geologic time


geologic time

Interval of time occupied by the Earth's geologic history, extending from c. 3.9 billion years ago (corresponding to the age of the oldest known rocks) to the present day. It is, in effect, the part of the Earth's history that is recorded in rock strata. The geologic time scale is classified in nested intervals distinguished by characteristic geologic and biologic features. From longest to shortest duration, the intervals are eon, era, period, and epoch.

This entry comes from Encyclopædia Britannica Concise.
For the full entry on geologic time, visit Britannica.com.

Seen & Heard

What made you look up geologic time? Please tell us what you were reading, watching or discussing that led you here.

Get Our Free Apps
Voice Search, Favorites,
Word of the Day, and More
Join Us on FB & Twitter
Get the Word of the Day and More