Output Type: Exploring for the Future Extended Abstract
Short Abstract: An advanced understanding of regional-scale metallogenic characteristics and ore-formation controls is fundamental for mineral discovery, particularly in underexplored covered terranes, such as the Delamerian Orogen of southeastern Australia. The Delamerian Orogen is defined as the spatial extent of rocks first deformed by the Delamerian Orogeny, though the Orogen was also affected by younger geodynamic events. Petrology of the mineralised host rocks from over 20 mineral prospects and deposits has led to the recognition of four types of mineral systems related to the geodynamic history of the Delamerian Orogen on mainland Australia, including (1) porphyry-epithermal; (2) volcanic-hosted massive sulphide (VHMS); (3) orogenic gold; and (4) mafic-ultramafic magmatic Cu-Ni-PGE systems. Several other prospects are yet to be classified due to insufficient data, although there is strong evidence to suggest that these are magmatic-hydrothermal in origin. Direct dating of hydrothermal alteration and mineralisation at key mineral deposits and prospects (using U-Pb in titanite and apatite, and Sm-Nd in fluorite) identified four major metallogenic events in the Delamerian Orogen margin. The middle to late Cambrian (505–494 Ma) mineral systems, throughout the eastern margin of the Delamerian Orogen, are potentially the most significant. However, our new dating indicates other metallogenic events at 590–580 Ma, 480–460 Ma, and 412–399 Ma. Analysis of data related to mineral systems fertility reveals crustal controls on the location and type of mineralisation in the Delamerian Orogen. Integration of Hf and O isotopes in zircon, and S isotopes in sulphide minerals indicates that the geology of the Orogen may host multiple opportunities for mineral system development. An indicative map of ca.600–400 Ma mineral system potential was developed by integrating this new data, together with other geological, geochemical and geophysical datasets within the geodynamic context of the Delamerian Orogen. Importantly, this study demonstrates the metallogenic characteristics of multiple types and episodes of mineral system development, and the geological processes that have controlled their formation to aid exploration.
Citation: Cheng, Y., Gilmore, P., Lewis, C., Roach, I., Clark, A., Mole, D., Pitt, L., Doublier, M., Sanchez, G., Schofield, A., O'Rourke, A., Budd, A., Huston, D., Czarnota, K., Meffre, S., Feig, S., Maas, R., Gilbert, S., Cairns, C., Cayley, R., Wise, T., Wade, C., Werner, M., Folkes, C. & Hughes, K., 2024. Mineral systems and metallogeny of the Delamerian Orogen margin. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts. Geoscience Australia, Canberra. https://doi.org/10.26186/149657
