Geologic time scale - Wikipedia
It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in …
Geologic Time Scale - Geology (U.S. National Park Service)
Oct 5, 2021 · Geologic time scale showing the geologic eons, eras, periods, epochs, and associated dates in millions of years ago (MYA).
GSA Geologic Time Scale - Geological Society of America
At GSA you'll find the resources, confidence, and connections you need to reach fulfilling new heights in your geoscience career.
Geologic time | Periods, Time Scale, & Facts | Britannica
Dec 1, 2025 · The geologic time scale is the “calendar” for events in Earth history. It subdivides all time into named units of abstract time called—in descending order of duration— eons, eras, …
Geologic Time Scale - Science Notes and Projects
Jan 11, 2025 · The Geologic Time Scale or Geological Time Scale (GTS) is a chronological framework that organizes Earth’s history into various units based on geological and …
Geologic Time Scale: A List of Eons, Eras, and Periods
May 13, 2025 · The geologic time scale is a system used by scientists to describe Earth's history in terms of major geological or paleontological events (such as the formation of a new rock …
Geologic Time Scale : Divisions, Periods and Eons » Geology ...
Feb 13, 2023 · The Geologic Time Scale is a system used by scientists to describe the timing and relationships between events in Earth's history. It covers a vast expanse of time, from the …
Geologic Time Scale | U.S. Geological Survey - USGS.gov
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, …
Geologic Time Scale - University of California Museum of ...
Rise of civilization and agriculture. Extinction of large mammals in northern hemisphere. Modern humans appear. Four major glaciations cause rapid shifts in ecological communities. …
The Geologic Time Scale – Geology 101 for Lehman College (CUNY)
This geologic time scale was assembled entirely on the basis of relative geologic ages, without knowing the absolute ages of any of the events, eons, or periods.