FEIÇÕES DE METAMORFISMO DE IMPACTO NO DOMO DE ARAGUAINHA

Abstract

In the present work some features of the Araguainha Dome are analised. This features are correlated to those described in the literature as produced by the impact of celestial bodies against the Earth's surface. The geologic context of the structure, whith central uplift and raised rim, the ocurrence of shatter cones in the Furnas Sandstone, the presence of polimict breccia with a vitreous matrix and the set of micro-features due to shock metamor-phism (as planar features in quartz and feldspar, presence of kink bands, etc.) constitute evidences that this type of process has ocurred in this area. This hypothesis is in agreement with the one proposed by Dietz et at. (1973) who classified the Araguainha Dome as a probable astrobleme.