Cambrian convergent margin configuration in the Delamerian Orogen of mainland Australia

Output type: Exploring for the Future Extended Abstract

Short Abstract: The Delamerian Orogen, with a length of ~1000 km on mainland Australia and a proven potential to host mineralisation, represents an evolving exploration opportunity. However, uncertainty surrounding the age and tectonic setting of the orogen is a barrier to confident exploration in frontier covered regions, such as the Loch Lilly-Kars Belt in western New South Wales and South Australia. A major area of uncertainty is the configuration and extent of the Cambrian convergent-margin system and lateral variations thereof. In this study, we highlight multidisciplinary data from new and legacy sources, including lithology, geochronology, geochemistry, potential-field geophysics, deep-crustal seismic, and magnetotelluric data that permit a revised interpretation of the geological framework for the Delamerian Orogen in mainland Australia, with an emphasis on the covered, central part of the system. These data indicate that a largely continuous, east-facing volcanic arc developed in the Delamerian Orogen in the Cambrian. The arc transitions from exhibiting a strong continental affinity in the Koonenberry Belt to having less continental affinity in the Grampians-Stavely Zone of Victoria. The Loch Lilly-Kars Belt is interpreted to have occupied a volcanic arc to incipient back-arc position in the middle Cambrian. 

Citation: Clark A.D., et al., 2024. Cambrian convergent margin configuration in the Delamerian Orogen of mainland Australia. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://doi.org/10.26186/149647