The Last Glacial Maximum and Deglacial History of the Seno Skyring Ice Lobe (52°S), Southern Patagonia

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dc.contributor.authorLira, Maria-Paz
dc.contributor.authorGarcia, Juan-Luis
dc.contributor.authorBentley, Michael J.
dc.contributor.authorJamieson, Stewart S. R.
dc.contributor.authorDarvill, Christopher M.
dc.contributor.authorHein, Andrew S.
dc.contributor.authorFernandez, Hans
dc.contributor.authorRodes, Angel
dc.contributor.authorFabel, Derek
dc.contributor.authorSmedley, Rachel K.
dc.contributor.authorBinnie, Steven A.
dc.date.accessioned2025-01-20T21:04:07Z
dc.date.available2025-01-20T21:04:07Z
dc.date.issued2022
dc.description.abstractThere are still many uncertainties about the climatic forcing that drove the glacier fluctuations of the Patagonian Ice Sheet (PIS, 38-55 degrees S) during the last glacial period. A key source of uncertainty is the asynchrony of ice lobe fluctuations between the northern, central, and southern PIS. To fully understand the regional trends requires careful mapping and extensive geochronological studies. This paper presents geomorphological and geochronological reconstructions of the glacial and deglacial landforms formed during the last glacial period at the Seno Skyring lobe, southernmost Patagonia (52 degrees S, 71 degrees W). We present a detailed geomorphological map, where we identify two moraine systems. The outer and older is named Laguna Blanca (LB) and the inner Rio Verde (RV). The LB moraines were built subaerially, whereas parts of the RV were deposited subaqueously under the palaeo lake Laguna Blanca, which developed during deglaciation. We conducted surface exposure Be-10 dating methods on boulder samples collected from LB and RV glacial margins. The moraine LB III and LB IV formed at 26.3 +/- 2.3 ka (n = 5) and 24.3 +/- 0.9 ka (n = 3), respectively. For the inner RV moraine, we obtained an age of 18.7 +/- 1.5 ka (n = 6). For the palaeo Laguna Blanca evolution, we performed Be-10 exposure ages on shoreline berms and optically stimulated luminesce dating to constrain the lake levels, and Be-10 depth profile dating on an outwash deposit formed by a partial lake drainage event, which occurred at 22 +/- 3 ka. For the RV moraine deglaciation, we performed radiocarbon dating of basal sediments in a peat bog, which indicates that the glacier retreated from the terminal RV moraine by at least c. 16.4 cal kyr BP. Our moraine geochronology shows an asynchrony in the maximum extents and a different pattern of ice advances between neighbouring lobes in southern Patagonia. We speculate that this may be due, at least in part, to the interaction between topography and the precipitation carried by the southern westerly wind belt. However, we found broad synchrony of glacial readvances contemporaneous with the RV moraine.
dc.fuente.origenWOS
dc.identifier.doi10.3389/feart.2022.892316
dc.identifier.eissn2296-6463
dc.identifier.urihttps://doi.org/10.3389/feart.2022.892316
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/93213
dc.identifier.wosidWOS:000829495200001
dc.language.isoen
dc.revistaFrontiers in earth science
dc.rightsacceso restringido
dc.subjectpatagonian ice sheet
dc.subjectglacial geomorphology
dc.subjectcosmogenic nuclide dating
dc.subjectproglacial lake evolution
dc.subjectgeochronology
dc.subject.ods13 Climate Action
dc.subject.odspa13 Acción por el clima
dc.titleThe Last Glacial Maximum and Deglacial History of the Seno Skyring Ice Lobe (52°S), Southern Patagonia
dc.typeartículo
dc.volumen10
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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