GEOLOGIA DO SEGMENTO NORTE DO ORÓGENO ITABUNA-SALVADOR-CURAÇÁ E GUIA DE EXCURSÃO

Abstract

GEOLOGY OF THE NORTHERN SEGMENT OF THE ITABUNA-SALVADOR-CURAÇÁ OROGEN AND FIELD-TRIP GUIDE The main geologic units that make up the northern segment of the Itabuna-Salvador-Curaçá Orogen and the Serrinha Orogen are reviewed, along with their geochronological data. The Serrinha Block comprises mesoarchean gneisses, migmatites and metamorphosed supracrustal rocks of the Santa Luz and Uauá complexes. These rocks are the basement to supracrustal rocks of the Paleoproterozoic Rio Itapicuru Greenstone Belt and the Rio Capim sequence. Granitic intrusions in the Serrinha Block are dated mostly in the range 2.13-2.02 Ga. On the other hand, the northern segment of the Itabuna-Salvador-Curaçá Block is made-up of orthogneisses and granulite facies rocks of the Caraíba Complex, mafic rocks of the São José do Jacuipe Suite and metamorphosed supracrustal rocks of the Tanque Novo-Ipirá Complex of Neoarchean age or older. The high-grade metamorphism associated with the continental collision that originated this orogenic belt, and intrusion of sintectonic granitoids, such as the Itiúba Syenite, has all taken place during the Paleoproterozoic.