Describe the three processes that are responsible for the formation of magmas.

The three processes responsible for the formation of magmas are: 1. Decompression Melting: This occurs when pressure on hot mantle rock decreases without significant change in temperature, often due to tectonic plate movement. This causes the rock to melt and form magma, commonly seen at divergent plate boundaries like mid-ocean ridges. 2. Flux Melting: This takes place when water is added to hot rock, lowering its melting temperature and causing it to melt into magma. This is typically seen at convergent plate boundaries, where oceanic crust subducts beneath another plate, releasing water and causing the overlying mantle to partially melt. 3. Heat Transfer Melting: This happens when mantle rocks are heated by intense heat from the Earth's core or an existing magma chamber, causing them to melt and form magma. This process is observed in hot spot volcanoes, where a plume of hot material rises through the lithosphere, forming magma as seen in the Hawaiian Islands.