The rare earth element geochemistry of surface sediments in four transects in the South China Sea and its geological significance

2015 ◽  
Vol 74 (3) ◽  
pp. 2511-2522 ◽  
Author(s):  
Fangwen Liu ◽  
Li Miao ◽  
Guanqiang Cai ◽  
Wen Yan
Keyword(s):  
Rare Earth ◽  
South China Sea ◽  
Rare Earth Element ◽  
South China ◽  
Earth Element ◽  
Surface Sediments ◽  
The South China Sea ◽  
Element Geochemistry ◽  
Geological Significance ◽  
China Sea

scholarly journals Formation of Tubular Carbonates within the Seabed of the Northern South China Sea

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 768
Author(s):  
Yuedong Sun ◽  
Jörn Peckmann ◽  
Yu Hu ◽  
Xudong Wang ◽  
Shanggui Gong ◽  
...  
Keyword(s):  
Rare Earth ◽  
South China Sea ◽  
Rare Earth Element ◽  
South China ◽  
Earth Element ◽  
Anaerobic Oxidation Of Methane ◽  
Fluid Migration ◽  
Bottom Currents ◽  
China Sea ◽  
Carbonate Formation

A remarkable exposure of tubular authigenic carbonates was found on the seafloor in the Dongsha area of the South China Sea (SCS). The tubular carbonates, around 2–3 cm in diameter and usually less than 10 cm in length, represent broken fragments of once-larger pipes that now protrude from muddy sediments. The morphology, carbon and oxygen stable isotope compositions, and trace and rare earth element contents of the carbonates were analyzed to decipher the mode of carbonate formation. The tubular carbonates exhibit a dark brown coating of iron and manganese hydrous oxides, indicating prolonged exposure to oxic bottom waters. The carbonate content of the micritic pipes falls between 12.5 and 67.3 wt.% with an average of 42.0 wt.%, suggesting formation within the sediment. This inference is supported by trace and rare earth element patterns including a moderate enrichment of middle rare earth elements. Low δ13C values (as low as −50.3‰, Vienna Pee Dee Belemnite (VPDB)) suggest that carbonate precipitation was induced by the anaerobic oxidation of methane. The unusually positive δ18O values of the carbonates (as high as +5.3‰, VPDB) are believed to reflect the destabilization of locally abundant gas hydrate. Taken together, it is suggested that pipe formation was initiated by sediment-dwelling organisms, such as crustaceans or bivalves. The burrows subsequently acted as conduits for upward fluid migration. The lithification of the sediment directly surrounding the conduits and the partial filling of the conduits with carbonate cement resulted in the formation of tubular carbonates. Turbidity currents, sediment slumps, or the vigorous emission of fluids probably induced the fragmentation of tubular carbonates within the sediment. The carbonate fragments had been further subjected to winnowing by bottom currents. This study provides insight into the interaction of megafauna burrowing with fluid migration and carbonate formation at hydrocarbon seeps, highlighting the role of bottom currents and mass wasting on the formation of fragmented tubular carbonates.

DISTRIBUTION OF THE CLAY MINERALS IN SURFACE SEDIMENTS OF THE SOUTH CHINA SEA AND THEIR PROVENANCE

2010 ◽  
Vol 30 (4) ◽  
pp. 57-66 ◽  
Author(s):  
Qian GE ◽  
Fengyou CHU ◽  
Jingpu LIU ◽  
Yuansheng DU ◽  
Zuo XUE ◽  
...  
Keyword(s):  
South China Sea ◽  
Clay Minerals ◽  
South China ◽  
Surface Sediments ◽  
The South China Sea ◽  
The South ◽  
China Sea

Carbon isotopic record of foraminifers in surface sediments from the South China Sea and its significance

2005 ◽  
Vol 50 (2) ◽  
pp. 162-166 ◽  
Author(s):  
Xinrong Cheng ◽  
Pinxian Wang ◽  
Baoqi Huang ◽  
Chuanlian Liu ◽  
Zhimin Jian ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Surface Sediments ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Carbon Isotopic

Source and distribution of lead in the surface sediments from the South China Sea as derived from Pb isotopes

2010 ◽  
Vol 60 (11) ◽  
pp. 2144-2153 ◽  
Author(s):  
Laimin Zhu ◽  
Laodong Guo ◽  
Ziyou Gao ◽  
Guan Yin ◽  
Ben Lee ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Surface Sediments ◽  
The South China Sea ◽  
Pb Isotopes ◽  
The South ◽  
China Sea

Grain size and geochemistry of surface sediments in northwestern continental shelf of the South China Sea

2012 ◽  
Vol 70 (1) ◽  
pp. 363-380 ◽  
Author(s):  
Guanqiang Cai ◽  
Li Miao ◽  
Hongjun Chen ◽  
Guihua Sun ◽  
Jiaoqi Wu ◽  
...  
Keyword(s):  
Grain Size ◽  
South China Sea ◽  
Continental Shelf ◽  
South China ◽  
Surface Sediments ◽  
The South China Sea ◽  
The South ◽  
China Sea
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