DOI: 10.1016/j.quascirev.2016.09.028
Scopus记录号: 2-s2.0-85009403794
论文题名: Deglacial history of the Pensacola Mountains, Antarctica from glacial geomorphology and cosmogenic nuclide surface exposure dating
作者: Bentley M.J. ; Hein A.S. ; Sugden D.E. ; Whitehouse P.L. ; Shanks R. ; Xu S. ; Freeman S.P.H.T.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2017
卷: 158 起始页码: 58
结束页码: 76
语种: 英语
英文关键词: Antarctica
; Cosmogenic isotopes
; Glacial geomorphology
; Ice sheet history
Scopus关键词: Geomorphology
; Glacial geology
; Glaciers
; Isotopes
; Landforms
; Antarctic ice sheets
; Antarctica
; Cosmogenic isotopes
; Cosmogenic nuclide surface-exposure dating
; Glacial geomorphology
; Glacial Isostatic Adjustments
; Ice sheet history
; Last Glacial Maximum
; Ice
; cosmogenic radionuclide
; deglaciation
; geomorphological mapping
; glacier retreat
; glacioisostasy
; Holocene
; ice stream
; ice thickness
; isotopic composition
; Last Glacial Maximum
; radiocarbon dating
; Antarctic Ice Sheet
; Antarctica
; East Antarctica
; Ellsworth Mountains
; Pensacola Mountains
; Southern Ocean
; Weddell Sea
; West Antarctica
英文摘要: The retreat history of the Antarctic Ice Sheet is important for understanding rapid deglaciation, as well as to constrain numerical ice sheet models and ice loading models required for glacial isostatic adjustment modelling. There is particular debate about the extent of grounded ice in the Weddell Sea embayment at the Last Glacial Maximum, and its subsequent deglacial history. Here we provide a new dataset of geomorphological observations and cosmogenic nuclide surface exposure ages of erratic samples that constrain the deglacial history of the Pensacola Mountains, adjacent to the present day Foundation Ice Stream and Academy Glacier in the southern Weddell Sea embayment. We show there is evidence of at least two glaciations, the first of which was relatively old and warm-based, and a more recent cold-based glaciation. During the most recent glaciation ice thickened by at least 450 m in the Williams Hills and at least 380 m on Mt Bragg. Progressive thinning from these sites was well underway by 10 ka BP and ice reached present levels by 2.5 ka BP, and is broadly similar to the relatively modest thinning histories in the southern Ellsworth Mountains. The thinning history is consistent with, but does not mandate, a Late Holocene retreat of the grounding line to a smaller-than-present configuration, as has been recently hypothesized based on ice sheet and glacial isostatic modelling. The data also show that clasts with complex exposure histories are pervasive and that clast recycling is highly site-dependent. These new data provide constraints on a reconstruction of the retreat history of the formerly-expanded Foundation Ice Stream, derived using a numerical flowband model. © 2016 The Author(s) 资助项目: We thank the British Antarctic Survey pilots and operations staff who facilitated the work in the Pensacola Mountains. Particular thanks to James Wake for his assistance in the field. The work reported here forms part of NERC grants NE/F014260/1, NE/F014252/1, and NE/F014228/1. We thank Greg Balco and a second, anonymous reviewer for their comments, which improved the paper.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59315
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geography, Durham University, Lower Mountjoy, South Rd, Durham, United Kingdom; School of Geosciences, University of Edinburgh, Drummond St, Edinburgh, United Kingdom; AMS Laboratory, Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride, United Kingdom
Recommended Citation:
Bentley M.J.,Hein A.S.,Sugden D.E.,et al. Deglacial history of the Pensacola Mountains, Antarctica from glacial geomorphology and cosmogenic nuclide surface exposure dating[J]. Quaternary Science Reviews,2017-01-01,158