128 GONDWANALAND AND GONDWANA GONDWANALAND AND GONDWANA J J Veevers, Macquarie University, Sydney, NSW, Australia ß 2005, Elsevier Ltd All Rights Reserved Introduction Gondwanaland existed from the 600–500 Ma accretion of the African and South American terranes to Antarctica–Australia–India, through the 320 Ma merging with Laurussia to form Pangaea, until breakup between 180 Ma and 100 Ma (Figures and 2) The name Gondwanaland was introduced in 1885 by Eduard Suess for the regions with the Glossopteris flora, in particular the Gondwana System of peninsular India In 1912 Alfred Wegener interpreted Gondwanaland as the supercontinent with Gondwanan floras Later there was a view that Gondwanaland should be replaced by Gondwana, which, interpreted as ‘Land of the Gonds’, included one ‘land’ already Semantic confusion of supercontinent and stratigraphical system was averted when ‘wana’ was found to stand for ‘forest’, so that Gondwanaland means the supercontinent and Gondwana means the Indian kingdom of forest dwellers The distinction is valuable because the Gondwana facies started only after Gondwanaland merged with Laurussia to form Pangaea However, not all workers use this terminology This account of Gondwanaland is told through a set of maps that stretch from assembly, through the merger with Laurussia to form Pangaea, to breakup Early–Middle Cambrian (530–500 Ma) In the Early–Middle Cambrian, Gondwanaland was bounded to the north (at the modern coordinates of Africa) by terranes now in Laurentia, Europe, and Asia, and to the west and south by a trench (Figures and 4) The interior was crossed by fold belts generated during the terminal Pan-Gondwanaland (600–500 Ma) deformation, which endowed Gondwanaland with a thick buoyant crust and lithosphere, and nonmarine siliciclastic deposits behind a peripheral shoreline Between 650 Ma and 570 Ma, stress (Figure 3) was generated from the oblique collisions of, first, Avalonia–Cadomia with the West African Craton and, second, West Gondwanaland with East Gondwanaland during the closure of the Mozambique Ocean The West African Craton, which was rotated counterclockwise, imparted clockwise rotation to the Amazonia Craton, which, in turn, rotated the Congo Craton counterclockwise Between 550 Ma and 490 Ma, stress was generated first by oblique subduction of the Palaeo-Pacific Plate beneath Antarctica and second by transcurrence beneath Avalonia– Cadomia and the West African and Amazonia Cratons The India–East Antarctica–West Australia Craton was driven into counterclockwise rotation, which imparted clockwise rotation to the North Australia Craton, modelled by dextral shear along small circles about a pole in the Pacific A fold belt was extruded between the West African and Congo Cratons, and another between the Congo and Amazonia Cratons The cycle ended at about 500 Ma with final convergence along the Palaeo-Pacific margin and uplift and cooling in Gondwanaland The heat emitted during convergence, added to that generated during the Pan-Gondwanaland cycle, built buoyancy into Gondwanaland by underplating the lower crust with mafic magma to promote isostatic uplift and concomitant downwearing The shoreline alongside Antarctica, through Australia and north-west India, continued along the northern margin to the Levant and north-east Africa, with marine sediment deposited in belts of terrigenous, mixed, and carbonate facies across West Africa and southwards (in modern coordinates) into South America (past the north pole) and then across the Damara fold belt, to link with carbonate in the Transantarctic Mountains, and over flood basalt on the Australian platform In the south-east, a newly generated marginal basin started to close by north-eastward-directed subduction beneath a volcanic arc Above subducting slabs, the margin includes granite in the Suwannee terrane of Florida, granite in Argentina and beside a rift projected towards the Transantarctic Mountains, the string of Ross plutons, the Delamerian granites, and granites in north-eastern Australia The Prydz-Leeuwin Belt and Mozambique Orogenic Belt were metamorphosed Early Ordovician (490–458 Ma) In the Early Ordovician the north pole lay in the Sahara (Figure 5), but ice did not appear until 444 Ma Australia was crossed by the (Larapintine) sea behind a magmatic arc generated by westwards-directed subduction of ocean floor that was flooded by fans of quartzose sediment from Antarctica Areas of Pan-Gondwanaland deformation had cooled The shoreline lapped the Beardmore Shelf and Table Mountain Shelf In the ancestral Parana´