干旱区生态环境知识资源中心(Arid): 乌伦古湖全新世气候变化的环境磁学记录

Arid

	乌伦古湖全新世气候变化的环境磁学记录
其他题名	HOLOCENE ENVIRONMENTAL CHANGE REORDED BY MAGNETIC PROPERTIES OF WULUNGU LAKE SEDIMENT
	刘宇航 1; 夏敦胜 2; 周爱锋 1; 张俊辉 1; 赵家驹 1; 张英 1
来源期刊	第四纪研究
ISSN	1001-7410
出版年	2012
卷号	32 期号:4 页码:803-811
中文摘要	对位于新疆北部阿勒泰地区福海县的乌伦古湖WLG10C孔岩芯进行了环境磁学分析,以平行孔(WLG10B) AMS~(14)C测年为年代框架,重建了该地区全新世以来气候环境变化。结果显示:1)乌伦古湖磁性矿物以细颗粒亚铁磁性矿物为主,并含有少量不完整反铁磁性矿物和富铁绿泥石类粘土顺磁性矿物,磁学参数X~(ARM)和X~(ARM)/X可用作气候变化代用指标,记录了研究区气候环境变化;2)研究区在全新世早期(7300cal.aB.P.以前)为冷干气候,中、晚全新世(7300cal.aB.P.以来)为暖湿气候。在4600cal.aB.P.左右为该湖高湖面时期,在3500~2500cal.aB.P.之间存在与全球范围一致的突发冷事件。乌伦古湖全新世气候变化与周边环境记录较一致,气候变化模式符合中亚干旱区全新世气候变化西风模式。
英文摘要	There has been long lasting debate on the climate change mode during the Holocene in Xinjiang region where the climate is very sensitive to the terminal lakes in arid areas.The Wulungu Lake,located in Fuhai county,Xinjiang,Northwestern China,traverses the area between 46°59’~47°25’N and 87°00’~87°35’E,with an area of 927km~2 and a maximum depth of 16m(average depth is 8m).Two parallel cores,WLG10B with a length of 397cm and WLG10C with a length of 271cm,were obtained in the northeast corner of the lake area(47°21’50.5N,87°27’07.2E).Environmental magnetic parameters of the lacustrine sediments of WLG10C core were conducted.Low frequency(470Hz)and high frequency(4700Hz)magnetic susceptibilities were measured by a MS2 magnetometer(Bartington,England), X_(ARM) was calculated based on the ARM measured by a DTECH AF demagnetizer with a peak AF field of 50mT and DC bias field of 0.05mT.IRMs and SIRM were imparted by an MMPM10 pulse magnetizer,while all remanence measurements were made by a Minispin magnetometer.Thermomagnetic curves(J-T curve)were determined using a variable field translation balance(VFTB)(heating/cooling cycles were measured from 25℃ to 700℃ in 114mT magnetic field). WLG10C core date framework was established based on AMS~(14)C age dating,from which the age of the core at the depth of 230cm was determined as about 7300aB.P.The climate change during the Holocene of Wulungu Lake was reconstructed.The result shows that the main magnetic minerals in the sediments are fine-grained ferrimagnetic minerals,with a small amount of anti-ferromagnetic and paramagnetic minerals.As a potential climate proxy,X~(ARM) and X~(ARM)/X of the lake sediment can be used to reconstruct palaeoenvironment in the arid area.The magnetic proxies implied that the environment during the Early Holocene was cold and dry,while that during the Middle and Late Holocene was warm and wet.The lake surface level is high during about 4600cal.aB.P.There was a sudden cold event between 3500cal.aB.P.and 2500cal.aB.P.,which is consistent with the global cold event during the same period.The climate change during the Holocene recorded by WLG10C is consistent with the records in its adjacent areas,and obeys "the arid Central Asian westerly mode".
中文关键词	乌伦古湖 ; 西风模式 ; 环境磁学 ; 全新世
英文关键词	Wulungu Lake westerly model Holocene environmental magnetism
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOSCIENCES MULTIDISCIPLINARY
WOS研究方向	Geology
CSCD记录号	CSCD:4669165
来源机构	兰州大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/227923
作者单位	1.兰州大学西部环境与气候变化研究院, 西部环境教育部重点实验室, 兰州, 甘肃 730000, 中国; 2.兰州大学西部环境与气候变化研究院, 西部环境教育部重点实验室;;中国科学院沙漠与沙漠化重点实验室, 兰州, 甘肃 730000, 中国
推荐引用方式 GB/T 7714	刘宇航,夏敦胜,周爱锋,等. 乌伦古湖全新世气候变化的环境磁学记录[J]. 兰州大学,2012,32(4):803-811.
APA	刘宇航,夏敦胜,周爱锋,张俊辉,赵家驹,&张英.(2012).乌伦古湖全新世气候变化的环境磁学记录.第四纪研究,32(4),803-811.
MLA	刘宇航,et al."乌伦古湖全新世气候变化的环境磁学记录".第四纪研究 32.4(2012):803-811.