Review: secular tectonic evolution of Archean continental crust: interplay between horizontal and vertical processes in the formation of the Pilbara Craton, Australia

摘要: The Archean Pilbara Craton contains five geologically distinct terranes – the East Pilbara, Karratha, Sholl, Regal and Kurrana Terranes all of which are unconformably overlain by 3.02- to 2.93-Ga De Grey Superbasin. 3.53–3.17 Ga Terrane (EP) represents ancient nucleus craton that formed through three mantle plume events at 3.53–3.43, 3.35–3.29 3.27–3.24 Ga. Each event resulted in eruption thick dominantly basaltic volcanic successions on older crust 3.72 Ga, melting generate first tonalite-trondhjemite-granodiorite (TTG), then progressively more evolved granitic magmas. In each case, magmatism was accompanied uplift crustal extension. combination conductive heating from below, thermal blanketing above, internal buried granitoids during these led episodes partial convective overturn upper middle crust. These caused severe depletion subcontinental lithospheric mantle, making EP a stable, buoyant, unsubductable continent c. 3.2 Ga. Extension accompanying latest rifting protocontinent margins between 3.2 3.17 Ga. After 3.2 Ga, horizontal tectonic forces dominated over vertical forces, as revealed geology (Karratha, Sholl Regal) West Superterrane. 3.12-Ga Whundo Group is fault bounded, 10-km-thick succession with geochemical characteristics modern oceanic arcs (including boninites evidence for flux melting) indicate steep subduction. At 3.07 Ga, Terrane, 3.27-Ga Karratha 3.2-Ga accreted together onto Prinsep Orogeny. This followed development Superbasin an intracontinental sag basin widespread plutonism (2.99–2.93 Ga) result orogenic relaxation slab break off. Craton-wide compressional deformation 2.95–2.93 Ga culminated 2.91-Ga accretion 3.18 Ga EP. compression amplification dome-and-keel structure Final cratonization effected emplacement 2.89–2.83 Ga post-tectonic granites.