Paleoenvironmental implications of new OSL dates on the formation of the "Shell Bar" in the Qaidam Basin, northeastern Qinghai-Tibetan Plateau

ISL OpenIR > 青海盐湖研究所知识仓储

	Paleoenvironmental implications of new OSL dates on the formation of the "Shell Bar" in the Qaidam Basin, northeastern Qinghai-Tibetan Plateau
	Lai, ZhongPing1,2 ; Mischke, Steffen 3,4; Madsen, David 5
	2014-02-01
发表期刊	JOURNAL OF PALEOLIMNOLOGY
卷号	51 期号:2 页码:197-210
关键词	Osl Dating Depositional Origin Paleoenvironmental Change Late Pleistocene Shell Bar Qaidam Basin Qinghai-tibetan Plateau (Qtp)
摘要	A geological feature in the Qaidam Basin known as the "Shell Bar" contains millions of freshwater clam shells buried in situ. Since the 1980s, this feature in the now hyper-arid basin has been interpreted to be lake deposits that provide evidence for a warmer and more humid climate than present during late marine isotope stage 3 (MIS 3). Global climate during late MIS 3 and the last glacial maximum, however, was cold and dry, with much lower sea levels. We re-investigated the feature geomorphologically and sedimentologically, and employed optically stimulated luminescence (OSL) dating to verify the chronology of the sediments. We interpret the Shell Bar to be a remnant of a river channel formed by a stream that ran across an exposed lake bed during a regressive lake phase. Deflation of the surrounding older, fine-grained lacustrine deposits has left the fluvial channel sediments topographically inverted, indicating the erosive nature of the landscape. Luminescence ages place the formation of the Shell Bar in MIS 5 (similar to 113-99 ka), much older than previous radiocarbon ages of < 40 ka BP, but place the paleoclimatic inferences more in accord with other regional and global climate proxy records. We present a brief review of the age differences derived from C-14 and OSL dating of some critical sections that were thought to represent a warmer and more humid climate than present during late MIS 3. We attribute the differences to underestimation of C-14 ages. We suggest that C-14 ages older than similar to 25 ka BP may require re-investigation, especially dates on samples from arid regions.
语种	英语
引用统计
文献类型	期刊论文
条目标识符	http://ir.isl.ac.cn/handle/363002/5659
专题	青海盐湖研究所知识仓储中国科学院青海盐湖研究所
作者单位	1.Chinese Acad Sci, Qinghai Inst Salt Lakes, CAS Key Lab Salt Lake Resources & Chem, Xining 810008, Peoples R China 2.Chinese Acad Sci, State Key Lab Cryosphere Sci, Cold & Arid Reg Environm & Engn Res Inst, Lanzhou 730000, Peoples R China 3.Univ Potsdam, Inst Earth & Environm Sci, D-14476 Potsdam, Germany 4.Free Univ Berlin, Inst Geol Sci, D-12249 Berlin, Germany 5.Univ Texas Austin, Texas Archeol Res Lab, Austin, TX 78712 USA
推荐引用方式 GB/T 7714	Lai, ZhongPing,Mischke, Steffen,Madsen, David. Paleoenvironmental implications of new OSL dates on the formation of the "Shell Bar" in the Qaidam Basin, northeastern Qinghai-Tibetan Plateau[J]. JOURNAL OF PALEOLIMNOLOGY,2014,51(2):197-210.
APA	Lai, ZhongPing,Mischke, Steffen,&Madsen, David.(2014).Paleoenvironmental implications of new OSL dates on the formation of the "Shell Bar" in the Qaidam Basin, northeastern Qinghai-Tibetan Plateau.JOURNAL OF PALEOLIMNOLOGY,51(2),197-210.
MLA	Lai, ZhongPing,et al."Paleoenvironmental implications of new OSL dates on the formation of the "Shell Bar" in the Qaidam Basin, northeastern Qinghai-Tibetan Plateau".JOURNAL OF PALEOLIMNOLOGY 51.2(2014):197-210.