Decreasing the pressure on hot rock generates most magma. Group startsTrue or False

The variations in the composition of magmas govern whether eruptions are peaceful or explosive.Group startsTrue or False

All metamorphic rocks are created in the presence of high heat and high pressure.Group of answer choicesTrueFalse

Basaltic magma has the lowest viscosity, so more of it reaches the surface; the more viscous rhyolitic magmas are so sluggish that they tend to be trapped deep below the surface where they cool, solidify, and grow into the larger mineral crystals of plutonic rocks.Group startsTrue or False

The cooling and crystallization of magma leads to the formation of igneous rock.El enfriamiento y cristalización del magma conduce a la formación de rocas ígneas. True False

The lowest temperatures and highest SiO2SiO2 contents occur in rhyolitic magma, material so viscous that it commonly does not flow.Group startsTrue or False