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Timeline of Geological History
In Geological History, we standardize on the Geological Time Scale (GTS).
The definition of standardized international units of GTS is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS). Their primary objective is to precisely define global chronostratigraphic units of the International Chronostratigraphic Chart (ICC), which are in turn used to define geochronological units.
The Geological Time Scale
The GTS is divided into chronostratigraphic units and their corresponding geochronologic units.
- Chronostratigraphy is a part of stratigraphy. Stratigraphy is the branch of geology concerned with the study of rock layers (strata) and layering (stratification).
- Chronostratigraphy is one of the three subdivisions of stratigraphy (the other two being lithostratigraphy and biostratigraphy), dealing with placing an absolute age to rock strata. By placing absolute ages on rock strata, we are able to relate them to their relative formation in time, and hence assign geochronological time periods to them.
- A chronostratigraphic unit is a body of rock, layered or unlayered, that is defined between stratigraphic horizons which represent specified intervals of geologic time. They include all rocks representative of a specific interval of geologic time.
- Geochronology is the branch of geology that aims to determine the age of rocks, fossils and sediments either through absolute or relative means.
- A geochronological unit is a subdivision of geologic time.
In simple terms, chronostratigraphy deals with the dating of physical evidence, and geochronology deals with forming the temporal evidence extrapolated from it. In other words, chronostatigraphic units define a rock's identity according to age, while geochronographic units define the time period in which the rock was formed.
Much like saying "Egyptian Civilization" formed in "3 Millenia BC".
A Global Boundary Stratotype Section and Point (GSSP) is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundaries of stages on the geologic time scale. (Recently this has been used to define the base of a system)
A Global Standard Stratigraphic Age (GSSA) is a numeric only, chronologic reference point used to define the base of geochronologic units prior to the Cryogenian period. These points are arbitrarily defined. They are used where GSSPs have not yet been established. Research is ongoing to define GSSPs for the base of all units that are currently defined by GSSAs.
The units used in GTS are as follows:
| Chronostratigraphic Units (Strata Type) | Geochronometric Units (Time) | Time Span |
|---|---|---|
| Eonothem | Eon | Several hundred million years to two billion years |
| Erathem | Era | Tens to hundreds of millions of years |
| System | Period | Millions of years to tens of millions of years |
| Series | Epoch | Hundreds of thousands of years to tens of millions of years |
| Subseries | Subepoch | Thousands of years to millions of years |
| Stage | Age | Thousands of years to millions of years |
Timeline of GTS (list)
Hadean, Archean, Proterozoic, Phanerozoic
Eoarchean Era, Mesoarchean Era, Paleoarchean Era, Neoarchean Era, Paleoproterozoic Era, Mesoproterozoic Era, Neoproterozoic Era, Paleozoic Era, Mesozoic Era, Cenozoic Era
Siderian, Rhyacian, Orosirian, Statherian, Calymmian, Ectasian, Stenian, Tonian, Cryogenian, Ediacaran, Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene, Quaternary
Terreneuvian, Series 2, Miaolingian, Furongian, Lower/Early Ordovician, Middle Ordovician, Upper/Late Ordovician, Llandovery, Wenlock, Ludlow, Pridoli, Lower/Early Devonian, Middle Devonian, Upper/Late Devonian, Mississippian, Pennsylvanian, Cisuralian, Guadalupian, Lopingian, Lower/Early Triassic, Middle Triassic, Upper/Late Triassic, Lower/Early Jurassic, Middle Jurassic, Upper/Late Jurassic, Lower/Early Cretacious, Upper/Late Cretaceous, Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, Holocene
Fortunian, Stage 2, Stage 3, Stage 4, Wuliuan, Drumian, Guzhangian, Paibian, Jiangshanian, Stage 10, Tremadocian, (formerly Arenig), Floian, Dapingian, Darriwilian, Sandbian, Katian, Hirnantian, Rhuddanian, Aeronian, Telychian, Sheinwoodian, Homerian, Gorstian, Ludfordian, Lochkovian, Pragian, Emsian, Eifelian, Givetian, Frasnian, Famennian, Tournaisian, Visรฉan, Serpukhovian, Bashkirian, Moscovian, Kasimovian, Gzhelian, Asselian, Sakmarian, Artinskian, Kungurian, Roadian, Wordian, Capitanian, Wuchiapingian, Changhsingian, Induan, Olenekian, Anisian, Ladinian, Carnian, Norian, Rhaetian, Hettangian, Sinemurian, Pliensbachian, Toarcian, Aalenian, Bajocian, Bathonian, Callovian, Oxfordian, Kimmeridgian, Tithonian, Berriasian, Valanginian, Hauterivian, Barremian, Aptian, Albian, Cenomanian, Turonian, Coniacian, Santonian, Campanian, Maastrichtian, Danian, Selandian, Thanetian, Ypresian, Lutetian, Bartonian, Priabonian, Rupelian, Chattian, Aquitanian, Burdigalian, Langhian, Serravallian, Tortonian, Messinian, Zanclean, Piacenzian, Gelasian, Calabrian, Chibanian, Upper/Late ('Tarantian'), Greenlandian, Northgrippian, Meghalayan
Timeline of GTS (tree)
- Hadean Eon
- Archean Eon
- Eoarchean Era
- Mesoarchean Era
- Paleoarchean Era
- Neoarchean Era
- Proterozoic Eon
- Paleoproterozoic Era
- Siderian Period
- Rhyacian Period
- Orosirian Period
- Statherian Period
- Mesoproterozoic Era
- Calymmian Period
- Ectasian Period
- Stenian Period
- Neoproterozoic Era
- Tonian Period
- Cryogenian Period
- Ediacaran Period
- Paleoproterozoic Era
- Phanerozoic Eon
- Paleozoic Era
- Cambrian Period
- Terreneuvian Epoch
- Fortunian Age
- Cambrian Stage 2 Age
- Cambrian Series 2 Epoch
- Cambrian Stage 3 Age
- Cambrian Stage 4 Age
- Miaolingian Epoch
- Wuliuan Age
- Drumian Age
- Guzhangian Age
- Furongian Epoch
- Paibian Age
- Jiangshanian Age
- Cambrian Stage 10 Age
- Terreneuvian Epoch
- Ordovician Period
- Lower/Early Ordovician Epoch
- Tremadocian Age
- Floian Age (formerly Arenig Age)
- Middle Ordovician Epoch
- Dapingian Age
- Darriwilian Age
- Upper/Late Ordovician Epoch
- Sandbian Age
- Katian Age
- Hirnantian Age
- Lower/Early Ordovician Epoch
- Silurian Period
- Llandovery Epoch
- Rhuddanian Age
- Aeronian Age
- Telychian Age
- Wenlock Epoch
- Sheinwoodian Age
- Homerian Age
- Ludlow Epoch
- Gorstian Age
- Ludfordian Age
- Pridoli Epoch
- Llandovery Epoch
- Devonian Period
- Lower/Early Devonian Epoch
- Lochkovian Age
- Pragian Age
- Emsian Age
- Middle Devonian Epoch
- Eifelian Age
- Givetian Age
- Upper/Late Devonian Epoch
- Frasnian Age
- Famennian Age
- Lower/Early Devonian Epoch
- Carboniferous Period
- Mississippian Epoch
- Tournaisian Age
- Visรฉan Age
- Serpukhovian Age
- Pennsylvanian Epoch
- Bashkirian Age
- Moscovian Age
- Kasimovian Age
- Gzhelian Age
- Mississippian Epoch
- Permian Period
- Cisuralian Epoch
- Asselian Age
- Sakmarian Age
- Artinskian Age
- Kungurian Age
- Guadalupian Epoch
- Roadian Age
- Wordian Age
- Capitanian Age
- Lopingian Epoch
- Wuchiapingian Age
- Changhsingian Age
- Cisuralian Epoch
- Cambrian Period
- Mesozoic Era
- Triassic Period
- Lower/Early Triassic Epoch
- Induan Age
- Olenekian Age
- Middle Triassic Epoch
- Anisian Age
- Ladinian Age
- Upper/Late Triassic Epoch
- Carnian Age
- Norian Age
- Rhaetian Age
- Lower/Early Triassic Epoch
- Jurassic Period
- Lower/Early Jurassic Epoch
- Hettangian Age
- Sinemurian Age
- Pliensbachian Age
- Toarcian Age
- Middle Jurassic Epoch
- Aalenian Age
- Bajocian Age
- Bathonian Age
- Callovian Age
- Upper/Late Jurassic Epoch
- Oxfordian Age
- Kimmeridgian Age
- Tithonian Age
- Lower/Early Jurassic Epoch
- Cretaceous Period
- Lower/Early Cretaceous Epoch
- Berriasian Age
- Valanginian Age
- Hauterivian Age
- Barremian Age
- Aptian Age
- Albian Age
- Upper/Late Cretaceous Epoch
- Cenomanian Age
- Turonian Age
- Coniacian Age
- Santonian Age
- Campanian Age
- Maastrichtian Age
- Lower/Early Cretaceous Epoch
- Triassic Period
- Cenozoic Era
- Paleogene Period
- Paleocene Epoch
- Danian Age
- Selandian Age
- Thanetian Age
- Eocene Epoch
- Ypresian Age
- Lutetian Age
- Bartonian Age
- Priabonian Age
- Oligocene Epoch
- Rupelian Age
- Chattian Age
- Paleocene Epoch
- Neogene Period
- Miocene Epoch
- Aquitanian Age
- Burdigalian Age
- Langhian Age
- Serravallian Age
- Tortonian Age
- Messinian Age
- Pliocene Epoch
- Zanclean Age
- Piacenzian Age
- Miocene Epoch
- Quaternary Period
- Pleistocene Epoch
- Gelasian Age
- Calabrian Age
- Chibanian Age
- Late/Upper Pleistocene (Tarantian Age)
- Holocene Epoch
- Greenlandian Age
- Northgrippian Age
- Meghalayan Age
- Pleistocene Epoch
- Paleogene Period
- Paleozoic Era