Base of Eocene
Base of Capitanian
Base of Ectasian
Base of Cryogenian
Base of Jiangshanian
Base of Pennsylvanian
Base of Pliensbachian
Base of Kimmeridgian
Base of Emsian
Base of Proterozoic
Base of Callovian
Base of Coniacian
The Present
Base of Cambrian Stage 10
Base of Thanetian
Base of Jurassic
Base of Middle Mississippian
Base of Visean
Base of Oligocene
Base of Telychian
Base of Drumian
Base of Tortonian
Base of Late Devonian
Base of Cambrian Series 2
Base of Changhsingian
Base of Olenekian
Base of Neogene
Base of Homerian
Base of Katian
Base of Selandian
Base of Mesoproterozoic
Formation of the Earth
Base of Piacenzian
Base of Darriwillian
Boundaries in the International Chronostratigraphic Chart
Base of Maastrichtian
Base of Famennian
Base of Pragian
Base of Aptian
Base of Priabonian
Boundaries in the International Chronostratigraphic Chart
Base of Devonian
Base of Late Mississippian
Base of Cambrian Stage 4
Base of Calabrian
Base of Miaolingian
Base of Phanerozoic
Base of Pridoli
Base of Messinian
Base of Archean
Base of Paleoarchean
Base of Mesoarchean
Base of Neoarchean
Base of Rhyacian
Base of Orosirian
Base of Statherian
Base of Stenian
Base of Neoproterozoic
Base of Ediacaran
Base of Cambrian Stage 2
Base of Guzhangian
Base of Furongian
Base of Ordovician
Base of Floian
Base of Middle Ordovician
Base of Late Ordovician
Base of Hirnantian
Base of Silurian
Base of Aeronian
Base of Wenlock
Base of Ludlow
Base of Ludfordian Stage
Base of Middle Devonian
Base of Givetian
Base of Carboniferous
Base of Middle Pennsylvanian
Base of Late Pennsylvanian
Base of Gzhelian
Base of Permian
Base of Sakmarian
Base of Artinskian
Base of Kungurian
Base of Guadalupian
Base of Wordian
Base of Lopingian
Base of Mesozoic
Base of Middle Triassic
Base of Ladinian
Base of Late Triassic
Base of Norian
Base of Rhaetian
Base of Sinemurian