List of Global Boundary Stratotype Sections and Points explained

This is a list of Global Boundary Stratotype Sections and Points. Since 1977, Global Boundary Stratotype Sections and Points (abbreviated GSSPs) are internationally agreed upon reference points on stratigraphic sections of rock which define the lower boundaries of stages on the geologic time scale. They are selected by the International Commission on Stratigraphy based on multiple factors, but their accessibility and the degree to which they are representative of the same boundary on sections worldwide are among the most important.

Since GSSPs require well-preserved sections of rock without interruptions in sedimentation, and since most are defined by different stages of animal life, defining them becomes progressively more difficult as one goes farther back in time.

Organization of this list

This list is divided first into the geologic eras of the Phanerozoic (the Cenozoic, the Mesozoic, and the Paleozoic) and then into the geologic periods of each era. Each period is marked below the era bar on top of its subdivided epochs and stages. Each stage is assigned an age in mya, an acronym for million years ago, which is the age at which it began. Most of these ages are derived from astronomical cycles in sediments, magnetic data, biostratigraphic data, and radiometric dating methods. The GSSP assigned to each stage is that stage's lower boundary and oldest point.

Ages are given in "million year ago" (mya). They are obtained with different radiometric dating methods depending on the type of rock and its age. Ages that have a tilde (~) prefix are approximate ages for GSSPs that have not been defined or not been accurately dated.

The Status column has a "golden spike" for every GSSP which has been formally agreed by the ICS. Those without have only candidate sections which have not yet been formally ratified. The clock stands for times that are currently defined only by an age.

The "Defining markers" column lists the evidence in the rock used to define the boundary. (Ideally, these are applicable in rock sections worldwide.) Most of the boundaries rely on the fossil record (biologic), paleomagnetic data (magnetic), and/or climate data determined by carbon and oxygen isotopes.

List

Cenozoic

Quaternary

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Holocene
		Meghalayan			Mawmluh Cave, Meghalaya, India	Climatic: 4.2 kiloyear event.		^[1] ^[2]
		Northgrippian			NGRIP1 ice core,Greenland	Climatic: 8.2 kiloyear event.
		Greenlandian			NGRIP2 ice core,Greenland	Climatic: End of the Younger Dryas stadial.		^[3]
Pleistocene
		Upper/Late			-	Climatic: Marine Isotope Substage 5e	-	-
	Chibanian			Chiba, Japan	Magnetic: Brunhes-Matuyama magnetic reversal.		^[4]
	Calabrian			Vrica Section,Calabria, Italy	Magnetic: Approximately 15 ka after the end of magnetic polarity chronozone C2n (Olduvai). Biologic: Immediately above extinction Discoaster brouweri (Haptophyte). Sedimentologic: Boundary between a sapropelic bed and marine claystones.		^[5]
	Gelasian			Monte San Nicola Section,Gela, Sicily, Italy	Magnetic: Base of magnetic polarity chronozone C2r (Matuyama). Biologic: Extinction of Discoaster pentaradiatus and Discoaster surculus (Haptophyte).		^[6]

Neogene

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Pliocene
	Piacenzian			Punta Piccola Section,Porto Empedocle, Sicily, Italy	Magnetic: Base of magnetic polarity chronozone C2An (Gauss). Biologic: Extinction of Globorotalia margaritae and Pulleniatina primalis (Planktonic foraminifera).		^[7]
	Zanclean			Heraclea Minoa sectionHeraclea Minoa, Cattolica Eraclea, Sicily, Italy	Magnetic: Top of magnetic polarity chronozone C3r. Biologic: First appearance of Ceratolithus acutus and near extinction of Triquetrorhabdulus rugosus (Haptophyte).		^[8]
Miocene
	Messinian			Oued Akrech section,Rabat, Morocco	Magnetic: Within magnetic polarity chronozone C3Br.1r. Biologic: First regular occurrence of the Globorotalia miotumida (Planktonic foraminifera). Biologic: First appearance of Amaurolithus delicatus (Haptophyte).		^[9]
	Tortonian			Monte dei Corvi Beach section,Ancona, Italy	Magnetic: Within normal-polarity subchron C5r.2n Biologic: Last Common Occurrence of the Discoaster kugleri (Haptophyte). Biologic: Last Common Occurrence of the Globigerinoides subquadratus (Planktonic foraminifera). Climatic: Oxygen isotope event Mi-5.		^[10]
	Serravallian			Ras il Pellegrin section,Fomm ir-Riħ Bay, Malta	Magnetic: Within magnetic polarity chronozone C5ABr. Biologic: Below first appearance of Sphenolithus heteromorphus (Haptophyte) Climatic: Mi3b isotopic event (Global cooling episode).		^[11]
	Langhian			At 17.84 m in the 'Lower La Vedova Beach' section, Ancona, Italy	Magnetic: Near top of magnetic polarity chronozone C5Cn.1n. Biologic: Near first appearance of Praeorbulina glomerosa (Planktonic foraminifera).
	Burdigalian			Candidate sections: Astronomically tuned ODP core (e.g. Ceara Rise, Leg 154)	Near FAD of Globigerinoides altiaperturus (planktonic foraminifer) or near top of magnetic polarity chronozone C6An	-
	Aquitanian			Lemme-Carrosio Section,Carrosio, Italy	Magnetic: Base of magnetic polarity chronozone C6Cn.2n. Biologic: Near first appearance of Paragloborotalia kugleri (Planktonic foraminifera).		^[12]

Paleogene

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Oligocene
	Chattian			Monte Cagnero, Central Apennines, Italy	Biological: last occurrence of the planktonic foraminifer Chiloguembelina (Base of Foram Zone P21b)		^[13]
	Rupelian			Massignano quarry section,Massignano, Ancona, Italy	Biologic: Extinction of Hantkenina and Cribrohantkenina (Planktonic foraminifera).		^[14]
Eocene
	Priabonian			Alano section,Piave river, Venetian Prealps, Belluno, Italy	Biologic: Last appearance of large acarininids and Morozovelloides crassatus; The Base of common and continuous Cribrocentrum erbae and the Top of Chiasmolithus grandis Magnetic: The Base of Chronozone C17n and Subchron C17n.2n		^[15]
	Bartonian			Contessa highway sectionGubbio, Central Apennines, Italy	Biologic: Near Extinction of Reticulofenestra reticulata (Haptophyte)		-
	Lutetian			Gorrondatxe sea-cliff section, Western Pyrenees, Basque Country, Spain	Biologic: First appearance of Hantkenina (Planktonic foraminifera).		^[16]
	Ypresian			Dababiya section,Luxor, Egypt	Climatic: Base of negative Carbon Isotope Excursion (CIE).		^[17] ^[18]
Paleocene
	Thanetian			Zumaia Section,Basque Country, Spain	Magnetic: Base of magnetic polarity chronozone C26n.		^[19]
	Selandian			Zumaia Section,Basque Country, Spain	Chemical: Onset of sea-level drop and carbon isotope shift. Magnetic: 30 precession cycles after the top of magnetic polarity Chron 27n
	Danian			El Kef Section,El Kef, Tunisia	Iridium enriched layer associated with a major meteorite impact and subsequent extinction event.		^[20]

Mesozoic

Cretaceous

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Upper
	Maastrichtian			Grande Carrière quarry,Landes, France	Biologic: 12 biostratigraphic criteria Biologic: First appearance of Pachydiscus neubergicus (Ammonite) is just above the boundary.		^[21]
	Campanian			Bottaccione, Gubbio, Italy	Magnetic: Base of Chron C33r.		^[22] ^[23]
	Santonian			Olazagutia, Spain	Biologic: First appearance of Cladoceramus undulatoplicatus (Inoceramid bivalve).
	Coniacian			Salzgitter-Salder quarry, Germany	Biologic: First appearance of Cremnoceramus rotundatus (Inoceramid bivalve).
	Turonian			Rock Canyon,Colorado, United States	Biologic: First appearance of Watinoceras devonense (Ammonite).		^[24]
	Cenomanian			Mont Risoux,Hautes-Alpes, France	Biologic: First appearance of Rotalipora globotruncanoides (Planktonic foraminifera)		^[25]
Lower
	Albian			Col de Pré-Guittard section, Arnayon, Drôme, France	Biologic: first appearance of the planktonic foraminiferan Microhedbergella renilaevis.		^[26] ^[27]
	Aptian			Candidate section: Gorgo a Cerbara, Piobbico, Central Apennines, Italy	Magnetic: Base of magnetic polarity chronozone M0r. Biologic: Near first appearance of Paradeshayesites oglanlensis (Ammonite).	-	-
	Barremian			Río Argos, Caravaca de la Cruz, Murcia Province, Spain	Biologic: First appearance of Ammonite Taveraidiscus hugii.	-	^[28]
	Hauterivian			La Charce, Drôme, France	Biologic: First appearance of the Ammonite genus Acanthodiscus.		^[29] ^[30]
	Valanginian			Candidates sections: Montbrun-les-Bains, Drôme, France Cañada Luenga, Betic Cordillera, Spain	Biologic: First appearance of Calpionellites darderi (Calpionellid). Biologic: First appearance of Thurmanniceras pertransiens (Ammonite).	-	-
	Berriasian			Candidate section: Vaca Muerta, Neuquén Basin, Argentina^[31]	Candidates: Magnetic—base of Chron M18r Base of Calpionellid zone B

Jurassic

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Upper
	Tithonian			Candidate sections: Mt. Crussol, France Canjuers, France Fornazzo, Sicily	Magnetic: Base of magnetic polarity chronozone M22An. Biologic: Near first appearance of Hybonoticeras hybonotum (Ammonite). Biologic: First appearance of genus Gravesia (Ammonite).	-	-
	Kimmeridgian			Flodigarry, Isle of Skye, Scotland, U.K.	Biologic: First appearance of Pictonia baylei (Ammonite).
	Oxfordian			Candidate sections: Redcliff Point, Dorset, England, U.K. Savouron, Provence, France	Biologic: Horizon of Cardioceras redcliffense (Ammonite).	-	-
Middle
	Callovian			Candidate sections: Pfeffingen, Swabian Alb, Germany Russia	Biologic: First appearance of genus Kepplerites (Ammonite).	-	-
	Bathonian			Ravin du Bès, Bas-Auran, Alpes de Haute, France	Biologic: First appearance of Gonolkites convergen (Ammonite).		^[32]
	Bajocian			Cabo Mondego, Portugal	Biologic: First appearance of Hyperlioceras mundum, Hyperlioceras furcatum, Braunsina aspera, and Braunsina elegantula(Ammonite) Biologic: First appearance of genus Hyperlioceras (Ammonite).		^[33]
	Aalenian			Fuentelsaz, Spain	Biologic: First appearance of Leioceras opalinum and Leioceras lineatum Biologic: First appearance of genus Leioceras (Ammonite).		^[34]
Lower
	Toarcian			Peniche, Portugal	Biologic: First appearance of D. (E.) simplex (Ammonite).		^[35]
	Pliensbachian			Robin Hood's Bay, Yorkshire, England, U.K.	Biologic: First appearance of Bifericeras donovani and genera Apoderoceras (Ammonite).		^[36]
	Sinemurian			East Quantoxhead, West Somerset, England, UK	Biologic: First appearance of the Vermiceras quantoxense, Vermiceras palmeri (Ammonite).		^[37]
	Hettangian			Kuhjoch section, Karwendel mountains, Northern Calcareous Alps, Austria	Biologic: Near first appearance of smooth Psiloceras spela group (Ammonite).

Triassic

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Upper
	Rhaetian	~		Candidate sections: Steinbergkogel, Austria Pignola-Abriola, Italy^[38] Turkey British Columbia	Biologic: First appearance of Misikella posthernsteini (Conodont). Biologic: Near first appearance of genus Cochloceras (Ammonite). Biologic: Near first appearance of Epigondolella mosheri (Conodont). Biologic: Near first appearance of Proparvicingula moniliformis (radiolarian).	-	-
	Norian	~		Candidate sections: Black Bear Ridge, British Columbia Pizzo Mondello, Sicily	Base of Stikinoceras kerri ammonoid zone and near FAD of Metapolygnathus echinatus within the M. communisti conodont zones.	-	-
	Carnian	~		Prati di Stuores, Dolomites, Italy	Biologic: First appearance of Daxatina canadensis (Ammonite). Biologic: Near first appearance of Metapolygnathus polygnathiformis (Conodont). Magnetic: Above magnetic zone S2n.		^[39]
Middle
	Ladinian	~		Bagolino, Lombardian pre-Alps, Italy	Biologic: First appearance of Eoprotrachyceras curionii (Ammonite). Biologic: First appearance of Budurovignathus praehungaricus (Conodont).		^[40]
	Anisian			Candidate sections: Desli Caira, Northern Dobruja, Romania Guandao, Guizhou, China	Biologic: First appearance of Chiosella timorensis (Conodont). Magnetic: Base of magnetic zone MT1n.
Lower
	Olenekian			Candidate sections: Mud (Muth) village, Spiti valley, India Chaohu, China	Biologic: First appearance of Neospathodus waageni (Conodont). Biologic: Near first appearance of genera Flemingites and Euflemingites (Ammonite).
	Induan	251.9		Meishan, Zhejiang, China	Biologic: First appearance of Hindeodus parvus (Conodont).

Paleozoic

Permian

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Lopingian
	Changhsingian			Zhejiang, China	Biologic: Near first appearance of Clarkina wangi (Conodont).		^[41]
	Wuchiapingian			Penglaitan Section,Laibin, Guangxi, China	Biologic: First appearance of Clarkina postbitteri postbitteri (Conodont).		^[42]
Guadalupian
	Capitanian			Nipple Hill, Guadalupe Mountains, Texas, U.S.A.	Biologic: First appearance of Jinogondolella postserrata (Conodont).
	Wordian			Guadalupe Pass, Guadalupe Mountains, Texas, U.S.A.	Biologic: First appearance of Jinogondolella aserrata (Conodont).
	Roadian			Stratotype Canyon, Guadalupe Mountains, Texas, U.S.A.	Biologic: First appearance of Jinogondolella nanginkensis (Conodont).
Cisuralian
	Kungurian			Candidate section: Mechetlino, Southern Ural Mountains, Russia	Biologic: Near first appearance of Neostreptognathodus pnevi (Conodont).	-
	Artinskian			Dalny Tulkas section, Southern Ural Mountains, Russia	Biologic: First appearance of Sweetognathus whitei (Conodont).
	Sakmarian			Usolka section, Southern Urals, Russia	Biologic: First appearance of Mesogondolella monstra (Conodont).		^[43] ^[44]
	Asselian			Aidaralash, Ural Mountains, Kazakhstan	Biologic: First appearance of Streptognathodus isolatus within the morphotype Streptognathodus wabaunsensis chronocline (Conodont).		^[45]

Carboniferous

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Pennsylvanian
	Gzhelian			Candidate sections: Ural mountains Nashui, Luodian County, Guizhou, China	Biologic: First appearance Idiognathodus simulator and close to first appearance of Shumardites	-
	Kasimovian			Candidate sections: Ural mountains United States Nashui, Luodian County, Guizhou, China	Biologic: First appearance of Protriticites or 1 million years older Montiparus montiparus	-
	Moscovian			Candidate sections: Ural mountains Nashui, Luodian County, Guizhou, China	Biologic: First appearance of Idiognathoides postsulcatus or Declinognathodus donetzianus	-
	Bashkirian			Arrow Canyon, Nevada, United States	Biologic: First appearance of Declinognathodus nodiliferus (Conodont).		^[46]
Mississippian
	Serpukhovian			Candidate sections: Verkhnyaya Kardailovka, Ural mountains Nashui, Luodian County, Guizhou, China	Biologic: First appearance of Lochriea ziegleri	-
	Visean			Pengchong Section,Guangxi, China	Biologic: First appearance of Eoparastaffella simplex
	Tournaisian			La Serre, Montagne Noire, France	Biologic: First appearance of Siphonodella sulcata (Conodont). In 2006 it was discovered that this GSSP has biostratigraphic problems.		^[47]

Devonian

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Upper
	Famennian			Coumiac quarry,Montagne Noire, France	Biologic: Abundant occurrence of Palmatolepis triangularis (Conodont). Biologic: Upper Kellwasser Extinction of all Ancyrodella and Ozarkodina and most Palmatolepis, Polygnathus, and Ancyrognathus. Biologic: Coincides with the first appearance of Phoenixites frechi (Goniatite).		^[48]
	Frasnian			Col du Puech de la Suque, Montagne Noire, France	Biologic: First appearance of Ancyrodella rotundiloba (Conodont).		^[49]
Middle
	Givetian			Jebel Mech Irdane, Tafilalt, Morocco	Biologic: First appearance of Polygnathus hemiansatus (Conodont). Biologic: Just below first appearance of Maenioceras (Goniatite).		^[50]
	Eifelian			Wetteldorf Richtschnitt section,Wetteldorf, Eifel, Germany	Biologic: First appearance of Polygnathus costatus partitus (Conodont).		^[51]
Lower
	Emsian			Zinzil'ban Gorge, Uzbekistan	Biologic: First appearance of Polygnathus kitabicus (Conodont).		^[52]
	Pragian			Velká Chuchle quarryVelká Chuchle, Prague, Czech Republic	Biologic: First appearance of Eognathodus sulcatus (Conodont).		^[53]
	Lochkovian			Klonk, Prague, Czech Republic	Biologic: First appearance of Monograptus uniformis (graptolite).

Silurian

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Přídolí				Požáry Section,Řeporyje District, Prague, Czech Republic	Biologic: First appearance of Monograptus parultimus (Graptolite).		^[54]
Ludlow
	Ludfordian			Sunnyhill, Ludlow, Shropshire, England, U.K.	Imprecise GSSP. Biologic: Near first appearance of Saetograptus leintwardinensis (Graptolite).		^[55]
	Gorstian			Pitch Coppice, Ludlow, Shropshire, England, U.K.	Biologic: First appearance Saetograptus (Colonograptus) varians
Wenlock
	Homerian			Whitwell Coppice, Homer, England, U.K.	Biologic: First appearance of Cyrtograptus lundgreni (Graptolite).
	Sheinwoodian			Hughley Brook, Apedale, England, U.K.	Imprecise GSSP. Will be reexamined. Biologic: Currently between acritarch biozone 5 and last appearance of Pterospathodus amorphognathoides. Candidate boundaries are a conodont boundary (Ireviken datum 2) which is close to the murchisoni graptolite biozone.
Llandovery
	Telychian			El Pintado section, Province of Seville, Spain	Biologic: FAD of the graptolite Spirograptus guerichi		^[56] ^[57]
	Aeronian			Hlásná Třebaň section, Czech Republic	Biologic: First appearance of Demirastrites triangulatus (Graptolite).		^[58]
	Rhuddanian			Dob's Linn, Moffat, Dumfries-shire, Scotland, U.K.	Biologic: First appearance of Akidograptus ascensus and Parakidograptus acuminatus (Graptolite). 1.6 m above the base of the Birkhill Shale Formation.

Ordovician

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Upper
	Hirnantian			Wangjiawan sectionWangjiawan, Yichang, China	Biologic: First appearance of Normalograptus extraordinarius (Graptolite). Climatic: Base of major positive carbon isotope excursion. Climatic: Beginning of sea-level fall associated with onset of a major glaciation.		^[59]
	Katian			Black Knob Ridge section,Oklahoma, United States	Biologic: First appearance of Diplacanthograptus caudatus (Graptolite). Climatic: Just below base of Guttenberg carbon isotope excursion.		^[60]
	Sandbian			Fågelsång sectionSularp Brook, Skåne, Sweden	Biologic: First appearance of Nemagraptus gracilis (Graptolite). 1.4 m below a phosphorite marker bed.		^[61]
Middle
	Darriwilian			Huangnitang SectionHuangnitang Village, Changshan, Zhejiang, China	Biologic: First appearance of Undulograptus austrodentatus (Graptolite).		^[62]
	Dapingian			Huanghuachang sectionHuanghuachang, Yichang, China	Biologic: Lowest appearance of Baltoniodus triangularis (Conodont).		^[63] ^[64]
Lower
	Floian			Diabasbrottet quarry,Västergötland, Sweden	Biologic: Lowest appearance of Tetragraptus approximatus (Graptolite).		^[65]
	Tremadocian			Greenpoint sectionGreen Point, Newfoundland, Canada	Biologic: First appearance of Iapetognathus fluctivagus (Conodont). Biologic: Planktonic graptolites occur 4.8 m above boundary. Climatic: Coincides with a peak in carbon isotopes.		^[66]

Cambrian

Epoch	Stage	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Furongian
	Stage 10			Candidate sections: Duibian, Zhejiang, China Lawson Cove, Utah, United States	Candidates: Biologic: First appearance of Lotagnostus americanus (Trilobite). Biologic: First appearance of Cordylodus andresi (Conodont). Biologic: First appearance of Eoconodontus notchpeakensis (Conodont).	-	^[67]
	Jiangshanian	~		Duibian B SectionDuibian, Zhejiang, China	Biologic: First appearance of Agnostotes orientalis (Trilobite).		^[68]
	Paibian	~		Paibi sectionPaibi, Hunan, China	Biologic: First appearance of the agnostoid Glyptagnostus reticulatus (Trilobite). Climatic: Coincides with base of the Steptoean positive carbon isotope excursion (SPICE).		^[69]
Miaolingian
	Guzhangian	~		Luoyixi sectionLuoyixi, Guzhang, Hunan, China	Biologic: First appearance of Lejopyge laevigata (Trilobite).		^[70]
	Drumian	~		Drumian sectionWheeler Shale, Utah, U.S.A.	Biologic: First appearance of Ptychagnostus atavus (Trilobite).		^[71]
	Wuliuan	~		Wuliu-Zengjiayan, Guizhou, China	Biologic: First appearance of Oryctocephalus indicus (Trilobite).		^[72] ^[73]
Series 2
	Stage 4	~		None	Biologic: First appearance Arthricocephalus chauveaui (Trilobite species). Biologic: First appearance Olenellus or Redlichia (Trilobite genera).	-	^[74]
	Stage 3	~		None	Biologic: First appearance of trilobites (possibly Lemdadella)	-	^[75] ^[76]
Terreneuvian
	Stage 2	~		None	Biologic: First appearance of small shelly fauna or archaeocyathids	-	-
	Fortunian			Fortune head section,Newfoundland, Canada	Biologic: First appearance of Treptichnus pedum (trace fossil).		^[77]

Precambrian

Proterozoic

Era	Period	Age (mya)	Status	GSSP location	Defining markers	Geographic Coordinates	References
Neoproterozoic
	Ediacaran	~		Enorama Creek sectionFlinders Ranges, South Australia	Geologic: Worldwide distinct cap carbonates. Isotopic: Beginning of a distinctive pattern of secular changes in carbon isotopes.		^[78]
	Cryogenian	~		Defined chronometrically with an interim calibrated age of ca. 720 Ma. GSSP is in progress.	Geologic: the GSSP has been recommended to be placed at a stratigraphic level beneath the first appearance of widespread glaciation associated with the Sturtian glacial epoch.^[79]	-
	Tonian			Defined chronometrically	-	-	^[80]
Mesoproterozoic
	Stenian			Defined chronometrically	-	-
	Ectasian			Defined chronometrically	-	-
	Calymmian			Defined chronometrically	-	-
Paleoproterozoic
	Statherian			Defined chronometrically	-	-
	Orosirian			Defined chronometrically	-	-
	Rhyacian			Defined chronometrically	-	-
	Siderian			Defined chronometrically	-	-

Archean and Hadean

Eon	Era	Age (mya)	Status	GSSP/GSSA location	Defining markers	Geographic Coordinates	References
Archean
	Neoarchean			-	Defined chronometrically	-	-
	Mesoarchean			-	Defined chronometrically	-	-
	Paleoarchean			-	Defined chronometrically	-	-
	Eoarchean	4031		Along the Acasta River, Northwest Territories, Canada	Defined chronometricallyTen oldest U-Pb zircon ages
Hadean	-	4567.3		-	Defined chronometricallyFormation of the Solar System	-

See also

• Global Boundary Stratotype Section and Point (GSSP)
• International Commission on Stratigraphy (ICS)
• Geologic Time Scale
• History of the Earth
• Geological history of Earth

External links

• International Commission on Stratigraphy (ICS)

Notes and References

1. Walker . Mike . Head . Martin J. . Berkelhammer . Max . Björck . Svante . Cheng . Hai . Cwynar . Les . Fisher . David . Gkinis . Vasilios . Long . Anthony . Lowe . John . Newnham . Rewi . Rasmussen . Sune Olander . Weiss . Harvey . Formal ratification of the subdivision of the Holocene Series/ Epoch (Quaternary System/Period): two new Global Boundary Stratotype Sections and Points (GSSPs) and three new stages/subseries . Episodes . 1 December 2018 . 41 . 4 . 213–223 . 10.18814/epiiugs/2018/018016 . free . 28 August 2020.
2. Head . Martin J. . Formal subdivision of the Quaternary System/Period: Present status and future directions . Quaternary International . 17 May 2019 . 500 . 32–51 . 10.1016/j.quaint.2019.05.018 . 2019QuInt.500...32H . 182783922 . 28 August 2020.
3. Walker . Mike . Johnsen, Sigfus . Rasmussen, Sune Olander . Popp, Trevor . Steffensen, Jørgen-Peder . Gibbard, Phil . Hoek, Wim . Lowe, John . Andrews, John . Björck, Svante . Cwynar, Les C. . Hughen, Konrad . Kershaw, Peter . Kromer, Bernd . Litt, Thomas . Lowe, David J. . Nakagawa, Takeshi . Newnham, Rewi. Svante Björck . Phil Gibbard . Schwander, Jakob . Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records . Journal of Quaternary Science . 1 January 2009 . 24 . 1 . 3–17 . 10.1002/jqs.1227 . 2009JQS....24....3W . free.
4. Web site: Global Boundary Stratotype Section and Point . International Commission of Stratigraphy . 3 August 2024.
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