1. Metamorphism:
* Most likely outcome: Intense heat and pressure cause the igneous rock to transform into a metamorphic rock. This process, called metamorphism, changes the rock's mineral composition, texture, and sometimes even its chemical composition.
* Examples: Granite can transform into gneiss, basalt into schist, and gabbro into amphibolite.
* Factors influencing the outcome: The type of igneous rock, the temperature, pressure, and duration of the heat and pressure, as well as the presence of fluids, all influence the specific metamorphic rock that forms.
2. Partial Melting:
* Under extreme conditions: If the heat and pressure are very high, the igneous rock can partially melt, forming magma. This molten rock can then rise and solidify, forming new igneous rocks.
* Importance: This process is crucial in the rock cycle, as it allows for the formation of new igneous rocks from existing ones.
3. Recrystallization:
* At lower temperatures: Intense heat and pressure can cause existing minerals within the igneous rock to recrystallize. This means that the minerals change their size, shape, and arrangement within the rock.
* Examples: Smaller crystals can grow larger, or the existing minerals can form new, more stable structures.
4. Deformation:
* High pressure: High pressure can cause the igneous rock to deform, changing its shape and possibly creating folds, faults, or other structural features.
In summary:
Intense heat and pressure can cause igneous rock to undergo significant changes, resulting in the formation of metamorphic rocks, the creation of magma, the recrystallization of existing minerals, or the deformation of the rock itself. The specific outcome depends on the exact conditions of the heat and pressure.
