A 37,000-year environmental magnetic record of aeolian dust deposition from Burial Lake, Arctic Alaska
A 37,000-year environmental magnetic record of aeolian dust deposition from Burial Lake, Arctic Alaska
Environmental magnetism and radiocarbon dating of Burial Lake sediments constrain the timing and magnitude of regional aeolian deposition for the Noatak region of western Arctic Alaska for the last ∼37,000 years. Burial Lake (68.43°N, 159.17°W, 21.5 m water depth) is optimally located to monitor regional dust deposition because it is perched above local drainage and isolated from glacial processes. Cores collected in the summer of 2010 were studied through the application of magnetizations and progressive alternating field (AF) demagnetization of u-channel samples, with additional data provided by computed tomography (CT) derived density, hysteresis measurements, isothermal remanent magnetization (IRM) acquisition experiments, organic carbon content, biogenic silica, physical grain size, radiocarbon dating of wood, seeds, and plant macrofossils, point source magnetic susceptibility, and X-ray fluorescence (XRF). With similar magnetic properties to regional Alaskan loess deposits, low coercivity, highly magnetic material deposited during the late-Pleistocene contrasts with a high coercivity, weakly magnetic component found throughout the record, consistent with locally-derived detritus. The relative proportion of low coercivity to high coercivity magnetic material, defined by the S-Ratios, is used to reconstruct the regional input of dust to the basin over time. A four-fold decrease in the low coercivity component through the deglacial transition is interpreted to reflect diminished dust input to the region. Comparisons with potential sources of dust show that the timing of deposition in Burial Lake is largely consistent with general aridity, lack of vegetative cover, and increased windiness, rather than glacial advances or retreats. The influence from subaerial exposure of continental shelves cannot be ruled out as a significant far-field source of dust to interior Alaska during the Last Glacial Maximum (LGM), but is unlikely to have been the sole source, or to have contributed to increased dust in both the early and late Holocene.
81-97
Dorfman, J.M.
0336e4ec-29eb-4170-b603-040a3d994e76
Stoner, J.S.
07fdf2db-cd5b-4d16-a148-c3cf67a1aaf8
Finkenbinder, M.S.
246545d7-79e1-4296-876d-d10077909786
Abbott, M.B.
3cc55c60-688c-4438-86af-896856f75e07
Xuan, C.
3f3cad12-b17b-46ae-957a-b362def5b837
St-Onge, G.
6bd6c30d-2ded-4432-8a8a-59ab4c8fce5a
1 November 2015
Dorfman, J.M.
0336e4ec-29eb-4170-b603-040a3d994e76
Stoner, J.S.
07fdf2db-cd5b-4d16-a148-c3cf67a1aaf8
Finkenbinder, M.S.
246545d7-79e1-4296-876d-d10077909786
Abbott, M.B.
3cc55c60-688c-4438-86af-896856f75e07
Xuan, C.
3f3cad12-b17b-46ae-957a-b362def5b837
St-Onge, G.
6bd6c30d-2ded-4432-8a8a-59ab4c8fce5a
Dorfman, J.M., Stoner, J.S., Finkenbinder, M.S., Abbott, M.B., Xuan, C. and St-Onge, G.
(2015)
A 37,000-year environmental magnetic record of aeolian dust deposition from Burial Lake, Arctic Alaska.
Quaternary Science Reviews, 128, .
(doi:10.1016/j.quascirev.2015.08.018).
Abstract
Environmental magnetism and radiocarbon dating of Burial Lake sediments constrain the timing and magnitude of regional aeolian deposition for the Noatak region of western Arctic Alaska for the last ∼37,000 years. Burial Lake (68.43°N, 159.17°W, 21.5 m water depth) is optimally located to monitor regional dust deposition because it is perched above local drainage and isolated from glacial processes. Cores collected in the summer of 2010 were studied through the application of magnetizations and progressive alternating field (AF) demagnetization of u-channel samples, with additional data provided by computed tomography (CT) derived density, hysteresis measurements, isothermal remanent magnetization (IRM) acquisition experiments, organic carbon content, biogenic silica, physical grain size, radiocarbon dating of wood, seeds, and plant macrofossils, point source magnetic susceptibility, and X-ray fluorescence (XRF). With similar magnetic properties to regional Alaskan loess deposits, low coercivity, highly magnetic material deposited during the late-Pleistocene contrasts with a high coercivity, weakly magnetic component found throughout the record, consistent with locally-derived detritus. The relative proportion of low coercivity to high coercivity magnetic material, defined by the S-Ratios, is used to reconstruct the regional input of dust to the basin over time. A four-fold decrease in the low coercivity component through the deglacial transition is interpreted to reflect diminished dust input to the region. Comparisons with potential sources of dust show that the timing of deposition in Burial Lake is largely consistent with general aridity, lack of vegetative cover, and increased windiness, rather than glacial advances or retreats. The influence from subaerial exposure of continental shelves cannot be ruled out as a significant far-field source of dust to interior Alaska during the Last Glacial Maximum (LGM), but is unlikely to have been the sole source, or to have contributed to increased dust in both the early and late Holocene.
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Accepted/In Press date: 13 August 2015
e-pub ahead of print date: 29 September 2015
Published date: 1 November 2015
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Local EPrints ID: 427754
URI: http://eprints.soton.ac.uk/id/eprint/427754
ISSN: 0277-3791
PURE UUID: 298cc01c-1dff-4b28-9927-2f7a897dba07
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Date deposited: 28 Jan 2019 17:30
Last modified: 16 Mar 2024 04:16
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Author:
J.M. Dorfman
Author:
J.S. Stoner
Author:
M.S. Finkenbinder
Author:
M.B. Abbott
Author:
G. St-Onge
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