Historia ambiental de la Laguna Seca, Tartagal Salta, Noroeste Argentino

Abstract

ENVIRONMENTAL HISTORY OF LAGUNA SECA, TARTAGAL SALTA, NORTHWEST ARGENTINA. First results from an interdisciplinary research on the history of landscape in the mountain range of Tartagal, Province of Salta (NW Argentina) for the 1959/2012 period are given. Geochemical, mineralogical and palynological studies with high temporal resolution have been performed in sediments of a core from Laguna Seca (22°21’1.81”S, 63°52’10.90”W). Dentations by 210Pb show that the sedimentary record comprises 53 years. Sediments are composed of reddish massive clays and silts, with interbedded clays rich in organic matter and fibrous plants macro remains in the base of the core. Presence of quartz, illite and clinochlorite is prominent; most relevant geochemical components are Al, Si and K. Redundancy analysis indicates that most of chemical elements are associated to terrigenous minerals (quartz, albite and illite). Pollen types found belong to the Yungas forest, like Alnus acuminata, Anadenanthera colubrina, Celtis sp. and Schinus sp. Geochemical, mineralogical and palynological results are consistent with the annual precipitation in Tartagal during last decades, and reflect some correlation with phenomena of mass movement as well as landslides occurred in the mountain range of Tartagal and its oriental piedmont. The multiproxies data integration has generated the basis for reconstructing changes in vegetation, climate and history of anthropogenic disturbance during the Holocene in Subandine Sierra the Northwest Argentine