Variance of Bottom Water Temperature at the Continental Margin of the Northern South China Sea

2021 ◽  
Vol 126 (2) ◽  
Author(s):  
Peng‐Qi Huang ◽  
Xian‐Rong Cen ◽  
Shuang‐Xi Guo ◽  
Yuan‐Zheng Lu ◽  
Sheng‐Qi Zhou ◽  
...  
Keyword(s):  
South China Sea ◽  
Water Temperature ◽  
Continental Margin ◽  
South China ◽  
Bottom Water ◽  
Northern South China Sea ◽  
Bottom Water Temperature ◽  
China Sea

scholarly journals Widespread hydrothermal vents and associated volcanism record prolonged Cenozoic magmatism in the South China Sea

2021 ◽  
Author(s):  
Fang Zhao ◽  
Christian Berndt ◽  
Tiago M. Alves ◽  
Shaohong Xia ◽  
Lin Li ◽  
...  
Keyword(s):  
South China Sea ◽  
Continental Margin ◽  
South China ◽  
Hydrothermal Vents ◽  
Northern South China Sea ◽  
Contact Metamorphism ◽  
Magnetic Data ◽  
Geochemical Data ◽  
Time Interval ◽  
China Sea

The continental margin of the northern South China Sea is considered to be a magma-poor rifted margin. This work uses new seismic, bathymetric, gravity, and magnetic data to reveal how extensively magmatic processes have reshaped the latter continental margin. Widespread hydrothermal vent complexes and magmatic edifices such as volcanoes, igneous sills, lava flows, and associated domes are confirmed in the broader area of the northern South China Sea. Newly identified hydrothermal vents have crater- and mound-shaped surface expressions, and occur chiefly above igneous sills and volcanic edifices. Detailed stratigraphic analyses of volcanoes and hydrothermal vents suggest that magmatic activity took place in discrete phases between the early Miocene and the Quaternary. Importantly, the occurrence of hydrothermal vents close to the present seafloor, when accompanied by shallow igneous sills, suggest that fluid seepage is still active, well after main phases of volcanism previously documented in the literature. After combining geophysical and geochemical data, this study postulates that the extensive post-rift magmatism in the northern South China Sea is linked to the effect of a mantle plume over a long time interval. We propose that prolonged magmatism resulted in contact metamorphism in carbon-rich sediments, producing large amounts of hydrothermal fluid along the northern South China Sea. Similar processes are expected in parts of magma-poor margins in association with CO2/CH4 and heat flow release into sea water and underlying strata.

scholarly journals Palaeoenvironment and Its Control on the Formation of Miocene Marine Source Rocks in the Qiongdongnan Basin, Northern South China Sea

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Wenhao Li ◽  
Zhihuan Zhang ◽  
Weiming Wang ◽  
Shuangfang Lu ◽  
Youchuan Li ◽  
...  
Keyword(s):  
South China Sea ◽  
Continental Margin ◽  
South China ◽  
Northern South China Sea ◽  
Qiongdongnan Basin ◽  
Source Rocks ◽  
Hydrocarbon Potential ◽  
China Sea ◽  
Marine Source ◽  
Main Factors

The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter.

scholarly journals Phytoplankton growth and physiological responses to a plume front in the northern South China Sea

2017 ◽  
Author(s):  
Qian P. Li ◽  
Weiwen Zhou ◽  
Yinchao Chen ◽  
Zhengchao Wu
Keyword(s):  
South China Sea ◽  
South China ◽  
Bottom Water ◽  
Frontal Zone ◽  
Northern South China Sea ◽  
River Estuary ◽  
Phytoplankton Growth ◽  
Frontal System ◽  
China Sea ◽  
Plume Water

Abstract. Due to a strong river discharge during April–June 2016, a persistent salinity front, with freshwater flushing seaward on the surface but seawater moving landward at the bottom, was formed in the coastal waters west of the Pearl River Estuary (PRE) over the Northern South China Sea (NSCS) shelf. Hydrographic measurements revealed that the salinity front was influenced by both river plume and coastal upwelling. Shipboard nutrient-enrichment experiments with size-fractionation chlorophyll-a measurements were performed on both sides of the front as well as the front zone to diagnose the spatial variations of phytoplankton physiology across the frontal system. We also assessed the size-fractionated responses of phytoplankton to the treatment of plume water at the frontal zone and the seaside of the front. Biological impact of vertical mixing or upwelling was further examined by the response of surface phytoplankton to the addition of local bottom water. Our results suggested that there was a large variation of phytoplankton physiology on the seaside of the front driven by dynamic nutrient fluxes, although P-limitation was prevailing on the shore-side of the front and at the frontal zone. The spreading of plume water at the frontal zone would directly improve the growth of micro-phytoplankton, while nano- and pico-phytoplankton growths could become saturated at high percentages of plume water. Also, the mixing of bottom water would stimulate the growth of surface phytoplankton on both sides of the front by altering the surface N / P ratio closer to the Redfield stoichiometry. In summary, phytoplankton growth and physiology could be profoundly influenced by physical dynamics of the frontal system during the spring–summer of 2016.

Cenozoic subsidence characteristics and evolution at a hyper-extended continental margin: Revealed by 3D high-resolution seismic data from the Baiyun Sag, northern South China Sea

2021 ◽  
Author(s):  
Penggao Fang ◽  
Weiwei Ding ◽  
Yanghui Zhao
Keyword(s):  
South China Sea ◽  
Continental Crust ◽  
Continental Margin ◽  
South China ◽  
Northern South China Sea ◽  
Tectonic Subsidence ◽  
China Sea ◽  
Baiyun Sag ◽  
Passive Margins ◽  
Seismic Sections

<p>The hyper-extended continental crust in the passive margins, which recording the extensional processes in relation with the breakup of continental crust and lithosphere as well as the onset of seafloor spreading, have been widely recognized and studied at present-day rifted margins. The Baiyun Sag (BS) represents one of the hyper-extended continental marginal basins with a sharply thinned continental crust from 25 km to 7 km over a ~ 50 km distance along the Northern South China Sea, which experienced syn-rift to post-rift during the Cenozoic. Although the Cenozoic infill of the BS has been extensively described, newly acquired 3D seismic profiles revealed a thick succession (up to 10 km) with thicken syn-rift but relatively thin post-rift strata particularly well imaged in the central part. The imaged succession is controlled by the interaction between well-developed detachment systems and depth-dependent stretching, resulting in different and complex subsidence architecture. Attempts had been made to quantify the subsidence in the BS, while most studies were only carried out in a limit set with one or few 2D seismic sections and generally focused on the post-rift subsidence but ignoring that in the syn-rift stage. As result, we investigate the interaction between spatial-temporal distributions of tectonic subsidence from continent break-up to post-rift and the evolution of hyper-extended rift systems along the relatively young age passive margins.</p><p>In this presentation we analyze the vertical and horizontal motions of tectonic subsidence and sedimentary processes with integrated high-quality multi-channel seismic profile grid data (~30 seismic sections). This study enables us to 1) interpret the main unconformities and analyze the depth conversion of the BS, 2) reconstruct the tectonic subsidence from syn-rift to post-rift, 3) provide a 3D subsidence analysis unravelling the temporal and spatial architecture of Cenozoic infill of the BS. The main objectives of this contribution is to discuss the possible mechanisms accounting for the origin and subsidence at the BS, reveal its interrelationships with magmatic activities, and explore the style of rift to post-rift subsidence pattern at a hyper-extended continental margin.</p>

scholarly journals Structural inversion in the northern South China Sea continental margin and its tectonic implications

2017 ◽  
Vol 28 (6) ◽  
pp. 891-922
Author(s):  
Chin-Da Huang ◽  
Tung-Yi Lee ◽  
Ching-Hua Lo ◽  
Sun-Lin Chung ◽  
Jong-Chang Wu ◽  
...  
Keyword(s):  
South China Sea ◽  
Continental Margin ◽  
South China ◽  
Northern South China Sea ◽  
China Sea ◽  
Tectonic Implications ◽  
Structural Inversion

Temporal variability in bottom water structures of the continental slope in the northern South China Sea

2021 ◽  
Author(s):  
Ling Qu ◽  
Yuan‐Zheng Lu ◽  
Xian‐Rong Cen ◽  
Shuang‐Xi Guo ◽  
Peng‐Qi Huang ◽  
...  
Keyword(s):  
South China Sea ◽  
Continental Slope ◽  
South China ◽  
Temporal Variability ◽  
Bottom Water ◽  
Northern South China Sea ◽  
China Sea
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