Holocene paleohydrological reconstruction in a high-altitude periglacial basin (Central Andes): a joint paleolimnological-geomorphological view

MATEO MARTINI; GUERRA, LUCIA; ELISEO FLORES; HAJDAS, IRKA; VOGEL, HANDRIK; ARIZTEGUI, DANIEL

Congreso; IPA-ILA Congress; 2022

High-altitudewetlands and rock glaciers correspond to exceptional climate-sensitive archivesoccupying the current periglacial areas from the Central Andes. In this study, weanalyze the sedimentary record of the Laguna Leoneajo wetland (22°S/65°W at4526 m a.s.l), which is located in small-periglacial basin at the SantaVictoria range of Northwestern Argentina. The Laguna Leoneajo wetland issituated in a glacial valley, downstream of an active and relict rock glacier. Robustradiocarbon dating, geochemical and physical data from a composite sedimentarycore, reaching the lake basement, comprise the record of the lake-environmentalhistory since the last deglaciation, and document the hydrological changes occurredduring the last 15,000 years. Complementary geomorphological analysis and the monitoringof the rock glacier activity located upstream of the Laguna Leoneajo wetland, arecombined with the paleolimnological data in order to reconstruct the evolutionof this periglacial basin. The beginning of the lake record, the time offormation of the present-day relict rock glacier and its collapse, and theirconnection with major climate changes occurred in the Central Andes, as well asthe equilibrium (or not) of the periglacial landforms with the current climateconditions are the main topics discussed along this work. Outcomes of this researchprovide essential hydrological and environmental knowledge to a region which islargely fresh-water-restricted and thus, fragile under a climate warmingscenario.