• 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 hansi-font-family: ’Times New Roman’">δ15N records in the South China Seahansi-font-family: ’Times New Roman’">（SCShansi-font-family: ’Times New Roman’">） have been found to vary little during glacial-interglacial cycles,which is quite different from hansi-font-family: ’Times New Roman’">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 hansi-font-family: ’Times New Roman’">δ15N ,2-methyl hopanoid index, and crenarchaeol during the period from marine isotope stage hansi-font-family: ’Times New Roman’">（MIShansi-font-family: ’Times New Roman’">）3 to 5 from a site in the southern SCS. The sediment core MD05-2897 is located at 08hansi-font-family: ’Times New Roman’">°49.53hansi-font-family: ’Times New Roman’">＇N, 111 hansi-font-family: ’Times New Roman’">°26.51hansi-font-family: ’Times New Roman’">＇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 hansi-font-family: ’Times New Roman’">δ15N ranged between 3.6hansi-font-family: ’Times New Roman’">‰ and 5.7hansi-font-family: ’Times New Roman’">‰, 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 hansi-font-family: ’Times New Roman’">（ indicated by 2-methyl hopanoid indexhansi-font-family: ’Times New Roman’">） and archaeal ammonia oxidation hansi-font-family: ’Times New Roman’">（ indicated by crenarchaeolhansi-font-family: ’Times New Roman’">） might be responsible for the hansi-font-family: ’Times New Roman’">δ15N lowering during interglacial times.