Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland
Two megafloods in the canyon of the Jokulsi i Fjóllum, the major northern routeway for glaciovolcanic floods from Vatnajókull, have been closely dated by 14C AMS dates from Betula macrofossils within peat immediately below beds of flood-deposited sand. Ages of c. 4415 and c. 4065 yr BP (5020 and 461...
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crsagepubl:10.1191/0959683606hl956rr 2023-05-15T16:34:02+02:00 Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland Kirkbride, Martin P. Dugmore, Andrew J. Brazier, Vanessa 2006 http://dx.doi.org/10.1191/0959683606hl956rr http://journals.sagepub.com/doi/pdf/10.1191/0959683606hl956rr en eng SAGE Publications http://journals.sagepub.com/page/policies/text-and-data-mining-license The Holocene volume 16, issue 4, page 605-609 ISSN 0959-6836 1477-0911 Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change journal-article 2006 crsagepubl https://doi.org/10.1191/0959683606hl956rr 2022-05-26T08:16:20Z Two megafloods in the canyon of the Jokulsi i Fjóllum, the major northern routeway for glaciovolcanic floods from Vatnajókull, have been closely dated by 14C AMS dates from Betula macrofossils within peat immediately below beds of flood-deposited sand. Ages of c. 4415 and c. 4065 yr BP (5020 and 4610 cal. yr BP) are consistent with the presence of the Hekla 4 tephra (c. 3830 yr BP) resting on the upper surface of the younger flood sand. These sediments are correlated across the Jókulsa a Fjollum canyon with the upper flood sands in a stack recording around 16 flood events. Deposits on both sides of the canyon were trimmed by the last megaflood after the Hekla 3 tephra fall at c. 2900 yr BP, and the highest Holocene flood stages were at the culmination of a series peaking at c. 3500 yr BP. These floods have wider palaeoclimatic significance because they require the formation of large subglacial reservoirs below Vatnajókull. Therefore, the dated floods indicate that a large composite ice cap covered volcanoes in the southeastern highlands through the early and middle Holocene, and that flood routeways largely switched to the south after c. 3500 yr BP. Article in Journal/Newspaper Hekla Ice cap Iceland SAGE Publications (via Crossref) The Holocene 16 4 605 609 |
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SAGE Publications (via Crossref) |
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English |
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Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
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Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change Kirkbride, Martin P. Dugmore, Andrew J. Brazier, Vanessa Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland |
topic_facet |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
description |
Two megafloods in the canyon of the Jokulsi i Fjóllum, the major northern routeway for glaciovolcanic floods from Vatnajókull, have been closely dated by 14C AMS dates from Betula macrofossils within peat immediately below beds of flood-deposited sand. Ages of c. 4415 and c. 4065 yr BP (5020 and 4610 cal. yr BP) are consistent with the presence of the Hekla 4 tephra (c. 3830 yr BP) resting on the upper surface of the younger flood sand. These sediments are correlated across the Jókulsa a Fjollum canyon with the upper flood sands in a stack recording around 16 flood events. Deposits on both sides of the canyon were trimmed by the last megaflood after the Hekla 3 tephra fall at c. 2900 yr BP, and the highest Holocene flood stages were at the culmination of a series peaking at c. 3500 yr BP. These floods have wider palaeoclimatic significance because they require the formation of large subglacial reservoirs below Vatnajókull. Therefore, the dated floods indicate that a large composite ice cap covered volcanoes in the southeastern highlands through the early and middle Holocene, and that flood routeways largely switched to the south after c. 3500 yr BP. |
format |
Article in Journal/Newspaper |
author |
Kirkbride, Martin P. Dugmore, Andrew J. Brazier, Vanessa |
author_facet |
Kirkbride, Martin P. Dugmore, Andrew J. Brazier, Vanessa |
author_sort |
Kirkbride, Martin P. |
title |
Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland |
title_short |
Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland |
title_full |
Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland |
title_fullStr |
Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland |
title_full_unstemmed |
Radiocarbon dating of mid-Holocene megaflood deposits in the Jokulsa a Fjollum, north Iceland |
title_sort |
radiocarbon dating of mid-holocene megaflood deposits in the jokulsa a fjollum, north iceland |
publisher |
SAGE Publications |
publishDate |
2006 |
url |
http://dx.doi.org/10.1191/0959683606hl956rr http://journals.sagepub.com/doi/pdf/10.1191/0959683606hl956rr |
genre |
Hekla Ice cap Iceland |
genre_facet |
Hekla Ice cap Iceland |
op_source |
The Holocene volume 16, issue 4, page 605-609 ISSN 0959-6836 1477-0911 |
op_rights |
http://journals.sagepub.com/page/policies/text-and-data-mining-license |
op_doi |
https://doi.org/10.1191/0959683606hl956rr |
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The Holocene |
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4 |
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605 |
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1766023782519013376 |