SEISMIC-REFLECTION PROFILING IN THE PROTEROZOIC ARUNTA BLOCK, CENTRAL AUSTRALIA - PROCESSING FOR TESTING MODELS OF TECTONIC EVOLUTION

The region extending from the northern Amadeus Basin to the Northern Arunta Province is characterised by a large change in Bouguer gravity (1400 μ s-2), abrupt changes in teleSeismic travel-time residuals and large thrust structures in which rocks from the lower crust are now exposed at the surface. Deep Seismic reflection data, other geophysical data and geological mapping within this region have contributed to the development of a crustal model that would result from "thick-skinned" tectonic processes, in which deformation occurred along moderately dipping thrusts or shear zones that extended from the surface down to at least the crust-mantle boundary. Two important features of this model have emerged with the help of unconventional stacking techniques. The first is a series of reflections from the Redbank Deformed Zone that can be traced from surface outcrop to depths of more than 30 km. The second is evidence of a fault extending through the crust and displacing the Moho. © 1990.