Age dating geology
Other subdivisions reflect the evolution of life; the Archean and Proterozoic are both eons, the Palaeozoic, Mesozoic and Cenozoic are eras of the Phanerozoic eon.
The three million year Quaternary period, the time of recognizable humans, is too small to be visible at this scale.
Apart from the Late Heavy Bombardment, events on other planets probably had little direct influence on the Earth, and events on Earth had correspondingly little effect on those planets.
Construction of a time scale that links the planets is, therefore, of only limited relevance to the Earth's time scale, except in a Solar System context.
For example, the boundary between the Cretaceous period and the Paleogene period is defined by the Cretaceous–Paleogene extinction event, which marked the demise of the non-avian dinosaurs and many other groups of life.
Older time spans, which predate the reliable fossil record (before the Proterozoic eon), are defined by their absolute age.
For example, the lower Jurassic Series in chronostratigraphy corresponds to the early Jurassic Epoch in geochronology.
A major shift in thinking came when James Hutton presented his Theory of the Earth; or, an Investigation of the Laws Observable in the Composition, Dissolution, and Restoration of Land Upon the Globe Hutton proposed that the interior of Earth was hot, and that this heat was the engine which drove the creation of new rock: land was eroded by air and water and deposited as layers in the sea; heat then consolidated the sediment into stone, and uplifted it into new lands.
In the late 17th century Nicholas Steno (1638–1686) pronounced the principles underlying geologic (geological) time scales.