Who Organized the Geologic Time Scale?

The first geologic time scale that included absolute dates

was published in 1913 by the British geologist Arthur Holmes. He greatly furthered the newly created discipline of geochronology and published the world-renowned book The Age of the Earth in which he estimated Earth's age to be at least 1.6 billion years.

Why is it important to establish a time scale?

Gradually, geologists discovered evolutionary successions of fossils that helped them determine the relative ages of groups of rocks. ... The geologic time scale is an important tool used to portray the history of the Earth—a standard timeline used to describe the age of rocks and fossils, and the events that formed them.

How is the geological scale organized?

Scientists use the geologic time scale to illustrate the order in which events on Earth have happened. The geologic time scale was developed after scientists observed changes in the fossils going from oldest to youngest sedimentary rocks. ... The geologic time scale is divided into eons, eras, periods, and epochs.