Stratigraphy and structure of the Torlesse Supergroup (Triassic-Jurassic) in the foothills of the southern Alps near Hawarden (S60–61), Canterbury

Abstract

The lithology of Triassic-Jurassic Torlesse Supergroup sediments in a 140 km² area of the Canterbury foothills is described, and a geological map is presented. Analysis of the structures indicates that Upper Triassic rocks structurally overlie Upper Jurassic rocks and are separated from them by a tectonic slide. Other tectonic slides are recognised and movement patterns which might have led to their development are discussed. Subsequent deformation during the Rangitata orogeny includes flexing about steeply inclined axes, and wrench faulting. Kaikoura deformation consists of block faulting and tilting.