<P> The geologic time scale (GTS) is a system of chronological dating that relates geological strata (stratigraphy) to time, and is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships of events that have occurred during Earth's history . The tables of geologic time spans, presented here, agree with the nomenclature, dates and standard color codes set forth by the International Commission on Stratigraphy . </P> <P> The primary defined divisions of time are eons, in sequence the Hadean, the Archean, the Proterozoic and the Phanerozoic . The first three of these can be referred to collectively as the Precambrian supereon . Eons are divided into eras, which are in turn divided into periods, epochs and ages . </P> <P> The following four timelines show the geologic time scale . The first shows the entire time from the formation of the Earth to the present, but this gives little space for the most recent eon . Therefore, the second timeline shows an expanded view of the most recent eon . In a similar way, the most recent era is expanded in the third timeline, and the most recent period is expanded in the fourth timeline . </P>

He earth's geological time scale is divided into four main