a science that deals with the history of the earth as recorded in rocks
"The student studied geology to understand how ancient volcanoes shaped the landscape based on layers of rock."
The science that studies the structure of the earth (or other planets), together with its origin and development, especially by examination of its rocks.
"Geologists use radiometric dating to determine when volcanic eruptions occurred, providing key insights into Earth's geological history."
In plain English: Geology is the study of Earth's rocks, layers, and how they change over time.
"The geology professor explained how mountains are formed from ancient volcanic activity."
Usage: Geology is the scientific study of Earth's physical structure, substance, history, and processes. Use this term when referring to the broad discipline itself rather than specific rocks or geological features like "geological formation."
The word "geology" comes from the ancient Greek words for "earth" and "study." It entered English during the Renaissance to describe the scientific field dedicated to studying our planet.