Luminescence dating of glacial advances at Lago Buenos Aires (similar to 46 degrees S), Patagonia



Smedley, RK ORCID: 0000-0001-7773-5193, Glasser, NF and Duller, GAT
(2016) Luminescence dating of glacial advances at Lago Buenos Aires (similar to 46 degrees S), Patagonia. Quaternary Science Reviews: the international multidisciplinary research and review journal, 134. pp. 59-73.

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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.

Item Type: Article
Uncontrolled Keywords: Patagonia, Glacial, Geomorphology, Luminescence, Single grains, Feldspar
Depositing User: Symplectic Admin
Date Deposited: 24 Jan 2018 07:51
Last Modified: 19 Jan 2023 06:42
DOI: 10.1016/j.quascirev.2015.12.010
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3016722