Resumo

REMESAL, Marcela B; CERREDO, María Elena; CORDENONS, Pablo D  e  ALBITE, Juan M. Rev. Mus. Argent. Cienc. Nat. [online]. 2019, vol.21, n.2, pp.179-194. ISSN 1853-0400.

This contribution deals with the Corona Chico Vulcanites, within the Somún Curá Magmatic Province, northern Extra-Andean Patagonia. The studied area is located to the north of the Alta Sierra de Somún Curá Volcanic Complex and is made of several basaltic volcanic buildings of varied morphologies: spatter cones, tuff ring and long lava flows related to small shield volcanoes (of scutulum type). Petrographic characteristics as well as whole rock chemical composition suggest a time progressive increase in alkalis content and a shift from early transitional terms to basanitic rocks in the latest stages. A simulation of the source yielded for Las Lomadas rocks an astenospheric source in the garnet-spinel facies, with associated low partial melting percentages (< 7-8%). Within the studied rock set, the spatter cones sequence displays geochemical affinities with the basaltic component of Alta Sierra de Somún Curá Volcanic Complex.

Palavras-chave : Corona Chico Vulcanites; Somún Curá Magmatic Province; Petrology.