Metamorphism Explained — Types of Metamorphic Rocks, Foliation, and Tectonic Settings | Chapter 8 from Earth: Portrait of a Planet
Metamorphism Explained — Types of Metamorphic Rocks, Foliation, and Tectonic Settings | Chapter 8 from Earth: Portrait of a Planet How do rocks transform without melting? Chapter 8 of Earth: Portrait of a Planet by Stephen Marshak uncovers the science of metamorphism—the process by which pre-existing rocks are altered under the influence of heat, pressure, stress, or hydrothermal fluids. For a comprehensive podcast summary, watch the full video on YouTube , or explore the detailed written breakdown below. What Is Metamorphism? Metamorphism is the solid-state transformation of a protolith (pre-existing rock) into a new type of rock with a different mineral assemblage or texture, without melting. This process is driven by changes in temperature, pressure, differential stress, or the presence of hydrothermal fluids. Key Metamorphic Processes Recrystallization: Changes the size and shape of grains without changing mineral identity. Phase Change: Transforms a mineral i...