Faults in many different tectonic settings contain a significant proportion of clay. Clays typically have frictional strength that is lower than predicted by Byerlee’s rule, and have been proposed as a means to allow slip on ’weak’ faults. Moreover, clay-rich fault rocks are low permeability and have the capacity to seal overpressured fluids into fault zones during the seismic cycle. Measurements of the frictional strength of synthetic clay-rich fault gouges both at low slip velocity and high slip velocity are presented to show the effect on earthquake nucleation and propagation through fault zones containing a high proportion of these materials. Permeability of natural and synthetic fault gouges measured at elevated temperature and with different pore fluids highlight the physico-chemical interactions that may operate in clay-rich faults at conditions commensurate with those in the brittle crust.
Daniel Faulkner est professeur de géologie au département des Sciences de la Terre et de l'Océan à l'Université de Liverpool.
Géologue de terrain et expérimentateur, il centre ses travaux sur la circulation des fluides dansla croûte terrestre, les propriétés de friction des zones de faille..Cliquer ICI pour fermer
Dernière mise à jour : 20/07/2012