As distinct from small to medium-size impact events, large asteroid impacts producing explosions more powerful than 107 TNT-equivalent, represented by craters and rebound domes larger than about 100 km in diameter have major consequences including the triggering of major seismic events, tsunami events and extinction episodes. Such events are manifested by the Archaean similar to 3.25-3.24 Ga impact cluster and associated transformation from greenstone-granite terrains to semi-continental assemblages (Glikson AY, Vickers J, Earth Planet Sci Lett 241:11-20, 2006). These impact events are considered in Chap. 6. The oldest identified mega-impact is the similar to 3 Ga Maniitsoq structure in southwest Greenland, while younger mega-impact structures >100 km in diameter include the Vredefort and Sudbury structures. Phanerozoic mega-impacts include the Woodleigh impact structure, Warburton twin structures, Chicxulub and Popigai structures. The global tectonic consequences of some of these mega-impacts are yet to be elucidated.