Geological timescale. Artwork representing the geological timescale from 4.567 billion years ago (top right) to the present day (bottom right). The lower half of the strip represents four geological eras: the Precambrian (grey),the Paleozoic (blue),the Mesozoic (green),and the Cenozoic (yellow). The upper half of the strip represents various geological eras,periods and epochs (19 shown here). From top to bottom: Hadean,Archean,Proterozoic,Cambrian,Ordovician,Silurian,Devonian,Carboniferous,Permian,Triassic,Jurassic,Cretaceous,Paleocene,Eocene,Oligocene,Miocene,Pliocene,Pleistocene,and Holocene. For labels,see C021/3470 and C021/3471 |