Bimodal volcanism of back-arc basin formation and in the products of both continental and oceanic hotspots (e.g. Yellowstone and the Canary Islands). Bimodal volcanism is normally explained as a result of partial melting of the crust, creating granitic magmas, during the emplacement of large volumes of relatively hot basaltic magma from a mantle source. The two magma types then form separate magma chambers giving rise to periodic eruption of both types of lava. Bimodal volcanism Bimodal volcanism is the eruption of both mafic and felsic lavas from a single volcanic centre with little or no lavas of intermediate composition. This type of
Grenville Province orogeny and metamorphism. Pinwarian magmatism has stopped by this time. Gabbros were formed in the northern Grenville Province around 1.46-1.43 Ga, named the Michael-Shabogamo gabbros. From 1.42 to 1.35 Ga, there is no magmatic activity. After this period and until the end of the mid-Elsonian, the Nain Plutonic Suite is emplaced in Labrador. Felsic magmatism dominates the north and south areas of Labrador while mafic magmatism dominates the central area of Labrador. Felsic magmatism ceases and accretion of island arcs occurs in the Central Metasedimentary Belt. Mixed compression and extension caused broad mafic magmatism during this time. This could be