1. Eon: The largest division of geologic time, spanning hundreds of millions to billions of years. Examples include the Precambrian Eon and the Phanerozoic Eon.
2. Era: A subdivision of an eon, typically lasting tens to hundreds of millions of years. Examples include the Paleozoic Era, Mesozoic Era, and Cenozoic Era.
3. Period: A subdivision of an era, lasting tens of millions of years. Examples include the Cambrian Period, Jurassic Period, and Quaternary Period.
4. Epoch: A subdivision of a period, lasting millions to tens of millions of years. Examples include the Paleocene Epoch, Miocene Epoch, and Holocene Epoch.
5. Age: The smallest division of geologic time, lasting thousands to hundreds of thousands of years. Ages are often named after specific rock formations or fossils found within them.
Therefore, the correct order from longest to shortest is: Eon > Era > Period > Epoch > Age.
