Geochemistry of Ediacaran cap dolostones across the Yangtze Platform, South China: implications for diagenetic modification and seawater chemistry in the aftermath of the Marinoan glaciation

doi:10.1144/jgs2016-145

	Geochemistry of Ediacaran cap dolostones across the Yangtze Platform, South China: implications for diagenetic modification and seawater chemistry in the aftermath of the Marinoan glaciation
	Hohl, Simon V.1,2; Becker, Harry 1; Jiang, Shao-Yong 2,3; Ling, Hong-Fei 2; Guo, Qingjun 4; Struck, Ulrich 5
刊名	JOURNAL OF THE GEOLOGICAL SOCIETY
	2017-09-01
卷号	174 期号:5 页码:893-912
ISSN号	0016-7649
DOI	10.1144/jgs2016-145
通讯作者	Hohl, Simon V.(shohl@zedat.fu-berlin.de)
英文摘要	Cap dolostones of the Ediacaran Doushantuo Formation (Yangtze Platform, South China) from various palaeo-water depths were studied to evaluate the extent of their diagenetic alteration and to assess temporal and spatial variations of seawater chemistry in the aftermath of the Marinoan glaciation. Diagenetic fluid overprint is common in cap dolostone lithologies. However, the mobilization of trace elements and the modification of Sr and O isotopic compositions are variable and were controlled by multiple stages of fluid overprint. The highest Sr-87/Sr-86 ratios (up to 0.7246) occur in cap dolostones from the palaeo-slope environment at the Huanglianba section, whereas cap dolostones deposited in platform settings and in one of the distal basinal settings reveal Sr-87/Sr-86 ratios close to the proposed late Neoproterozoic seawater composition (0.7077). Shale-normalized REE + Y patterns of carbonate leachates display enrichments of heavy over light REE and superchondritic Y/Ho ratios, typical of seawater. However, Y/Ho ratios in the cap dolostones are always lower than modern seawater values, which is interpreted to reflect dilution of the seawater signal by continent-derived meltwater influx during deglaciation. Negative Ce anomalies in carbonate leachates from platform and slope sections suggest that oxidized conditions existed in shallow marine environments shortly after the Marinoan glaciation, whereas positive or no resolvable Ce anomalies in basin settings indicate that the latter remained anoxic. Redox stratification of the Yangtze margin at the beginning of the Ediacaran is further supported by the relative enrichment of redox-sensitive trace metals in basinal sections. These data may indicate moderately anoxic (less than 10 mu M dissolved O-2) and presumably manganous conditions during the deposition of cap dolostones in the deeper realms of the Yangtze basin.
资助项目	German Research Foundation (DFG Research Group FOR 736)[Be 1820/4-2] ; German Research Foundation (DFG Research Group FOR 736)[Star 356/42] ; National Science Foundation of China[41230102] ; National Science Foundation of China[41173008] ; National Science Foundation of China[41473018] ; Major State Basic Research 973 Program of China[2013CB835000]
WOS关键词	RARE-EARTH-ELEMENTS ; NEOPROTEROZOIC DOUSHANTUO FORMATION ; MULTICOMPONENT CARBONATE SYSTEM ; PLASMA-MASS SPECTROMETRY ; TRACE-ELEMENTS ; OCEAN OXYGENATION ; GORGES AREA ; ISOTOPE STRATIGRAPHY ; HYDROTHERMAL ORIGIN ; CHEMICAL DIAGENESIS
WOS研究方向	Geology
语种	英语
出版者	GEOLOGICAL SOC PUBL HOUSE
WOS记录号	WOS:000412699500009
资助机构	German Research Foundation (DFG Research Group FOR 736) ; National Science Foundation of China ; Major State Basic Research 973 Program of China
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/62375]
专题	中国科学院地理科学与资源研究所
通讯作者	Hohl, Simon V.
作者单位	1.Free Univ Berlin, Inst Geol Wissensch, Malteserstr 74-100, D-12249 Berlin, Germany 2.Nanjing Univ, Dept Earth Sci, State Key Lab Mineral Deposits Res, 163 Xianlin Ave, Nanjing 210023, Jiangsu, Peoples R China 3.China Univ Geosci, Fac Earth Resources, State Key Lab Geol Proc & Mineral Resources, Wuhan 430074, Hubei, Peoples R China 4.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Ctr Environm Remediat, Beijing 100101, Peoples R China 5.Museum Nat Kunde Berlin, Leibniz Inst Evolut & Biodivers Sci, Invalidenstr 43, D-10115 Berlin, Germany
推荐引用方式 GB/T 7714	Hohl, Simon V.,Becker, Harry,Jiang, Shao-Yong,et al. Geochemistry of Ediacaran cap dolostones across the Yangtze Platform, South China: implications for diagenetic modification and seawater chemistry in the aftermath of the Marinoan glaciation[J]. JOURNAL OF THE GEOLOGICAL SOCIETY,2017,174(5):893-912.
APA	Hohl, Simon V.,Becker, Harry,Jiang, Shao-Yong,Ling, Hong-Fei,Guo, Qingjun,&Struck, Ulrich.(2017).Geochemistry of Ediacaran cap dolostones across the Yangtze Platform, South China: implications for diagenetic modification and seawater chemistry in the aftermath of the Marinoan glaciation.JOURNAL OF THE GEOLOGICAL SOCIETY,174(5),893-912.
MLA	Hohl, Simon V.,et al."Geochemistry of Ediacaran cap dolostones across the Yangtze Platform, South China: implications for diagenetic modification and seawater chemistry in the aftermath of the Marinoan glaciation".JOURNAL OF THE GEOLOGICAL SOCIETY 174.5(2017):893-912.