A continuum mechanics model for normal faulting using a strain-rate softening rheology: implications for thermal and rheological controls on continental and oceanic rifting

Details A continuum mechanics model for normal faulting using a strain-rate softening rheology: implications for thermal and rheological controls on continental and oceanic rifting A continuum mechanics model for normal faulting using a strain-rate softening rheology: implications for thermal and rheological controls on continental and oceanic rifting

Sep 2002

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002e%26psl.202..725b&link_type=abstract

Earth and Planetary Science Letters, Volume 202, Issue 3-4, p. 725-740.

Mathematics

Logic

19

Scientific paper

We use a strain-rate-dependent visco-plastic rheology in a finite element model to investigate the effects of crustal rheology and thermal structure on the development of normal faults in 2-D extending lithosphere. Strain-rate softening in the brittle regime is used to simulate the rate-dependence of frictional strength observed in laboratory studies. Results of numerical experiments show that efficient strain-rate softening can result in localized zones of high strain rate, which develop in response to the rheology and boundary conditions and are not imposed a priori. We argue that these zones of localized shearing are analogous to faults and use the calculated deformation field to predict the preferred location of fault formation for a range of thermal and rheologic conditions. When no regional temperature gradient is imposed, deformation is predicted to be distributed between several sets of conjugate normal faults. However, in the presence of a horizontally varying temperature field, faulting is calculated to focus where the lithosphere is thinnest, forming rift-like topography. Model results predict that when crustal thickness is sufficiently small that no ductile layer is present in the lower crust, deformation is mantle-dominated and rift half-width is controlled primarily by the vertical geothermal gradient. In contrast, when crustal thickness is large enough that the stress accumulation in the upper crust becomes much greater than the stress accumulation in the upper mantle, deformation becomes crust-dominated and the calculated rift half-width is a function of both crustal rheology and the vertical geothermal gradient. This implies that deformation in the brittle upper crust does not behave independently of a strong upper mantle, even in situations where ductile flow occurs in the lower crust.

Affiliated with

Also associated with

No associations

Rating

A continuum mechanics model for normal faulting using a strain-rate softening rheology: implications for thermal and rheological controls on continental and oceanic rifting does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A continuum mechanics model for normal faulting using a strain-rate softening rheology: implications for thermal and rheological controls on continental and oceanic rifting, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A continuum mechanics model for normal faulting using a strain-rate softening rheology: implications for thermal and rheological controls on continental and oceanic rifting will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1046156