Resumo

DEL VALLE OVIEDO, Natalia  e  ASTINI, Ricardo A. Depósitos volcanosedimentarios del cretácico en las cumbres y vertiente oriental de la Sierra chica, Córdoba, y redefinición de la formación El Pungo. Rev. Asoc. Geol. Argent. [online]. 2014, vol.71, n.4, pp.472-483. ISSN 0004-4822.

Recent sedimentological and stratigraphic studies along Road El Cuadrado across the Sierra Chica of Córdoba have allowed identification and characterization of a volcaniclastic unit, previously unidentified, that seems equivalent to the Cretaceous “Vulcanita de El Pungo” (Gordillo y Lencinas 1967a). The unit includes primary fall-out deposits, possible surge deposits, gravity flow deposits and reworked deposits, together with small patches of basaltic flows within the “estancia La Sureña”. These rocks would constitute relicts of syneruptive strombolian and freatomagmatic facies associations generated close to a basaltic monogenic volcanic system. The correlation with similar units elsewhere along the Sierra Chica (central Argentina) allows suggesting that this volcanosedimentary record would have filled synrift basins contemporaneous with the opening of the Atlantic Ocean. Subsequent tectonic inversion and uplifting of the Sierra Chica unroofed, eroded and reworked this stratigraphic interval, which discontinuously outcrops along the Provincial Road E-57.

Palavras-chave : Volcanosedimentary processes; Strombolian; Freatomagmatic; Synrift; Cretaceous.

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