干旱区生态环境知识资源中心(Arid): 末次冰期以来南海北部沉积有机碳记录及其古植被环境信息

Arid

	末次冰期以来南海北部沉积有机碳记录及其古植被环境信息
其他题名	ORGANIC CARBON RECORDS SINCE THE LAST GLACIAL PERIOD IN THE NORTHERN SOUTH CHINA SEA SEDIMENTS:IMPLICATIONS FOR VEGETATION AND ENVIRONMENTAL CHANGES
	周斌 1; 郑洪波 1; 杨文光 2; 韦刚健 3; 李丽 4; 王慧 4
来源期刊	第四纪研究
ISSN	1001-7410
出版年	2011
卷号	31 期号:3 页码:498-505
中文摘要	末次冰期以来南海北部深海沉积物中陆源植被碎屑来源及其指示的植被类型变化等一直存在争议。正构烷烃比值、正构烷烃碳同位素(delta~(13)C_(alk))及总有机碳同位素(~(13)C_(TOC))等有机碳指标的应用可能为之提供新的证据。南海北部MD05-2905岩芯中正构烷烃比值C31/C27,C31/(C31+C27+C29)和ACL(长链烷烃平均链长)等呈现末次冰期高,全新世低的变化,指示末次冰期草本植物相对增多,全新世木本植物较多。delta~(13)C_(TOC)及delta~(13)C_(alk)均呈现末次冰期相对偏正,全新世偏负的变化,指示C4植物在冰期增多,间接印证草本植物的增多。末次冰期,由于相对冷干的气候、大气CO_2浓度的降低,以及低海平面导致陆架的广阔出露,均有利于更多草本植物的生长。末次冰消期及全新世随着温度的升高及降水的增多,森林植被发育,C_3植物相对较多。该岩芯碳同位素结果与南海北部孢粉结果的对比表明,南海北部深海沉积中正构烷烃指标指示南海北部周边较大区域范围的植被变化信息。
英文摘要	The pollen-based vegetation type and the provenance of terrestrial plant remnants since the last glacial period retrieved from the Northern South China Sea(SCS)have been controversial.Organic carbon records such as n-alkanes ratios stable carbon isotopic compositions of n-alkanes(delta~(13)C_(alk))and total organic carbon(delta~(13)C_(TOC))in the sediments from core MD05-2905(20°08.17’N117°21.61’E 1647m water depth)which located on the continental slope of the Northern SCS may supply new evidence for changes in terrestrial vegetations.This core has a total length of 11.94m and spanned the time period of ca.28kaB.P.to 2kaB.P.according to ten AMS 14C dates.n-Alkanes ratios such as C31/C27 C31/(C31+C27+C29)ACL(average chain length of long-chain n-alkanes)from core MD05-2905 showing similar variation trend revealed a pattern of glacial to interglacial variability.n-Alkanes ratios of C31/C27 presents fluctuation variations with higher average value of 2.2 during the last glacial period and lower average value of 1.6 during the Holocene while decreasing gradually with a average value of 2.0 during the deglaciation of 16~10kaB.P.This indicates that there was increasing grassy vegetation in the last glacial period and more woody vegetation in the Holocenedelta~(13)C_(alk)and delta13CTOC values were more positive in the glacial period than in the Holocene which indicates that C4 plants increased at the LGM and that more woody plants in the Holocene.At the LGM increasing grassy vegetations developed in land and in the enlarged exposed continental shelf due to relatively cold-arid climate and lower atmospheric CO_2 concentration.During the deglaciation and Holocene more closed forest(C_3 plants)flourished due to higher temperature and precipitation.Comparison between carbon isotopic compositions and pollen data from adjacent cores in Northern SCS at LGM indicated that plant remains in the core were not only from the continental shelf dominated by C3 grass Artemisia but also from southeast mainland and Taiwan island that were characterized by abundant C_4 flora.Alkanes records from core MD05-2905 can recover the regional vegetation changes around the Northern South China Sea.
中文关键词	南海北部 ; 末次冰期 ; C_3/C_4植物 ; 正构烷烃 ; 单体碳同位素
英文关键词	Northern South China Sea last glacial period C4 plants n-alkanes delta13 C
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOLOGY
WOS研究方向	Geology
CSCD记录号	CSCD:4207580
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/226343
作者单位	1.南京大学地球科学与工程学院表生地球化学研究所, 南京, 江苏 210093, 中国; 2.成都理工大学沉积地质研究院, 成都, 四川 610059, 中国; 3.中国科学院广州地球化学研究所, 广州, 广东 510640, 中国; 4.同济大学, 海洋地质国家重点实验室, 上海 200092, 中国
推荐引用方式 GB/T 7714	周斌,郑洪波,杨文光,等. 末次冰期以来南海北部沉积有机碳记录及其古植被环境信息[J],2011,31(3):498-505.
APA	周斌,郑洪波,杨文光,韦刚健,李丽,&王慧.(2011).末次冰期以来南海北部沉积有机碳记录及其古植被环境信息.第四纪研究,31(3),498-505.
MLA	周斌,et al."末次冰期以来南海北部沉积有机碳记录及其古植被环境信息".第四纪研究 31.3(2011):498-505.