A Timescale is a scale used to represent periods of time. Option: Have students make a timeline of their lives in their notebooks. Have them include at least 3 events from the class ... of a ...

Prehistoric time line, geologic time scale, photos, facts, maps, and more from National Geographic. Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history.

According to the International Union of Geological Sciences (IUGS), the professional organization in charge of defining Earth’s time scale, we are officially in the Holocene (“entirely recent ...

In 1913, before he even earned his doctoral degree, he proposed the first geological time scale, based on the fairly recently discovered phenomenon of radioactivity. Using his quantititive time ...

The geologic time scale is divided into eons ... such as the transition from Jurassic to Cretaceous 145.5 million years ago. The largest extinction events define a change in era. The end of the ...