What are the 4 eons of the geologic time scale?

For example, the entire age of the earth is divided into four eons: the Hadean Eon, the Archean Eon, the Proterozoic Eon, and the Phanerozoic Eon. These four eons are further subdivided into eras (Table 7.3).

What are the 4 divisions of the geologic time scale in order?

The geologic time scale is divided into (from longest to shortest): eons, eras, periods, epochs and ages.

What are the 4 geologic eras from oldest to most recent?

The four main ERAS are, from oldest to youngest: PreCambrian, Palaeozoic, Mesozoic and Cenozoic.

What is eons in geologic time scale?

eon, Long span of geologic time. In formal usage, eons are the longest portions of geologic time (eras are the second-longest). Three eons are recognized: the Phanerozoic Eon (dating from the present back to the beginning of the Cambrian Period), the Proterozoic Eon, and the Archean Eon.

What are eons divided into?

Eons are divided into smaller time intervals known as eras. In the time scale above you can see that the Phanerozoic is divided into three eras: Cenozoic, Mesozoic and Paleozoic. Very significant events in Earth’s history are used to determine the boundaries of the eras.

How are geologic time periods divided?

In the Geologic Time Scale, time is generally divided on the basis of the earth’s biotic composition, with the Phanerozoic Eon (i.e. the Paleozoic, Mesozoic and Cenozoic Eras) representing the period of Earth’s history with advanced life forms, and the Pre Cambrian (or Proterozoic and Hadean Eras) representing the …

What is an example of geologic time scale?

An Example Of The Geologic Time Scale In Use

A well-known period of the geologic time scale is the Jurassic Period, made famous by the film Jurassic Park. The Jurassic Period began around 201 million years ago (Mya), and ended around 145 Mya.