Mesoscopic structures and multiple deformation in the Otago schist

Abstract

Over very large areas in Otago mesoscopic structures of different ages can be mapped in the schist. Folds produced since the onset of metamorphism appear to have resulted from at least three phases of deformation. The first phase probably gave rise to large recumbent folds. The second phase may have catalysed retrogressive metamorphism on a regional scale. The third phase was probably related to Tertiary faulting. The first two phases may have been separate orogenies or parts of a single complex orogeny.