Category
page 1Geological eons
eon
subdivision of geological time; short than a supereon and longer than an era

eonothem
thumb|200px|right|Horseshoe Canyon Formations exposed in Horseshoe Canyon (Alberta)|Horseshoe Canyon near [[Drumheller, Alberta.]]
thumb|200px|right|Oxfordian (Upper Jurassic) cyclic sediments at Péry-Reuchenette, near Tavannes, kanton Bern, Switzerland. Alternating layers are limestone (light, more competent) and [[marl/clay; dominant cycle is the 200000 year-cycle.]]
Chaotian
proposed era of the Hadean eon