The MIS 3 maximum of the Torres del Paine and Última Esperanza ice lobes in Patagonia and the pacing of southern mountain glaciation

García, Juan‐Luis; Hein, Andrew S.; Binnie, Steven A.; Gomez, Gustavo A.; González, Mauricio A.; Dunai, Tibor J.

doi:10.1016/j.quascirev.2018.01.013

Cited by 50 publications

(108 citation statements)

References 92 publications

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“…Although some glaciers showed extensive retreat at this time and never recovered, other glaciers readvanced to full glacial extent until the very end of the LGM at 18 ka, giving a short-term asymmetry of Patagonian glacier responses to the deglacial signal. The close paleoclimate link between the WDC and some Patagonian glacier records exposes the sensitivity of both sites to the changes in the Southern Ocean sea surface temperatures and sea ice extent, ultimately controlled by local insolation (WAIS Divide Project Members, 2013), and thereby suggesting a paleoclimate teleconnection between mid- and high latitudes (e.g., Kaplan et al 2008; Denton et al, 2010; WAIS Divide Project Members, 2013; Darvill et al, 2016; García et al, 2018).…”

Section: Discussionmentioning

confidence: 99%

Early deglaciation and paleolake history of Río Cisnes Glacier, Patagonian Ice Sheet (44°S)

et al. 2018

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The timing, structure, and landscape change during the Patagonian Ice Sheet deglaciation remains unresolved. In this article, we provide a geomorphic, stratigraphic, and geochronological deglacial record of Río Cisnes Glacier at 44°S and also from the nearby Río Ñirehuao and Río El Toqui valleys (45°S) in Chilean Patagonia. Our 14C, 10Be, and optically stimulated luminescence data indicate that after the last glacial maximum, Río Cisnes Glacier experienced ~100 km deglaciation between >19.0 and 12.3 ka, accompanied by the formation of large glacial paleolakes. Deglaciation was interrupted by several ice readvances, and by 16.9±0.3 ka, Río Cisnes Glacier extended only ~40% of its full glacial extent. The deglaciation of Río Cisnes Glacier and other sensitive Patagonian glaciers occurred at least 1 ka earlier than the ca. 17.8 ka normally assumed for the local termination, coincident with West Antarctic isotope records. This early deglaciation can be linked to an orbital forcing–driven decline of Southern Ocean sea ice associated with a distinct atmospheric warming that is apparent for West Antarctica through Patagonia.

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Section: Discussionmentioning

confidence: 99%

Early deglaciation and paleolake history of Río Cisnes Glacier, Patagonian Ice Sheet (44°S)

et al. 2018

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“…García et al, 2019;Iglesias et al, 2016;Van Daele et al, 2016) there remains a general lack of published detailed mapping and geochronological data across the northeastern sector of the former ice sheet, between ∼39°S and ∼46.5°S (Darvill et al, 2015;Davies et al, 2020;Mendelová et al, 2017). Robust reconstructions from this region are needed to understand fully the PIS response to the Last Glacial Maximum (LGM) at these latitudes, and to investigate latitudinal dependencies on the timing of the local LGM throughout Patagonia (Darvill et al, 2015;Davies et al, 2020;García et al, 2018;Sagredo et al, 2011). A vital component of such reconstructions is detailed, glacier-scale geomorphological mapping (Chandler et al, 2018;Clark et al, 2018;Evans & Orton, 2015).…”

Section: Introductionmentioning

confidence: 99%

The glacial geomorphology of the Río Corcovado, Río Huemul and Lago Palena/General Vintter valleys, northeastern Patagonia (43°S, 71°W)

et al. 2020

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This study presents the first detailed glacial geomorphological map of the sediment-landform assemblages formed by three eastern outlet glaciers of the former Patagonian Ice Sheet. These glaciers occupied the Río Corcovado, Río Huemul and Lago Palena/General Vintter valleys, Chubut province, Argentina (43°S, 71°W). By combining remote sensing and field-mapping, we build on previous ice-sheet scale mapping and geological surveys to provide highresolution spatial information on local ice-contact glaciogenic, glaciofluvial, glaciolacustrine, and subglacial landforms. Twenty-five landform types, many of which are newly mapped in the region, were digitized as georeferenced shapefiles over a 5300 km 2 area. This map enables the identification of former ice-flow directions, relative ice-margin positions and glaciofluvial drainage pathways for each preserved Quaternary glaciation. It also elucidates the former areal extent, geolocation and spillways of glaciolacustrine bodies formed during the last deglaciation. The map delivers an essential framework on which to build robust glacier-scale geomorphological and geochronological reconstructions.

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“…Even when the nature of these millennial-scale climate changes are still a subject of debate and we cannot expect to find their record in our coastal assemblages (sea level was lower than present during MIS 4-3), they are documented for southern South America, both in surface waters off Chile (Lamy et al, 2004;Kaiser et al, 2005) and in the Andean continental record (García et al, 2018), and northwards off Brazil (Carvahlo-Campos et al, 2016). The less stable climate during MIS 3 and MIS 2 compared to MIS5 (Brook and Buizert, 2018) and the associated oscillations in atmospheric CO 2 concentrations -that remain so far unexplained or at least poorly constrained-, in the southern westerlies wind belt position, in release of icebergs, subglacial meltwater and in iron inputs from icebergs/meltwater around western Antarctica-Drake Passage must have had pronounced impacts on productivity (Ó Cofaigh et al, 2014;Armour and Bitz, 2015;Gottschalk et al, 2016) and are expected to have affected the geochemical properties of the southern SWA in a measurable way.…”

Section: Which Changes Could Explain the Different Holocene Pattern?mentioning

confidence: 91%

“…11C) a number of environmental changes were reported to have occurred linked to Patagonia including the rising sea-level from the Last Glacial Maximum (MIS 2; lowest sea-level globally at -120 m ca. 22 ka or 48 ka in southern Chile; García et al, 2018) across the glacial-interglacial transition (−40 m at ca. 11 ka) into the Holocene (Ponce et al, 2011;Isla and Schnack, 2016).…”

Section: Which Changes Could Explain the Different Holocene Pattern?mentioning

confidence: 99%

Late Quaternary nearshore molluscan patterns from Patagonia: Windows to southern southwestern Atlantic-Southern Ocean palaeoclimate and biodiversity changes?

Aguirre

Richiano

Voelker

et al. 2019

Global and Planetary Change

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Varied approaches (palaeobiodiversity, palaeobiogeography, bioerosion, geochemistry) to unique Patagonian late Quaternary molluscan assemblages in the southwestern Atlantic, with ages especially from interglacial Marine Isotope Stage (MIS) 5e and MIS 1, provide large-scale and long-temporal palaeoenvironmental data for the southern SWA. Together with new patterns of δ 18 O and δ 13 C variations in modern, mid-Holocene, and Late to Middle Pleistocene shells of Protothaca antiqua (Bivalvia) and the coeval Pleistocene Tegula atra (Gastropoda), the overall sources of evidence illustrate possible responses to recent palaeoclimate and sea-ice changes around the southernmost SWA-western Antarctica, leading to modern conditions. For the mid-Holocene, the influence of the Hypsithermal is confirmed. In the northern Golfo San Matías, the highest δ 18 O and δ 13 C values support higher salinity and sea surface temperatures (SST), and a Golfo San Matías Front stronger than today. Lower δ 18 O values in the northern Golfo San Jorge (GSJ) compared to the Late to Middle Pleistocene suggest warmer mid-Holocene waters, independently supported by thermally anomalous molluscan taxa, geographical shifts of areas of endemism and absence of T. atra (cold water proxy); overall higher δ 13 C values compared to present suggest higher productivity. For the Late to Middle Pleistocene (particularly MIS 5e), highest δ 13 C values (relative to modern and mid-Holocene trends) match with the location of tidal fronts and areas of maximum chlorophyll-a concentrations today. Accordingly, these fronts may have been already active and significantly intensified due to the prevailing climate conditions that included colder waters and stronger upwelling from the southern GSJ southwards. This is independently supported by palaeobiogeographical and bioerosion trends and the dominance of the cold water species T. atra during the Pleistocene, which is dispersed from the SE Pacific

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The MIS 3 maximum of the Torres del Paine and Última Esperanza ice lobes in Patagonia and the pacing of southern mountain glaciation

Cited by 50 publications

References 92 publications

Early deglaciation and paleolake history of Río Cisnes Glacier, Patagonian Ice Sheet (44°S)

Early deglaciation and paleolake history of Río Cisnes Glacier, Patagonian Ice Sheet (44°S)

The glacial geomorphology of the Río Corcovado, Río Huemul and Lago Palena/General Vintter valleys, northeastern Patagonia (43°S, 71°W)

Late Quaternary nearshore molluscan patterns from Patagonia: Windows to southern southwestern Atlantic-Southern Ocean palaeoclimate and biodiversity changes?

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