Mount Pleasant Caldera rock. The Intercaldera Sequence comprises formations that crop out from overlying flows in triangularly shaped area, and includes thick volcanic ash (tuff), thick breccia layers, and intermediate to felsic igneous rocks that tend to intrude the above layers and are typically located along caldera margin faults. The Exocaldera Sequence contains ash flow tuffs, mafic lavas, alluvial redbeds, and porphyritic felsic lavas that are distributed across five different layers. The late Caldera-Fill Sequence contains rocks that are similar to those of the outflows of the other, older layers, and comprises two formations and two relatively minor intrusive lava flows. The volcanic
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