španjolski

Valvas arqueológicas y temperatura superficial del canal Beagle: nuevas aproximaciones a la extinción del los Yámana

In the southernmost region of South America an aboriginal canoer tradition based on the successful exploitation of marine resources - specially on pinnipeds - was developed since 6500 years ago to the last century. The descendants of these aborigens (Yámanas or Yaghans) may be considered extinct soon after first European settlements were established in the area. The traditional explication of this collapse due to the diseases introduced by the Europeans is not sufficient. The archaeologists presented the hypothesis that one of the mayor factors which caused the extinction was a notorious depletion of the pinniped stock, the principal basis of their sustenance, caused by overhunting affected by the Europeans from the XVIII. century. In this aspect the historical origins are not sufficient to establish a causal relation. The another reason could be possible environmental changes, above all the surface sea water temperature, which could had modified the marine biota in the region. This article analyzes the behavior of sea water temperature by means of the isotopic composition (d18O) in shells Mytilus edulis from archaeological sites at Beagle Channel, as well as from modern shells in the area. The ages of archaeological samples were obtained by radiocarbon measurement of charcoal remains, perfectly associated with shell samples. Results obtained do not indicate any meaningful change of temperature along the period under study which could implicate the depletion of the pinniped population in the region, so reinforcing the archaeological hypothesis that the principal reason of Yámana extinction was the overhunting.

valvas; radiocarbono; isotopo estable 18O; paleoclimatologia; canal Beagle

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