海洋地质与第四纪地质2025，Vol.45Issue(1)：68-78,11.DOI:10.16562/j.cnki.0256-1492.2023092101
南海东北部末次冰盛期以来有机碳通量变化及驱动机制
Variation of organic carbon flux in the northeastern South China Sea since the Last Glacial Maximum and the driving mechanism
摘要
Abstract
To investigate the variations of organic carbon flux and their driving mechanisms since the Last Glacial Maximum(LGM),we examined The variation of total organic carbon(TOC),total nitrogen(TN),and stable organic carbon isotope(δ13CTOC)in core MD18-3569 collected offshore of southwestern Taiwan in the northeastern part of the South China Sea.Results indicate that the values of TOC and TN ranged from 0.13%to 0.40%and 0.017%to 0.061%,which exhibit a characteristic pattern of higher values during glacial periods and lower values during the Holocene.The values of C/N ratio and δ13CTOC ranged from 5.90 to 8.58 and-25.15‰～-22.61‰,which indicate a mixed marine-terrigenous source for organic carbon at MD18-3569.Marine organic carbon mainly originates from marine primary producers,primarily marine algae,while terrigenous organic carbon primarily comes from rivers in southwestern Taiwan.According to the marine-terrigenous end-member model calculations,the values of marine organic carbon flux and terrigenous organic carbon flux ranged 0.01～0.12 g·cm-2·ka-1 and 0.05～0.21 g·cm-2·ka-1,respectively.The marine organic flux had generally been decreased since the LGM.The high marine organic carbon flux during the glacial period might be due to stronger East Asian winter monsoon that enhanced the vertical mixing of seawater,which increased the nutrient content and consequently the marine primary productivity in the upper seawater.In contrast,terrigenous organic carbon flux showed an increasing trend since the LGM duo likely to the impact of precipitation from the East Asian summer monsoon on the rivers in the southwestern Taiwan.Sea level changes since the LGM also played a certain role in this process by the shifting of river mouth.Therefore,the East Asian monsoon system resulted in significant influence on the burial of organic carbon in the northeastern South China Sea since the LGM.关键词
有机碳/东亚季风/末次冰盛期/海平面变化/南海东北部Key words
organic carbon/East Asian monsoon/Last Glacial Maximum/sea level change/northeastern South China Sea分类
海洋科学引用本文复制引用
高健祺,周辛全,刘传联..南海东北部末次冰盛期以来有机碳通量变化及驱动机制[J].海洋地质与第四纪地质,2025,45(1):68-78,11.基金项目
国家自然科学基金重点项目"用南海沉积物中长链烯酮重建中新世大气二氧化碳浓度变化"(41930536) （41930536）
海洋碳汇与生物地球化学过程基础科学中心项目(42188102) （42188102）
国家自然科学基金委青年科学基金项目"南亚降雨量轨道尺度变化机制研究"(42206060) （42206060）
