• 责任者：Li Zhiyang (Key Laboratory of Marginal Sea Geology ; Guangzhou Institute of Geochemistry ; Chinese Academy of Sciences ; Guangzhou 510640 ; China) ; Zhang Jie
• 刊名：Quaternary Sciences
• 出版年：2013
• 卷期：33(1)
• 关键词：第四纪 ; Quaternary ; 细菌 ; bacteria ; 氮循环 ; nitrogen cycle ; 南海 ; South China Sea
• 页码：p.34-38
• 图表：illus., 29 refs.
• 分类号：1400
• issnNo：ISSN1001-7410
• isbnNo：CN11-2708/P

Sedimentary δ15N records in the South China Sea（SCS） have been found to vary little during glacial-interglacial cycles,which is quite different from δ15N records in the tropical eastern Pacific and may be caused by local nitrogen biogeochemical processes. In this study,we reported downcore results of sedimentary δ15N ,2-methyl hopanoid index, and crenarchaeol during the period from marine isotope stage （MIS）3 to 5 from a site in the southern SCS. The sediment core MD05-2897 is located at 08°49.53＇N, 111 °26.51＇E and with a water depth of 1658m. Sediments are calcarious and silicious silty clay with no turbidite. The upper part of the core covering a history since MIS 2 was lost. Samples were lcm thick and were collected every 12cm downcore from 0 to 9.6m depth. The δ15N ranged between 3.6‰ and 5.7‰, with lower values during MIS 5. Corresponding to the lower values during MIS 5, 2-methyl hopanoid index and crenarchaeol exhibited higher values, suggesting that enhanced cyanobacterial N2 fixation （ indicated by 2-methyl hopanoid index） and archaeal ammonia oxidation （ indicated by crenarchaeol） might be responsible for the δ15N lowering during interglacial times.