scholarly journals Reactive Iron and Iron‐Bound Organic Carbon in Surface Sediments of the River‐Dominated Bohai Sea (China) Versus the Southern Yellow Sea

2019 ◽  
Vol 124 (1) ◽  
pp. 79-98 ◽  
Author(s):  
Di Wang ◽  
Mao‐Xu Zhu ◽  
Gui‐Peng Yang ◽  
Wei‐Wei Ma
Keyword(s):  
Organic Carbon ◽  
Yellow Sea ◽  
Bohai Sea ◽  
Surface Sediments ◽  
Southern Yellow Sea ◽  
Reactive Iron ◽  
The Southern Yellow Sea

scholarly journals Dominant Role of Sea Level on the Sedimentary Environmental Evolution in the Bohai and Yellow Seas Over the Last 1 Million Years

2021 ◽  
Vol 9 ◽  
Author(s):  
Xuefa Shi ◽  
Zhengquan Yao ◽  
Jianxing Liu ◽  
Shuqing Qiao ◽  
Yanguang Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Yellow Sea ◽  
Bohai Sea ◽  
Dominant Role ◽  
Sedimentary Environment ◽  
Middle Pleistocene ◽  
Southern Yellow Sea ◽  
Sea Level Fluctuations ◽  
The Southern Yellow Sea

Transgression and regression deposits from the shallow continental margin provide information on orbital-scale variations in sea level, climate change, and local tectonics. In this study, we conduct a high-resolution chronological and sedimentological analysis of a 125-m core (NHH01) drilled in the southern Yellow Sea. We developed a high-resolution age model at the orbital timescale over the last ∼1 Myr by the astronomical tuning of the sediment grain size. Sedimentological analysis and environmental proxies reveal that the study area is characterized by cyclic alternations of neritic and littoral/fluvial deposits controlled by glacial–interglacial sea-level changes. These results confirm the earlier assumption that sea-level fluctuations play a dominant role in the sedimentary architecture of the southern Yellow Sea. Moreover, only low-frequency sea-level fluctuations (∼100 kyr) were preserved in the NHH01 sequence; however, additional high-frequency (∼40 kyr) sea-level variations were also present in the sediments of the shallower Bohai Sea. Despite the large spatial difference, this finding implies that the sedimentary environment in the eastern marginal seas of China had been influenced by the sea level as a whole over the last 1 Myr. The comparison of the sedimentary environment with other cores from the Bohai Sea, Yellow Sea, and coastal region, as well as records from Indonesia and Japan, reveals that a consistent initiation of large-scale marine transgression occurred at ∼0.8–1 Ma. This phenomenon was likely caused by the long duration of glacio-eustatic high sea-level stands following the Middle Pleistocene transition, which is characterized by a shift in glacial cycles from 40 to 100 kyr.

scholarly journals Methoxylated and hydroxylated polybrominated diphenyl ethers in surface sediments from the southern Yellow Sea: spatial distribution and potential producers

2015 ◽  
Vol 12 (3) ◽  
pp. 366 ◽  
Author(s):  
Ying Fan ◽  
Jing Lan ◽  
Jiaokai Wang ◽  
Zongshan Zhao ◽  
Meixun Zhao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Yellow Sea ◽  
Polybrominated Diphenyl Ethers ◽  
Surface Sediments ◽  
Dry Weight ◽  
Marine Phytoplankton ◽  
Southern Yellow Sea ◽  
Terrestrial Organic Matter ◽  
The Southern Yellow Sea ◽  
Diphenyl Ethers

Environmental context Methoxylated and hydroxylated polybrominated diphenyl ethers are of increasing concern owing to their global distribution and potential ecological risks. We investigated the spatial distribution and sources of these brominated compounds in surface sediments from the southern Yellow Sea, China. The results suggest that marine phytoplankton may be the potential producers of these compounds, thereby providing new insights into their occurrence and provenance in marine environments. Abstract Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have recently caused worldwide concern; however, there have been very limited studies on their presence in marine sediments. In the present study, MeO-PBDEs, OH-PBDEs and phytoplankton biomarkers were determined in surface sediments from the southern Yellow Sea. MeO-PBDEs and OH-PBDEs are ubiquitous in southern Yellow Sea sediments, with total contents ranging from 43.0 to 571.4pgg–1 dry weight. High contents of these compounds mainly concentrated in the central southern Yellow Sea basin, and their spatial distributions generally presented a seaward-increasing trend. By comparing with total organic carbon and terrestrial organic matter contributions in sediments, these compounds were inferred to originate mainly from marine production rather than from terrigenous inputs. Statistical analysis shows that there are significant correlations between MeO-PBDEs, OH-PBDEs and phytoplankton biomarkers, indicating that MeO-PBDEs and OH-PBDEs are mainly natural compounds, and the phytoplankton are likely to be their potential producers in the southern Yellow Sea, especially for dinosterol.

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