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Dienekes briefly introduced a new paper which attempted to reassess the age of the earliest human settlements in southern Chile and Argentina through radiocarbon dating. This is an important anthropological paper since the dates on peopling of Americas are being pushed back further and further. You may remember the seaweed analysis from Monte Verde, Chile from May, which confirmed the older, contested radiocarbon dates of the site.

This new paper, “AMS 14C dating of early human occupation of southern South America,” is similar in that the authors reanalyze carbon bearing material (charcoal or animal remains) from the Arroyo Seco 2, Paso Otero 5, Piedra Museo, and Cueva Tres Tetas sites in Argentina and the Cueva de Lago Sofia 1 and Tres Arroyos sites in Chile.

For all but one of the sites, the re-dating yielded consistent results to the previously published dates. But Arroyo Seco 2 had older dates, calibrated to as old as 14,000 years ago. And in fact show three different occupation periods, one around 14,170 to 13,840 years ago, another around 13,710 to 13-350 years ago, and a final one around 13,210 to 12,950 years ago. If you had any doubt on whether or not the material indicate human occuptation, the bones from Arroyo Seco 2 clearly show signs of human modification and were found associated with a lithic assemblage. An example of megafauna taphonomy from Arroyo Seco 2 can be found at this link. Also there, you’ll see some of the stone tools and artifacts recovered.

The authors challenge the Monte Verde site, stating their analysis has pinpointed the earliest known occupation in South America, but the difference is only in 50 radiocarbon years. Somewhat negligible given that level of atmospheric 14C haven’t been strictly constant…. even over 50 years they can vary. Regardless, this study reconfirms what many recent studies have been telling us, that there were pre-Clovis cultures in the Americas existing for several thousand years.

Just who those people were and how they got there is still rather unresolved. Craniofacial analysis of human burials from the site dating to 8,500 years ago (I know, no where close to 14,000 years ago) indicates that those Arroyo Seco 2 people differ considerably from the more or less contemporaneous Lagoa Santa people. But, mitochondrial analysis suggests that extant populations are related to those that made the migrations over Beringia. It is certainly possible that other people traveled by boat and did not contribute a significant impact to the current genetic makeup of south American populations. Either way, the Americas was peopled much earlier than what I was personally taught, and that is exciting.

    J STEELE, G POLITIS (2008). AMS 14C dating of early human occupation of southern South America Journal of Archaeological Science DOI: 10.1016/j.jas.2008.09.024
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