Neotectonic reactivation of shear zones and implications for faulting style and geometry in the continental margin of NE Brazil

Author(s)

Bezerra, F. H. R. ^{[1, 2]} ; Rossetti, D. F. ^[3] ; Oliveira, R. G. ^[4] ; Medeiros, W. E. ^{[1, 5]} ; Brito Neves, B. B. ^[6] ; Balsamo, F. ^[7] ; Nogueira, F. C. C. ^{[2, 8]} ; Dantas, E. L. ^{[2, 9]} ; Andrades Filho, C. ^[10] ; Goes, A. M. ^[6]

Affiliation

^[1] Univ Fed Rio Grande do Norte, BR-59072970 Natal, RN - Brazil

^[2] CNPq, INCT ET, Inst Nacl Ciencia & Tecnol Estudos Tecton, Brasilia, DF - Brazil

^[3] Inst Nacl Pesquisas Espaciais INPE, Sao Jose Dos Campos, SP - Brazil

^[4] Serv Geol Brasil CPRM, Rio De Janeiro - Brazil

^[5] Inst Nacl Ciencia & Tecnol Geofis Petr CNPq, INCT GP, Brasilia, DF - Brazil

^[6] Univ Sao Paulo, Inst Geociencias, BR-05508 Sao Paulo - Brazil

^[7] Univ Parma, I-43100 Parma - Italy

^[8] Univ Fed Campina Grande, Campina Grande, Paraiba - Brazil

^[9] Univ Brasilia, BR-70910900 Brasilia, DF - Brazil

^[10] Univ Estadual Rio Grande do Sul, Porto Alegre, RS - Brazil

• Document type: Journal article
• Source: TECTONOPHYSICS; v. 614, p. 78-90, FEB 18 2014.
• Web of Science Citations: 25

Abstract

The eastern continental margin of South America comprises a series of rift basins developed during the breakup of Pangea in the Jurassic-Cretaceous. We integrated high resolution aeromagnetic, structural and stratigraphic data in order to evaluate the role of reactivation of ductile, Neoproterozoic shear zones in the deposition and deformation of post-rift sedimentary deposits in one of these basins, the Paraiba Basin in northeastern Brazil. This basin corresponds to the last part of the South American continent to be separated from Africa during the Pangea breakup. Sediment deposition in this basin occurred in the Albian-Maastrichtian, Eocene-Miocene, and in the late Quaternary. However, our investigation concentrates on the Miocene-Quaternary, which we consider the neotectonic period because it encompasses the last stress field. This consisted of an E-W-oriented compression and a N-S-oriented extension. The basement of the basin forms a slightly seaward-tilted ramp capped by a late Cretaceous to Quaternary sedimentary cover similar to 100-400 m thick. Aeromagnetic lineaments mark the major steeply-dipping, ductile E-W- to NE-striking shear zones in this basement. The ductile shear zones mainly reactivated as strike-slip, normal and oblique-slip faults, resulting in a series of Miocene-Quaternary depocenters controlled by NE-, E-W-, and a few NW-striking faults. Faulting produced subsidence and uplift that are largely responsible for the present-day morphology of the valleys and tablelands in this margin. We conclude that Precambrian shear zone reactivation controlled geometry and orientation, as well as deformation of sedimentary deposits, until the Neogene-Quaternary. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 12/06010-5 - Post-rift tectonosedimentary evolution of the Paraíba basin, Northeastern Brazil
• Grantee: Dilce de Fátima Rossetti
• Support type: Regular Research Grants