Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica
Lake sediment cores from Midge Lake, Livingston Island, South Shetland Islands and Sombre Lake, Signy Island, South Orkney Islands were analysed for volcanic tephra using light microscopy and magnetic susceptibility. Cores were dated using published 14C and 210Pb chronologies. Electron probe microan...
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Cambridge University Press
1998
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Online Access: | http://nora.nerc.ac.uk/id/eprint/504058/ https://doi.org/10.1017/S0954102098000030 |
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ftnerc:oai:nora.nerc.ac.uk:504058 2023-05-15T13:48:08+02:00 Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica Hodgson, Dominic A. Dyson, Coral L. Jones, Vivienne J. Smellie, John L. 1998 http://nora.nerc.ac.uk/id/eprint/504058/ https://doi.org/10.1017/S0954102098000030 unknown Cambridge University Press Hodgson, Dominic A. orcid:0000-0002-3841-3746 Dyson, Coral L.; Jones, Vivienne J.; Smellie, John L. 1998 Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica. Antarctic Science, 10 (01). 13-20. https://doi.org/10.1017/S0954102098000030 <https://doi.org/10.1017/S0954102098000030> Publication - Article PeerReviewed 1998 ftnerc https://doi.org/10.1017/S0954102098000030 2023-02-04T19:38:15Z Lake sediment cores from Midge Lake, Livingston Island, South Shetland Islands and Sombre Lake, Signy Island, South Orkney Islands were analysed for volcanic tephra using light microscopy and magnetic susceptibility. Cores were dated using published 14C and 210Pb chronologies. Electron probe microanalyses of discrete tephra glass shards were undertaken to characterise the tephra geochemically in order to identify possible source volcanoes and refine tephrochronological data for the region. Results identified five tephra horizons in a core from Midge Lake. Four of these tephra at 3–4 cm, 8–9 cm (c. 450 yr BP), 15–16 cm (c. 755 ± 105 yr BP) and 21–22 cm (c. 1340 ± 100 yr BP) consisted of sodic basaltic to basalticandesitic glasses, containing abundant labradoritic feldspar inclusions, and a single ‘acidic’ tephra was found at 2–3 cm. Seven tephra horizons were identified in the Sombre Lake core including three basaltic tephra at 3–9 cm (30 ± 4 yr BP to 125 ± 25 yr BP), 31–32 cm and 44–46 cm (1325 ± 50 14C yr BP) and four acidic tephra at 21–22 cm and 24–25 cm, 33–36 cm (c. 1021 14C yr BP) and 54–56 cm (c. 1450 14C yr BP). These are the first tephra to be identified from the South Orkney Islands. Geochemical and grain size analysis indicated that the analysed Midge Lake tephra were derived from the Quaternary Deception Island volcano. Smaller grain sizes, congruent geochemical data and prevailing wind directions also indicate this volcano as the likely source of Sombre Lake tephra. Results highlight the importance of establishing geochemical consistency between tephra deposited across wide geographical areas, during apparently synchronous time periods, if they are to be used in a regional tephrochronology. Article in Journal/Newspaper Antarc* Antarctic Science Antarctica Deception Island Livingston Island Signy Island South Orkney Islands South Shetland Islands Natural Environment Research Council: NERC Open Research Archive South Shetland Islands Deception Island ENVELOPE(-60.633,-60.633,-62.950,-62.950) South Orkney Islands ENVELOPE(-45.500,-45.500,-60.583,-60.583) Livingston Island ENVELOPE(-60.500,-60.500,-62.600,-62.600) Signy Island ENVELOPE(-45.595,-45.595,-60.708,-60.708) Sombre Lake ENVELOPE(-45.615,-45.615,-60.687,-60.687) Midge Lake ENVELOPE(-61.088,-61.088,-62.636,-62.636) Antarctic Science 10 1 13 20 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
Lake sediment cores from Midge Lake, Livingston Island, South Shetland Islands and Sombre Lake, Signy Island, South Orkney Islands were analysed for volcanic tephra using light microscopy and magnetic susceptibility. Cores were dated using published 14C and 210Pb chronologies. Electron probe microanalyses of discrete tephra glass shards were undertaken to characterise the tephra geochemically in order to identify possible source volcanoes and refine tephrochronological data for the region. Results identified five tephra horizons in a core from Midge Lake. Four of these tephra at 3–4 cm, 8–9 cm (c. 450 yr BP), 15–16 cm (c. 755 ± 105 yr BP) and 21–22 cm (c. 1340 ± 100 yr BP) consisted of sodic basaltic to basalticandesitic glasses, containing abundant labradoritic feldspar inclusions, and a single ‘acidic’ tephra was found at 2–3 cm. Seven tephra horizons were identified in the Sombre Lake core including three basaltic tephra at 3–9 cm (30 ± 4 yr BP to 125 ± 25 yr BP), 31–32 cm and 44–46 cm (1325 ± 50 14C yr BP) and four acidic tephra at 21–22 cm and 24–25 cm, 33–36 cm (c. 1021 14C yr BP) and 54–56 cm (c. 1450 14C yr BP). These are the first tephra to be identified from the South Orkney Islands. Geochemical and grain size analysis indicated that the analysed Midge Lake tephra were derived from the Quaternary Deception Island volcano. Smaller grain sizes, congruent geochemical data and prevailing wind directions also indicate this volcano as the likely source of Sombre Lake tephra. Results highlight the importance of establishing geochemical consistency between tephra deposited across wide geographical areas, during apparently synchronous time periods, if they are to be used in a regional tephrochronology. |
format |
Article in Journal/Newspaper |
author |
Hodgson, Dominic A. Dyson, Coral L. Jones, Vivienne J. Smellie, John L. |
spellingShingle |
Hodgson, Dominic A. Dyson, Coral L. Jones, Vivienne J. Smellie, John L. Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica |
author_facet |
Hodgson, Dominic A. Dyson, Coral L. Jones, Vivienne J. Smellie, John L. |
author_sort |
Hodgson, Dominic A. |
title |
Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica |
title_short |
Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica |
title_full |
Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica |
title_fullStr |
Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica |
title_full_unstemmed |
Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica |
title_sort |
tephra analysis of sediments from midge lake (south shetland islands) and sombre lake (south orkney islands), antarctica |
publisher |
Cambridge University Press |
publishDate |
1998 |
url |
http://nora.nerc.ac.uk/id/eprint/504058/ https://doi.org/10.1017/S0954102098000030 |
long_lat |
ENVELOPE(-60.633,-60.633,-62.950,-62.950) ENVELOPE(-45.500,-45.500,-60.583,-60.583) ENVELOPE(-60.500,-60.500,-62.600,-62.600) ENVELOPE(-45.595,-45.595,-60.708,-60.708) ENVELOPE(-45.615,-45.615,-60.687,-60.687) ENVELOPE(-61.088,-61.088,-62.636,-62.636) |
geographic |
South Shetland Islands Deception Island South Orkney Islands Livingston Island Signy Island Sombre Lake Midge Lake |
geographic_facet |
South Shetland Islands Deception Island South Orkney Islands Livingston Island Signy Island Sombre Lake Midge Lake |
genre |
Antarc* Antarctic Science Antarctica Deception Island Livingston Island Signy Island South Orkney Islands South Shetland Islands |
genre_facet |
Antarc* Antarctic Science Antarctica Deception Island Livingston Island Signy Island South Orkney Islands South Shetland Islands |
op_relation |
Hodgson, Dominic A. orcid:0000-0002-3841-3746 Dyson, Coral L.; Jones, Vivienne J.; Smellie, John L. 1998 Tephra analysis of sediments from Midge Lake (South Shetland Islands) and Sombre Lake (South Orkney Islands), Antarctica. Antarctic Science, 10 (01). 13-20. https://doi.org/10.1017/S0954102098000030 <https://doi.org/10.1017/S0954102098000030> |
op_doi |
https://doi.org/10.1017/S0954102098000030 |
container_title |
Antarctic Science |
container_volume |
10 |
container_issue |
1 |
container_start_page |
13 |
op_container_end_page |
20 |
_version_ |
1766248719038021632 |