The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils.

Geologic time, the extensive interval of time occupied by the geologic history of Earth. Formal geologic time begins with the Archean Eon (4.0 billion to 2.5 billion years ago) and continues …

Oct 5, 2021 · Geologic time scale showing the geologic eons, eras, periods, epochs, and associated dates in millions of years ago (MYA).

Jan 11, 2025 · Learn about the geologic time scale or GTS. Discover what it is, how it is divided, and the characteristics of each time period.

Jan 23, 2026 · The answer is the geologic time scale, a system that divides Earth’s history into eons, eras, periods, and epochs. It’s the timeline that connects rocks to time — and time to life.

Geologists have divided Earth's history into a series of time intervals. These time intervals are not equal in length like the hours in a day. Instead the time intervals are variable in length. This is …

The Geologic Time Scale above is a helpful reference to use along with the information provided below. The left half shows a timeline of Earth’s geologic history which is split into Eons, Eras, …

What does the time scale represent? The geologic time scale divides up the history of the earth based on life-forms that have existed during specific times since the creation of the planet. …

An overview of the geologic time scale and the principles that underpin it. It is maintained by the International Commission on Stratigraphy and is structured hierarchically, divided into eons, …

May 13, 2025 · Scientists use the geologic time scale to organize Earth's long history into eons, eras, and periods. The Phanerozoic eon is known for the appearance and dominance of …