Output Type: Exploring for the Future Extended Abstract
Short Abstract: We have used new magnetotelluric data collected in the Curnamona Province and Delamerian Orogen to image electrical resistivity structures. Our resistivity model confirms crustal-scale conductive features mapped by AusLAMP models, i.e., the prominent Curnamona Province Conductor and the two Nackara Arc conductors, and resolves them in greater detail. The new model also reveals several apparently continuous arcuate conductors within the lower crust extending from the Eastern Nackara Arc Conductor to Broken Hill, and further into the Delamerian Orogen. In the west, these conductors coincide with the dominant structural grain of the Delamerian Orogen and are interpreted to represent ancient fluid pathways associated with major faults in the area. The eastern conductor diverts from the dominant structural grain in the Grasmere knee zone. The source of this conductor is enigmatic, although possibilities could include complex deformation as the Cambrian convergent margin was deformed in the Delamerian Orogeny, or younger events such as the emplacement of the late-Silurian Allambie Woolshed Granite. The conductive features provide new insights for understanding the geodynamic events and potential mineral systems associated with the transition from Proterozoic Australia in the west to the mostly Phanerozoic Tasmanides in the east. These conductivity anomalies may represent large-scale trans-crustal structures, which can place fundamental control on the spatial distribution and formation of mineral systems in the Curnamona Province and Delamerian Orogen.
Citation: Jiang, W., Clark, A., Cheng, Y., Doublier, M., Hitchman, A. & Duan, J., 2024. Unveiling electrical resistivity structures along the undercover Delamerian Orogen, Southeast Australia. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://doi.org/10.26186/149232
