Earth history is punctuated by numerous periods of magmatic activity during which especially large volumes of mainly mafic magma were emplaced.
These Large Igneous Provinces (LIPs) represent huge events with magma volumes exceeding 100 000 km3 and frequently even larger than 1 Mkm3. They are mainly mafic (-ultramafic) magmatic events of intraplate affinity and occur in both continental and oceanic settings. Their duration is typically either short (<5 Ma) or consist of multiple short pulses over a maximum of a few 10s of Ma.
LIPs comprise volcanic packages (flood basalts) and a plumbing system of dyke swarms, sill complexes, layered intrusions, and a crustal magmatic underplate. Various origins are considered but evidence favors mantle-plume involvement for many LIPs (Ernst and Buchan, 2001).
The term “Large Igneous Province” was initially proposed by Coffin and Eldholm (1994). Since the first categorization of LIPs substantial progress has been made in extending the LIP record back to the Paleozoic, Proterozoic, and Archean (Ernst, 2014).
Most research on LIPs has focused on the dramatic flood basalts which characterize Mesozoic-Cenozoic events, both continental flood basalts and the flood basalts within ocean basins (oceanic plateaus and ocean-basin flood basalts) (Ernst, 2014). These parts of the LIP record are generally well preserved. The short duration of emplacement is evident from the main stage of flood-basalt magmatism, which consists of monotonous sequences up to several kilometers thick of large tabular flow units and that commonly lack any significant interlayered sediments (e.g., Bryan et al., 2010).
Figure 1: Examples of large-volume basaltic units from LIPs. A) Deccan lavas, India. B) Sand Hollow flood basalt flow, Columbia River LIP. C) North Atlantic LIP, near Trongisvágur, Suðuroy Island, Faroes. D) Finger Mountain Sill of the Ferrar Dolerite, Antarctica. From Bryan et al. (2010).
Pre-Mesozoic LIPs are more greatly affected by erosion, which largely removes their flood basalts and exposes their plumbing systems. Therefore, continental LIPs of Paleozoic and Proterozoic age typically consist of giant dyke swarms (defined as those > 300 km long), sill provinces, large layered intrusions, and remnant of flood basalts (Ernst and Buchan, 2001).
Figure 2: Left: Franklin LIP dyke, Canada. Right: Kattsund-Koster dyke swarm in the Koster Islands, Sweden. (Wikipedia.org)
Most Archean volcanic rocks occur as deformed and fault-fragmented packages termed greenstone belts. A major type of greenstone belts consists of tholeiite-komatiite sequences, which are the best candidates for being remnants of Archean LIPs (e.g., Ernst and Buchan, 2001; Barnes et al., 2012).
Intraplate magmatism, including events of LIP scale, are also present on other planets and moons such as Mars, Venus, Mercury, the Moon, and Io (Ernst, 2014).
Large Igneous Provinces: Research applications
