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Geology Homepage

Geologic Time Scale

I have decided to add a geologic time scale, which can be useful when someone mentions a fossil from a certain age, or a time in Earth's history before man. The folowing time scale is largely adapted from International Commission on Stratigraphy (ICS). There may be some different names associated with each time division, and all of the dates are somewhat tentative, depending on the method used to derive the dates. The ages given on the right hand side are very generalized. An example of how the reader might interpret them could be as follows:

When looking at the Gelasian stage, the time is from about 2.58 million years ago, to about 1.81 million years ago, give or take about 100,000 years. Other ages might have more of a variance, especially the farther back in time one goes.

Eon	Era	Period	Epoch	Stage	Age (in millions of years)
Phanerozoic	Cenozoic	Quarternary	Holocene		0.01 to Recent
			Pleistocene	Calabrian	1.81
		Neogene	Pliocene	Gelasian	2.58
				Piacenzian	3.60
				Zanclean	5.32
			Miocene	Messinian	7.12
				Tortonian	11.2
				Serravallian	14.8
				Langhian	16.4
				Burdigalian	20.5
				Aquitanian	23.8
		Paleogene	Oligocene	Chattian	28.5
				Rupelian	33.7
			Eocene	Priabonian	37.0
				Bartonian	41.3
				Lutetian	49.0
				Ypresian	55.0
			Paleocene	Thanetian	57.9
				Selandian	61.0
				Danian	65.5
	Mesozoic	Cretaceous	Late	Maastrichtian	71.3
				Campanian	83.5
				Santonian	85.8
				Coniacian	89.0
				Turonian	93.5
				Cenomanian	98.9
			Early	Albian	112.2
				Aptian	121.0
				Barremian	127.0
				Hauterivian	132.0
				Valanginian	136.5
				Berriasian	142.0
		Jurassic	Late	Tithonian	150.7
				Kimmeridgian	154.1
				Oxfordian	159.4
			Middle	Callovian	164.4
				Bathonian	169.2
				Bajocian	176.5
				Aalenian	180.1
			Early	Toarcian	189.6
				Pliensbachian	195.3
				Sinemurian	201.9
				Hettangian	205.1
		Triassic	Late	Rhaetian	209.6
				Norian	220.7
				Carnian	227.4
			Middle	Ladinian	234.3
				Anisian	241.7
			Early	Olenekian	244.8
				Induan	250
	Paleozoic	Permian	Lopingian	Changhsingian	253.4
				Wuchiapingian
			Guadalupian	Capitanian	265
				Wordian
				Roadian
			Cisuralian	Kungurian
				Artinskian	283
				Sakmarian
				Asselian	292
		Carboniferous	Pennsylvanian	Gzhelian
				Kasimovian
				Moscovian
				Bashkirian	320
			Mississipian	Serpukhovian	327
Visean				342
Tournaisian				354
Devonian		Late	Famennian	364
			Frasnian	370
		Middle	Givetian	380
			Eifelian	391
		Early	Emsian	400
			Pragian	412
			Lochkovian	417
Silurian		Pridoli		419
		Ludlow	Ludfordian
			Gorstian	423
		Wenlock	Homerian
			Sheinwoodian	428
		Llandovery	Telychian
			Aeronian
			Rhuddanian	440
Ordovician		Late	6th stage
			5th stage
		Middle	Darriwilian	467.5
			3rd stage
		Early	2nd stage
			Tremadocian	495
Cambrian		Furongian		500
		Middle		520
		Early		540
Proterozoic	Neoproterozoic	Ediacaran	No defined Epochs		650
		Cryogenian			850
		Tonian			1000
	Mesoproterozoic	Stenian			1200
		Ectasian			1400
		Calymmian			1600
	Paleoproterozoic	Statherian			1800
		Orosirian			2050
		Rhyacian			2300
		Siderian			2500
Archean	Neoarchean	No Defined Periods			2800
	Mesoarchean				3200
	Paleoarchean				3600
	Eoarchean