Geological Timescale

The earth’s history has been divided into

a series of time intervals called the

Geological Timescale.

The geological timescale helps us divide

the vast periods of time into manageable

time frames. Geologists have divided the

Earth’s history into eras, periods and

epochs. These time intervals vary in

length according to significant events in

the history of the Earth. They are not

equal divisions of time like years,

Geological Times

Eons:

Eons are the longest time periods and are hundreds of millions of years long.

The Phanerozoic eon is the most recent eon and began about 500 million

years ago.

Eras:

Eras are the smaller time periods that the eons are divided into. The

Phanerozoic eon is divided into three eras, the Cenozoic, Mesozoic and the

Paleozoic eras. The divisions between these eras is determined by very

significant events in the history of the Earth.

Periods:

The eras are made up of varying numbers of periods of different lengths of

time. For example, the Palaeozoic is sub divided into the Permian,

Carboniferous, Devonian, Silurian, Ordovician and Cambrian Periods.

C(carboniferous)

lever

O(ordovician)

tters

S(silurian)

wim

D(devonian)

own

C(cambridge period)

annal

P(pernian)

addling