Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1017/S0954102001000608 |
Were the Larsemann Hills ice-free through the Last Glacial Maximum? | |
Hodgson, DA; Noon, PE; Vyverman, W; Bryant, CL; Gore, DB; Appleby, P; Gilmour, M; Verleyen, E; Sabbe, K; Jones, VJ; Ellis-Evans, JC; Wood, PB | |
通讯作者 | Hodgson, DA |
来源期刊 | ANTARCTIC SCIENCE
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ISSN | 0954-1020 |
出版年 | 2001 |
卷号 | 13期号:4页码:440-454 |
英文摘要 | Lake sediments in the Larsemann Hills contain a great diversity of biological and physical markers from which past environments can be inferred. In order to determine the timing of environmental changes it is essential to have accurate dating of sediments. We used radiometric ((210)Pb and (137)Cs), radiocarbon (AMS (14)C) and uranium series ((238)U) methods to date cores from eleven lakes. These were sampled on coastal to inland transects across the two main peninsulas, Broknes and Stornes, together with a single sample from the Bolingen Islands. Radiometric dating of recent sediments yielded (210)Pb levels below acceptable detection limits. However, a relatively well-defined peak in (137)Cs gave a date marker which corresponds to the fallout maximum from the atmospheric testing of atomic weapons in 1964/65. Radiocarbon (AMS 14C) measurements showed stratigraphical consistency in the age-depth sequences and undisturbed laminae in some cores provides evidence that the sediments have remained undisturbed by glacial action. In addition, freshwater surface sediments were found to be in near-equilibrium with modem (14)C, and not influenced by radiocarbon contamination processes. This dating program, together with geomorphological records of ice flow directions and glacial sediments, indicates that parts of Broknes were ice-free throughout the Last Glacial Maximum and that some lakes have existed continuously since at least 44 ka BP. Attempts to date sediments older than 44 ka BP using (238)U dating were inconclusive. However, supporting evidence for Broknes being ice-free is provided by an Optically Stimulated Luminescence date from a glaciofluvial deposit. In contrast, Stornes only became ice-free in the mid to late Holocene. This contrasting glacial history results from the Dalk Glacier which diverts ice around Broknes. Lakes on Broknes and some offshore islands therefore contain the oldest known lacustrine sediment records from eastern Antarctica, with the area providing an ice-free oasis and refuge for plants and animals throughout the Last Glacial Maximum. These sediments are therefore well placed to unravel a unique limnological sequence of environmental and climate changes in East Antarctica from the late Pleistocene to the present. This information may help better constrain models of current climate changes and ensure the adequate protection of these lakes and their catchments from the impacts of recent human occupation. |
英文关键词 | Antarctic deglaciation Holocene lakes Larsemann Hills Pleistocene |
类型 | Article |
语种 | 英语 |
国家 | England ; Belgium ; Scotland ; Australia |
收录类别 | SCI-E |
WOS记录号 | WOS:000172734600012 |
WOS关键词 | EAST-ANTARCTICA ; VESTFOLD HILLS ; GLACIOFLUVIAL SEDIMENTS ; DIATOM ASSEMBLAGES ; MASS-SPECTROMETER ; CONTINENTAL-SHELF ; MARINE-SEDIMENTS ; SIGNY ISLAND ; SALINE LAKES ; PRYDZ BAY |
WOS类目 | Environmental Sciences ; Geography, Physical ; Geosciences, Multidisciplinary |
WOS研究方向 | Environmental Sciences & Ecology ; Physical Geography ; Geology |
来源机构 | University of London |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/140269 |
作者单位 | (1)British Antarctic Survey, NERC, Cambridge CB3 0ET, England;(2)Univ Ghent, Dept Biol, Lab Protistol & Aquat Ecol, B-9000 Ghent, Belgium;(3)Nat Environm Res Council Radiocarbon Lab, E Kilbride G75 0QF, Lanark, Scotland;(4)Macquarie Univ, Dept Phys Geog, N Ryde, NSW 2109, Australia;(5)Univ Liverpool, Environm Radioact Res Ctr, Dept Math Sci, Liverpool L69 3BX, Merseyside, England;(6)Open Univ, Dept Earth Sci, Nat Environm Res Council, Uranium Series Facil, Milton Keynes MK7 6AA, Bucks, England;(7)UCL, Environm Change Res Ctr, London WC1H 0AP, England;(8)Univ London Royal Holloway & Bedford New Coll, Dept Geog, Egham TW20 0EX, Surrey, England |
推荐引用方式 GB/T 7714 | Hodgson, DA,Noon, PE,Vyverman, W,et al. Were the Larsemann Hills ice-free through the Last Glacial Maximum?[J]. University of London,2001,13(4):440-454. |
APA | Hodgson, DA.,Noon, PE.,Vyverman, W.,Bryant, CL.,Gore, DB.,...&Wood, PB.(2001).Were the Larsemann Hills ice-free through the Last Glacial Maximum?.ANTARCTIC SCIENCE,13(4),440-454. |
MLA | Hodgson, DA,et al."Were the Larsemann Hills ice-free through the Last Glacial Maximum?".ANTARCTIC SCIENCE 13.4(2001):440-454. |
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