Tectônica e sedimentação neogênica-quaternária na planície literânea do Rio Assu, Bacia Potiguar

Abstract

A detailed geomorphological survey using Light Detection and Ranging was carried out along the western part of Assu River, NE, Brazil. The study was complemented by a series of shallow boreholes, sediment benthic foraminifera indicators, as well as radiocarbon and optically stimulated luminescence dating and permitted to reconstruct the evolution of this area from the late Pleistocene until the present. The shallow embayment, which is now completely infilled formed within the limits of antecedent morphology developed since the last interglacial. The main forcing factors responsible for repositioning of the shoreline, which ran at an angle of ca. 35% to the present coast in Early/mid Holocene were: (1) tectonic activity along Afonso Bezerra a strike-slip fault line which defines the horst-graben structure of Mel dome, (2) fast inundation of the shallow paleovalley embayment during the last pulse of Holocene transgression ca. 7500 cal BP, and (3) fast progradation of the Assu estuary through accretion of coastal drift and fluvial sediments.