Basement architecture from the Pilbara Craton to the Aileron Province: new insights from deep seismic reflection line 18GA-KB1

Crustal architecture places first-order controls on the distribution of mineral and energy resources. However, despite its importance, it is poorly constrained over much of northern Australia. Here, we present a full crustal interpretation of deep seismic reflection profile 18GA-KB1 that extends over 872 km from the Eo- to Mesoarchean Pilbara Craton to the Paleoproterozoic Aileron Province, transecting a range of stratigraphic and tectonic basement units, some of which are completely concealed by younger rocks. The seismic profile provides the first coherent image through this relatively poorly understood part of Australian geology and yields major new insights about the crustal architecture, geometry and definition of the different geological and seismic provinces and their boundaries. Key findings include the following: (1) The Pilbara Craton shows a three-component horizontal crustal layering, where the granite– greenstone East Pilbara Terrane is largely confined to the upper crust. (2) The Pilbara Craton has an extensive reworked margin, the Warrawagine Seismic Province, that thins towards the east, and underlies the western and central Rudall Province. (3) At the largest scale, the Rudall Province shows an approximately funnel-shaped geometry, with limited differences in seismic character between the various terranes. (4) The western Kidson Sub-basin is underlain by rocks of the Neoproterozoic Yeneena Basin and Rudall Province. (5) The central and eastern part of the Kidson Sub-basin rests on the coherent, relatively poorly structured Punmu Seismic Province, which is truncated by the steep, crustal-scale Lasseter Shear Zone, that marks the boundary to the Aileron Province to the east. Citation: Doublier, M.P., Johnson, S.P., Gessner, K., Howard, H., Chopping, R., Smithies, R.H., Martin, D.McB.,Kelsey, D.E., Haines, P.w., Hickman, A., Czarnota, K., Southby, C., Champion, D.C., Huston, D.L., Calvert, A.J., Kohanpour, F., Moro, P., Costelloe, R., Fomin, T. and Kennett, B.L.N., 2020. Basement architecture from the Pilbara Craton to the Aileron Province: new insights from deep seismic reflection line 18GA-KB1. 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.