McLaren, SandraSandiford, Michael. APowell, Roger2015-12-132015-12-130091-7613http://hdl.handle.net/1885/81370Proterozoic terranes in Australia record complex tectonic histories in the interval 1900-1400 Ma that have previously been interpreted by means of simple intracratonic or plate-tectonic models. However, these models do not fully account for (1) repeated tectonic reactivation (both orogenesis and rifting), (2) mainly high-temperature-low-pressure metamorphism, (3) rifting and sag creating thick sedimentary basins, (4) the nature and timing of voluminous felsic magmatism, (5) relatively large aspect ratio orogenic belts, and (6) a general paucity of diagnostic plate-boundary features. A key to understanding these histories is the observation that Australian Proterozoic terranes are characterized by an extraordinary, but heterogeneous, enrichment of the heat-producing elements. This enrichment must contribute to long-term lithospheric weakening, and thus we advocate a hybrid lithospheric evolution model with two tectonic switches: plate-boundary-derived stresses and heat-producing-element-related lithospheric weakening. The Australian Proterozoic crustal growth record is therefore a function of the magnitude of these stresses, the way in which the heat-producing elements are distributed, and how both of these change with time.Keywords: Intracratonics; Plate-tectonic models; Proterozoic terranes; Tectonic reactivation; Catchments; Geology; Sediments; Tectonics; crustal evolution; heat flow; plate tectonics; Proterozoic; rheology; Australasia; Australia; Eastern Hemisphere; World Differentiation; Heat sources; Plate tectonics; Rheology200510.1130/G21544.12015-12-11