NEOTECTONIC INFLUENCE ON BARRIERS ISLANDS SYSTEM MORPHOLOGY, NORTHEAST BRAZIL

Aiming the global understanding of neotectonic events performance along coastal Cenozoic, this study integrate geological subsurface records by vibracorer with morphostructural lineaments analyses of Coast Province by digital processing of satellite images. Description of coastal sedimentary deposits by vibracorer drilling technic has been relevant, since it allows the facies sedimentary description of the substrate at low cost. Besides, digital processing techniques of vibracore radiographic images have brought a synoptic, fast and resourceful view for description of these sedimentary deposits. This article was developed in holocenic sedimentary deposits of a barrier island and sand spits system, typical of northern coast of Rio Grande do Norte State, Northeast Brazil. This environment is highly susceptible to erosional/depositional processes and strongly affected by wind regime, hydrodynamic and by reactivation of early structures. It is installed on a coastal zone marked by the reactivation of preterit structures of the Carnaubais and Afonso Bezerra Fault System. This study applied chemical and physical sedimentary analysis associated with digital processing techniques of radiographic images. This allowed recognizing four distinct sedimentary facies: Sand Siliciclastic with Granule and Gravels, Sand Siliciclastic, Terrigenous Mud and Sandy Marl. The analysis and interpretation of vibrocores endorsed to identify muddy facies (describing Intertidal Flat subfacies) and sandy facies (describing Tidal Inlet subfacies) interbeds, that highlight the intense coastal dynamic which the region is subjected, suggesting that the opening and closing of tidal channels occur in short time interval (range of years) and preferably in situations prior geological structural discontinuity. Thus, integration of vibracorer sampling with analysis of geophysical and lithological sections, and geometry of barriers islands system through mapping structural lineaments, allowed correlating the effects of neotectonic changes of coastal morphology and geometry, recognizing the influence of tectonic control of the Carnaubais and Afonso Bezerra Fault System reactivation and the direction of tidal channel aperture.