DOI: 10.1016/j.tecto.2020.228442
论文题名: Numerical modeling of flexural stresses in the upper crust of NE Brazil – Implications for stress regimes in intraplate settings
作者: Leite Neto G.S. ; Ferreira J.M. ; Moreira J.A.M. ; Bezerra F.H.R. ; do Nascimento A.F.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2020
卷: 784 语种: 英语
中文关键词: Flexural stresses
; Numerical stress modeling
; Reactivation of Pernambuco Shear Zone
; Stress superposition
; Stresses in Northeast Brazil
英文关键词: Forecasting
; Stresses
; Bouguer anomaly
; Flexural stress
; Fourier domains
; Internal loads
; Inviscid fluids
; Long wavelength
; Stress regime
; Surface loads
; Topography
; Bouguer anomaly
; intraplate process
; numerical model
; stress field
; upper crust
; Brazil
英文摘要: We model the contribution of the stresses generated by the topography and density heterogeneities in the stress field of NE Brazil and the interplay between these and regional stresses. Our model consists of a horizontally layered elastic slab (the lithosphere) that floats above an inviscid fluid (the asthenosphere), where the surface load is generated by the topography and bathymetry, and the internal loads are calculated from the Bouguer anomalies. The deviatoric flexural stresses are calculated in the Fourier domain. Our results showed local flexural stresses with magnitudes comparable to those of the plate-wide stresses, and mainly controlled by the long-wavelength Bouguer anomalies. Scenarios for the total stress field were calculated by superposing different values for an E-W-oriented regional compression. We predict the stress axes orientations and stress regimes for the equatorial margin and the Pernambuco Shear Zone (PESZ) region. However, we highlight the importance of spreading stresses, not considered here, in rotating the maximum horizontal compression (SHmax) predictions. The prediction of stress regime and stress axes orientation in PESZ using low to zero regional compression suggest that a decoupling of the shallow stresses from the plate-wide stresses might occur in this region. Another possible explanation found was that the spreading stresses might counterbalance the regional stresses. We conclude that the superposition of principally flexural and plate-wide stresses explains reasonably the observed stress regimes and SHmax orientations in a great part of NE Brazil. Furthermore, flexural stresses are playing an important role in the reactivation of the PESZ, possibly controlling the stress field. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170636
Appears in Collections: 气候变化与战略
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作者单位: Programa de Pós-Graduação em Geodinâmica e Geofísica, Universidade Federal do Rio Grande do Norte, Campus Universitário, Natal, RN 59078-970, Brazil; Departamento de Geofísica, Universidade Federal do Rio Grande do Norte, Campus Universitário, Natal, RN 59078-970, Brazil; Departamento de Geologia, Universidade Federal do Rio Grande do Norte, Campus Universitário, Natal, RN 59078-970, Brazil
Recommended Citation:
Leite Neto G.S.,Ferreira J.M.,Moreira J.A.M.,et al. Numerical modeling of flexural stresses in the upper crust of NE Brazil – Implications for stress regimes in intraplate settings[J]. Tectonophysics,2020-01-01,784