DOI: 10.1016/j.quascirev.2020.106208
论文题名: Early glacial maximum and deglaciation at sub-Antarctic Marion Island from cosmogenic 36Cl exposure dating
作者: Rudolph E.M. ; Hedding D.W. ; Fabel D. ; Hodgson D.A. ; Gheorghiu D.M. ; Shanks R. ; Nel W.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2020
卷: 231 语种: 英语
英文关键词: Chlorine-36
; Cosmogenic isotopes
; Geomorphology
; Glacial
; Glaciation
; Last glacial maximum
; Marion island
; MIS 3
; Pleistocene
; Southern ocean
; Sub-Antarctic
Scopus关键词: Climate change
; Geomorphology
; Isotopes
; Cosmogenic isotopes
; Glacial
; Glaciation
; Last Glacial Maximum
; Marion island
; Pleistocene
; Southern ocean
; Sub-Antarctic
; Glacial geology
; bedrock
; chronology
; cooling
; geomorphology
; glacial history
; glaciation
; Holocene
; Last Glacial Maximum
; marine isotope stage
; Postglacial
; Southern Hemisphere
; subantarctic region
; westerly
; Antarctica
; Auckland [North Island]
; French Southern Territories
; Georgia
; Indian Ocean
; Indian Ocean (South)
; Kerguelen
; Kerguelen Islands
; Marion Island
; Patagonia
; Prince Edward Islands
; South Georgia
; Southern Ocean
; United States
英文摘要: Southern Hemisphere glacial chronologies can provide valuable insights into interactions between glaciation and past climate changes, but are not well constrained on most sub-Antarctic islands. We present the first cosmogenic 36Cl exposure ages of deglaciated bedrock surfaces and moraine deposits from sub-Antarctic Marion Island in the southern Indian Ocean. Results show that the ice reached a local Last Glacial Maximum before 34 ka and retreated, with no re-advances, but possibly minor stand stills, until ∼17 ka. This early deglaciation left island surfaces below 850 m a.s.l. ice-free after ∼19 ka, and any subsequent advances during the Antarctic Cold Reversal or Holocene cooling periods would have been restricted to the interior. This glacial chronology is similar to that of some other sub-Antarctic Islands (e.g. the Kerguelen archipelago, Auckland and Campbell islands, and possibly South Georgia) and a number of other Southern Hemisphere glaciers (e.g. in Patagonia and New Zealand) and adds to evidence that suggest the Southern Hemisphere was in a glacial maxima earlier than the global LGM. We suggest a combination of declining temperatures, a northward migration of oceanic fronts and the Southern Hemisphere westerly winds (causing precipitation changes), as well as the physiography of Marion Island, created optimal conditions for glacier growth during Marine Isotope Stage (MIS) 3 instead of MIS 2. Our findings redefine the glacial history of Marion Island, and have implications for future investigations on post-glacial landscape development and ecological succession. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/158995
Appears in Collections: 气候变化与战略
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作者单位: Department of Geography and Environmental Science, University of Fort Hare, 1 King Williamstown Road, Alice, 5700, South Africa; Department of Geography, University of South Africa, P O Box 392, Unisa, Florida 0003, South Africa; Scottish Universities Environmental Research Centre, Rankine Avenue, East Kilbride, G75 0QF, United Kingdom; British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
Recommended Citation:
Rudolph E.M.,Hedding D.W.,Fabel D.,et al. Early glacial maximum and deglaciation at sub-Antarctic Marion Island from cosmogenic 36Cl exposure dating[J]. Quaternary Science Reviews,2020-01-01,231