Tectonic inversion assessed by integration of geological and geophysical data: The intracontinental Rio do Peixe Basin, NE Brazil

Abstract

Common basin models assume that the post‐rift tectonic evolution of most basins is usually associated with tectonic quiescence. However, tectonic inversion during the post‐rift phase has been proposed for several sedimentary basins worldwide, but how and why it happens is still a matter of debate, especially in intracontinental settings where the lithosphere is old and thick. Here, we use geological and geophysical data from the Rio do Peixe Basin in NE Brazil to show evidence that intracontinental sedimentary basins can be tectonically inverted by far‐field compressive stresses acting on pre‐existing weakness zones of lithospheric‐scale where stresses can concentrate and inversion can occur. Geomorphological and field data combined with seismic reflection, gravimetric and borehole data show that: (a) inversion occurred along two main Precambrian lithospheric‐scale shear zones, the Patos (E‐W trending) and Portalegre (NE‐SW trending), which had already been reactivated as basin‐bounding faults during the earlier rift stage; (b) post‐rift reactivation affected (mostly) the original master normal faults with the largest rift displacements, and locally produced new reverse faults; (c) during contraction, deformation was partitioned between fault reactivation and buckling of the incompetent sediment pushed against the hard basement; (d) all these signs of inversion have been observed in the field and can be demonstrated on seismic reflection profiles; and (e) combined gravimetric and seismic data show that the main structures of the basin were followed by an inversion. These data are consistent with the operation of WSW‐ENE horizontal maximum compressive stress as a result of combined pushes of the Mid‐Atlantic Ridge (towards the W) and the Andes (towards the E), responsible for the post‐rift oblique inversion of normal faults inherited from the rift phase and formed with vertical maximum compressive stress.

The interplay between basement fabric, rifting, syn‐rift folding, and inversion in the Rio do Peixe Basin, NE Brazil

“…Understanding the kinematic link between syn-rift fault geometry and folding is important because they control the distribution and architecture of syn-rift depocentres and, consequently, of the key elements for petroleum systems and CO 2 sequestration. Their link is also fundamental to understanding the evolution of a particular basin and/or rifted margin and the presence or not of post-rift inversion (cf., Nogueira et al, 2015;Vasconcelos et al, 2021).…”

Analogue modelling of basin inversion: the role of oblique kinematics and implications for the Araripe Basin (Brazil)

“…In fact, recent work shows that mild inversion did take place in the basin 510 (Cardoso, 2010) and also other studies detected inversion in basins from the same rifting system as the Araripe Basin (e.g. Rio do Peixe Basin, Potiguar Basin, Bezerra et al, 2020;Vasconcelos et al, 2021).…”

“…Similarly, the Borborema Province contains high topographies and evidence of recent uplift (Lamarque and Julià, 2019;Neto et al, 2019). Other basins in the BNRS also present evidence of tectonic inversion (Vasconcelos et al, 2021;Bezerra et al, 2020). In the Araripe Basin, Marques et al (2014) proposed that inversion resulted from far-field ENE-WSW directed horizontal stress.…”

An Integrated Structural and Magnetic Fabric Study to Constrain the Progressive Extensional Tectonics of the Rio do Peixe Basin, Brazil

“…The sub‐basins are elongated following the trend of their border faults: NE‐SW Portalegre Fault (Brejo das Freiras), E‐W Malta Fault (Sousa) and NE‐SW Rio Piranhas Fault (Pombal). Two main depocenters were identified in the basin by gravimetry (de Castro et al., 2007; Nogueira et al., 2004) and seismic data (Rapozo et al., 2021; Vasconcelos et al., 2021). In the BFSB, the depocenter is localized in the southern zone of the Portalegre Fault and follows the fault trend.…”