earth's geological time scale is divided into four main eons.
earth's geological time scale is divided into four main eons.
he earth's geological time scale is divided into four main?
eons
bullet::::- the geological time scale relates stratigraphy to time. the deep time of earth’s past is divided into units according to events which took place in each period. for example, the boundary between the cretaceous period and the paleogene period is defined by the cretaceous–paleogene extinction event. the largest unit is the supereon, composed of eons. eons are divided into eras, which are in turn divided into periods, epochs and ages. it is not a true mathematical unit, as all ages, epochs, periods, eras or eons don't have the same length; instead, their length is determined by the geological and historical events that define them individually.
unit of time
bullet::::- timeline of the geologic history of the united states









































bullet::::- timeline of human evolution









































bullet::::- timeline of natural history









































bullet::::- timeline of paleontology









































section::::external links.









































bullet::::- nasa: geologic time









































bullet::::- gsa: geologic time scale









































bullet::::- british geological survey: geological timechart









































bullet::::- geowhen database









































bullet::::- international commission on stratigraphy time scale









































bullet::::- chronos.org









































bullet::::- national museum of natural history – geologic time









































bullet::::- seegrid: geological time systems information model for the geologic time scale









































bullet::::- exploring time from planck time to the lifespan of the universe
geologic time scale