Tectonic Regimes

Abstract
The concept of tectonic regimes is developed so as to specify the symmetry and orientation of bulk deformation for use in tectonic analysis. Four symmetry patterns combined with possible arrangements of principal axes in vertical and horizontal directions as in a compression belt give thirteen regimes which are in turn defined and tentatively related to some known tectonic structures. A theoretical orogenic sequence of regimes is developed and the paper concludes with a review of some of the difficulties.