DOI: 10.1016/j.palaeo.2016.12.034
论文题名: Temporal constraints for the Late Wisconsinan deglaciation of western Canada using eolian dune luminescence chronologies from Alberta
作者: Munyikwa K. ; Rittenour T.M. ; Feathers J.K.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
卷: 470 起始页码: 147
结束页码: 165
语种: 英语
英文关键词: Canada
; Deglaciation
; Eolian dunes
; Laurentide Ice Sheet
; Luminescence dating
; Wisconsinan
英文摘要: The Laurentide Ice Sheet (LIS) covered most of Canada during the Last Glacial Maximum. Sometime after 20 cal. ka BP, the LIS began to recede from western Canada and, by 11 cal. ka BP, it had retreated from most of the province of Alberta. Due to the scarcity of datable contemporaneous organic materials, the precise timing of the retreat of the ice sheet from the region remains poorly constrained so that the chronology of the sequential positions of the ice sheet margin between 20 and 11 cal. ka BP is largely tentative. In this study, we use luminescence dating of postglacial eolian deposits, sourced primarily from glaciolacustrine and deltaic sediments in central and northern Alberta, to provide an updated chronology for the retreat of the LIS from the region. We examine 14 new and 13 previously published quartz optically stimulated luminescence (OSL) ages, as well as 19 previously published K-feldspar infrared stimulated luminescence ages. The chronologies are used to constrain successive regional ice sheet margin positions that are geomorphically recognizable across the region between 16 and 11 ka (calendar years). These data suggest that the LIS may have retreated from central Alberta earlier than portrayed in radiocarbon derived deglaciation models. We propose that the OSL chronology from postglacial dunes constrains the deglaciation of the region more accurately because luminescence dating does not rely on the development of vegetation to produce material for dating. Implications for the revised chronology include an improved timing of the emergence of an ice-free corridor that may have been used for Paleoindian migration into the Americas as well as enhanced age constraints on when meltwater drainage routes to the Arctic became open in relationship to the Younger Dryas. The chronology could also provide improved constraints for geophysical models that reconstruct regional isostatic rebound which followed deglaciation. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/67921
Appears in Collections: 过去全球变化的重建
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作者单位: Centre for Science, Athabasca University, 1 University Drive, Athabasca, Alberta, Canada; Department of Geology, Utah State University, Logan, UT, United States; Department of Anthropology, Denny Hall M-32, University of Washington, Seattle, WA, United States
Recommended Citation:
Munyikwa K.,Rittenour T.M.,Feathers J.K.. Temporal constraints for the Late Wisconsinan deglaciation of western Canada using eolian dune luminescence chronologies from Alberta[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01,470