Neotectonic record in South American passive margin based on morphostructural analysis of northern Paraíba Basin, Brazil
Alves, Fabio Corrêa; Rossetti, Dilce de Fátima
published: Aug 1, 2017
manuscript accepted: May 17, 2017
manuscript received: Apr 14, 2016
ArtNo. ESP022006102000, Price: 29.00 €
Abstract There has been increased publications focusing tectonic structures in Neogene and Quaternary deposits of northeastern Brazil, despite its localization in the South American passive margin. Faults and folds are particularly abundant in deposits of these ages exposed in the central and southern parts of Paraíba Basin. In contrast, an overall scarcity of outcrops has precluded investigation of the northern part of this basin, but this work shows that this area also displays a tectonically-controlled relief. The survey consisted in integrating morphostructural analysis, transverse topographic symmetry factor (TTSF) index and a few geological data aiming to test the tectonic influence in this area and investigate both the extent and styles of deformation. Our data derived from the digital elevation model (DEM) of the Shuttle Radar Topography Mission (SRTM), as well as existing cartographic data and geological information derived from outcrops and drills. The results revealed: anomalous drainage patterns, such as trellis and associated subtypes; abrupt channel inflections forming obtuse to right angles; compressed and isolated meanders; and morphostructural lineaments with trends compatible with regional tectonic structures of northeastern Brazil. In addition, the TTSF index was efficient to evidence tectonically-controlled asymmetrical sub-basins on Late Pleistocene-Holocene sedimentary deposits. This work also revealed a dome-like structure related to an anticline in the central part of the study area. We concluded that the relief of northern Paraíba Basin reflects faults and folds formed by extension and compression within a strike-slip regime, evidencing the relevance of tectonic reactivation during a relatively recent evolution (i.e., Late Pleistocene-Holocene) of the South American passive margin.