Holocene glaciations of Hielo Patagonico (Patagonia Icefield), South America: A brief review

The Hielo Patagonico (Patagonia Icefield), South America, is the largest temperate ice body in the Southern Hemisphere with more than 70 major outlet glaciers and a total area of ca. 17,200 km(2). For the Hielo Patagonico, two major schemes for the Holocene glaciations (Neoglaciations) have been proposed. Mercer first proposed three Neoglaciations, I at 4500-4000 years before the present (yr BP), II at 2700-2000 yr BP and III at the 17-19th centuries. Aniya later postulated a scheme of four Neoglaciations, I at ca. 3600 yr BP, II at 2400-2200 yr BP, III at 1600-900 yr BP, and IV at the 17-19th centuries, which is congruent with other regions of the Andes. The main differences are the age of Neoglaciation I and the existence of a Neoglaciation at 1600-900 yr BP. After examining the dates given by other studies, although scanty, I propose a new scheme of five Neoglaciations, I at 4500-4000 yr BP, II at 3600-3300 yr BP, III at 2700-2000 yr BP, IV at 1600-900 yr BP and V at 17-19th centuries, that is, the Little Ice Ace (LIA). In addition, there were two earlier Holocene glaciations, probably at 5700-5000 yr BP and 8100-6800 (or 7500) yr BP. Two older ages, 8800-8500 yr BP and 9700-9100 yr BP, are uncertain.