A year is divided into months, weeks, and days. The geologic time scale is also

divided into time categories. What are the time divisions that are used for the

geologic time scale and what determines how they are divided?

Geologic time is known to be divided into four long segments which are termed as the eons. It determines the time and probable historic events which occurred in this time.

The four long segments of the eon area:

Hadean: The Hadean is the eon which predates the Archean. The Hadean eon started with the beginning of the Earth abour 4,6 million years ago. Archean: During this eon, the Earh cooled down to support the existence of life. Proterozoic:During this eon, more complex life began to form. This eon started about 2500 million years ago. Phanerozoic : This is the current geologic eon with all the diversified form of life.

The Phanerozoic eon is the eon which can be recognized by the division of eras. The eras of the Phanerozoic eon are: Paleozoic, Mesozoic, and Cenozoic. Eras are further divided into periods.