Flood basalts, continental breakup and the dispersal of Gondwana: evidence for periodic migration of upwelling mantle flows (plumes)

The present study used igneous provinces, mainly continental flood volcanics or oceanic plateaus, at times associated with regional updoming, major rifting and continental breakup, together with its precisely dated magmatic events, as indications for paths of plume activity. First-generation plumes -such as the Permo-Carboniferous European-northwest African "EUNWA", and the Jurassic Karoo and Northwest Australia -and convergent environments (Variscan Orogen, the Pacific and the Tethyan subduction zones, respectively) seem to be genetically associated. This may indicate that mantle plumes tend to be initiated by long-lived downwelling lithospheric slabs causing instabilities at the lower mantle boundary layers.