# Stress field associated with elliptical inclusions in a deforming matrix: Mathematical model and implications for tectonic overpressure in the lithosphere

## Détails

ID Serval

serval:BIB_59B0EDD100AC

Type

**Article**: article d'un périodique ou d'un magazine.

Collection

Publications

Institution

Titre

Stress field associated with elliptical inclusions in a deforming matrix: Mathematical model and implications for tectonic overpressure in the lithosphere

Périodique

Tectonophysics

ISSN-L

0040-1951

Statut éditorial

Publié

Date de publication

2014

Volume

631

Pages

37-49

Notes

Times Cited: 2

Si

2

Si

2

Résumé

Shear zones and competent layers and boudins represent viscosity heterogeneities within the rock mass. Differences in viscosity impel differences in strain rates between the background material and the heterogeneities. In this work, we represent the viscosity heterogeneities as elliptical inclusions. We use the Kolosov-Muskhelishvili equations for the incompressible viscous flow problem in and around elliptical inclusions. Systematic investigation of the stress equilibrium at the matrix inclusion interface shows that the mean stress, equivalent to the total pressure, is not continuous across viscosity boundaries. The results predict that pressure and stress perturbations depend strongly on the orientation of the elliptical heterogeneity with respect to the far-field stresses. A viscosity ratio of 10 between the inclusion and the surrounding material is sufficient to produce pressure discontinuities approximately equal to the magnitude of the effective shear stress of the strongest rock under the considered physical conditions. Comparison of the analytical solutions with thermo-mechanical models confirms pressure incongruity and suggests that dynamic parameters such as pressure and effective shear stress vary spatially and temporally within deforming, two-viscosity rock systems. As a corollary, the dependence of metamorphic phase equilibria on thermodynamic pressure implies that shear zones, taken as weak inclusions, and boudins, taken as hard inclusions, may record non-lithostatic pressure during deformation. (C) 2014 Elsevier B.V. All rights reserved.

Création de la notice

02/10/2015 17:33

Dernière modification de la notice

20/08/2019 15:13