Palynology and paleoenvironmental conditions during the last 12,600 cal. Years BP at Salinas del Bebedero (San Luis, Argentina)

摘要

The availability of late Quaternary paleoenvironmental information in centralwestern Argentina is still scarce because of the paucity of archives recording past environmental changes. This work reports palynological and sedimentological analyses of a sedimentary sequence from a core taken in the Salinas del Bebedero playa-lake basin (33°20'S-66°45'W), with the main objective of contributing towards the knowledge on vegetation and paleoenvironmental history in central western Argentina during the last c. 12,600 cal. yrs BP. Sedimentological results suggest a maximum lake high-stand c. 12,600 after which lake levels decreased until c. 3600 cal. yrs BP when modern lake levels were reached. Pollen analysis suggests a regional vegetation with Monte-Espinal affinity similar to the present-day vegetation, which essentially remained unchanged during the Holocene. Prior to that time, the predominance of halophytic communities around c. 12,600 cal. yrs BP suggests more arid conditions due to lower precipitation (and/or higher temperatures) compared with the present day conditions.