Igneous and Metamorphic Rocks: Regional Metamorphism

Regional metamorphism affects large rock areas, typically at plate boundaries where rocks are deeply buried. The pressure and heat from thick layers, along with possible magma contact, lead to the formation of metamorphic rocks like schist.

Explain the process that leads to the formation of large areas of metamorphic rocks.

What is schist and how is it related to regional metamorphism?