Kinematic history of serpentinites in the faulted margins of the Hastings Block, New England Orogen, eastern Australia

Serpentinites along the boundaries of the Hastings Block, southern New England Orogen, eastern Australia, contain S, C and C' structures that provide information on the kinematic history of faults bounding the block. The serpentinite bodies at Yarras on the western boundary of the Hastings Block within the Ralfes Creek, Taylors Creek and Old Highway-Yarras Mountain Trail Faults display dominantly sinistral strike-slip or oblique-slip movement. Serpentinite bodies between these faults record dextral strike-slip and oblique-slip movement histories as well as sinistral strike-slip or oblique-slip and rare normal, dip-slip movement. The Mt George Serpentinite consists of a northeast-oriented section folded and displaced by movement on a west-northwest section of the Peel-Manning Fault System. Serpentinite structures suggest the west-northwest section initially underwent dextral strike-slip, which reoriented the northeast-oriented section, and subsequently sinistral strike-slip movement. Preliminary studies of serpentinites elsewhere around the periphery of the Hastings Block indicate localised effects due to readjustment of the block during its interaction with the Nambucca Block on its northern margin. The structures observed in the serpentinites are thought to have occurred during and after the Hunter-Bowen Orogeny and prior to stitching of the accretionary-subduction and forearc by the 228 Ma Werrikimbe Caldera.