What process occurs during contact metamorphism?

The process that occurs during contact metamorphism involves the heating of surrounding rock due to the proximity of molten rock, or magma. This intense heat alters the physical and chemical characteristics of the surrounding rocks without them becoming completely molten. In essence, the heat from the magma can lead to recrystallization of minerals, resulting in changes to the texture and mineral composition of the existing rock. This process typically occurs in localized areas where magma intrudes into cooler rock formations, creating what is known as a contact aureole around the intrusion.

The other processes mentioned do not accurately describe contact metamorphism. The collision of tectonic plates primarily refers to regional metamorphism rather than the localized effects of contact metamorphism. Pressure buildup in fault zones is related to deformation and earthquake activity, while the formation of igneous rocks is a result of cooling magma rather than the metamorphosis of existing rocks in the vicinity of that magma.