Caracterização estrutural do afloramento, km 2, SE-200, Domínio Canindé, Faixa de Dobramento Sergipana, Sergipe

Abstract

This work describes the structural aspects of a road outcrop (Km 2), along the SE-200, Canindé de São Francisco, northwest of Sergipe. Also, this paper addresses a better understanding about the different deformational phases described for the Canindé de São Francisco area. The study provides information that can contribute to a better elucidation about the structural geology of the area, and thus to be able to help in future interpretations regarding the tectonic environment responsible for the evolution of the Canindé Domain. The outcrop is located in the Canindé Domain, in the northern part of the Sergipano Fold Belt, and presents a great lithological diversity such as metasedimentary rocks, schists, amphibolites and syenogranites, as well as important suture zones related to the collision of the Pernambuco- Alagoas Block and the São Francisco Craton. Based on the fieldwork information four lithological units could be defined for the area: Metassedimentary Unit, Schist Unit, Amphibolite Unit and Syenogranite Unit. The structures were grouped into four deformation phases: D1, with a Sn foliation, distinguished by the preferential orientation of mafic and felsic bands, D2 which is represented by minor local folds Fn, an important later phase called D3, marked by an expressive foliation called Sn+1, and D4, represented by a brittle phase capable of generating faults and fractures. In addition, thin sections were analyzed and demonstrated some mechanisms of deformation that are essentially formed in a brittle manner. Evidence of a transpressive zone is observed in the area due to the existence of a heterogeneous deformation marked by the combination of coaxial and non-coaxial structures. A late metamorphism is also recognized in the greenschist facies, marked by the presence of chlorite, which concentrates punctually but possibly represents the record of a "posterior" hydrothermal process in the Canindé de São Francisco area.