Open AccessVisco‐elastic modelling of lithospheric stresses arising from density contrasts
Author(s) -
Park M. J. M.,
Westbrook G. K.
Publication year - 1983
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1983.tb01909.x
Subject(s) - lithosphere , geology , crust , finite element method , continental crust , viscosity , viscoelasticity , shear (geology) , geophysics , stress (linguistics) , tectonics , passive margin , shear stress , seismology , mechanics , petrology , physics , rift , thermodynamics , linguistics , philosophy , quantum mechanics
Summary. A method has been developed for application in conjunction with finite element analysis which can be used to model the stress distributions arising from lateral changes in thickness and density of lithospheric layers. It is especially applicable to those situations where there are large lateral variations in density and rock materials are comparatively weak such as the upper crust of active and passive continental margins. The full effect of gravitational body forces is incorporated in a visco‐elastic finite element model which is solved within an iterative scheme that preserves the observed or designed shape of the model. If so desired, further deformations can be studied in the ‘pre‐stressed’ model. To compare the method with others used previously, it was applied to a passive continental margin. A model in which the lower crust had a viscosity a factor of 10 smaller than that of the upper crust provided a stress distribution consistent with observational evidence of structure and tectonics. The average shear stress, of 60 MPa, predicted in the continental crust was close to that derived by Artyushkov, using an analytical method.