Spatial Modeling Of Neotectonics On The Discovery Coast, South Of The State Of Bahia

This work aims to model neotectonics events present on the Discovery Coast, southern Bahia State, where Neogene sediments of the Barreiras Formation outcrop. The study area is dominated by tablelands that reach the coast, originating sea cliffs up to 40 m high. Field studies were developed in order to observe, describe, measure and interpret geological structures, especially joints and faults that indicate the action of neotectonics. From the MDT/SRTM data, processed through Geographic Information Systems (GIS) using ArcMap, a set of thematic maps was made, highlighting the structural indices (lineament map, lineament density and lineament frequency), geomorphological indices (drainage density, flow frequency and humidity topographic index) and morphotectonic indices (relief amplitude and slope gradient). In addition, it was applied the weighted linear combination technique (WLC), identifying areas that would keep records of the most recent tectonic action. Field data and image analysis demonstrated a higher density of lineaments in the NW-SE and secondarily in the NE-SW direction totaling 908 and 722 respectively. The originated map highlights a stronger action of the neotectonics in the Camurugi, Trancoso and Caraiva basins, evidenced by structural block tilting and modification of drainage patterns. The integration of the maps highlighting the structural, geomorphological and morphotectonic indices, proved to be an effective method for modeling tectonic events, confirming the neotectonics action on the Discovery Coast and opening possibilities for further studies to develop along the eastern Brazilian Coast.