Structure of melange and associated units in the Torlesse accretionary wedge, Tararua Range, New Zealand

Abstract

Deformation of the Late Jurassic ‐Early Cretaceous Torlesse Complex in the southeastern Tararua Range is characterised by development of melange, several generations of folds, faults at both a low angle and high angle to bedding, shear foliation, and cleavage. The region has undergone the following deformational sequence: (1) Development of at least two fold generations; (2) Fragmentation and disruption by faulting. Faults at a low angle and high angle to bedding have disrupted the sequence, in places producing chaotically disrupted units (melange). The Tauherinikau Melange represents a probable along‐strike northern continuation of the Esk Head Melange from the South Island; (3) Post‐melange folding; (4) Holocene faulting. Overall, the deformation is consistent with accretion at a convergent plate margin, followed by the present strike‐slip dominant regime.

Keywords:

• Tararua Range
• accretionary wedge
• deformation
• melange
• folds
• shear foliation
• faults