The surface sediment types and their rare earth element characteristics from the continental shelf of the northern south China sea

2014 ◽  
Vol 88 ◽  
pp. 185-202 ◽  
Author(s):  
Shuhong Wang ◽  
Nan Zhang ◽  
Han Chen ◽  
Liang Li ◽  
Wen Yan
Keyword(s):  
Rare Earth ◽  
South China Sea ◽  
Continental Shelf ◽  
Rare Earth Element ◽  
South China ◽  
Surface Sediment ◽  
Earth Element ◽  
Northern South China Sea ◽  
China Sea ◽  
Sediment Types

scholarly journals Rare Earth Element Distributions in Continental Shelf Sediment, Northern South China Sea

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3540
Author(s):  
Qian Ge ◽  
Z. George Xue ◽  
Fengyou Chu
Keyword(s):  
Rare Earth ◽  
South China Sea ◽  
Continental Shelf ◽  
South China ◽  
Northern South China Sea ◽  
Hainan Island ◽  
Sediment Provenance ◽  
Adjacent Area ◽  
China Sea ◽  
Qiongzhou Strait

A total of 388 surface sediment samples taken from the northern South China Sea (SCS) continental shelf were analyzed to characterize the signature of their rare earth elements (REEs). The average REEs concentration was 192.94 μg/g, with a maximum of 349.07 μg/g, and a minimum of 32.97 μg/g. The chondrite-normalized REEs pattern exhibits a remarkably light REEs accumulation, a relatively flat heavy REEs pattern, and a negative Eu anomaly. We subdivided the study area into three zones using the characteristics of REEs and statistical characteristics. Zone I: continental shelf off western Guangdong Province. Here, the sediment provenance is mainly river-derived from the Pearl River, Taiwanese rivers, and those in the adjacent area. Zone II: Qiongzhou Strait and Leizhou Peninsula. Here, the sediment provenance consists of the Qiongzhou Strait and the Hainan Island. Zone III: Hainan Island and SCS slope sediments are dominated. The REEs compositions are mainly controlled by source rock properties, hydrodynamic conditions, and an intensity of chemical weathering. We reconstructed the sediment dispersal and transport route using the REEs compositions, grain size, and other geochemical characteristics throughout the study area.

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.

scholarly journals Propagation characteristics of near-inertial waves along the continental shelf in the wake of the 2008 Typhoon Hagupit in the northern South China Sea

2018 ◽  
Vol 94 (4) ◽  
pp. 1293-1311 ◽  
Author(s):  
Wenxiang Ding ◽  
Chujin Liang ◽  
Guanghong Liao ◽  
Junde Li ◽  
Feilong Lin ◽  
...  
Keyword(s):  
South China Sea ◽  
Continental Shelf ◽  
South China ◽  
Northern South China Sea ◽  
Propagation Characteristics ◽  
Inertial Waves ◽  
China Sea
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