Implications of overprinting deformations and fold interference patterns in the Melbourne Zone, Lachlan Fold Belt

Abstract

Upper crustal shortening associated with development of a northeast‐directed thrust‐belt during dextral strike‐slip ‘docking’ of the Melbourne Zone with the Tabberabbera Zone has led to complex deformation patterns and regional scale fold interference in the Nagambie‐Rushworth area of central Victoria. Mutually interfering, contemporaneous and diachronous north‐south and northeast‐southwest shortening deformations have locally produced ‘dome and basin’ fold patterns due to interference of east‐west and northwest‐southeast fold sets. In the northern part of the zone first generation folds are east‐west‐trending, cut by north‐dipping thrust faults and have a weak, east‐west trending, steeply dipping S, slaty cleavage. To the south, first generation folds are northwest‐southeast trending and show curvilinear axial surface traces and overprinting cleavages in an area of overlapping deformation fronts. The major control is the northeast transport of the Melbourne Zone along a major mid‐crustal detachment whose...