Defining major structures and their depth extent under cover in the southern Thomson Orogen, New South Wales

Abstract

Regional geophysical datasets are critical to the task of uncovering the basement geology of the southern Thomson Orogen in far western New South Wales. As part of a National Collaborative Framework project, aeromagnetic, gravity and seismic data have being processed and interpreted to construct the structural framework. Subdivision into structural domains has been validated and constrained by geological information, relying on observations and measurements from sparse drill holes and outcrops. Boundaries between structural domains are complex and poorly understood. This study aimed to recognise major faults and, where possible, define their displacements, depth extent, and understand their dynamics and timing. Analysis of available company and government seismic surveys provided details for some of the major fault systems such as the Olepoloko Fault, Culgoa Lineament, and also for many newly recognised fault trends The seismic interpretations were reconciled with deep sourced aeromagnetic and gravity gradients that were enhanced by multiscale edge analysis. The structural framework will underpin geochronology and mineral systems studies as the Southern Thomson Orogen project continues.