Global Boundary Stratotype Section and Points

Global Boundary Stratotype Sections and Points (GSSPs) are reference points on stratigraphic sections of rock which define the lower boundaries of stages on the geologic time scale. Since 1977, the ICS has maintained the international GSSP register.

Rules

A geologic section has to fulfill a set of criteria to be adapted as a GSSP by the ICS. The following list summarizes the criteria:

  • A GSSP has to define the lower boundary of a geologic Stage.
  • The lower boundary has to be defined using a primary marker (usually first appearance datum of a fossil species).
    • There should also be secondary markers (other fossils, chemical, geomagnetic reversal).
    • The horizon in which the marker appears should have minerals that can be radiometrically dated.
    • The marker has to have regional and global correlation in outcrops of the same age
    • The marker should be independent of facies.
  • The outcrop has to have an adequate thickness
  • Sedimentation has to be continuous without any changes in facies
  • The outcrop should be unaffected by tectonic and sedimentary movements, and metamorphism
  • The outcrop has to be accessible to research and free to access.
    • This includes that the outcrop has to be located where it can be visited quickly (International airport and good roads), has to be kept in good condition (Ideally a national reserve), in accessible terrain, extensive enough to allow repeated sampling and open to researchers of all nationalities.

GSSP Tables

The tables containing summaries of Period’s GSSPs and links to individual Stage’s GSSPs are given below.

Links to each are presented in the menu of the left.

GSSP Tables

Quaternary

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Cenozoic Erathem
Quaternary Period
Holocene Series
Meghalayan Stage 4,250 yr b2k (before 2000 CE) Mawmluh Cave, Meghalaya, India 25°15'44''N; 91°42'54''E depth 7.45 mm in the speleothem KM-A Climatic - End of the Younger Dryas cold spell, which is reflected in a shift in deuterium excess values Ratified 2018

Episodes 2018; 41(4): 213-223. (PDF)

Quaternary Sci., Vol. 500, pp 32-51, 2019

Northgrippian Stage 8,236 yr b2k (before 2000 CE) North Greenland Ice Core Project, core NGRIP1, central Greenland ice sheet 75.1000°N 42.3200°W 1228.67 m in the NGRIP1 ice core Climatic – 8.2 ka event Ratified 2018

Episodes 2018; 41(4): 213-223. (PDF)

Greenlandian Stage 11,700 yr b2k (before 2000 CE) North Greenland Ice Core Project, core NGRIP2, central Greenland ice sheet 75.1000°N 42.3200°W 1492.45 m in the NGRIP2 ice core abrupt shift to lower deuterium excess values Holocene GSSP ratifed 2008; Lower Holocene Subseries and Greenlandian Stage ratified: 2018

Episodes 31(2) 2008; 264–267

Episodes 2018; 41(4): 213-223. (PDF)

Pleistocene Series
Upper Stage GSSP presently undefined but provisionally dated at ~129 ka GSSP not presently defined - - Provisionally climatic – Marine Isotope Substage 5e Ratified in name only 2020 Head, M.J., Pillans, B., and Zalasiewicz, J.A., [submitted 2020]
Middle & Chibanian Stage 0.7741 Chiba section, Japan 35°17'39.6''N, 140°08'47.5''E lower boundary of the Byk-E tephra bed Magnetic – GSSP is 1.1 m below the directional midpoint of the Matuyama/Brunhes paleomagnetic reversal and occurs immediately below the top of Marine Isotope Substage 19c. Ratified 2020 Suganuma, Y., et al., Episodes [submitted 2020].
Calabrian Stage 1.80 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) Magnetic - ∼8m below the observed top of the Olduvai (C2n) normal polarity subchron. GSSP level coincides with the transition from MIS 65 to 64 Ratified 1985 as base of Pleistocene; Ratified 2011 as base of Calabrian Episodes 8/2, p. 116 - 120, 1985; Episodes 35/3, p. 388-397, 2012
Head, M.J., 2019
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 between ~0 and ~3 m above GSSP (Head, 2019) not ∼1 m (20 kyr) below it as reported by Rio et al. (1994, 1998). GSSP level is within Marine Isotope Stage 103. Ratified 1996 as base of Gelasian; Ratified 2009 as base of Pleistocene and Quaternary

Episodes 21/2, p. 82 - 87, 1998

Episodes 33/3, p. 152-158, 2010

Quaternary Sci., Vol. 500, pp 32-51, 2019

Neogene

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Cenozoic Erathem
Neogene Period
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 7.246 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 Oxygen-isotopic event (global cooling episode) Mi3b; near calcareous nannofossil LAD of Sphenolithus heteromorphus Ratified 2007 Episodes, 32/3, 152 - 166, 2009;
Langhian Stage 15.97 Potentially in astronomicallytuned ODP core (Leg 154) or in Italy (Moria or La Vedova )     Near planktonic foraminifer FAD of Praeorbulina glomerosa and top of magnetic polarity chronozone C5Cn.1n    
Burdigalian Stage 20.44 Potentially in astronomicallytuned ODP core     Near planktonic foraminifer FAD of Globigerinoides altiaperturus or near top of magnetic polarity chronozone C6An    
Aquitanian Stage 23.03 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

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Cenozoic Erathem
Paleogene Period
Oligocene Series
Chattian Stage 28.1 Possibly Monte Cagnero, Umbria-Marche region, Italy     Potentially extinction of planktonic foraminifer Chiloguembelina (base Foram Zone P21b); or an isotopic/climatic event    
Rupelian Stage 33.9 Massignano, near Ancona, Italy 43.5328°N 13.6011°E base of a 0.5m thick greenishgrey marl bed 19m above base of section Foraminifer LAD Hantkenina and Cribrohantkenina Ratified 1992 Episodes 16/3, p.379 - 382, 2001
Eocene Series
Priabonian Stage 37.8 Alano section, Piave River; Veneto Prealps, Belluno province, N. Italy   Tiziano Bed Calcareous nannofossil near FAD Chiasmolithus oamaruensis (base Zone NP18)    
Bartonian Stage 41.2 Contessa highway section near Gubio, Central Apennines, Italy     Calcareous nannofossil near LAD Reticulofenestra reticulata    
Lutetian Stage 47.8 Gorrondatxe section, Basque Country, Spain 43°22'46.47"N, 3°00'51.61"W dark marl at 167.85 m in Gorrondatxe sea-cliff section LO of calcareous nannofossil Blackites inflatus (CP12a/b boundary); middle of polarity Chron C21r Ratified 2011 Episodes 34/2, p.86 - 108, 2011
Ypresian Stage 56.0 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 43.3006°N 2.2594°W 30.5m above the base of Itzurun Formation Magnetic - Base of Chron C26n Ratified 2008 Episodes 34/4, p.220 - 243, 2011
Selandian Stage 61.6 Zumaia section, northern Spain 43.3006°N 2.2594°W base of the red marls of Itzurun Formation 2nd radiation of the calcareous nannofossil group Fasciculithus and sea-level fall Ratified 2008 Episodes 34/4, p.220 - 243, 2011
Danian Stage 66.0 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

Cretaceous

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Mesozoic Erathem
Cretaceous Period
Upper Cretaceous Series
Maastrichtian Stage 72.1±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 83.6±0.2 candidates are in southern England and in Texas     Crinoid LAD Marsupites testudinarius    
Santonian Stage 86.3 ± 0.5 Olazagutia, Navarra, Spain 42.8668°N 2.1968°W 94.4 m in the Cantera de Margas quarry section the FO of the inoceramid bivalve Platyceramus undulatoplicatus Ratified 2013 Episodes 37/1, p. 2 - 13, 2014
Coniacian Stage 89.8 ± 0.3 candidates are in Poland (Slupia Nadbrzena), USA (Pueblo, Colorado), and Germany (Salzgitter-Sadler Quarry)     Inoceramid bivalve FAD Cremnoceramus rotundatus (sensu Tröger non Fiege)    
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 Rotalipora globotruncanoides Ratified 2002 Episodes 27/1, p. 21 - 32, 2004
Lower Cretaceous Series
Albian Stage ~113.0 Southeastern France     Candidates include: (1) calcareous nannofossil FAD of Praediscosphaera columnata (= P. cretacea of some earlier studies), (2) carbon-isotope excursion (black-shale episode), (3) ammonite    
Aptian Stage ~125.0 candidate is Gorgo a Cerbara, Piobbico, Umbria-Marche, central Italy     Magnetic - base of Chron M0r; near FAD of Paradeshayesites oglanlensis ammonite zone    
Barremian Stage ~129.4 candidate is Río Argos near Caravaca, Murcia Province, Spain     Ammonite FAD Spitidiscus hugii - Spitidiscus vandeckii group    
Hauterivian Stage ~132.9 candidate is La Charce village, Drôme Province, southeast France     Ammonite FAD of genus Acanthodiscus (especially A. radiatus)    
Valanginian Stage ~139.8 candidates are near Montbrunles- Bains (Drôme province, SE France) and Cañada Luenga (Betic Cordillera, S. Spain)     Calpionellid FAD Calpionellites darderi (base of Calpionellid Zone E); followed by ammonite FAD "Thurmanniceras" pertransiens    
Berriasian Stage ~145.0       Candidates include: (1) Magnetic - base of Chron M18r, (2) Base of Calpionellid zone B, (3) ammonite FAD of Berriasella jacobi    

Jurassic

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Mesozoic Erathem
Jurassic Period
Upper Jurassic Series
Tithonian Stage 152.1 ± 0.9 candidates are Mt. Crussol or Canjuers (SE France) and Fornazzo (Sicily, S. Italy)     Near base of Hybonoticeras hybonotum ammonite zone and lowest occurrence of Gravesia genus, and the base of magnetic polarity Chron M22An    
Kimmeridgian Stage 157.3 ± 1.0 candidate is Flodigarry (Isle of Skye, NW Scotland) 57.6000°N 6.2000°W   Ammonite near base of Pictonia baylei ammonite zone of Boreal realm Anticipated 2009  
Oxfordian Stage 163.5 ± 1.0 candidates are Redcliff Point (Dorset, SW England) and Savouron (Provence, SE France)     Ammonite Cardioceras redcliffense Horizon at base of the Cardioceras scarburgense Subzone (Quenstedtoceras mariae Zone)    
Middle Jurassic Series
Callovian Stage 166.1 ± 1.2 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 168.3 ± 1.3 Ravin du Bès, Bas-Auran area, Alpes de Haute Provence, France 43.9606°N 6.3153°E base of limestone bed RB07 Ammonite FAD Gonolkite convergens (defines base of Zigzagiceras zigzag Zone) Ratified 2008 Episodes 32/4, p. 222 - 248, 2009
Bajocian Stage 170.3 ± 1.4 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 174.1 ± 1.0 Fuentelsaz, Spain 41.1708°N 1.8333°W base of Bed FZ 107 Ammonite FAD Leioceras opalinum and Leioceras lineatum Ratified 2000 Episodes 24/3, p.166 - 175, 2001
Lower Jurassic Series
Toarcian Stage 182.7 ± 0.7 Peniche (Portugal) 39.3708ºN 9.3853ºW base of bed 15e (Couches de passage), uppermost Lemede Formation FO of the ammonite D. (E.) simplex co-occurring with D. (E.) pseudocommune and D. (E.) polymorphum . Ratified 2014  
Pliensbachian Stage 190.8 ± 1.0 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 199.3 ± 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 201.3 ± 0.2 Kuhjoch section, Tyrol, Austria 47.4839°N 11.5306°E 5.80 m above top of Koessen Formation FO of ammonite Psiloceras spelae tirolicum, FO of aragonitic foraminifer Praegubkinella turgescens Ratified 2010 Episodes 36/3, p. 162-198, 2013

Triassic

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Mesozoic Erathem
Triassic Period
Upper Triassic Series
Rhaetian Stage ~208.5 Key sections in Austria, British Columbia (Canada), and Turkey     Near FAD of ammonite Cochloceras, conodonts Misikella spp. and Epigondolella mosheri, and radiolarian Proparvicingula moniliformis    
Norian Stage ~227 Candidates are Black Bear Ridge in British Columbia (Canada) and Pizzo Mondello, Sicily (Italy)     Base of Stikinoceras kerri ammonoid zone and near FAD of Metapolygnathus echinatus within the M. communisti conodont zones    
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 of the ammonoid Daxatina canadensis; just below FO of conodont Paragondolella polygnathiformis and base of normal-polarity magnetic zone S2n Ratified 2008 Episodes 35/3, p. 414 - 430, 2012
Middle Triassic Series
Ladinian Stage ~242 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 247.2 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 Magnetic - base of magnetic polarity MT1n Anticipated 2009 Albertiana 36, 2007.
Lower Triassic Series
Olenekian Stage 251.2 Candidate GSSP Mud (Muth) village, Spiti valley, northwest India 31.9654°N 78.0246°E base of Bed 13A-2, about 4.8m up in Mikin Formation., Section M04 (~4000 m elevation Conodont FAD Neospathodus 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 2009 Albertiana 36, 2007
Induan Stage 252.17 ± 0.06 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

Permian

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Paleozoic Erathem
Permian Period
Lopingian Series
Changhsingian Stage 254.14 ± 0.07 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 259.8 ± 0.4 Penglaitan, Guanxi 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 265.1 ± 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 268.8 ± 0.5 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 272.3 ± 0.5 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 283.5 ± 0.6 candidates are in southern Ural Mtns.     Near conodont FAD Neostreptognathus pnevi - N. exculptus Anticipated 2009  
Artinskian Stage 290.1 ± 0.26 candidates are in southern Ural Mtns.     Conodont FAD Sweetognathus whitei Anticipated 2009  
Sakmarian Stage 295.0 ± 0.18 candidate is at Kondurovsky, Orenburg Province, Russia.     Near conodont FAD Sweetognathus merrelli Anticipated 2009  
Asselian Stage 298.9 ± 0.15 Aidaralash Creek, Kazakhstan 50.2458°N 57.8914°E 27m above the base of Bed 19, Aidaralash Creek Conodont FAD of isolated-nodular morphotype of Streptognathodus "wabaunsensis" Ratified 1996 Episodes 21/1, p. 11-18, 1998

Carboniferous

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Paleozoic Erathem
Carboniferous Period
Pennsylvanian SubPeriod (series Classification Approved In 2004)
Upper Pennsylvanian Series
Gzhelian Stage 303.7 ± 0.1 candidates are in southern Urals or Nashui (south China).     Conodont FAD Idiognathodus simulator (s.str.). Close to FAD of ammonoid Shumardites.    
Kasimovian Stage 307.0 ± 0.1 candidates are in southern Urals, southwest USA and Nashui (south China).     Fusulinid FAD Protriticites, which is near ammonoid FAD Eothalossoceras. Alternative (higher) base is fusulinid FAD Montiparus montiparus, which is near conodont FAD Idiognathodus sagittalis. Stage given here is the higher version; the lower one is about 1 myr older.    
Middle Pennsylvanian Series
Moscovian Stage 315.2 ± 0.2 candidates are in southern Urals or Nashui (south China).     Either conodont FAD Idiognathoides postsulcatus or Declinognathodus donetzianus.    
Lower Pennsylvanian Series
Bashkirian Stage 323.2 ± 0.4 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 SubPeriod
Upper Mississippian Series (series Classification Approved In 2004)
Serpukhovian Stage 330.9 ± 0.2 candidates are Verkhnyaya Kardailovka (Urals) or Nashui (China)     Conodont FAD Lochriea ziegleri    
Middle Mississippian Series
Visean Stage 346.7 ± 0.4 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 358.9 ± 0.4 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

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Paleozoic Erathem
Devonian Period
Upper Devonian Series
Famennian Stage 372.2 ± 1.6 Coumiac Quarry, near Cessenon, Montagne Noire, France 43.4613°N 3.0403°E Base of Bed 32a Conodont FAD Palmatolepis triangularis, just above a major extinction horizon (Kellwasser Event) with conodont LADs Ancyrodella and Ozarkodina, and Goniatite LADs of Gephuroceratidae and Beloceratidae Ratified 1993 Episodes 16/4, p. 433-441, 1993
Frasnian Stage 382.7 ± 1.6 Col du Puech de la Suque, Montage Noire, France 43.5032°N 3.0868°E base of Bed 42' 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 387.7 ± 0.8 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 393.3 ± 1.2 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 407.6 ± 2.6 Zinzil'ban Gorge in the Kitab State Geological Reserve, Uzbekistan 39.2000°N 67.3056°E base of Bed 9/5 Conodont FAD Polygnathus kitabicus Ratified 1995 Episodes 20/4, p. 235-240, 1997
Pragian Stage 410.8 ± 2.8 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 419.2 ± 3.2 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

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Paleozoic Erathem
Silurian Period
Přídolí Series 423.0 ± 2.3 Požáry Section, Reporyje, Prague, Czech Republic 50.0277°N 14.3249°E within Bed 96 Graptolite FAD Monograptus parultimus Ratified 1984 Episodes 8/2, p. 101-103, 1985; Geol. Series, Nat. Mus. Wales, 9, p. 90 - 100, 1989
Ludlow Series
Ludfordian Stage 425.6 ± 0.9 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 427.4 ± 0.5 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 430.5 ± 0.7 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 433.4 ± 0.8 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 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 438.5 ± 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 440.8 ± 1.2 Trefawr Track Section, Wales, UK 52.0300°N 3.7000°W within Trefawar 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 443.8 ± 1.5 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)

Ordovician

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Paleozoic Erathem
Ordovician Period
Upper Ordovician Series
Hirnantian Stage 445.2 ± 1.4 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 Normalograptus extraordinarius Ratified 2006 Episodes 29/3, p. 183-196, 2006
Katian Stage 453.0 ± 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 458.4 ± 0.9 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 467.3 ± 1.1 Huangnitang section, Changshan, Zhejiang Province, SE China 28.8539°N 118.4897°E base of Bed AEP 184 Graptolite FAD Undulograptus austrodentatus Ratified 1987 Episodes 20/3, p. 158-166, 1997
Dapingian Stage 470.0 ± 1.4 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 477.7 ± 1.4 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 485.4 ± 1.9 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

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Phanerozoic Eonothem
Paleozoic Erathem
Cambrian Period
Furongian Series
Stage 10 ~489.5 candidate section is Duibian (Zhejiang province, China)     Trilobite FAD of Lotagnostus americanus. An internal subStage division might be FAD of Codylodus adesei conodont    
Jiangshanian Stage ~494 Duibian B section, Zhejiang province, China 28°48.958'N 118°36.896'E 28.2 m in Duibian B section FAD of agnostid trilobite Agnostotes orientalis and the FO of polymerid trilobite Irvingella angustilimbata Ratified 2011 Episodes 35/4, p.462-477, 2012
Paibian Stage ~497 Wuling Mountains, Huayuan County, NW Hunan Province, Chin 28.3895°N 109.5257°E at 396 m in the Huaqiao Formation Trilobite FAD Glyptagnostus reticulatus Ratified 2003 Lethaia 37, p. 365-379, 2004
Series 3
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 Trilobite 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 Trilobite FAD Ptychagnostus atavus Ratified 2006 Episodes 30/2,p. 85-95, 2007
Stage 5 ~509 candidate sections are Wuliu-Zengjiayan (east Guizhou, China) and Split Mountain (Nevada, USA)     Trilobite, potentially FAD of Oryctocephalus indicus    
Series 2
Stage 4 ~514       Trilobite FAD Olenellus or Redlichia    
Stage 3 ~521       Trilobites - their FAD    
Terreneuvian Series
Stage 2 ~529       Small Shelly Fossils, or Archaeocyathid species    
Fortunian Stage 541.0 ± 1.0 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

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Precambrian Super-Eonothem
Proterozoic Eonothem
Neoproterozoic Erathem
Ediacaran Period ~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 Period 720 Defined chronometrically; but will be replaced by GSSP. First glacial episode occurred after 750 Ma       Ratified 1990 Episodes 14/2,1991
Tonian Period 1000 Defined chronometrically       Ratified 1990 Episodes 14/2,1991
Mesoproterozoic Erathem
Stenian Period 1200 Defined chronometrically       Ratified 1990 Episodes 14/2,1991
Ectasian Period 1400 Defined chronometrically       Ratified 1990 Episodes 14/2,1991
Calymmian Period 1600 Defined chronometrically       Ratified 1990 Episodes 14/2,1991
Paleoproterozoic Erathem
Statherian Period 1800 Defined chronometrically       Ratified 1990 Episodes 14/2,1991
Orosirian Period 2050 Defined chronometrically       Ratified 1990 Episodes 14/2,1991
Rhyacian Period 2300 Defined chronometrically       Ratified 1990 Episodes 14/2,1991
Siderian Period 2500 Defined chronometrically, but it will be replaced by GSSP       Ratified 1990 Episodes 14/2,1991

Archean

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Precambrian Super-Eonothem
Archean Eonothem
Neoarchean Erathem 2800 Defined chronometrically       Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992
Mesoarchean Erathem 3200 Defined chronometrically       Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992
Paleoarchean Erathem 3600 Defined chronometrically       Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992
Eoarchean Erathem 4000 Base is not defined       Subcomm. decision 1996, but not submitted to ICS Informally in Episodes 15/2, 1992

Hadean

Stage Age (Ma) GSSP Location Latitude, Longitude Boundary Level Correlation Events Status Reference
Precambrian Super-Eonothem
Hadean Eonothem ~4600       Formation of planet Earth. Informal term