Structural framework and Mesozoic-Cenozoic evolution of Ponta Grossa Arch, Parana Basin, southern Brazil

The integration of structural analyses of outcrops, aerial photographs, satellite images, aeromagnetometric data, and digital terrain models can establish the structural framework and paleostress trends related to the evolution of Ponta Grossa Arch, one of the most important structures of the Parana Basin in southern Brazil. In the study area, the central-northern region of Parana State, Brazil, the arch crosses outcropping areas of the Piramboia, Botucatu, and Serra Geral Formations (Sao Bento Group, Mesozoic). The Piramboia and Botucatu Formations are composed of quartz sandstones and subordinated siltstones. The Serra Geral Formation comprises tholeiitic basalt lava flows and associated intrusive rocks. Descriptive and kinematic structural analyses reveal the imprint of two brittle deformation phases: D1, controlled by the activation of an extensional system of regional faults that represent a progressive deformation that generated discontinuous brittle structures and dike swarm emplacement along a NW-SE trend, and D2, which was controlled by a strike-slip (transtensional) deformation system, probably of Late Cretaceous-Tertiary age, responsible for important fault reactivation along dykes and deformation bands in sandstones. (c) 2007 Elsevier Ltd. All rights reserved.