Resumo

PECSKAY, Z.; HALLER, M.J.  e  NEMETH, K.. Rev. Asoc. Geol. Argent. [online]. 2007, vol.62, n.1, pp.25-29. ISSN 0004-4822.

The Crater Basalt volcanic field is one of the Quaternary intraplate basaltic fields in northern Patagonia. A systematic geological, volcanological and geochronological study of CBVF indicates a multistage history of eruptions of basaltic volcanoes. K/Ar dating, using whole rock samples shows that the measured analytical ages are fully consistent with the available stratigraphic control. The radiometric ages fall into three distinct, internally consistent age groups, which give evidence that there were at least three major episodes of volcanic activity, at about 1.0 Ma, 0.6 Ma and 0.3 Ma ago. The age differences appear to be just significant, even although less than 10 % radiogenic argon was found in the isotope analysis of whole rock samples.

Palavras-chave : Basalts; Quaternary; Patagonia; Geochronology.

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