Structural analysis of the deforming tectonics of the Itajaí basin, Santa Catarina, Brazil

Abstract

Structural analysis of the ltajat' Group has confirmed and increase in deformation magnitude from NW to SE, toward the more deformed zone of the Dom Feliciano mobile belt. This condition is in agreement with the predícted characterístics of a foreland basin deformed ín a convergent environment. Two families of tectoníc structures were recognízed, both corresponding to different deformatíon phases and associated stress fíelds. The first represents the late coflisional phase of the orogenic cycfe, which caused the development of reverse faufts, asymmetric folds, anda conjugate system of strike-sfip faults. The progressive evolution of this convergence led to the change from a frontal to an oblique collision, with dextral-reverse kinematics. The second phase records a post-collisional extensional pulse, leading to the reactivation of earlíer structures and inversíon of movements along the conjugate system of strike-slip faults.