Across the Arid Diagonal: deglaciation of the western Andean Cordillera in southwest Bolivia and northern Chile

Ward, David B.; Thornton, Rachel M.; Cesta, Jason M.

doi:10.18172/cig.3209

Cited by 13 publications

(34 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…5). Glaciers advanced in nearby parts of the southern Central Andes around this time, for example the Nevado de Chañi (24°S; Martini et al, 2017) and the Sierra de Quilmes (26°S; Zech et al, 2017), as well as farther north at the Chajnantor plateau (23°S; Ward et al, 2015;, Uturuncu volcano (22°S; Blard et al, 2014;Ward et al, 2017), and the Cordillera Huayhuash in Peru (10°S; Hall et al, 2009). We therefore infer that the M1 advance at the Sierra de Aconquija occurred within a more widespread wet period in the Central Andes, corresponding to the summer insolation maximum around 40-45 ka, during which the SASM was intensified.…”

Section: Moraine Unit M1mentioning

confidence: 99%

“…Prior works identified anomalously old outliers on the grounds that they (i) sit far away from age clusters (e.g., Martini et al, 2017); (ii) violate the local stratigraphic order (e.g., Bromley et al, 2016;Ward et al, 2017;Zech et al, 2017); (iii) can be identified by statistical testing (e.g., Smith et al, 2005a,b;Jomelli et al, 2011);or (iv) by field observations that suggest a particular boulder is significantly older or was derived from hillslope debris (e.g., Martin et al, 2018).…”

Section: Nuclide Inheritancementioning

confidence: 99%

“…Much of the Central Andes are currently unglaciated due to the relatively warm and dry climate in this region. However, during the past several tens of thousands of years, the Central Andes experienced glacial advances during cooler and wetter episodes associated with orbital cycles and millennial-scale climate events (Smith et al, 2005a,b;Jomelli et al, 2014;Bromley et al, 2016;Martini et al, 2017;Ward et al, 2017). These climate changes have been reconstructed using archives and proxies including lake cores and shorelines (Sylvestre et al, 1999;Baker et al, 2001;Placzek et al, 2006Placzek et al, , 2013Baker and Fritz, 2015), plant fossils and pollen (Chepstow-Lusty et al, 2005;Maldonado et al, 2005;Torres et al, 2016), stable isotopes (Cruz et al, 2005;Wang et al, 2007;Kanner et al, 2012), ice cores (Thompson et al, 1995(Thompson et al, , 1998Ramirez et al, 2003), biomarkers (Fornace et al, 2016), and basin sediments (Nester et al, 2007;Steffen et al, 2009Steffen et al, , 2010Bekaddour et al, 2014;Schildgen et al, 2016;Tofelde et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Timing of past glaciation at the Sierra de Aconquija, northwestern Argentina, and throughout the Central Andes

D’Arcy

Schildgen

Strecker

et al. 2019

Quaternary Science Reviews

View full text Add to dashboard Cite

Advances in cosmogenic nuclide exposure dating have made moraines valuable terrestrial recorders of palaeoclimate. A growing number of moraine chronologies reported from the Central Andes show that tropical glaciers responded sensitively to past changes in precipitation and temperature over timescales ranging from 10 3 to 10 5 years. However, the causes of past glaciation in the Central Andes remain uncertain. Explanations have invoked insolation-modulated variability in the strength of the South American Summer Monsoon, teleconnections with the North Atlantic Ocean, and/or cooling in the Southern Hemisphere.The driver for these past climate changes is difficult to identify, partly due to a lack of dated moraine records, especially in climatically sensitive areas of the southern Central Andes.Moreover, new constraints are needed on precisely where and when glaciers advanced. We use cosmogenic 10 Be produced in situ to determine exposure ages for three generations of moraines at the Sierra de Aconquija, situated at 27°S on the eastern flank of the southern Central Andes. These moraines record glacier advances at approximately 22 ka and 40 ka, coincident with summer insolation maxima in the sub-tropics of the Southern Hemisphere, as well as at 12.5 ka and 13.5 ka during the Younger Dryas and the Antarctic Cold Reversal, respectively. We also identify minor glaciation during Bond Event 5, also known as the 8.2 ka event. These moraines register past climate changes with high fidelity, and currently constitute the southernmost dated record of glaciation on the eastern flank of the Central Andes. To contextualise these results, we compile 10 Be data reported from 144 moraines in the eastern Central Andes that represent past glacier advances. We re-calculate exposure ages from these data using an updated reference production rate, and we re-interpret the moraine ages by taking the oldest clustered boulder age (after the exclusion of outliers attributed to nuclide inheritance) as closest to the timing of glacier advance-an approach for which we provide empirical justification. This compilation reveals that Central Andean glaciers have responded to changes in temperature and precipitation. We identify cross-latitude advances in phase with insolation cycles, the last global glacial maximum, and episodes of strengthened monsoonal moisture transport including the Younger Dryas and Heinrich Stadials 1 and 2. Our results from the Sierra de Aconquija allow us to constrain the southerly limit of enhanced precipitation associated with Heinrich Stadials at ~25°S. More broadly, our findings demonstrate at both local and regional scales that moraines record past climate variability with a fine spatial and temporal resolution.3

show abstract

Section: Moraine Unit M1mentioning

confidence: 99%

Section: Nuclide Inheritancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Timing of past glaciation at the Sierra de Aconquija, northwestern Argentina, and throughout the Central Andes

D’Arcy

Schildgen

Strecker

et al. 2019

Quaternary Science Reviews

View full text Add to dashboard Cite

show abstract

“…La evolución de éstos glaciares se corresponde con otros estudios para los Andes Centrales (Espizua 1999(Espizua , 2002(Espizua y 2004Moreiras et al, 2016) y en general en la cordillera de los Andes (Ackert, et al 2008;Glasser, et al 2008;Martinez et al, 2011;Martini et al, 2017;Rabassa et al, 2011;Ward et al, 2017;Zech et al, 2017;Vargo et al, 2018), habiéndose identificado en diversos depósitos morrénicos de los Andes Áridos los eventos del Último Máximo Glacial y el Tardiglaciar (Moreiras et al, 2016y Martini et al, 2017.…”

Section: Discussionunclassified

“…Las glaciaciones ocurridas durante el periodo Cuaternario, han modelado intensamente el relieve actual de la cordillera de los Andes (Ackert, et al 2008;Glasser, et al 2008;Martinez et al, 2011;Martini et al, 2017;Ward et al, 2017;Zech et al, 2017;Vargo et al, 2018). Durante el Pleistoceno (2,58 a 0,0117 Ma) y Holoceno (desde hace 11,700 ka antes del presente, BP) han ocurrido diversos eventos de descenso de temperatura y avances de los frentes de hielo glacial.…”

Section: Introductionunclassified

Reconstrucción geomorfológica del último máximo glaciar en la cuenca del río San Juan, Argentina

Forte

Villarroel

2019

CyG

View full text Add to dashboard Cite

show abstract

Chronology of Late Pleistocene glacial advances in a Mount Mercedario catchment, Subtropical Andes of Argentina (32° S)

Jeanneret,

Moreiras,

Merchel

et al. 2024

J Quaternary Science

View full text Add to dashboard Cite

Glacial fluctuations leave distinct imprints on the landscapes of mountain environments, such as moraines and outwash terraces, that allow the reconstruction of past environmental changes. Unraveling the environmental history of the valleys of the Subtropical Andes of Argentina poses challenges due to the complex interplay of various surficial processes driven by both climatic and tectonic forces, which affects the preservation of glacial deposits. Consequently, there are few studies on past glaciations in this region compared to the rest of the Andes. This study focused on the lower section of the Blanco River Basin and the piedmont of the Frontal Cordillera in the south of San Juan Province, Argentina. A comprehensive geomorphological map of glacial landforms was created, along with sedimentological studies of outwash terraces. Additionally, numerical ages were obtained for both landforms using terrestrial cosmogenic nuclides for moraine boulders and luminescence dating for sandy layers in the outwash terraces. Our findings reveal at least two glacial advances since the Last Glacial Maximum (LGM), each associated with distinct outwash levels. The Río Blanco Advance occurred during the LGM, and the Laguna Advance is assigned to the late stages of the LGM, both with their corresponding outwash terraces. Additionally, the Amarillo Advance is believed to have occurred during the Holocene period and an older Marine Istope Stage 5 d named Guanaquito Advance. The provided data add valuable numerical information about glacial fluctuations since the LGM and also reveal the impact of glacial downwasting on piedmont landforms.

show abstract

Across the Arid Diagonal: deglaciation of the western Andean Cordillera in southwest Bolivia and northern Chile

Abstract: ABSTRACT. Here we review published cosmogenic records of glaciation and deglaciation from the western cordillera of the arid subtropical Andes of northern

Cited by 13 publications

References 56 publications

Timing of past glaciation at the Sierra de Aconquija, northwestern Argentina, and throughout the Central Andes

Timing of past glaciation at the Sierra de Aconquija, northwestern Argentina, and throughout the Central Andes

Reconstrucción geomorfológica del último máximo glaciar en la cuenca del río San Juan, Argentina

Chronology of Late Pleistocene glacial advances in a Mount Mercedario catchment, Subtropical Andes of Argentina (32° S)

Contact Info

Product

Resources

About