Thursday, 19 November 2015

New dates for Monte Verde pushes back arrival of first humans in South America

Chilean site was first occupied at least 18,500 years ago

Monte Verde in southern Chile is a peat bog in the terraces of Chinchihuapi Creek in the MaullĂ­n river basin, midway between the Pacific coast and the Andean mountains. There is well-preserved evidence of human occupation including wooden tent remains, foundations and floors of huts, hearths, wooden lances, mortars, and large numbers of stone tools. The site was apparently occupied all year round. A wide range of coastal and mountain habitats were exploited including marshes, wetlands, forests, estuaries, and rocky and sandy shorelines.

Evidence of habitation was not thought to pre-date the 14,600 year horizon identified at the site MV-II, although there was evidence of an earlier cultural horizon (MV-I). The MV-II dates in themselves made Monte Verde attractive to opponents of the long-running ‘Clovis First’ orthodoxy, which holds that the culture originally identified at Clovis, New Mexico represents the earliest human settlement of the New World. The Clovis culture is noted for its distinctive leaf-shaped spear points, which were first found in the 1930s. Clovis sites dating from 13,250 years ago are widespread across the United States and Central America to as far south as Panama. Assuming that the first Americans reached the New World via the Beringia land bridge that linked Alaska with Siberia during the last Ice Age, a human presence in South America 14,600 years ago is problematic to Clovis First.  

However, even earlier dates have now been obtained for Monte Verde. Archaeologists carried out spatially-intermittent excavations and core drillings across an area lying between MV-II and the two sites of CH-I and CH-II, located on the south side of the creek, 500 m upstream of MV-II. These revealed stone tools, faunal remains, and evidence of fires widespread across the study area albeit vertically and horizontally discontinuous. These appear to represent ephemeral seasonal activities carried out over a long period of time between shallow channels of a now-buried braided system of streams that fed into the river. Radiocarbon and Optically Stimulated Luminescence dating has yielded a range of dates from 18,500 to 14,500 years ago, with implications that humans reached the New World much earlier than previously believed.

Dillehay, T. et al., New Archaeological Evidence for an Early Human Presence at Monte Verde, Chile. PLoS One 10 (11) (2015).

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