An era is a substantial geological time unit lasting several hundred million years.
Understanding Geological Time: Eras in Context
In geology, time is divided into hierarchical units. Here's how an era fits in:
- Eon: The largest division of geological time. Several eras make up an eon.
- Era: A significant portion of geological time, lasting for several hundred million years. Geologists use eras to describe long series of rock strata they deem important enough to name.
- Period: Eras are further divided into periods.
- Epoch: Periods are subdivided into epochs.
Example of an Era: The Mesozoic Era
A well-known example is the Mesozoic Era, also known as the "Age of Reptiles" or "Age of Dinosaurs." This era lasted from approximately 252 to 66 million years ago. This era showcases how an era encompasses vast geological and biological changes on Earth.
