A plate tectonic model of the Palaeozoic tectonic history of New South Wales

Abstract

Abstract An updated∗ tectonic model for the Palaeozoic tectonic history of New South Wales, based on actualistic models of plate tectonics, has resulted from tectonic analyses and syntheses during the compilation of the Tectonic Map of New South Wales. Most emphasis is given to marginal seas, which characterize Pacific marginal mobile zones. Marginal seas form in the regime of lithospheric tension under the influence of retrograde motion of the Benioff zone, and during the formation of a new Benioff zone, or during formation of spheno‐ and rhombochasms. Additional mechanisms for obduction zone formation are suggested: the development of an obduction zone at the originally coupled continental margin is important. Three basic types of volcanic chains are distinguished: volcanic arcs, volcanic arches, and volcanic rifts, in the formation of which both primary subduction zones at major plate margins, and secondary subduction zones which develop in marginal seas may be concerned. During the Palaeozoic the east...