The last deglaciation of Peru and Bolivia

Abstract

ABSTRACT. The tropical Andes of Peru and Bolivia are important for preserving geomorphic evidence of multiple glaciations, allowing for refinements of chronology to aid in understanding climate dynamics at a key location between hemispheres. This review focuses on the deglaciation from Late-Pleistocene maximum positions near the global Last Glacial Maximum (LGM). We synthesize the results of the most recent published glacial geologic studies from 12 mountain ranges or regions within

The state of knowledge on the deglaciation of America in 2017

“…in Venezuela, Colombia and Ecuador. Mark et al (2017) do the same in the Central Andes of Peru and Bolivia. Alcalá-Reygosa (2017) provides an example of the deglaciation of the HualcaHualca volcano, situated in southwest Peru.…”

“…In the Northern Andes, there is still scarce information about the initial and most marked phases of deglaciation. Mark et al (2017) show the average date of the maximum glacial extent would have been 25 ka in Peru and Bolivia, but it would include a broad chronological range of ±7 ka. The deglaciation would have already been significant by 20 ka or even earlier.…”

“…In their contribution, Mark et al (2017) indicate that the synchronous or asynchronous nature of the deglaciation of the Tropical Andes is still a matter of debate. In fact, this debate has been going on for over 40 years, and can be extended to the entire Andean region, along with the possibility of the synchrony, or not, of events occurring in the Andes and the evolution of the glaciers in the rest of the northern hemisphere and, in particular, with the evolution of the temperature of the North Atlantic.…”

“…According to Angel et al (2017), the knowledge of the deglaciation history of the Northern Andes is very limited and, therefore, we cannot draw general conclusions from it yet, although most of glacial advances are acknowledged contemporary to the H1. Mark et al (2017) refer to the diverse positive advances that interrupted deglaciation in Peru and Bolivia between 20-18 ka, where a good number of moraines are dated with an average of 18.9 ± 0.5 ka, always coinciding with wet phases. These authors acknowledge a clear impact of the H1 event, as seen from the numerous moraines with an average age of 16.1 ±1.1 ka.…”

Geomorphological response to the Lateglacial-Holocene palaeoenvironmental changes in the NE piedmont of the Sierra de Aconquija (Tafí Valley, NW Argentina)

“…Glacial and Periglacial geomorphological studies from the tropical Andes and N Argentina and Chile have acquired increasing importance in recent years, especially when considering improvements in our understanding of the chronological and regional paleoenvironment (Payne, 1998, Rodbell et al, 2009Ahumada et al, 2017;Azócar and Brenning, 2010;Martini et al, 2013Martini et al, , 2017Zech et al, 2009Zech et al, , 2017Jomelli et al, 2014Jomelli et al, , 2017Janke et al, 2015;Solomina et al, 2015;Ward et al, 2015Ward et al, , 2017Mark et al 2017). The main importance of the mountainous area is the isolated character of the glacial and periglacial testimonies due to its arid conditions.…”