Geology and tectonic of the capÃo bonito topographic 1:50.000 map, southeast of sÃo paulo state

Abstract

The 1: 50.000 Capão Bonito Topographic Map is situated at the southern end of São Paulo state, in the south-central Ribeira Belt, in the northern portion of the Apiaí Terrain. The area involves rocks from the Açungui Supergroup metavolcanic-sedimentary sequence, constituted by the Água Clara Formation and the Votuverava Group metassediments of Meso and Neoproterozoic age. Três Córregos Complex and Capão Bonito Neoproterozoic Granite are also present. Itararé Group sedimentary rocks, associated with Serra Geral basic magmatism also occur covered by recent quaternary sediments. The geological evolution is determined by the Neoproterozoic tectonic-metamorphic arrangement, defined by three deformation phases. The two initial events are related to a tangential tectonic linked to the collisional phase, consequent thickening of crustal masses and the emplacement and deformation of the Três Córregos syn collisional Complex. The posterior deformation is marked by a transcurrent/transpressive tectonics which occurs associated with the late magmatic ascent and the present elongated structuring of the Capão Bonito Granite post-collisional rocks. The progressive regional metamorphism is of Barrovian type, with rocks in high green schist facies; local occurrences of contact metamorphism; and the dynamic event that represents a retro metamorphic character.