Aeolian sequence and archaeological record in the Fuegian steppe, Argentina

CORONATO, ANDREA; FANNING, PATRICIA; SALEMME, MONICA; ORÍA, JIMENA; PICKARD, JOHN; PONCE, JUAN FEDERICO

QUATERNARY INTERNATIONAL

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: New York; Año: 2011 vol. 245 p. 122 - 135

1040-6182

A 20 m thick sequence of aeolian deposits and paleosols, deposited over Tertiary marine sediments adjacent to the shallow saline ephemeral Lake Arturo, is described. A deposit of archaeological stone artefacts and bone, the Lake Arturo 1 archaeological site, located in a deflation hollow near the top of the aeolian sequence is also presented. The sequence of nine aeolian deposits, including 8 paleosoils and capped by the contemporary soil, provides evidence of environmental changes which have occurred during the Holocene in the cold Fuegian steppe along the Holocene, perhaps beginning as early as the Late Glacial-Early Holocene transition. A preliminary chronostratigraphy is provided by a guanaco bone embedded within Palaosol 4, radiocarbon dated to 5.8 ky B.P., and a tephra layer between Palaeosols 4 and 5 which is interpreted as the product corresponding to the Mt. Burney 2 eruption (3.2 ky B.P.). We suggest that the accumulation of the aeolian sediments occurred as a result of both local acquisition of fines derived from the weathering and erosion of the basal Tertiary marine sediments and deflation from the intermittently dry lake bed, as well as accumulation of deposition of material transported by wind from more distant sources. The orientation of the aeolian deposits suggests a more northwesterly wind direction instead of the present westerlies. Evidence of human occupation in Lake Arturo 1 is interpreted as a place for primary butchering and raw material acquisition.