scholarly journals Rare earth elements and carbon isotope geochemistry of the Doushantuo Formation in South China: Implication for middle Ediacaran shallow marine redox conditions

2012 ◽  
Vol 57 (16) ◽  
pp. 1998-2006 ◽  
Author(s):  
ChuanMing Zhou ◽  
ShaoYong Jiang ◽  
ShuHai Xiao ◽  
Zhe Chen ◽  
XunLai Yuan
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Carbon Isotope ◽  
South China ◽  
Isotope Geochemistry ◽  
Redox Conditions ◽  
Doushantuo Formation ◽  
Shallow Marine

Organic Carbon Isotope Geochemistry of the Neoproterozoic Doushantuo Formation, South China

2010 ◽  
Vol 80 (5) ◽  
pp. 670-683 ◽  
Author(s):  
GUO Qingjun ◽  
LIU Congqiang ◽  
Harald STRAUSS ◽  
Tatiana GOLDBERG ◽  
ZHU Maoyan ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Isotope ◽  
South China ◽  
Isotope Geochemistry ◽  
Doushantuo Formation ◽  
Organic Carbon Isotope

scholarly journals Predominantly Ferruginous Conditions in South China during the Marinoan Glaciation: Insight from REE Geochemistry of the Syn-glacial Dolostone from the Nantuo Formation in Guizhou Province, China

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 348 ◽  
Author(s):  
Shangyi Gu ◽  
Yong Fu ◽  
Jianxi Long
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
South China ◽  
Climate Models ◽  
Shape Index ◽  
Redox Conditions ◽  
Guizhou Province ◽  
Apparent Lack ◽  
Anoxic Waters ◽  
Significant Enrichment

The Neoproterozoic Era witnessed two low-latitude glaciations, which exerted a fundamental influence on ocean–atmosphere redox conditions and biogeochemical cycling. Climate models and palaeobiological evidence support the belief that open waters provided oases for life that survived snowball Earth glaciations, yet independent geochemical evidence for marine redox conditions during the Marinoan glaciation remains scarce owing to the apparent lack of primary marine precipitates. In this study, we explore variability in rare earth elements (REEs) and trace metal concentrations in dolostone samples of the Cryogenian Nantuo Formation taken from a drill core in South China. Petrological evidence suggests that the dolostone in the Nantuo Formation was formed in near-shore waters. All the examined dolostone samples featured significant enrichment of manganese (345–10,890 ppm, average 3488 ppm) and middle rare earth elements (MREEs) (Bell Shape Index: 1.43–2.16, average 1.76) after being normalized to Post-Archean Australian Shale (PAAS). Most dolostone samples showed slight to no negative Ce anomalies (Ce*/Ce 0.53–1.30, average 0.95), as well as positive Eu anomalies (Eu*/Eu 1.77–3.28, average 1.95). This finding suggests that the dolostone samples were deposited from suboxic to iron-enriched and anoxic waters. Although total REE concentrations correlated positively with Th concentrations in dolostone samples, MREE-enriched PAAS-normalized patterns preclude the conclusion that REEs were largely introduced by terrestrial contamination. Rather, we interpret the correlation between REEs and Th as an indication that the former were transported by colloids and nanoparticles in meltwaters. Taken together, we propose that anoxic and ferruginous water columns dominated in South China during the Marinoan glaciation with a thin oxic/suboxic layer restricted to coastal waters. The extreme anoxic and ferruginous conditions prevailing in the Cryogenian would have provided a baseline for subsequent transient Ediacaran ocean oxygenation and life evolution.

Rare earth elements and yttrium in ferromanganese deposits from the South China Sea: distribution, composition and resource considerations

2018 ◽  
Vol 37 (7) ◽  
pp. 41-54 ◽  
Author(s):  
Yi Zhong ◽  
Zhong Chen ◽  
Francisco Javier Gonzalez ◽  
Xufeng Zheng ◽  
Gang Li ◽  
...  
Keyword(s):  
Rare Earth ◽  
South China Sea ◽  
Rare Earth Elements ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Distribution Composition ◽  
Ferromanganese Deposits
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