Neotectonic Reactivations in the Rio Paraíba do Sul Shear Zone (Southeastern Brazil)

Abstract

This study aims to investigate neotectonic activities in the region of the Rio Paraiba do Sul Shear Zone, an importantgeotectonic feature adjacent to the central segment of the Continental Rift of Southeastern Brazil, and contiguous areas.The methodology used in this work is based on the integration of morphostratigraphic and structural data analysis. Theanalysis of the fault/striae pairs observed in Cenozoic sediments and weathered basement rocks was highlighted in order tocharacterize neotectonic stress fields. The relationship among the different fracturing patterns, geologic units affected bythese events and overlapping patterns of striae on a same fault plain lead to the characterization of three neotectonic stageswhich could be correlated to the neotectonic events described for the Southeastern Brazil: E-W left-lateral transcurrentstage (Miocene); E-W right-lateral transcurrent stage (Pleistocene/Holocene); and NW-SE extensional stage (Holocene).These neotectonic stages have a strong relationship with the reactivation of the preexisting structural anisotropies.

Keywords

• Neotectonics
• Southeastern Brazil
• Rio Paraíba do Sul Shear Zone