Mount Meager massif are covered with their eruptive products and serve as the surface expressions of intrusions. As a result, they provide a unique opportunity to study the relationships between magma chambers and their lavas. The mafic (rich in magnesium and iron), intermediate (between mafic and felsic) and felsic (rich in feldspar and quartz) volcanic rocks of the massif were erupted from at least eight volcanic vents. The Bridge River Vent is a relatively young volcanic crater that formed during an eruption about 2,400 years ago. This eruption ranged in character from explosive to effusive and involved lava dome extrusion, pyroclastic flows, lahars
Granite This leads to significant extraction of hydrous felsic melts from granulite-facies resitites. A-type granites occur in the Koettlitz Glacier Alkaline Province in the Royal Society Range, Antarctica. The rhyolites of the Yellowstone Caldera are examples of volcanic equivalents of A-type granite. H-type granites were suggested for hybrid granites, which were hypothesized to form by mixing between mafic and felsic from different sources, e.g. M-type and S-type. However, the big difference in rheology between mafic and felsic magmas makes this process hardly happening in nature. An old, and largely discounted process, granitization states that granite is formed in place through extreme