DOI: 10.1016/j.quascirev.2013.09.026
Scopus记录号: 2-s2.0-84900456242
论文题名: Investigating absolute chronologies of glacial advances in the NW sector of the Cordilleran Ice Sheet with terrestrial in situ cosmogenic nuclides
作者: Stroeven A.P. ; Fabel D. ; Margold M. ; Clague J.J. ; Xu S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 92 起始页码: 429
结束页码: 443
语种: 英语
英文关键词: Cordilleran Ice Sheet
; Exposure dating
; Pleistocene glaciations
; Yukon Territory
Scopus关键词: Glaciers
; Isotopes
; Shielding
; Cordilleran ice sheet
; Cosmogenic nuclides
; Exposure dating
; Exposure durations
; Glacial advances
; Marine oxygen isotopes
; Pleistocene
; Yukon Territory
; Glacial geology
; Cordilleran Ice Sheet
; cosmogenic radionuclide
; dating method
; geochronology
; geological mapping
; glaciation
; glacier advance
; ice thickness
; marine isotope stage
; moraine
; Pleistocene
; Postglacial
; Canada
; Yukon Territory
英文摘要: Geologic mapping in Yukon Territory, Canada, over the past 100 years has revealed a consistent pattern of diminishing Cordilleran Ice Sheet (CIS) extent during successively younger glaciations. Although this pattern is generally accepted, there is still much uncertainty about the number of glaciations, their ages, and the dynamics of the different lobes that constituted the digitate ice sheet margin, their subglacial thermal regimes, and ice thicknesses. We address uncertainties in the timing of glaciation using cosmogenic nuclide exposure dating at key localities that straddle several major lobes of the CIS in west-central Yukon Territory. Differences in exposure duration within what are thought to be the same map units are perhaps due to inheritance (older than expected), but more likely result from postglacial shielding (younger than expected) or surface erosion. Despite a significant spread in exposure durations on moraines and within map units, and tending to rely on longest exposure durations on moraines due to postglacial degradation and shielding, our results indicate that the McConnell glacial advance occurred during Marine Oxygen Isotope Stage (MIS) 2, judging from oldest minimum apparent exposure ages of 15.7±1.5 and 17.7±1.6ka, a Gladstone glacial advance occurred before 51.8±4.7ka (MIS 4) and Reid glacial advances before 79.8±7.3 and 82.8±7.5ka (consistent with MIS 6). Traces of even older glacial advances predate 100ka (107.5±9.9-154.3±14.2ka). © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60291
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Physical Geography and Quaternary Geology, Bolin Center for Climate Research, Stockholm University, S-106 91 Stockholm, Sweden; School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, Lanark, Scotland, United Kingdom; Department of Geography, Durham University, Durham DH1 3LE, United Kingdom; Centre for Natural Hazard Research, Simon Fraser University, Burnaby, BC V6B 1R8, Canada; SUERC-AMS, Scottish Universities Environmental Research Centre, East Kilbride G75 0QF, Scotland, United Kingdom
Recommended Citation:
Stroeven A.P.,Fabel D.,Margold M.,et al. Investigating absolute chronologies of glacial advances in the NW sector of the Cordilleran Ice Sheet with terrestrial in situ cosmogenic nuclides[J]. Quaternary Science Reviews,2014-01-01,92