Luminescence age and palaeoenvironmental implications of a late Pleistocene ground wedge on the northeastern Tibetan Plateau

doi:10.1002/ppp.386

CORC > 地球环境研究所 > 中国科学院地球环境研究所 > 黄土与第四纪地质国家重点实验室（1985-2004）

	Luminescence age and palaeoenvironmental implications of a late Pleistocene ground wedge on the northeastern Tibetan Plateau
	Porter, SC; Singhvi, A; An, ZS; Lai, ZP
刊名	PERMAFROST AND PERIGLACIAL PROCESSES
	2001
卷号	12 期号:2 页码:203-210
关键词	ice-wedge cast Pleistocene permafrost palaeoenvironment Tibet
DOI	10.1002/ppp.386
文献子类	Article
英文摘要	A periglacial ground wedge in bajada gravel near the northern base of the Qinghai Nan Shan underlies loess of late- and postglacial age. The composition and structure of the wedge fill are consistent with an ice-wedge origin, implying former permafrost and relatively moist conditions at this locality. A luminescence date of 15,100 +/- 1600 years from the wedge fill marks the end of ice-wedge activity, which is inferred to have been during the last glaciation. The present mean annual air temperature (MAAT) (-0.7 degreesC) is too high to produce frost cracking and ice-wedge formation, but snowline depression of ca. 700-800 m in the adjacent mountains is consistent with a reduction in MAAT of at least 3.8 degreesC during the last glacial maximum. Such a temperature depression would reduce MAAT to values equivalent to Arctic regions now experiencing active ice-wedge growth. The absence of loess of full-glacial age and the presence of a weakly developed palaeosol atop the bajada gravel imply a stable, cold land surface. Qinghai Lake, although reduced in size at that time, likely raised local humidity to levels that favoured ice-wedge growth in this low-altitude sector (ca. 3000-3400 m) of the Tibetan Plateau. Copyright (C) 2001 John Wiley & Sons, Ltd.
学科主题	Physical Geography ; Geology
WOS关键词	WESTERN CHINA ; QAIDAM BASIN ; LAKE ; PERMAFROST ; EVOLUTION ; QINGHAI ; LOESS
WOS研究方向	Geography, Physical ; Geology
语种	英语
出版者	JOHN WILEY & SONS LTD
WOS记录号	WOS:000169567400005
内容类型	期刊论文
源URL	[http://ir.ieecas.cn/handle/361006/11926]
专题	黄土与第四纪地质国家重点实验室（1985-2004）
推荐引用方式 GB/T 7714	Porter, SC,Singhvi, A,An, ZS,et al. Luminescence age and palaeoenvironmental implications of a late Pleistocene ground wedge on the northeastern Tibetan Plateau[J]. PERMAFROST AND PERIGLACIAL PROCESSES,2001,12(2):203-210.
APA	Porter, SC,Singhvi, A,An, ZS,&Lai, ZP.(2001).Luminescence age and palaeoenvironmental implications of a late Pleistocene ground wedge on the northeastern Tibetan Plateau.PERMAFROST AND PERIGLACIAL PROCESSES,12(2),203-210.
MLA	Porter, SC,et al."Luminescence age and palaeoenvironmental implications of a late Pleistocene ground wedge on the northeastern Tibetan Plateau".PERMAFROST AND PERIGLACIAL PROCESSES 12.2(2001):203-210.