The study of the materials that make up Earth and the processes that form and change those materials is called geology.

Here's a breakdown of what geology encompasses:

* Materials: Geology examines rocks, minerals, soil, water, and even the atmosphere.

* Processes: This includes things like:

* Plate tectonics: The movement of Earth's tectonic plates, causing earthquakes, volcanoes, and mountain building.

* Weathering and erosion: The breakdown and transport of Earth's surface by wind, water, and ice.

* Sedimentation: The deposition of eroded material, forming layers of rock.

* Metamorphism: The transformation of existing rocks by heat and pressure.

* Volcanism: The eruption of molten rock (magma) from the Earth's interior.

Geology is a vast and fascinating field that helps us understand the history of our planet, its current state, and its potential future.