Were the Larsemann Hills ice-free through the Last Glacial Maximum?
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), r...
Published in: | Antarctic Science |
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2001
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Online Access: | https://researchers.mq.edu.au/en/publications/d3965e4f-8acf-4ffe-ae1c-d5ec17cbc05c https://doi.org/10.1017/S0954102001000608 https://research-management.mq.edu.au/ws/files/62193435/Publisher%20version%20(open%20access).pdf http://www.scopus.com/inward/record.url?scp=18044375349&partnerID=8YFLogxK |
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ftmacquarieunicr:oai:https://researchers.mq.edu.au:publications/d3965e4f-8acf-4ffe-ae1c-d5ec17cbc05c 2024-09-15T17:48:27+00:00 Were the Larsemann Hills ice-free through the Last Glacial Maximum? Hodgson, D. A. Noon, P. E. Vyverman, W. Bryant, C. L. Gore, D. B. Appleby, P. Gilmour, M. Verleyen, E. Sabbe, K. Jones, V. J. Ellis-Evans, J. C. Wood, P. B. 2001 application/pdf https://researchers.mq.edu.au/en/publications/d3965e4f-8acf-4ffe-ae1c-d5ec17cbc05c https://doi.org/10.1017/S0954102001000608 https://research-management.mq.edu.au/ws/files/62193435/Publisher%20version%20(open%20access).pdf http://www.scopus.com/inward/record.url?scp=18044375349&partnerID=8YFLogxK eng eng info:eu-repo/semantics/openAccess Hodgson , D A , Noon , P E , Vyverman , W , Bryant , C L , Gore , D B , Appleby , P , Gilmour , M , Verleyen , E , Sabbe , K , Jones , V J , Ellis-Evans , J C & Wood , P B 2001 , ' Were the Larsemann Hills ice-free through the Last Glacial Maximum? ' , Antarctic Science , vol. 13 , no. 4 , pp. 440-454 . https://doi.org/10.1017/S0954102001000608 article 2001 ftmacquarieunicr https://doi.org/10.1017/S0954102001000608 2024-09-04T23:52:01Z 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 14 C) 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 modern 14 CO 2 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 Dålk 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 ... Article in Journal/Newspaper Antarc* Antarctic Science Antarctica Macquarie University Research Portal Antarctic Science 13 4 440 454 |
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Macquarie University Research Portal |
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ftmacquarieunicr |
language |
English |
description |
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 14 C) 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 modern 14 CO 2 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 Dålk 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 ... |
format |
Article in Journal/Newspaper |
author |
Hodgson, D. A. Noon, P. E. Vyverman, W. Bryant, C. L. Gore, D. B. Appleby, P. Gilmour, M. Verleyen, E. Sabbe, K. Jones, V. J. Ellis-Evans, J. C. Wood, P. B. |
spellingShingle |
Hodgson, D. A. Noon, P. E. Vyverman, W. Bryant, C. L. Gore, D. B. Appleby, P. Gilmour, M. Verleyen, E. Sabbe, K. Jones, V. J. Ellis-Evans, J. C. Wood, P. B. Were the Larsemann Hills ice-free through the Last Glacial Maximum? |
author_facet |
Hodgson, D. A. Noon, P. E. Vyverman, W. Bryant, C. L. Gore, D. B. Appleby, P. Gilmour, M. Verleyen, E. Sabbe, K. Jones, V. J. Ellis-Evans, J. C. Wood, P. B. |
author_sort |
Hodgson, D. A. |
title |
Were the Larsemann Hills ice-free through the Last Glacial Maximum? |
title_short |
Were the Larsemann Hills ice-free through the Last Glacial Maximum? |
title_full |
Were the Larsemann Hills ice-free through the Last Glacial Maximum? |
title_fullStr |
Were the Larsemann Hills ice-free through the Last Glacial Maximum? |
title_full_unstemmed |
Were the Larsemann Hills ice-free through the Last Glacial Maximum? |
title_sort |
were the larsemann hills ice-free through the last glacial maximum? |
publishDate |
2001 |
url |
https://researchers.mq.edu.au/en/publications/d3965e4f-8acf-4ffe-ae1c-d5ec17cbc05c https://doi.org/10.1017/S0954102001000608 https://research-management.mq.edu.au/ws/files/62193435/Publisher%20version%20(open%20access).pdf http://www.scopus.com/inward/record.url?scp=18044375349&partnerID=8YFLogxK |
genre |
Antarc* Antarctic Science Antarctica |
genre_facet |
Antarc* Antarctic Science Antarctica |
op_source |
Hodgson , D A , Noon , P E , Vyverman , W , Bryant , C L , Gore , D B , Appleby , P , Gilmour , M , Verleyen , E , Sabbe , K , Jones , V J , Ellis-Evans , J C & Wood , P B 2001 , ' Were the Larsemann Hills ice-free through the Last Glacial Maximum? ' , Antarctic Science , vol. 13 , no. 4 , pp. 440-454 . https://doi.org/10.1017/S0954102001000608 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1017/S0954102001000608 |
container_title |
Antarctic Science |
container_volume |
13 |
container_issue |
4 |
container_start_page |
440 |
op_container_end_page |
454 |
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1810289678533787648 |