GSSP Table - All Periods

Global Boundary Stratotype Section and Point (GSSP)
Ages from "Geologic Time Scale 2020" by F.M. Gradstein, J.G. Ogg, M.D. Schmitz and G.M. Ogg, (2020, Elsevier).

Cenozoic Era Mesozoic Era Paleozoic Era Precambrian All Periods
Stage Age (Ma) GTS 2020 GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eon
Cenozoic Era
Quaternary System
Holocene Series
Meghalayan Stage 0.00425 Mawmluh Cave, Meghalaya,India 25.2622°N 91.7150°E Mawmluh Cave speleothem dated at 4250yr bk2 (before AD2000) Stable isotope profile shows a shift to heavier isotopic values, Ratified 2018 Episodes 41/4, 2018
Northgrippian Stage 0.008236 borehole NGRIP1 in the central Greenland ice sheet 75.1000°N 42.3200°W 1228.67 m depth in NGRIP 1 ice core Climatic cooling following a period of generally rising temperatures during the Early Holocene Ratified 2018 Episodes 41/4, 2018
Greenlandian Stage 0.0118 NorthGRIP ice core, central Greenland 75.1000°N 42.3200°W 1492.45m depth in Borehole NGRIP2 Climatic -- End of the Younger Dryas cold spell, which is reflected in a shift in deuterium excess values Ratified 2008 Episodes 31/2, 2008; J. Quaternary Sci., Vol. 24 pp. 3-17, 2009; Episodes 41/4, 2018
Pleistocene Series
Upper Pleistocene Stage 0.126 Taranto, Italy 0.0000°N 0.0000°E 63.5 m below surface Climatic -- Base of the Eemian interglacial stage (= base of marine isotope stage 5e) before final glacial episode of Pleistocene. Episodes 31/2, 2008
Chibanian 0.78 Chiba, Japan Base of Byk-E tephra bed Byk-E tephra; 1.1 m below directional midpoint of Brunhes–Matuyama magnetic reversal (base of Chron 1n) Ratified 2019
Calabrian Stage 1.8 Vrica, Italy 39.0385°N 17.1348°E base of the marine claystone overlying the sapropelic marker Bed 'e' (Mediterranean Precession Related Sapropel, MPRS 176) top of Olduvai magnetic subchron is about 8 m above the GSSP Ratified 1985 Episodes 8/2, p. 116 - 120, 1985; Episodes 35/3, p. 388 - 397, 2012
Gelasian Stage 2.58 Monte San Nicola, Sicily, Italy 37.1469°N 14.2035°E base of marly layer overlying sapropel MPRS 250 Magnetic -- Matuyama/Gauss boundary (C2r/C2An) is 1m below GSSP. GSSP level is within Marine Isotope Stage 103. Definition as base of Quaternary and Pleistocene ratified 2009 Episodes 21/2, p. 82-87, 1998
Neogene System
Pliocene Series
Piacenzian Stage 3.6 Punta Piccola, Sicily, Italy 37.2889°N 13.4933°E base of the beige marl bed of small-scale carbonate cycle 77 (MPRS 347) Magnetic -- Gauss/Gilbert (C2An/C2Ar) magnetic reversal is recorded immediately above the GSSP Ratified 1997 Episodes 21/2, p. 88-93, 1998
Zanclean Stage 5.333 Eraclea Minoa, Sicily, Italy 37.3917°N 13.2806°E base of the Trubi Formation which corresponds to Insolation cycle 510 Magnetic -- base of the Thvera magnetic event (C3n.4n) is only 96 kyr (5 precession cycles) younger than the GSSP. Ratified 2000 Episodes 23/3, p. 179 - 187, 2000
Miocene Series
Messinian Stage 7.25 Oued Akrech, Morocco 33.9369°N 6.8125°W reddish layer of sedimentary cycle number 15 Planktonic foraminifer first regular occurrence of Globorotalia miotumida, and calcareous nannofossil FAD Amaurolithus delicatus Ratified 2000 Episodes 23/3, p. 172 - 178, 2000
Tortonian Stage 11.63 Monte dei Corvi Beach, near Ancona, Italy 43.5867°N 13.5694°E mid-point of sapropel layer of basic cycle number 76. Calcareous nannofossil last common occurrence of Discoaster kugleri Ratified 2003 Episodes 28/1, p. 6 - 17, 2005
Serravallian Stage 13.82 Ras il Pellegrin section, Fomm Ir-Rih Bay, west coast of Malta 35.9139°N 14.3361°E formation boundary between the Globigerina Limestone and Blue Clay Formation Oxygen-isotopic event (global cooling episode) Mi3b; near calcareous nannofossil LAD ofSphenolithus heteromorphus Ratified 2007 Episodes, 32/3, 152 - 166, 2009
Langhian Stage 15.99 St. Peter's Pool, Malta or La Vedova,Italy Base of magnetic polarity chron C5Br
Burdigalian Stage 20.45 Potentially in astronomically-tuned ODP core Near FAD of calcareous nannofossil Helicosphaera ampliaperta
Aquitanian Stage 23.04 Lemme-Carrioso Section, Allessandria Province, Italy 44.6589°N 8.8364°E 35m from the top of the section Magnetic -- base of Chron C6Cn.2n; planktonic foraminifer FAD of Paragloborotalia kugleri; calcareous nannofossil near LAD Reticulofenestra bisecta (base Zone NN1); Oxygen isotopic event Mi-1. Ratified 1996 Episodes 20/1, p. 23 - 28, 1997
Paleogene System
Oligocene Series
Chattian Stage 27.3 Monte Cagnero, Umbria-Marche region, Italy 43.6466°N 12.4677°E at meter level 197 HCO (highest common occurrence) of planktonic foraminifer Chiloguembelina cubensis Ratified 2016 Episodes 41/1, p. 17-32, 2018
Rupelian Stage 33.9 Massignano, near Ancona, Italy 43.5328°N 13.6011°E base of a 0.5m thick greenish-grey marl bed 19m above base of section Foraminifer LAD Hantkenina and Cribrohantkenina Ratified 1992 Episodes 16/3, p.379 - 382, 1993
Eocene Series
Priabonian Stage 37.7 Alano di Piave section, NE Italy 45.9142°N 11.9180°E Tiziano Bed at 63.57m Foraminifer LAD of Morozovelloides, Calcareous nannofossil acme of Cribrocentrum erbae Ratified 2020 Episodes 44/2, p.151-173, 2021
Bartonian Stage 41 Contessa highway section near Gubio, Central Apennines, Italy provisional: base of magnetic polarity chronozone C18r
Lutetian Stage 48.1 Gorrondatxe sea-cliff section,Basque Country, northern Spain 43.3796°N 3.0143°W at 167.85 metres in the Gorrondatxe section at a dark marly level Calcareous nannofossil FAD of Blackites inflatus Ratified 2011 Episodes 34/2, p. 86 - 108 2011
Ypresian Stage 56 Dababiya, near Luxor, Egypt 25.5000°N 32.5311°E base of Bed 1 in DBH subsection Carbon Isotope Excursion base, initiation of basal Eocene Thermal maximum ("PETM") Ratified 2003 Micropaleontology 49/1, p.41 - 59, 2003; Episodes 30/4, p. 271 - 286, 2007
Paleocene Series
Thanetian Stage 59.2 Zumaia section, northern Spain 43.2996°N 2.2609°W About 78 m above the Cretaceous/ Paleogene boundary; 6.5m above the base of Member B of the Itzurun Formation Magnetic -- Base of Chron C26n Ratified 2008 Episodes 34/4,p. 220-243, 2011
Selandian Stage 61.7 Zumaia section, northern Spain 43.2992°N 2.2610°W base of the red marls of Itzurun Formation Onset of a carbon isotope shift and sea-level drop, 30 precession cycles (~630 kyr) above the top of magnetic polarity Chron 27n Ratified 2008 Episodes 34/4,p. 220-243, 2011
Danian Stage 66 Oued Djerfane, west of El Kef, Tunisia 36.1537°N 8.6486°E reddish layer at the base of the 50cm thick, dark boundary clay Iridium geochemical anomaly. Associated with a major extinction horizon (dinosaurs, ammonites, foraminifers, etc.) Ratified 1991 Episodes 29/4, p. 263 - 278, 2006
Mesozoic Era
Cretaceous System
Upper Cretaceous Series
Maastrichtian Stage 72.2 ± 0.2 Tercis les Bains, Landes, France 43.6795°N 1.1133°W level 115.2 on platform IV of the geological site at Tercis les Bains Mean of 12 biostratigraphic criteria of equal importance. Closely above is FAD of ammonite Pachydiscus neubergicus. Boreal proxy is FAD of belemnite Belemnella lanceolata. Ratified 2001 Episodes 24/4, p. 229 -238, 2001
Campanian Stage 83.7 ± 0.5 Bottaccione Gorge Section at Gubbio, Umbria-Marche Basin, Italy 43.3627°N 12.5828°E level 221.53 m in the Bottaccione Gorge Section at Gubbio, Umbria-Marche Basin, Italy Base of Chron C33r Ratified 2022 Episodes 46/3, p. 451 – 490, 2023
Santonian Stage 85.7 ± 0.2 Olazagutia, Northern Spain 42.8681°N 2.1944°W at 94.4m in the eastern border of the "Cantera de Margas" quarry, Olazagutia, Spain Inoceramid bivalve FAD Platyceramus undulatoplicatus Ratified 2013 Episodes 37/1, p. 2-13, 2014
Coniacian Stage 89.4 ± 0.2 Salzgitter-Salder Section in northern Germany 52.1243°N 10.3295°E base of Bed 46 in the Grauweisse Wechselfolge of the Salzgitter-Salder Section in northern Germany Inoceramid bivalve FAD Cremnoceramus deformis erectus Ratified 2021 Episodes 45/2. p. 181 - 220, 2022
Turonian Stage 93.9 Pueblo, Colorado, USA 38.2822°N 104.7275°W base of Bed 86 of the Bridge Creek Limestone Member Ammonite FAD Watinoceras devonense Ratified 2003 Episodes 28/2,p. 93 - 104, 2005
Cenomanian Stage 100.5 Mount Risou, Hautes-Alpes, France 44.3925°N 5.5119°E 36 meters below the top of the Marnes Bleues Formation on the south side of Mont Risou Planktonic foraminifer FAD Thalmanninella globotruncanoides Ratified 2002 Episodes 27/1, p. 21-32, 2004
Lower Cretaceous Series
Albian Stage 113.2 ± 0.3 Col de Pré-Guittard, Arnayon, Drôme, France 44.4964°N 5.3114°E 37.4 m above the base of the Marnes Bleues Formation and 40 cm above the base of the Niveau Kilian Marker Bed near Col de Pré-Guittard. Planktonic foraminiferan FAD Microhedbergella renilaevis Ratified 2016 Episodes 40/3, p. 177-188. 2017
Aptian Stage 121.4 ± 0.6 candidate is Gorgo a Cerbara, Piobbico, Umbria-Marche, central Italy Magnetic -- base of Chron M0r; near FAD of Paradeshayesites oglanlensis ammonite zone
Barremian Stage 126.5 ± 0.7 candidate is Río Argos near Caravaca, Murcia Province, Spain Ammonite FAD Taveraidiscus hugii - Spitidiscus vandeckii group
Hauterivian Stage 132.6 ± 0.6 La Charce village, Drôme Province, southeast France base of Bed 189 of La Charce Section. Ammonite FAD of genus Acanthodiscus Ratified 2019 Episodes 44/2, p. 129 - 150, 2021
Valanginian Stage 137.7 ± 0.5 candidate near Caravaca Spain Calpionellid FAD Calpionellites darderi
Berriasian Stage 143.1 ± 0.6 candidate: Vocontian Basin of SE France, a section at Tré Maroua (Hautes -Alpes) Base of Calpionella alpina Subzone, middle of magnetozone M19n.2n
Jurassic System
Upper Jurassic Series
Tithonian Stage 149.2 ± 0.7 candidates are Mt. Crussol or Canjuers (SE France) or Swabia, Germany Near base of Hybonoticeras hybonotum ammonite zone and lowest occurrence of Gravesia genus, and the base of magnetic polarity Chron M22An
Kimmeridgian Stage 154.8 ± 0.8 Flodigarry (Isle of Skye, NW Scotland) 57.6000°N 6.2000°W upper part of Bed 35 of the Staffin Shale Formation, 1.25±0.01 m below the base of Bed 36 in block F6 in the foreshore at Flodigarry. Ammonite FAD Pictonia flodigarriensis, Prorasenia bowerbanki and Pictonia (Triozites) Ratified 2021 Episodes 46/2, p.281-307, 2023
Oxfordian Stage 161.5 ± 1 Thuoux Section, SE France Ammonite FAD Brightia thuouxensis
Middle Jurassic Series
Callovian Stage 165.3 ± 1.1 candidates are Pfeffingen (Swabian Alb, SW Germany) and in Russia Ammonite FAD of the genus Kepplerites (Kosmoceratidae) (defines base of Macrocephalites herveyi Zone in sub-Boreal province of Great Britain to southwest Germany)
Bathonian Stage 168.2 ± 1.2 Ravin du Bès, Bas-Auran area, Alpes de Haute Provence, France 43.9606°N 6.3153°E base of limestone bed RB07 Ammonite FAD Gonolkites convergens (defines base of Zigzagiceras zigzag Zone) Ratified 2008 Episodes 32/4, p. 222 - 248, 2009
Bajocian Stage 170.9 ± 0.8 Murtinheira Section, Cabo Mondego, Portugal 40.1992°N 8.9042°W base of Bed AB 11 Ammonite FAD Hyperlioceras mundum, Hyperlioceras furcatum, Braunsina aspera, and Braunsina elegantula Ratified 1996 Episodes 20/1, p.16 - 22, 1997
Aalenian Stage 174.7 Fuentelsaz, Spain 41.1708°N 1.8333°W base of Bed FZ 107 Ammonite FAD Leioceras opalinum and Leioceras lineatum Ratified 2000
Lower Jurassic Series
Toarcian Stage 184.2 ± 0.3 Ponta do Trovao, Peniche (Portugal) 39.3708°N 9.3853°W base of micritic limestone bed 15e in the uppermost Lemede Formation Ammonite FAD of Dactylioceras (Eodactylioceras) simplex co- occurring with D. (E.) pseudocommune and D. (E.) polymorphum Ratified 2014 Episodes 39/3, p. 460 - 481, 2016
Pliensbachian Stage 192.9 ± 0.3 Wine Haven, Robin Hood's Bay, Yorkshire Coast, England 54.4069°N 0.4975°W base of Bed 73b Ammonite association of Bifericeras donovani and Apoderoceras sp. Ratified 2005 Episodes 29/2, p. 93-106, 2006
Sinemurian Stage 199.5 ± 0.3 East Quantoxhead, SW England 51.1909°N 3.2364°W 0.90 m above the base of Bed 145 Ammonite FAD Vermiceras quantoxense, Vermiceras palmeri Ratified 2000 Episodes 25/1, p. 22-28, 2002
Hettangian Stage 201.4 ± 0.2 Kuhjoch section, Tyrol, Austria 47.4833°N 11.5306°E 5.80 m above the base of the Tiefengraben Member of the Kendelbach Formation Ammonite FAD of Psiloceras spelae tirolicum Ratified 2010 Episodes 36/3, p.162-198, 2013
Triassic System
Upper Triassic Series
Rhaetian Stage 205.7 ± 0.4 Candidates are Pizzo Mondello, Sicily (Italy) and Steinbergkogel, Austria Near FAD of conodonts Misikella posthernsteini s.s. or Misikella posthernsteini s.l.
Norian Stage 227.3 ± 0.4 Candidates are Black Bear Ridge in British Columbia (Canada) and Pizzo Mondello, Sicily (Italy) Base of Stikinoceras kerri ammonoid zone and near FAD of conodont Metapolygnathus communisti group, or top of M. parvus subzone , or FAD of bivalve Halobia austriaca
Carnian Stage 237 Prati di Stuores, Dolomites, Italy 46.5269°N 11.9303°E base of marly limestone bed SW4, 45m from base of San Cassiano Formation FAD ammonoid Daxatina canadensis, near conodont FAD "Paragondolella" polygnathiformis noah. Just above magnetic polarity zone S2n and above the maximum flooding surface of Sequence Lad 3 of Hardenbol et al (1998). Ratified 2008 Albertina 36, p. 78 - 97, 2007; Episodes, 35/3, p. 414 - 430
Middle Triassic Series
Ladinian Stage 241.5 Bagolino, Province of Brescia, Northern Italy 45.8193°N 10.4710°E base of a 15 - 20cm thick limestone bed overlying a distinctive groove ("Chiesense groove") of limestone nodules in a shaly matrix, located about 5m above the base of the Buchenstein Beds Ammonite FAD Eoprotrachyceras curionii (base of the E. curionii zone). Conodont FAD Budurovignathus praehungaricus is in the uppermost Anisian. Ratified 2005 Episodes 28/4, p. 233-244, 2005
Anisian Stage 246.7 ± 0.2 Candidate section at Desli Caira (Dobrogea, Romania); significant sections in Guizhou Province (China) and South Primorye (Russia) 45.0742°N 28.8022°E In Section B, the GSSP level will be either the FAD of conodont Chiosella timorensis at the base of Bed GR7 at ca. 7 m; OR the base of magnetozone MT1n at the 5.7 m level. Conodont FAD Chiosella timorensis or base of magnetic polarity MT1n Anticipated 2016 Albertiana 36, 2007.
Lower Triassic Series
Olenekian Stage 249.9 ± 0.2 Candidates Mud (Muth) village, Spiti valley, India, or Chaohu, China 0.0000°N 0.0000°E base of Bed 13A-2, about 4.8m up in Mikin Formation., Section M04 (~4000 m elevation Conodont FAD Novispathodus waageni, just above base of Rohillites rohilla ammonite zone, and below lowest occurrence of Flemingites and Euflemingites ammonite genera. Within a prominent positive Carbon-13 peak, and just above widely recognizable sequence boundary. Anticipated 2016 Albertiana 36, 2007.
Induan Stage 251.9 ± 0.3 Meishan, Zhejiang Province, China 31.0798°N 119.7058°E base of Bed 27c in the Meishan D Section Conodont FAD Hindeodus parvus Ratified 2001 Episodes 24/2, p. 102 - 114, 2001
Paleozoic Era
Permian System
Lopingian Series
Changhsingian Stage 254.2 ± 0.4 Meishan, Zhejiang Province, China 31.0819°N 119.7064°E base of Bed 4a-2, 88 cm above the base of the Changxing Limestone at the Meishan D Section Conodont FAD Clarkina wangi Ratified 2005 Episodes 29/3, p. 175-182, 2006
Wuchiapingian Stage 259.5 ± 0.4 Penglaitan, Guangxi Province, South China 23.6953°N 109.3211°E base of Bed 6k in the Penglaitan Section Conodont FAD Clarkina postbitteri postbitteri Ratified 2004 Episodes 29/4, p. 253-262, 2006
Guadalupian Series
Capitanian Stage 264.3 ± 0.4 Nipple Hill, SE Guadalupe Mountains, Texas, U.S.A 31.9091°N 104.7892°W 4.5m above the base of the outcrop section of the Pinery Limestone Member of the Bell Canyon Formation Conodont FAD Jinogondolella postserrata Ratified 2001
Wordian Stage 269.2 ± 0.4 Guadalupe Pass, Texas, U.S.A 31.8658°N 104.8328°W 7.6m above the base of the Getaway Ledge outcrop Section of the Getaway Limestone Member of the Cherry Canyon Formation Conodont FAD Jinogondolella aserrata Ratified 2001
Roadian Stage 274.4 ± 0.4 Stratotype Canyon, Texas, U.S.A 31.8767°N 104.8768°W 42.7m above the base of the Cutoff Formation Conodont FAD Jinogondolella nankingensis Ratified 2001
Cisuralian Series
Kungurian Stage 283.3 ± 0.4 candidate Pequob Mtns., Nevada, USA Near conodont FAD Neostreptognathus pnevi Anticipated 2016
Artinskian Stage 290.5 ± 0.4 Dal’ny Tulkas section in the southern Urals of Russia 53.8885°N 56.5162°E 0.6 m above the base of Bed 4b at the Dal’ny Tulkas section Conodont FAD Sweetognathus asymmetricus Ratified 2022 Episodes 46/4, p. 623-65, 2023
Sakmarian Stage 293.5 ± 0.4 Usolka section, Southern Urals, Russia. 53.9247°N 56.5287°E 55.4m above the base in Bed 26/3 Conodont FAD Mesogondolella monstra Ratified 2018 Episodes 43/4, p. 961-979, 2020
Asselian Stage 298.9 Aidaralash Creek, Kazakhstan 50.2458°N 57.8914°E 27m above the base of Bed 19, Aidaralash Creek Conodont FAD of Streptognathodus isolatus Ratified 1996 Episodes 21/1, p. 11-18, 1998
Carboniferous System
Pennsylvanian Subsystem (series Classification Approved In 2004)
Upper Pennsylvanian Series
Gzhelian Stage 303.7 ± 0.4 candidates are in southern Urals or Nashui (South China). Conodont FAD Idiognathodus simulator
Kasimovian Stage 307 ± 0.4 candidates are in southern Urals, and Nashui (South China). Conodont FAD Idiognathodus heckeli
Middle Pennsylvanian Series
Moscovian Stage 315.2 ± 0.4 candidates are in southern Urals or Nashui (South China). Conodont FAD Diplognathodus ellesmerensis
Lower Pennsylvanian Series
Bashkirian Stage 323.4 Arrow Canyon, Nevada 36.7333°N 114.7778°W 82.9m above the top of the Battleship Formation in the lower Bird Spring Formation Conodont FAD Declinognathodus noduliferus Ratified 1996 Episodes 22/4, p. 272-283, 1999
Mississippian Subsystem
Upper Mississippian Series (series Classification Approved In 2004)
Serpukhovian Stage 330.3 ± 0.4 candidates are Verkhnyaya Kardailovka (Urals) or Nashui (China) Conodont FAD Lochriea ziegleri
Middle Mississippian Series
Visean Stage 346.7 Pengchong, south China 24.4333°N 109.4500°E base of bed 83 in the Pengchong Section Benthic Foraminifer FAD Eoparastaffella simplex Ratified 2008 Episodes 26/2, p. 105-115, 2003
Lower Mississippian Series
Tournaisian Stage 359.3 ± 0.3 La Serre, France 43.5555°N 3.3573°E base of Bed 89 in Trench E' at La Serre, (but FAD now known to be at base of Bed 85) Conodont FAD Siphonodella sulcata
IMPRECISE (GSSP discovered in 2006 to have biostratigraphic problems, and can not be correlated with precision.)
Ratified 1990 Episodes 14/4, p. 331-336, 1991; Newsletters on Stratigraphy, 43/2, p. 195 - 205, 2009
Devonian System
Upper Devonian Series
Famennian Stage 372.1 ± 1.1 Coumiac Quarry, near Cessenon, Montagne Noire, France 43.4613°N 3.0403°E Base of Bed 32a Base of Conodont Palmatolepis triangularis Zone, just above a major extinction horizon (Kellwasser Event). Conodont FAD Palmatolepis subperlobata, conodont LADs Ancyrodella, Palmatolepis bogartensis and Ozarkodina, and Goniatite LADs of Gephuroceratidae and Beloceratidae Ratified 1993 Episodes 16/4, p. 433-441, 1993
Frasnian Stage 378.9 ± 1.2 Col du Puech de la Suque, Montage Noire, France 43.5032°N 3.0868°E base of Bed 42a' at Col du Puech de la Suque section E Conodont FAD Ancyrodella rotundiloba Ratified 1986 Episodes 10/2, p. 97-101, 1987
Middle Devonian Series
Givetian Stage 385.3 ± 1.2 Jebel Mech Irdane, Morocco 31.2374°N 4.3541°W base of Bed 123 Conodont FAD Polygnathus hemiansatus Ratified 1994 Episodes 18/3, p. 107-115, 1995
Eifelian Stage 394.3 ± 1.1 Wetteldorf, Eifel Hills, Germany 50.1496°N 6.4716°E 21.25m above the base of the exposed section, base of sample station WP30 Conodont FAD Polygnathus costatus partitus Ratified 1985 Episodes 8/2, p. 104-109, 1985
Lower Devonian Series
Emsian Stage 410.5 ± 1.1 Zinzil'ban Gorge in the Kitab State Geological Reserve, Uzbekistan 39.2000°N 67.3056°E base of Bed 9/5 Conodont FAD Eocostapolygnathus kitabicus. New Emsian base under discussion, potentially FAD of Eocostapolygnathus excavatus Ratified 1995 Episodes 20/4, p. 235-240, 1997
Pragian Stage 412.4 ± 1.1 Velká Chuchle, Prague, Czech Republic 50.0147°N 14.3726°E base of Bed 12 in Velká Chuchle Quarry Conodont FAD Eognathodus sulcatus sulcatus and Latericriodus steinachensis Morph beta Ratified 1989 Episodes 12/2, p. 109-113, 1989
Lochkovian Stage 419 ± 1.8 Klonk, near Prague, Czech Republic 49.8550°N 13.7920°E within Bed 20 Graptolite FAD Monograptus uniformis Ratified 1972 IUGS Series A, 5, p. 96-109, 1977
Silurian System
Přídolí Series 422.7 ± 1.6 Požáry Section, Reporyje, Prague, Czech Republic 50.0277°N 14.3249°E within Bed 96, about 2 m above the base of the Požáry Formation Graptolite FAD Neocolonograptus parultimus Ratified 1984 Episodes 8/2, p. 101-103, 1985; Geol. Series, Nat. Mus. Wales, 9, p. 90 - 100, 1989
Ludlow Series
Ludfordian Stage 425 ± 1.5 near Ludlow, UK 52.3592°N 2.7772°W coincident with the base of the Leintwardine Formation Imprecise. May be near base of Saetograptus leintwardinensis Graptolite zone. Ratified 1980 Lethaia 14; Episodes 5/3, p. 21-23, 1982; Geol. Series, Nat. Mus. Wales, 9, p. 73 - 90, 1989
Gorstian Stage 426.7 ± 1.5 near Ludlow, UK 52.3592°N 2.7772°W coincident with the base of the Lower Elton Formation Graptolite FAD Saetograptus (Colonograptus) varians Ratified 1980 Lethaia 14; Episodes 5/3, p. 21-23, 1982; Geol. Series, Nat. Mus. Wales, 9, p. 73 - 90, 1989
Wenlock Series
Homerian Stage 430.6 ± 1.3 Sheinton Brook, Homer, UK 52.6156°N 2.5647°W within upper part of the Apedale Member of the Coalbrookdale Formation Graptolite FAD Cyrtograptus lundgreni Ratified 1980 Lethaia 14; Episodes 5/3, p. 21-23, 1982; Geol. Series, Nat. Mus. Wales, 9, p. 51-73, 1989
Sheinwoodian Stage 432.9 ± 1.2 Hughley Brook, UK 52.5811°N 2.6389°W base of the Buildwas Formation Imprecise. Between the base of acritarch biozone 5 and LAD of conodont Pterospathodus amorphognathoides. The current GSSP does not coincide with the base of the Cyrtograptus centrifugus Biozone, as was supposed when the GSSP was defined. Restudy recommends a slightly higher and correlatable level on condonts -- the Ireviken datum 2, which coincides approximately with the base of the Cyrtograptus murchisoni Graptolite Biozone Ratified 1980 Lethaia 14; Episodes 5/3, p. 21-23, 1982; Geol. Series, Nat. Mus. Wales, 9, p. 51-73, 1989
Llandovery Series
Telychian Stage 438.6 ± 1.1 Cefn-cerig Road Section, Wales, UK 51.9700°N 3.7900°W within the Wormwood Formation Just above Brachiopod LAD Eocoelia intermedia and below FAD of Eocoelia curtisi Ratified 1984 Episodes 8/2, p. 101-103, 1985; Geol. Series, Nat. Mus. Wales, 9, p. 36-50, 1989
Aeronian Stage 440.5 Trefawr Track Section, Wales, UK 52.0300°N 3.7000°W within Trefawr Formation Graptolite FAD Monograptus austerus sequens Ratified 1984 Episodes 8/2, p. 101-103, 1985; Geol. Series, Nat. Mus. Wales, 9, p. 36-50, 1989
Rhuddanian Stage 443.1 ± 0.9 Dob's Linn, Scotland 55.4400°N 3.2700°W 1.6m above the base of the Birkhill Shale Formation Graptolite FAD Akidograptus ascensus Ratified 1984 Episodes 8/2, p. 101-103, 1985; Silurian Times No. 14 (2006); Episodes 31/3, p. 315 - 318, 2008
Ordovician System
Upper Ordovician Series
Hirnantian Stage 445.2 Wangjiawan North section, N of Yichang City, Western Hubei Province, China 30.9841°N 111.4197°E 0.39m below the base of the Kuanyinchiao Bed Graptolite FAD Metabolograptus extraordinarius Ratified 2006 Episodes 29/3, p. 183-196, 2006
Katian Stage 452.8 ± 0.7 Black Knob Ridge Section, Atoka, Oklahoma (USA) 34.4305°N 96.0746°W 4.0m above the base of the Bigfork Chert Graptolite FAD Diplacanthograptus caudatus Ratified 2006 Episodes 30/4, p. 258-270, 2007
Sandbian Stage 458.2 ± 0.7 Sularp Brook, Fågelsång, Sweden 55.7137°N 13.3255°E 1.4m below a phosphorite marker bed in the E14b outcrop Graptolite FAD Nemagraptus gracilis Ratified 2002 Episodes 23/2, p. 102-109, 2000
Middle Ordovician Series
Darriwilian Stage 469.4 ± 0.9 Huangnitang section, Changshan, Zhejiang Province, SE China 28.8539°N 118.4897°E base of Bed AEP 184 Graptolite FAD Undulograptus austrodentatus Ratified 1997 Episodes 20/3, p. 158-166, 1997
Dapingian Stage 471.3 ± 1 Huanghuachang Section, NE of Yichang city, Hubei Province, S. China 30.8605°N 110.3740°E 10.57 m above base of the Dawan Formation Conodont FAD of Baltoniodus triangularis Ratified 2007 Episodes 28/2, p. 105 - 117, 2005; Episodes 32/2, p. 96-113, 2009
Lower Ordovician Series
Floian Stage 477.1 ± 1.2 Diabasbrottet, Hunneberg, Sweden 58.3589°N 12.5024°E in the lower Tøyen Shale, 2.1m above the top of the Cambrian Graptolite FAD Tetragraptus approximatus Ratified 2002 Episodes 27/4, p. 265-272, 2004
Tremadocian Stage 486.9 ± 1.5 Green Point Section, western Newfoundland 49.6829°N 57.9653°W at the 101.8m level, within Bed 23, in the measured section Conodont FAD Iapetognathus fluctivagus Ratified 2000 Episodes 24/1, p. 19 - 28, 2001
Cambrian System
Furongian Series
Stage 10 491 Agnostoid arthropod FAD of Lotagnostus americanus
Jiangshanian 494.2 Duibian B Section (Zhejiang Province, China) 28.8160°N 118.6149°E 108.12m above the base of the Huayansi Formation at the base of an 8 cm thick layer of dark gray calcisiltites Agnostoid arthropod FAD of Agnostotes orientalis Ratified 2011
Paibian Stage 497 Wuling Mountains, Huayuan County, NW Hunan Province, China 28.3895°N 109.5257°E at 396 m in the Huaqiao Formation Agnostoid arthropod FAD Glyptagnostus reticulatus Ratified 2003 Lethaia 37, p. 365-379, 2004
Miaolingian Series
Guzhangian Stage 500.5 Louyixi, Guzhang County, NW Hunan Province, S. China 28.7200°N 109.9647°E 121.3 m above the base of the Huaqiao Formation Agnostoid arthropod FAD Lejopyge laevigata Ratified 2008 Episodes 32/1, p.41-55, 2009
Drumian Stage 504.5 Drum Mountains, Millard County, Utah, USA 39.5117°N 112.9915°W at the base of a dark-gray thinly laminated calcisiltite layer, 62 m above the base of the Wheeler Formation Agnostoid arthropod FAD Ptychagnostus atavus Ratified 2006 Episodes 30/2,p. 85-95, 2007
Wuliuan Stage 509 Wuliu-Zengjiayan section in Jianhe County, eastern Guizhou Province, China 26.7474°N 108.4138°E at the base of a silty mudstone layer (within bed 9) 52.8m above the base of the Kaili Formation in the Wuliu-Zengjiayan section Trilobite, FAD of Oryctocephalus indicus Ratified 2019 Episodes 42/2, p.165-184, 2019
Series 2
Stage 4 514.5 Trilobite FAD Olenellus or Redlichia
Stage 3 521 Trilobites -- their FAD
Terreneuvian Series
Stage 2 529 Small Shelly Fossils, FAD of Watsonella crosbyi or Aldanella attleborensis
Fortunian Stage 538.8 ± 0.6 Fortune Head, SE Newfoundland, Canada 47.0762°N 55.8310°W 2.4m above the base of Member 2 in the Chapel Island Formation Trace fossil FAD Trichophycus pedum Ratified 1992 Episodes 17/1&2, p. 95-100, 1994
Proterozoic Eon
Neoproterozoic Era
Ediacaran System 635 Enorama Creek, Flinders Ranges, South Australia 31.3314°S 138.6334°E base of the Marinoan cap carbonate (1) rapid decay of Marinoan ice sheets and onset of distinct cap carbonates throughout the world, and (2) the beginning of a distinctive pattern of secular changes in carbon isotopes. Ratified 1990 Lethaia 39, p.13-30, 2006
Cryogenian System 720 Onset of the first global glaciation Ratified 1990 Episodes 14/2,1991
Tonian System 1000 Defined chronometrically Ratified 1990 Episodes 14/2,1991
Mesoproterozoic Era
Stenian System 1200 Defined chronometrically Ratified 1990 Episodes 14/2,1991
Ectasian System 1400 Defined chronometrically Ratified 1990 Episodes 14/2,1991
Calymmian System 1600 Defined chronometrically Ratified 1990 Episodes 14/2,1991
Paleoproterozoic Era
Statherian System 1800 Defined chronometrically Ratified 1990 Episodes 14/2,1991
Orosirian System 2050 Defined chronometrically Ratified 1990 Episodes 14/2,1991
Rhyacian System 2300 Defined chronometrically Ratified 1990 Episodes 14/2,1991
Siderian System 2500 Defined chronometrically, but it will be replaced by GSSP Ratified 1990 Episodes 14/2,1991
Archean Eon
Neoarchean Era 2800 Defined chronometrically Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992
Mesoarchean Era 3200 Defined chronometrically Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992
Paleoarchean Era 3600 Defined chronometrically Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992
Eoarchean Era 4000 Base is not defined Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992
Hadean Eon 4560 Formation of planet Earth. Informal term