Last Minute Lecture

The Rock Cycle and Earth Systems Explained — Igneous, Sedimentary, and Metamorphic Transformations | Interlude C from Earth: Portrait of a Planet Rocks are not eternal—they’re constantly being transformed by the forces of our planet. In Interlude C of Earth: Portrait of a Planet , Stephen Marshak takes readers on a deep dive into the rock cycle, showing how Earth’s internal heat, tectonics, weathering, and biological processes connect all three major rock types into a dynamic, global system. For an accessible visual overview, watch the chapter video on YouTube , or keep reading for a comprehensive breakdown of the rock cycle and its place in Earth system science. What Is the Rock Cycle? The Rock Cycle: The continual transformation of rocks between igneous, sedimentary, and metamorphic forms over geologic time, driven by processes like melting, crystallization, weathering, erosion, burial, and metamorphism. Material Transfer: A single atom—like silicon—can migrate from ...

What Is a Rock? Rock Types, Classification, and Geologic Tools Explained | Interlude A from Earth: Portrait of a Planet What exactly is a rock, and why do geologists care so much about how it forms? In Interlude A of Earth: Portrait of a Planet , Stephen Marshak lays the groundwork for all of geology by defining the concept of a rock and introducing the genetic classification system that guides modern Earth science. For a clear and engaging summary, watch the chapter video on YouTube , or read below for a comprehensive guide to rocks and how we study them. What Is a Rock? The Geologic Definition Rock Definition: A rock is a coherent, naturally occurring solid composed of an aggregate of minerals, mineral grains, or glass. Clastic vs. Crystalline: Clastic rocks are made from cemented fragments, while crystalline rocks have interlocking mineral grains. The Three Genetic Rock Classes Igneous Rocks: Formed by the solidification of molten magma or lava (e.g., granit...