Geologic Time
The geologic time scale encompasses the history of the Earth. It is bracketed at the old end by the dates of the earliest solar system material at 4.567 Ga, (gigaannum: billion years ago) and the age of the Earth at 4.54 Ga at the beginning of the informally recognized Hadean eon. At the young end of the scale, it is bracketed by the present day in the Holocene epoch.
Read more about this topic: Geology
Famous quotes containing the word time:
“To measure life learn thou betimes, and know
Toward solid good what leads the nearest way;
For other things mild Heaven a time ordains,
And disapproves that care, though wise in show,
That with superfluous burden loads the day,
And, when God sends a cheerful hour, refrains.”
—John Milton (1608–1674)