Constraints on the morphology of the Moho are essential to establish reliable models of the subsurface and infer the evolution of the Australian crust. Reliable information on crustal thickness variations is important for thermal modelling and structural mapping, for both energy and mineral system studies. Here, we combine information from both passive seismic deployments and full-crustal reflection seismic profiling to produce a new representation of the character of the Moho in northern Australia. Data coverage has been dramatically improved by investments, under the Exploring for the Future program, in new deployments of passive seismic instrumentation and expansion of the network of reflection seismic profiles in the South Nicholson and Barkly regions. Using a new approach to combining results from different classes of seismic analysis, different spatial sampling associated with the various types of data have been taken into account. The resulting Moho surface reveals small-scale features not seen in previous models. New data reveal that some Moho discontinuities are clearly associated with known structures such as the Willowra Suture. Similar ~100 km wavelength undulations are visible in areas under cover that may indicate the presence of unknown major structures. Significant base metal mineral deposits appear to be localised along the edges of thicker crustal block.
Citation: Gorbatov, A., Medlin, A., Kennett, B.L.N., Doublier, M.P., Czarnota, K., Fomin, T. and Henson, P., 2020. Moho variations in northern Australia. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.