The subdivision of geological time into intervals of known duration. Related Articles: Book review: Introducing Metamorphism, by Ian SandersA field guide to Barbados (Part 1): IntroductionA very brief introduction to the QuaternaryCherokee Castle: A jewel in the Colorado Rocky MountainsVolcanoes, monsoons and a flooded supercontinent: The climate engine of the Carnian Pluvial Event« Back to Glossary Index