Post-Miocene tectonics and structural control of the Apodi-Mossoró drainage system

Abstract

In the central segment of the Potiguar Basin, in the area dissected by the Apodi-Mossoró River, neotectonic fault zones caused the reactivation of preexisting faults under the influence of the last stress field of post-Miocene age. These reactivations have  been expressed in the morphology of the fluvial channels. The analysis of Apodi-Mossoró River in its lower course indicate occurrence the neotectonic deformation and its impact on drainage network,  deformation structures in non-cohesive sediments, and drainage anomalies associated with the main systems of regional fault. The fault trends NE-SW and NW-SE and control the generation of alluvial and the related changes in the main channel morphology and reduction in it sinuosity values. This reduction occurs mainly in the sectors where the main channel drains it course in active fault zones. The drainage anomalies occur mostly in the form of elbows, with form linear segments between sinuous segments. These anomalies also, influence the deposition of Quaternary sediments.