Present and recent stress regime in the eastern part of the Pyrenees

Earthquake focal mechanisms and microtectonic analysis of fault striation a re presented in order to study the regional state of stress in the eastern part of the Pyrenees. The inversion of these data, carried out independentl y, shows a submeridian direction of the maximum horizontal stress, remainin g stable since the Plio-Quaternary until present time. This analysis confir ms the evolution of the regional stress from an extension regime at the end of the Aquitanian period to a regime presently characterised either by an intermediate (strike-slip) or by a compression stress regime. (C) 1999 Else vier Science B.V. All rights reserved.