Luminescence dating of glacial advances at Lago Buenos Aires (∼46 °S), Patagonia

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Luminescence dating of glacial advances at Lago Buenos Aires (∼46 °S), Patagonia. / Smedley, Rachel; Glasser, Neil; Duller, G. A T.

In: Quaternary Science Reviews, Vol. 134, 15.02.2016, p. 59-73.

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Smedley, Rachel ; Glasser, Neil ; Duller, G. A T. / Luminescence dating of glacial advances at Lago Buenos Aires (∼46 °S), Patagonia. In: Quaternary Science Reviews. 2016 ; Vol. 134. pp. 59-73.

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@article{e058edc0753b4ea882176adf38eae5cd,
title = "Luminescence dating of glacial advances at Lago Buenos Aires (∼46 °S), Patagonia",
abstract = "Understanding the timing of past glacial advances in Patagonia is of global climatic importance because of the insight this can provide into the influence on glacier behaviour of changes in temperature and precipitation related to the Southern Westerlies. In this paper we present new luminescence ages determined using single grains of K-feldspar from proglacial outwash sediments that were deposited by the Patagonian Ice Sheet around Lago Buenos Aires (∼46 °S), east of the contemporary Northern Patagonian Icefield. The new luminescence ages indicate that major outwash accumulations formed around ∼110 ± 20 ka to 140 ± 20 ka and that these correspond to the Moreno I and II moraine ridges, which were previously dated using cosmogenic isotope dating to 150 ± 30 ka. Luminescence dating at Lago Buenos Aires has also identified outwash sediments that were deposited during glacial advances ∼30.8 ± 5.7 ka and ∼34.0 ± 6.1 ka (MIS 3) that are not recorded in the moraine record. Younger outwash accumulations were then deposited between ∼14.7 ± 2.1 and 26.2 ± 1.6 ka which correspond to the Fenix I – V moraine ridges. The combined chronology suggests that glacial advances occurred ∼110 ± 20 ka to 150 ± 30 ka (MIS 6), ∼30.8 ± 5.7 ka to ∼34.0 ± 6.1 ka (MIS 3), and ∼14.7 ± 2.1 to 26.2 ± 1.6 ka (MIS 2) at Lago Buenos Aires. Overall luminescence dating using single grains of K-feldspar has excellent potential to contribute towards the ever-increasing geochronological dataset constraining the timings of glacial advances in Patagonia.",
keywords = "Patagonia, glacial, geomorphology, luminescence, single grains, Feldspar",
author = "Rachel Smedley and Neil Glasser and Duller, {G. A T.}",
year = "2016",
month = feb,
day = "15",
doi = "10.1016/j.quascirev.2015.12.010",
language = "English",
volume = "134",
pages = "59--73",
journal = "Quaternary Science Reviews",
issn = "0277-3791",
publisher = "Elsevier",

}

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TY - JOUR

T1 - Luminescence dating of glacial advances at Lago Buenos Aires (∼46 °S), Patagonia

AU - Smedley, Rachel

AU - Glasser, Neil

AU - Duller, G. A T.

PY - 2016/2/15

Y1 - 2016/2/15

N2 - Understanding the timing of past glacial advances in Patagonia is of global climatic importance because of the insight this can provide into the influence on glacier behaviour of changes in temperature and precipitation related to the Southern Westerlies. In this paper we present new luminescence ages determined using single grains of K-feldspar from proglacial outwash sediments that were deposited by the Patagonian Ice Sheet around Lago Buenos Aires (∼46 °S), east of the contemporary Northern Patagonian Icefield. The new luminescence ages indicate that major outwash accumulations formed around ∼110 ± 20 ka to 140 ± 20 ka and that these correspond to the Moreno I and II moraine ridges, which were previously dated using cosmogenic isotope dating to 150 ± 30 ka. Luminescence dating at Lago Buenos Aires has also identified outwash sediments that were deposited during glacial advances ∼30.8 ± 5.7 ka and ∼34.0 ± 6.1 ka (MIS 3) that are not recorded in the moraine record. Younger outwash accumulations were then deposited between ∼14.7 ± 2.1 and 26.2 ± 1.6 ka which correspond to the Fenix I – V moraine ridges. The combined chronology suggests that glacial advances occurred ∼110 ± 20 ka to 150 ± 30 ka (MIS 6), ∼30.8 ± 5.7 ka to ∼34.0 ± 6.1 ka (MIS 3), and ∼14.7 ± 2.1 to 26.2 ± 1.6 ka (MIS 2) at Lago Buenos Aires. Overall luminescence dating using single grains of K-feldspar has excellent potential to contribute towards the ever-increasing geochronological dataset constraining the timings of glacial advances in Patagonia.

AB - Understanding the timing of past glacial advances in Patagonia is of global climatic importance because of the insight this can provide into the influence on glacier behaviour of changes in temperature and precipitation related to the Southern Westerlies. In this paper we present new luminescence ages determined using single grains of K-feldspar from proglacial outwash sediments that were deposited by the Patagonian Ice Sheet around Lago Buenos Aires (∼46 °S), east of the contemporary Northern Patagonian Icefield. The new luminescence ages indicate that major outwash accumulations formed around ∼110 ± 20 ka to 140 ± 20 ka and that these correspond to the Moreno I and II moraine ridges, which were previously dated using cosmogenic isotope dating to 150 ± 30 ka. Luminescence dating at Lago Buenos Aires has also identified outwash sediments that were deposited during glacial advances ∼30.8 ± 5.7 ka and ∼34.0 ± 6.1 ka (MIS 3) that are not recorded in the moraine record. Younger outwash accumulations were then deposited between ∼14.7 ± 2.1 and 26.2 ± 1.6 ka which correspond to the Fenix I – V moraine ridges. The combined chronology suggests that glacial advances occurred ∼110 ± 20 ka to 150 ± 30 ka (MIS 6), ∼30.8 ± 5.7 ka to ∼34.0 ± 6.1 ka (MIS 3), and ∼14.7 ± 2.1 to 26.2 ± 1.6 ka (MIS 2) at Lago Buenos Aires. Overall luminescence dating using single grains of K-feldspar has excellent potential to contribute towards the ever-increasing geochronological dataset constraining the timings of glacial advances in Patagonia.

KW - Patagonia

KW - glacial

KW - geomorphology

KW - luminescence

KW - single grains

KW - Feldspar

UR - http://hdl.handle.net/2160/30609

U2 - 10.1016/j.quascirev.2015.12.010

DO - 10.1016/j.quascirev.2015.12.010

M3 - Article

VL - 134

SP - 59

EP - 73

JO - Quaternary Science Reviews

JF - Quaternary Science Reviews

SN - 0277-3791

ER -

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