What are Large Igneous Provinces?
Earth history is punctuated by short duration events (or dramatic pulses in longer duration events) during which large volumes of mainly mafic magmas were generated and emplaced by processes unrelated to “normal” sea-floor spreading and subduction. These Large Igneous Provinces (LIPs) are best preserved in the Mesozoic and Cenozoic where they occur as continental flood basalts, volcanic rifted margins, oceanic plateaus, and ocean basin flood basalts. Silicic rocks may also be associated.
Many LIPs can be linked to regional-scale uplift, continental rifting and breakup, and climatic shifts. In the Paleozoic and Proterozoic, LIPs are typically deeply eroded. They are represented by deep-level plumbing systems consisting of giant dyke swarms, sill provinces and layered intrusions. In the Archean the most promising LIP candidates are greenstone belts containing komatiites.
Large Igneous Provinces of the Circum-Pacific region (in red) emplaced since 250 Ma. From cover of Mahoney, J.J. and M.F. Coffin (eds.), Large Igneous Provinces: Continental, oceanic, and planetary flood volcanism. Amer. Geophys. Union Geophys. Mon. 100: 438 p., 1997.