DOI: 10.1016/j.tecto.2021.228979
论文题名: The role of tectonic inheritance in the development of a fold-thrust belt and superimposed rift: An example from the São Francisco basin, eastern Brazil
作者: Rodrigues R.T. ; Alkmim F.F.D. ; Reis H.L.S. ; Piatti B.G.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 815 语种: 英语
中文关键词: Intracontinental deformation
; Mechanical stratigraphy
; Reactivation
; Tectonic inheritance
英文关键词: Deformation
; Metals
; Seismology
; Stratigraphy
; Brazilian continental margin
; Effective mechanisms
; Evolutionary history
; Mechanical stratigraphy
; Paleostress analysis
; Prominent structures
; Stratigraphic interfaces
; Structural investigation
; Faulting
; continental margin
; deformation
; extensional tectonics
; fold and thrust belt
; Gondwana
; intracratonic basin
; normal fault
; rift zone
; stratigraphy
; Brazil
; Sao Francisco Basin
英文摘要: The São Francisco intracratonic basin, eastern Brazil, hosts multiple sedimentary successions younger than 1.8Ga that witnessed major plate reorganizations since its generation. During the Brasiliano/Pan-African Gondwana amalgamation, in the Ediacaran-Cambrian boundary, the western half of the basin was involved in the Brasília foreland fold-thrust belt, which propagated eastwards deforming its Proterozoic-Paleozoic strata. Lately, as the South Atlantic rift evolved giving rise to the Brazilian continental margin, the basin was affected by extensional tectonism leading to the development of the Cretaceous Abaeté half-graben. During this episode, elements related to a prominent structure of the Brasília foreland fold-thrust belt, the João Pinheiro fault, were reactivated controlling the graben architecture. Aiming to unravel the evolutionary history of the fault zone since its nucleation until its Cretaceous extensional reactivation, we conducted a structural investigation based on field, well-tied 2D seismic data, and paleostress analysis. Our study revealed that the fault represents an emergent ramp of the basal detachment of the Brasilia foreland fold-thrust belt. Formed under EW-oriented shortening, the structure exhibits a gentle recces-salient geometry in map view, which reflects variations in the detachment depth influenced by pre-orogenic rift structures. Trains of NS-trending chevron folds are abundant and their high symmetry and dominance are expressions of the control exerted by mechanical stratigraphy and low-friction basal detachment. The superposed Abaeté half-graben developed under an extensional regime with a NE-trending maximum extension. Under this condition, a stratigraphic interface along the João Pinheiro fault zone was reactivated giving rise to the graben border fault. NS- to NW-oriented preexisting bedding planes were activated as small normal faults. Although newly-formed faults are present, reactivation is the most effective mechanism of extension accommodation. Therefore, this study provides insights on the influence of tectonic inheritance on the architecture, deformation pattern, strain/stress partitioning and evolution of both extensional and compressional intracontinental systems. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170893
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Departamento de Geologia, Escola de Minas, Universidade Federal de Ouro Preto, Ouro Preto, MG 35.400-000, Brazil
Recommended Citation:
Rodrigues R.T.,Alkmim F.F.D.,Reis H.L.S.,et al. The role of tectonic inheritance in the development of a fold-thrust belt and superimposed rift: An example from the São Francisco basin, eastern Brazil[J]. Tectonophysics,2021-01-01,815