eukaryotic organisms. (C) 2014 Elsevier Ltd. All rights reserved.
学科主题	古生物学
WOS关键词	YANGTZE GORGES AREA ; FE ISOTOPE ; SOUTH CHINA ; DOUSHANTUO FORMATION ; AQUEOUS FE(II) ; ROCK RECORD ; REDOX STATE ; FRACTIONATION ; CONSTRAINTS ; EARTH
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000341925300006
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40553]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Geol, State Key Lab Continental Tecton & Dynam, Lab Isotope Geol, Beijing 100037, Peoples R China 2.Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550002, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Fan, Haifeng,Zhu, Xiangkun,Wen, Hanjie,et al. Oxygenation of Ediacaran Ocean recorded by iron isotopes[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2014,140:80-94.
APA	Fan, Haifeng,Zhu, Xiangkun,Wen, Hanjie,Yan, Bin,Li, Jin,&Feng, Lianjun.(2014).Oxygenation of Ediacaran Ocean recorded by iron isotopes.GEOCHIMICA ET COSMOCHIMICA ACTA,140,80-94.
MLA	Fan, Haifeng,et al."Oxygenation of Ediacaran Ocean recorded by iron isotopes".GEOCHIMICA ET COSMOCHIMICA ACTA 140(2014):80-94.