Dunas "perched" en la estepa fueguina: reservorio de información arqueológica y ambiental del Holoceno

A. CORONATO; M. SALEMME; J. ORIA; F. MARI; R. LÓPEZ

San Miguel de Tucumán

Congreso; XX CONGRESO GEOLÓGICO ARGENTINO; 2017

Perched dunes develop over the cliffs of most of the ephemeral shallow lakes of the fuegian steppe. They are formed by the alternation of massive aeolian deposits and edaphized ones which are distinguished from each other by depth, grain-size, color, edaphic structures and organic matter content. The edaphized levels are interpreted as paleosoils formed during wetter periods when the aeolian processes were less intense. A set of radiocarbon dating, obtained from organic matter in most of them and in different dunes, shows that they were formed all along the Holocene, since the Late Glacial-Early Holocene up to the historical times. This fact is considered as evidence of humid-arid periods cyclicity in the region. The present erosive processes as mass wasting, runoff, deflation and abrasion occurring in the dunes expose the archaeological records, mainly composed by faunal remains, lithic artifacts and charcoal. Perched dunes are characterized as high resolution reservoirs of archaeological contexts in a region where the archaeological visibility is low, mainly due to the dense grass cover.