A north–south-trending relatively high-strain shear zone active during the earliest stages of the ca 1.60–1.58 Ga Olarian Orogeny bounds domains characterised by different structural geometries in the northern Broken Hill Block. To the west of the shear zone Freyers Metasediments preserve Type 2 'mushroom' fold interference patterns between fold generations F2 and F3. Recumbent F2 folds are highly non-cylindrical. These were subsequently overprinted by north-orientated close to tight upright folds (F3). To the east of the shear zone, in the Parnell Formation, F2 folds are not developed and the structural grain reflects the F3 folding event. The shear zone is interpreted to represent a local detachment that accommodated lateral transportation of hangingwall rocks, producing non-cylindrical recumbent folding during thin-skinned deformation (D2). F3 folds represent thick-skinned deformation during the late stages of the Olarian Orogeny, folding rocks above and below the detachment. This resulted in zones of different structural geometry and strain pattern across the detachment. [ABSTRACT FROM AUTHOR]