黄河口附近海域沉积物中碳氮元素地球化学特征及有机质来源研究

本文调查分析了黄河口附近海域沉积物中碳氮元素地球化学特征及有机质来源研究。发现黄河口附近海域沉积物TOC、TN含量、C/N、δ13C以及δ15N分别为（0.40±0.19）%、（0.049±0.018）%、7.92±1.48、（-23.94±0.69）‰、（7.06±0.72）‰。其中TOC随着输送距离增加显著下降（P < 0.05），δ13C沿着输送距离增加极显著上升（P < 0.01）。黄河口附近海域沉积物有机质来源可分为陆源、河口源、海源3种来源。其含量分别为（44.6±6.5）%、（6.5±5.5）%、（48.9±6.1）%。陆源有机质含量随着输送距离增加显著下降，海源有机质含量随着输送距离增加显著上升（P < 0.05）。研究区域陆源有机碳埋藏速率为171~214 t/（km2·a），约20%左右黄河输送陆源有机碳埋藏在黄河口附近海域。黄河输送不仅影响了河口及周边海域有机质来源组成，还促进了陆源有机质在河口区域的埋藏。

Carbon,nitrogen geochemical character and organic matter source study in the coastal sediment of Yellow River Estuary

Carbon, nitrogen geochemical character and the sources of organic matter were studied in the coastal sediment of Yellow River Estuary.The concentration of total organic carbon (TOC) and total nitrogen (TN), C/N, δ13C, δ15N was (0.40±0.19)%、(0.049±0.018)%、7.92±1.48、(-23.94±0.69)‰、(7.06±0.72)‰ respectively.The concentration of TOC decreased significantly as distance from the river mouth increased offshore(P < 0.05), whereas δ13C increased very significantly(P < 0.01).In the study area, the organic matters in the sediment were constituted of terrestrial, estuarine and marine organic carbon.The contribution of terrestrial, estuarine and marine organic carbon to TOC pool was (44.6±6.5)%, (6.5±5.5)% and (48.9±6.1)% respectively.The contribution of terrestrial organic carbon to TOC pool decreased significantly as distance from the river mouth increased offshore(P < 0.05), whereas contribution of marine organic carbon to TOC pool increased significantly(P < 0.05).The bury rate of terrestrial organic carbon was 171~214 t/(km2·a)in the study area.And nearly 20% terrestrial organic carbon transported via estuary was buried in that area.Not only the sources but also the fates of organic matters were impacted by transportation of Yellow River.