Global Stratotype Sections and Points (original) (raw)
EON, Era, System, Series, Stages
Age (Ma)
GTS 2004
Est.
±Ma
Derivation of age
Principal correlative events
GSSP and location
Status
Publication
PHANEROZOIC Eon
Cenozoic Era
Neogene System
QUATERNARY Sub-System
2.588
-
-
Quaternary is a formal Sub-System (Sub-Era) of the Cenozoic time scale. It is the interval of oscillating climatic extremes (glacial and interglacial episodes) that was initiated at about 2.6 Ma (set equal to base of Gelasian stage), therefore it encompasses the Holocene and Pleistocene epochs and the late Pliocene.
Equivalent to GSSP of Gelasian at Monte San Nicola, Gela, Sicily, Italy. Correlates with Marine Isotopic stage 103, and base of magnetic polarity chronozone C2r (Matuyama)
ICS formal recommendation to INQUA and ICS; Sept 2005.
Proposal in Episodes 28 (2), p.118-120, 2005
Holocene Series
base Holocene
0.011784
0.00
Annual layer counting in ice core ("ka" is relative to AD2000); counting uncertainy is 69 years
End of the Younger Dryas cold spell, which is reflected in a shift in deuterium excess values, followed closely by changes in d18O, dust concentration, a range of chemical species, and by a change in annual layer thickness
NorthGRIP ice core, Greenland
GSSP anticipated in 2005
-
Pleistocene Series
base upper Pleistocene Subseries
0.126
0.00
Astronomical cycles in sediments
base of the Eemian interglacial stage (= base of marine isotope stage 5e) before final glacial episode of Pleistocene
Amsterdam-Terminal borehole (63.5 m below surface; 52°22'45"N; 4°54'52"E), Netherlands
GSSP anticipated in 2006
-
base middle Pleistocene Subseries
0.781
0.00
Astronomical cycles in sediments
Brunhes-Matuyama magnetic reversal
Candidate sections in Italy (Montalbano Jorica or Valle di Manche) and Japan (Chiba)
GSSP anticipated in 2007
-
1.806
0.00
Astronomical cycles in sediments
Just above top of magnetic polarity chronozone C2n (Olduvai) and the extinction level of calcareous nannofossil Discoaster brouweri (base Zone CN13). Above are lowest occurrence of calcareous nannofossil medium Gephyrocapsa spp. and extinction level of planktonic foraminifer Globigerinoides extremus.
Top of sapropel layer 'e', Vrica section, Calabria, Italy
Ratified 1985
Episodes 8 (2), p.116-120, 1985
Pliocene Series
base Gelasian Stage
2.588
0.00
Astronomical cycles in sediments
Isotopic stage 103, base of magnetic polarity chronozone C2r (Matuyama). Above are extinction levels of calcareous nannofossil Discoaster pentaradiatus and D. surculus (base Zone CN12c).
Midpoint of sapropelic Nicola Bed ("A5"), Monte San Nicola, Gela, Sicily, Italy
Ratified 1996
Episodes 21 (2), p.82-87, 1998
base Piacenzian Stage
3.600
0.00
Astronomical cycles in sediments
Base of magnetic polarity chronozone C2An (Gauss); extinction levels of planktonic foraminifers Globorotalia margaritae (base Zone PL3) and Pulleniatina primalis.
Base of beige layer of carbonate cycle 77, Punta Piccola, Sicily, Italy
Ratified 1997
Episodes 21 (2), p.88-93, 1998
base Zanclean Stage, base Pliocene Series
5.332
0.00
Astronomical cycles in sediments
Top of magnetic polarity chronozone C3r, ~100 kyr before Thvera normal-polarity subchronozone (C3n.4n). Calcareous nannofossils -- near extinction level of Triquetrorhabdulus rugosus (base Zone CN10b) and the lowest occurrence of Ceratolithus acutus.
Base of Trubi Fm (base of carbonate cycle 1), Eraclea Minoa, Sicily, Italy
Ratified 2000
Episodes 23 (3), p.179-187, 2000
Miocene Series
7.246
0.00
Astronomical cycles in sediments
Astrochronology age of 7.251 Ma; middle of magnetic polarity chronozone C3Br.1r; lowest regular occurrence of the Globorotalia conomiozea planktonic foraminifer group.
Base of red layer of carbonate cycle 15, Oued Akrech, Rabat, Morocco
Ratified 2000
Episodes 23 (3), p. 172-178, 2000
base Tortonian Stage
11.608
0.00
Astronomical cycles in sediments
Last Common Occurrences of the calcareous nannofossil Discoaster kugleri and the planktonic foraminifer Globigerinoides subquadratus. Associated with the short normal-polarity subchron C5r.2n.
Midpoint of sapropel 76, Monte dei Corvi beach section, Ancona, Italy
Ratified 2003
Episodes 28 (1), p.6-17, 2005
base Serravallian Stage
13.65
0.00
Astronomical cycles in sediments
Near lowest occurrence of nannofossil Sphenolithus heteromorphus, within magnetic polarity chronozone C5ABr, and Mi3b isotopic event (global cooling episode)
Candidate on Malta (Ras il Pellegrin section) at base of Blue Clay
GSSP anticipated in 2006
-
base Langhian Stage
15.97
0.00
Calibrated magnetic anomaly scale
Near first occurrence of planktonic foraminifer Praeorbulina glomerosa and top of magnetic polarity chronozone C5Cn.1n
Potentially in astronomically-tuned ODP core (Leg 154) or in Italy (Moria or La Vedere)
GSSP anticipated in 2008
-
base Burdigalian Stage
20.43
0.00
Calibrated magnetic anomaly scale
Near lowest occurrence of planktonic foraminifer Globigerinoides altiaperturus or near top of magnetic polarity chronozone C6An
Potentially in astronomically-tuned ODP core
Guide event is undecided. GSSP anticipated in 2008
-
base Aquitanian Stage, base Miocene Series, base Neogene System
23.03
0.00
Astronomical cycles in sediments
Base of magnetic polarity chronozone C6Cn.2n; lowest occurrence of planktonic foraminifer Paragloborotalia kugleri; near extinction of calcareous nannofossil Reticulofenestra bisecta (base Zone NN1).
35 m from top of Lemme-Carrosio section, Carrosio village, north of Genoa, Italy
Ratified 1996
Episodes 20 (1),p. 23-28, 1997
Paleogene System
Oligocene Series
base Chattian Stage
28.4
0.1
Calibrated magnetic anomaly scale relative to base-Miocene and C24n. Arbitrary 100 kyr uncertainty assigned.
Potentially extinction of planktonic foraminifer Chiloguembelina (base Foram Zone P21b); or an isotopic/climatic event
Possibly Monte Cagnero (Umbria-Marche region, Italy)
GSSP anticipated in 2006
-
base Rupelian Stage, base Oligocene Series
33.9
0.1
Calibrated magnetic anomaly scale relative to base-Miocene and C24n.
Planktonic foraminifer, extinction of Hantkenina
Base of marl bed at 19m above base of Massignano quarry, Ancona, Italy
Ratified 1992
Episodes 16 (3), p.379-382, 1993
Eocene Series
base Priabonian Stage
37.2
0.1
Calibrated magnetic anomaly scale relative to base-Miocene and C24n
Near lowest occurrence of calcareous nannofossil Chiasmolithus oamaruensis (base Zone NP18)
Tiziano Bed, Alano section (Piave River; Veneto Prealps, Belluno province, N. Italy)
GSSP anticipated in 2006
-
base Bartonian Stage
40.4
0.2
Calibrated magnetic anomaly scale relative to base-Miocene and C24n
Near extinction of calcareous nannofossil Reticulofenestra reticulata
-
GSSP anticipated in 2008
-
base Lutetian Stage
48.6
0.2
Calibrated magnetic anomaly scale relative to base-Miocene and C24n
Planktonic foraminifer, lowest occurrence of Hantkenina
Leading candidate is Agost section, Murcia province, Betic Cordilleras, Spain
GSSP anticipated in 2007
-
base Ypresian Stage, base Eocene Series
55.8
0.2
Astronomical cycles in sediments scaled from base-Paleocene
Base of negative carbon-isotope excursion
Dababiya Section near Luxor, Egypt
Ratified 2003
Micropaleontology v.49 (Suppl. 1), 2003. Episodes article in preparation
Paleocene Series
base Thanetian Stage
58.7
0.2
Astronomical cycles in sediments scaled from base Paleocene, using base of magnetic polarity chronozone C26n. Arbitrary 0.1 (2 precession cycles, plus the base-Paleogene radiometric) uncertainty assigned to all estimates.
Magnetic polarity chronozone, base of C26n
Leading candidate is Zumaya section, northern Spain
GSSP anticipated in 2007
-
base Selandian Stage
61.7
0.2
Astronomical cycles in sediments scaled from base Paleocene, using magnetic polarity chronozone placement of C27n.9
Undecided; possibilities include top or bottom of Foram Zone P3a, or C-13 excursion near base of calcareous nannofossil Zone NP5 (which would be ~1 myr younger than age estimate shown here)
Leading candidate is Zumaya section, northern Spain
Guide event is undecided. GSSP anticipated in 2007
-
base Danian Stage, base Paleogene System, base Cenozoic
65.5
0.3
Ar-Ar and U-Pb age agreement
Iridium geochemical anomaly. Associated with a major extinction horizon (foraminifers, calcareous nannofossils, dinosaurs, etc.);
Base of boundary clay, El Kef, Tunisia (but deterioration may require assigning a replacement section)
Ratified 1991
-
Mesozoic Era
Cretaceous System
Most Cretaceous substages also have recommended GSSP criteria
Upper Cretaceous Series
base Maastrichtian Stage
70.6
0.6
Estimated placement relative to Ar-Ar calibrated Sr-curve
Mean of 12 biostratigraphic criteria of equal importance. Closely above is lowest occurrence of ammonite Pachydiscus neubergicus. Boreal proxy is lowest occurrence of belemnite Belemnella lanceolata.
115.2 m level in Grande Carri�re quarry, Tercis-les-Bains, Landes province, SW France
Ratified 2001
Episodes 24 (4), p.229-238, 2001; Odin (ed.) IUGS Spec. Publ. Series, v.36, Elsevier, 910pp.
base Campanian Stage
83.5
0.7
Spline fit of Ar-Ar ages and ammonite zones.
Crinoid, extinction of Marsupites testudinarius
Leading candidates are in southern England and in Texas
GSSP anticipated in 2008
-
base Santonian Stage
85.8
0.7
Spline fit of Ar-Ar ages and ammonite zones.
Inoceramid bivalve, lowest occurrence of Cladoceramus undulatoplicatus
Leading candidates are in Spain, England and Texas
GSSP anticipated in 2007
-
base Coniacian Stage
89.3
1.0
Spline fit of Ar-Ar ages and ammonite zones.
Inoceramid bivalve, lowest occurrence of Cremnoceramus rotundatus (sensu Tröger non Fiege)
Base of Bed MK47, Salzgitter-Salder Quarry, SW of Hannover, Lower Saxony, northern Germany
GSSP anticipated in 2006
-
base Turonian Stage
93.5
0.8
Spline fit of Ar-Ar ages and ammonite zones
Ammonite, lowest occurrence of Watinoceras devonense
Base of Bed 120, Rock Canyon Anticline, east of Pueblo, Colorado, west-central USA
Ratified 2003
Episodes 28(1), p. 93-104, 2005
99.6
0.9
Spline fit of Ar-Ar ages and ammonite zones, plus monitor standard correction. Then cycle stratigraphy to place foraminifer datum relative to ammonite zonation.
Planktonic foraminifer, lowest occurrence of Rotalipora globotruncanoides
36 m below top of Marnes Bleues Formation, Mont Risou, Rosans, Haute-Alpes, SE France
Ratified 2002
Episodes 27 (1), p.21-32, 2004
Lower Cretaceous Series
base Albian Stage
112.0
1.0
Cycle-stratigraphy of FAD of P. columnata relative to base of Cenomanian, with large uncertainty due to lack of GSSP criteria
Candidates include: (1) calcareous nannofossil, lowest occurrence of Praediscosphaera columnata (= P. cretacea of some earlier studies), (2) carbon-isotope excursion (black-shale episode), (3) ammonite
-
Guide event is undecided. GSSP anticipated in 2008
-
base Aptian Stage
125.0
1.0
Base of M0r, as recomputed from Ar-Ar age from MIT guyot
Magnetic polarity chronozone, base of M0r; near base of Paradeshayesites oglanlensis ammonite zone
Leading candidate is Gorgo a Cerbara, Piobbico, Umbria-Marche, central Italy
GSSP anticipated in 2006
-
base Barremian Stage
130.0
1.5
Pacific spreading model for magnetic anomaly ages (variable rate), using placement at M5n.8.
Ammonite, lowest occurrence of Spitidiscus hugii � Spitidiscus vandeckii group
Leading candidate is R�o Argos near Caravaca, Murcia province, Spain
GSSP anticipated in 2006
-
base Hauterivian Stage
136.4
2.0
Pacific spreading model for magnetic anomaly ages (variable rate), using placement at base M11n
Ammonite, lowest occurrence of genus Acanthodiscus (especially A. radiatus)
Leading candidate is La Charce village, Drôme province, southeast France
GSSP anticipated in 2006
-
base Valanginian Stage
140.2
3.0
Pacific spreading model for magnetic anomaly ages (variable rate), using placement at M14r.3 (base T. pertransiens).
Calpionellid, lowest occurrence of Calpionellites darderi (base of Calpionellid Zone E); followed by the lowest occurrence of ammonite �Thurmanniceras� pertransiens
Leading candidates are near Montbrun-les-Bains (Drôme province, SE France) and Cañada Luenga (Betic Cordillera, S. Spain)
GSSP anticipated in 2007
-
base Berriasian Stage, base Cretaceous System
145.5
4.0
Pacific spreading model for magnetic anomaly ages (variable rate), assigning to base of Berriasella jacobi zone (M19n.2n.55)
Maybe near lowest occurrence of ammonite Berriasella jacobi
-
Guide event is undecided. GSSP anticipated in 2008
-
Jurassic System
Upper Jurassic Series
base Tithonian Stage
150.8
4.0
Pacific spreading model for magnetic anomaly ages (variable rate), assigning to base M22An
Near base of Hybonoticeras hybonotum ammonite zone and lowest occurrence of Gravesia genus, and the base of magnetic polarity chronozone M22An
Candidates are Mt. Crussol or Canjuers (SE France) and Fornazzo (Sicily, S. Italy)
Guide event is undecided. GSSP anticipated in 2007
-
base Kimmeridgian Stage
155.7
4.0
Pacific spreading model for magnetic anomaly ages (variable rate), assigning to base M26r.2 (Boreal ammonite definition)
Ammonite, near base of Pictonia baylei ammonite zone of Boreal realm
Candidate is Flodigarry (Isle of Skye, NW Scotland)
GSSP anticipated in 2006
-
base Oxfordian Stage
161.2
4.0
Pacific spreading model for magnetic anomaly ages (variable rate), assigning to base M36An
Ammonite, Brightia thuouxensis Horizon at base of the Cardioceras scarburgense Subzone (Quenstedtoceras mariae Zone)
Leading candidates are Savouron (Provence province, SE France) and Redcliffe Point (Dorset, SW England)
GSSP anticipated in 2006
-
Middle Jurassic Series
base Callovian Stage
164.7
4.0
Equal subzones scale Bajo-Bath-Callov
Ammonite, lowest occurrence of the genus Kepplerites (Kosmoceratidae) (defines base of Macrocephalites herveyi Zone in sub-Boreal province of Great Britain to southwest Germany)
Leading candidate is Pfeffingen, Swabian Alb, SW Germany
GSSP anticipated in 2006
-
base Bathonian Stage
167.7
3.5
Equal subzones scale Bajo-Bath-Callov
Ammonite, lowest occurrence of Parkinsonia (G.) convergens (defines base of Zigzagiceras zigzag Zone)
Candidates are in Iberia, and near Digne (SE France)
GSSP anticipated in 2007
-
base Bajocian Stage
171.6
3.0
Equal subzones scale Bajo-Bath-Callov
Ammonite, lowest occurrence of the genus Hyperlioceras (defines base of the Hyperlioceras discites Zone)
Base of Bed AB11, 77.8 m above base of Murtinheira section, Cabo Mondego, western Portugal
Ratified 1996
Episodes 20 (1), p.16-22, 1997
base Aalenian Stage
175.6
2.0
Duration of Aalenian-Toarcian from cycle stratigraphy
Ammonite, lowest occurrence of Leioceras genus
base of Bed FZ107, Fuentelsalz, central Spain
Ratified 2000
Episodes 24 (3), p.166-175, 2001
Lower Jurassic Series
base Toarcian Stage
183.0
1.5
Duration of Aalenian-Toarcian from cycle stratigraphy
Ammonite, near lowest occurrence of a diversified Eodactylites ammonite fauna; correlates with the NW European Paltus horizon.
Peniche (Portugal)
GSSP anticipated in 2006
-
base Pliensbachian Stage
189.6
1.5
Cycle-scaled linear Sr trend
Ammonite, lowest occurrences of Bifericeras donovani and of genera Apoderoceras ((defines base of Phricodoceras taylori subzone of Uptonia jamesoni ammonite zone)
Base of Bed 73b, Wine Haven section, Robin Hood's Bay, Yorkshire, England, UK
Ratified 2005
Proposal in Eclogae Geol. Helv. 96, p.275-297, 2003. Episodes article in preparation
base Sinemurian Stage
196.5
1.0
Cycle-scaled linear Sr trend
Ammonite, lowest occurrence of arietitid genera Vermiceras and Metophioceras
0.9 m above base of Bed 145, East Quantoxhead, Watchet, West Somerset, SW England, UK
Ratified 2000
Episodes 25 (1), p. 22-26, 2002
base Hettangian Stage, base Jurassic System
199.6
0.6
U-Pb age just below proposed GSSP for base-Jurassic
Near lowest occurrence of smooth Psiloceras planorbis ammonite group
-
Guide event is undecided. GSSP anticipated in 2007
-
Triassic System
Upper Triassic Series
base Rhaetian Stage
203.6
1.5
Magnetostratigraphic correlation to cycle-scaled Newark magnetic polarity pattern
Near lowest occurrence of ammonite Cochlocera, conodonts Misikella spp. and Epigondolella mosheri, and radiolarian Proparvicingula moniliformis
Key sections in Austria, British Columbia (Canada), and Turkey
Guide event is undecided. GSSP anticipated in 2008
-
base Norian Stage
216.5
2.0
Magnetostratigraphic correlation to cycle-scaled Newark magnetic polarity pattern
Base of Klamathites macrolobatus or Stikinoceras kerri ammonoid zones and the Metapolygnathus communisti or M. primitius conodont zones
Leading candidates are in British Columbia (Canada), Sicily (Italy), and possibly Slovakia, Turkey (Antalya Taurus) and Oman.
Guide event is undecided. GSSP anticipated in 2008
-
base Carnian Stage
228.0
2.0
Magnetostratigraphic correlation to cycle-scaled Newark magnetic polarity pattern
Near first occurrence of the ammonoids Daxatina or Trachyceras, and of the conodont Metapolygnathus polygnathiformis
Candidate section at Prati di Stuores, Dolomites, northern Italy. Important reference sections in Spiti (India) and New Pass, Nevada (USA).
Guide event is undecided. GSSP anticipated in 2007
-
Middle Triassic Series
base Ladinian Stage
237.0
2.0
U-Pb array by Mundil et al. on levels near Nevadites (= Secedensis) ammonite zone in Dolomites, plus placement relative to magnetostratigraphy corrlations to cycle-scaled Newark magnetic polarity pattern
Ammonoid, lowest occurrence of the Eoprotrachyceras curionii (base of the E. curionii zone; onset of the Trachyceratidae family. Above lowest Neogondolella praehungarica conodont
Top of "Chiesense groove", 5m above base of Buchenstein Beds, Caffaro river bed, Bagolino (Brescia province, N. Italy)
Ratified 2005
Episodes article in preparation
base Anisian Stage
245.0
1.5
Proportional subzonal scaling
Conodont, lowest occurrences of Chiosella timorensis
Candidate section at Desli Caira (Dobrogea, Romania); significant sections in Guizhou Province (China) and South Primorye (Russia)
GSSP anticipated in 2007
-
Lower Triassic Series
base Olenekian Stage
249.7
0.7
Composite standard from conodonts scaled to base-Anisian and base-Triassic
Conodont, lowest occurrence of Neospathodus waageni; near lowest occurrence of Flemingites and Euflemingites ammonite genera
Chaohu (Anhui province, E. China). Important sections in Spiti
GSSP anticipated in 2006
-
base Induan Stage, base Triassic System, base Mesozoic
251.0
0.4
U-Pb ages bracket GSSP (Bowring et al., 1998)
Conodont, lowest occurrence of Hindeodus parvus; termination of major negative carbon-isotope excursion. About 1 myr after peak of Late Permian extinctions.
Base of Bed 27c, Meishan, Zhejiang, China
Ratified 2001
Episodes 24 (2), p.102-114, 2001
Paleozoic Era
Permian System
Lopingian Series
base Changhsingian Stage
253.8
0.7
Permian-Carboniferous time scale is derived from calibrating a master composite section to selected radiometric ages
Conodont, near lowest occurrence of conodont Clarkina wangi
Base of Bed 4a-2, 88 cm above base of Changxing Limestone, Meishan D section (Zhejiang province, E. China)
Ratified 2005
Episodes article in preparation
base Wuchiapingian Stage
260.4
0.7
"
Conodont, lowest occurrence of Clarkina postbitteri postbitteri
Ratified 2004
Episodes article in preparation
Guadalupian Series
base Capitanian Stage
265.8
0.7
"
Conodont, lowest occurrence of Jinogondolella postserrata
4.5 m above base of Pinery Limestone Member, Nipple Hill, SE Guadalupe Mountains, Texas, USA
Ratified 2001
Episodes article in preparation
base Wordian Stage
268.0
0.7
"
Conodont, lowest occurrence of Jinogondolella aserrata
7.6 m above base of Getaway Ledge outcrop, Guadalupe Pass, SE Guadalupe Mountains, Texas, USA
Ratified 2001
Episodes article in preparation
base Roadian Stage
270.6
0.7
"
Conodont, lowest occurrence of Jinogondolella nanginkensis
42.7 m above base of Cutoff Formation, Stratotype Canyon, southern Guadalupe Mountains, Texas, USA
Ratified 2001
Episodes article in preparation
Cisuralian Series
base Kungurian Stage
275.6
0.7
"
Near lowest occurrence of conodont Neostreptognathus pnevi - N. exculptus
Leading candidates are in southern Ural Mtns.
GSSP anticipated in 2007
-
base Artinskian Stage
284.4
0.7
"
Conodont, lowest occurrence of conodont Sweetognathus whitei
Leading candidates are in southern Ural Mtns.
GSSP anticipated in 2007
-
base Sakmarian Stage
294.6
0.8
"
Conodont, near lowest occurrence of conodont Sweetognathus merrelli
Leading candidate is at Kondurovsky, Orenburg Province, Russia.
GSSP anticipated in 2006
-
base Asselian Stage, base Cisuralian Series, base Permian System
299.0
0.8
"
Conodont, lowest occurrence of Streptognathodus isolatus within the S. "wabaunsensis" conodont chronocline. 6 m higher is lowest fusilinid foraminifer Sphaeroschwagerina vulgaris aktjubensis
27 m above base of Bed 19, Aidaralash Creek, Aktöbe, southern Ural Mountains, northern Kazakhstan
Ratified, 1996
Episodes 21 (1), p.11-18, 1998
Carboniferous System
Pennsylvanian Subsystem (series classification approved in 2004)
Upper Pennsylvanian Series
base Gzhelian Stage
303.9
0.9
"
Near lowest occurrences of the fusulinids Daixina, Jigulites and Rugosofusulina, or lowest occurrence of conodont Idiognathodus simulator (s.str.). Close to lowest occurrence of ammonoid Shumardites.
-
Guide event is undecided. GSSP anticipated in 2007
-
base Kasimovian Stage
306.5
1.0
"
Near base of Obsoletes obsoletes and Protriticites pseudomontiparus fusulinid zone, or lowest occurrence of Parashumardites ammonoid
-
Guide event is undecided. GSSP anticipated in 2008
-
Middle Pennsylvanian Series
base Moscovian Stage
311.7
1.1
"
Near lowest occurrences of Declinognathodus donetzianus and/or Idiognathoides postsulcatus conodont species, and fusulinid species Aljutovella aljutovica
-
Guide event is undecided. GSSP anticipated in 2008
-
Lower Pennsylvanian Series
base Bashkirian Stage, base Pennsylvanian Subsystem
318.1
1.3
"
Conodont, lowest occurrence of Declinognathodus nodiliferus s.l.
82.9 m above top of Battleship Wash Fm., Arrow Canyon, southern Nevada, USA
GSSP ratified 1996. Subsystem rank with Mississippian and Pennsylvanian names ratified 2000.
Episodes 22 (4), p.272-283, 1999
Mississippian Subsystem
Upper Mississippian Series (series classification approved in 2004)
base Serpukhovian
326.4
1.6
"
Near lowest occurrence of conodont, Lochriea crusiformis
-
Guide event is undecided. GSSP anticipated in 2007
-
Middle Mississippian Series
base Visean
345.3
2.1
"
Foraminifer, lineage Eoparastaffella simplex morphotype 1/morphotype 2
Leading candidate is Pengchong, south China
GSSP anticipated in 2006
-
Lower Mississippian Series
base Tournaisian, base Mississippian Subsystem, base Carboniferous System
359.2
2.5
"
Conodont, above lowest occurrence of Siphonodella sulcata
Base of Bed 89, La Serre, Montagne Noir, Cabrières, southern France
Ratified 1990
Episodes 14 (4), p.331-336, 1991
Devonian System
Upper Devonian Series
374.5
2.6
Devonian time scale is a statistical fit of a composite biostratigraphic zonation (based on Figure 8 of Williams et al., 2000) to selected radiometric ages
Just above major extinction horizon (Upper Kellwasser Event), including conodonts Ancyrodella and Ozarkodina and goniatites of Gephuroceratidae and Beloceratidae
base of Bed 32a, upper Coumiac quarry, Cessenon, Montagne Noir, southern France
Ratified 1993
Episodes 16 (4), p.433-441, 1993
385.3
2.6
"
Conodont, lowest occurrence of Ancyrodella rotundiloba (defines base of Lower Polygnathus asymmetricus conodont Zone)
Base of Bed 42a', Col du Puech de la Suque section, St. Nazaire-de-Ladarez, SE Montagne Noir, southern France
Ratified 1986
Episodes 10 (2), p.97-101, 1987
Middle Devonian Series
base Givetian Stage
391.8
2.7
"
Conodont, lowest occurrence of Polygnathus hemiansatus, near base of goniatite Maenioceras Stufe
Base of Bed 123, Jebel Mech Irdane ridge, Tafilalt, Morocco
Ratified 1994
Episodes 18 (3), p.107-115, 1995
397.5
2.7
"
Conodont, lowest occurrence of Polygnathus costatus partitus; major faunal turnover
Base unit WP30, trench at Wetteldorf Richtschnitt, Schönecken-Wetteldorf, Eifel Hills, western Germany
Ratified 1985
Episodes 8 (2), p.104-109, 1985
Lower Devonian Series
base Emsian Stage
407.0
2.8
"
Conodont, lowest occurrence of Polygnathus kitabicus (= Po. dehiscens)
Base of Bed 9/5, Zinzil'ban Gorge, SE of Samarkand, Uzbekistan
Ratified 1995
Episodes 20 (4), p. 235-240, 1997
411.2
2.8
"
Conodont, lowest occurrence of Eognathodus sulcatus
Base of Bed 12, Valká Chuchle quarry, southwest part of Prague city, Czech Republic
Ratified 1989
Episodes 12 (2), p.109-113, 1989
base Lochkovian Stage, base Devonian System
416.0
2.8
base-Devonian from scale in Cooper (GTS 2004), which is 1 myr younger than Tucker et al (1998) estimate.
Graptolite, lowest occurrence of Monograptus uniformis
Within Bed 20, Klonk, Barrandian area, southwest of Prague, Czech Republic
Ratified 1972
Martinsson (ed.), The Silurian-Devonian Boundary, IUGS Series A, no.5, 349 pp., 1977
Silurian System [Holland and Bassett (eds), A Global Standard for the Silurian System, Nat. Mus. Wales, Geol. Series No.10, Cardiff, 325 pp., 1989]
Pridoli Series
base Pridoli Series (not subdivided in stages)
418.7
2.7
Silurian and Ordovician time scales are from calibrating a CONOP composite graptolite zonation to selecte radiometric ages
Graptolite, lowest occurrence of Monograptus parultimus
Within Bed 96, Pozáry section near Reporje, Barrandian area, Prague, Czech Republic
Ratified 1984
Episodes 8 (2), p.101-103, 1985
Ludlow Series
421.3
2.6
"
Imprecise. May be near base of Saetograptus leintwardinensis graptolite zone.
Base of lithological unit C, Sunnyhill Quarry, Ludlow, Shropshire, southwest England, UK
Ratified 1980
Lethaia 14, p.168, 1981; Episodes 5 (3), p.21-23, 1982
422.9
2.5
"
Imprecise. Just below base of local acritarch Leptobrachion longhopense range zone. May be near base of Neodiversograptus nilssoni graptolite zone
Base of lithological unit F, Pitch Coppice quarry, Ludlow, Shropshire, southwest England, UK
Ratified 1980
Lethaia 14, p.168, 1981; Episodes 5 (3), p.21-23, 1982
Wenlock Series
426.2
2.4
"
Graptolite, lowest occurrence of Cyrtograptus lundgreni (defines base of C. lundgreni graptolite zone)
Graptolite biozone intersection in stream section in Whitwell Coppice, Homer, Shropshire, southwest England, UK
Ratified 1980
Lethaia 14, p.168, 1981; Episodes 5 (3), p.21-23, 1982
428.2
2.3
"
Imprecise. Between the base of acritarch biozone 5 and extinction of conodont Pterospathodus amorphognathoides. However, the current GSSP does not coincide with the base of the Cyrtograptus centrifugus Biozone, as was supposed when the GSSP was define. Restudy has recommended a slightly higher and correlatable level on condonts -- the Ireviken datum 2, which coincides approximately with the base of the murchisoni graptolite biozone
Base of lithological unit G, Hughley Brook, Apedale, Shropshire, southwest England, UK
Ratified 1980
Lethaia 14, p.168, 1981; Episodes 5 (3), p.21-23, 1982
Llandovery Series
436.0
1.9
"
Brachiopods, just above extinction of Eocoelia intermedia and below lowest succeeding species Eocoelia curtisi. Near base of Monograptus turriculatus graptolite zone.
Locality 162 in transect d, Cefn Cerig road, Llandovery area, south-central Wales, UK
Ratified 1984
Episodes 8 (2), p.101-103, 1985
439.0
1.8
"
Graptolite, lowest occurrence of Monograptus austerus sequens (defines base of Monograptus triangulatus graptolite zone)
Base of locality 72 in transect h, Trefawr forestry road, north of Cwm-coed-Aeron Farm, Llandovery area, south-central Wales, UK
Ratified 1984
Episodes 8 (2), p.101-103, 1985
base Rhuddanian Stage, base Silurian System
443.7
1.5
"
Graptolites, lowest occurrences of Akidograptus ascensus, with FAD of Parakidograptus acuminatus occurring slightly higher
1.6 m above base of Birkhill Shale Fm., Dob's Linn, Moffat, Scotland, UK
Ratified 1984
Episodes 8 (2), p.98-100, 1985
Ordovician System
Upper Ordovician Series
base Hirnantian Stage
445.6
1.5
"
Graptolite, lowest occurrence of Normalograptus extraordinarius, base of major positive carbon-13 isotope excursion, and beginning of pronounced sea-level fall associated with onset of a major glaciation
0.39 m below base of Kuanyinchiao Bed, Wangjiawan North section, 42 km N. of Yichang city (west Hubei province, China)
GSSP anticipated in 2005
-
base of sixth stage (potentially "Katian")
455.8
1.6
"
Graptolite, lowest occurrence of Diplacanthograptus caudatus. Just below base of Guttenberg carbon-13 isotope excursion
4 m above base of Bigfort Chert, Black Knob Ridge section, 5 km NE of Atoka town (S. Oklahoma, USA)
GSSP anticipated in 2005
-
base of fifth stage (potentially "Sandbian")
460.9
1.6
"
Graptolite, lowest occurrence of Nemagraptus gracilis
1.4 m below phosphorite in E14a outcrop, Fågelsång, Scane, southern Sweden
Ratified 2002
Episodes 23 (2), p.102-109, 2000 (proposal; formal GSSP publication in preparation).
Middle Ordovician Series
468.1
1.6
"
Graptolite, lowest occurrence of Undulograptus austrodentatus
Base of Bed AEP184, 22 m below top of Ningkuo Fm., Huangnitang, Changshan, Zhejiang province, southeast China
Ratified 1987
Episodes 20 (3), p.158-166, 1997
base of third stage (not yet named)
471.8
1.6
"
Conodont, potentially lowest occurrence of Protoprioniodus aranda or of Baltoniodus triangularis
Candidate sections at Niquivil (Argentina) and Huanghuachang (China)
Guide event is undecided. GSSP anticipated in 2006
Proposal in Episodes 28 (2), p.105-117, 2005
Lower Ordovician Series
base of second stage (potentially "Floian")
478.6
1.7
"
Graptolite, lowest occurrence of Tetragraptus approximatus
Just above E bed, Diabasbrottet quarry, Västergötland, southern Sweden
Ratified 2002
Episodes 27 (4), p.265-272, 2004
base of Tremadocian stage, base Ordovician System
488.3
1.7
"
Conodont, lowest occurrence of Iapetognathus fluctivagus;just above base of Cordylodus lindstromi conodont Zone. Just below lowest occurrence of planktonic graptolites. Currently dated around 489 Ma
Within Bed 23 at the 101.8 m level, Green Point, western Newfoundland, Canada
Ratified 2000
Episodes 24 (1), p.19-28, 2001
Cambrian System
Overview of potential Cambrian subdivisions in Episodes 23 (3), p. 188-195, 2000
Upper ("Furongian") Series
Stage 10
-
-
-
Trilobite, lowest occurrence of Lotagnostus americanus. An internal substage division might be lowest occurrence of Codylodus adesei conodont
Candidate section is Duibian (Zhejiang province, China)
GSSP anticipated in 2008
-
Stage 9
-
-
-
Trilobite, lowest occurrence of Agnostotes orientalis
Candidate sections at Duibian (Zhejiang province, China) and Gonggiri (Korea)
GSSP anticipated in 2007
-
base Paibian Stage, base Furongian Series
501.0
2.0
Radiometric ages near primary marker level. Estimated age and uncertainty only
Trilobite, lowest occurrence of agnostoid Glyptagnostus reticulatus. Coincides with base of large positive carbon-isotope excursion
369.06 m above base of Huaqiao Fm, Paibi section, NW Hunan province, south China
Ratified 2003
Lethaia 37 (4), p.365-380, 2004
Series 3
Stage 7
-
-
-
Trilobite, lowest occurrence of Lejopyge laevigata
>Candidate sections are at Wangcun or nearby Luoyixi (NW Hunan province, S. China)
GSSP anticipated in 2007
-
Stage 6
-
-
-
Trilobite, lowest occurrence of Ptychagnostus atavus
Candidate section is Wangcun (NW Hunan province, S. China)
GSSP anticipated in 2006
-
Stage 5
513.0
2.0
Radiometric ages near primary marker level. Estimated age and uncertainty only
Trilobite, potentially lowest occurrence of Oryctocephalus indicus
Candidate sections are Wuliu-Zengjiayan (east Guizhou, China) and Split Mountain (Nevada, USA)
GSSP anticipated in 2007
-
Series 2
Stage 4
-
-
-
Trilobite, lowest occurrence of Olenellus or Redlichia
-
Guide event is undecided
-
Stage 3
-
-
-
Trilobites -- their lowest occurrence
-
-
-
Lower Series
Stage 2
-
-
-
Small Shelly Fossils, or Archaeocyathid species
-
Guide event is undecided
-
base Cambrian System, base Paleozoic Era, base Phanerozoic Eon
542.0
1.0
U-Pb age from Oman coinciding with the negative carbon excursion
Trace fossil, lowest occurrence of Treptichnus (Phycodes) pedum. Near base of negative carbon-isotope excursion
2.4 m above base of Member 2 of Chapel Island Fm., Fortune Head, Burin Peninsula, southeast Newfoundland, Canada
Ratified 1992
Episodes 17 (1&2), p.95-100, 1994.
PROTEROZOIC Eon
Pre-Cambrian eras and systems below Ediacaran are defined by absolute ages, rather than stratigraphic points.
Neoproterozoic Era
base Ediacaran System
630
-
Age suggested by Ediacaran Subcomm.; bracketed by radiometric ages of 600 and 635 Ma
Termination of Varanger (or Marinoan) glaciation.
"Base of the Marinoan cap carbonate (Nuccaleena Formation), immediately above the Elatina diamictite in the Enorama Creek section, Flinders Ranges, South Australia."
"Neoproterozoic III" (ratified 1990 with base defined chronometrically at 650 Ma) was formally replaced by Ediacaran Period and its GSSP in Feb 2004.
Summary in Science 305, p.621-622, 2004. Episodes article in preparation
Cryogenian System
850
-
Defined chronometrically; but will be replaced by GSSP
Base = 850 Ma
-
Ratified 1990. GSSP replacement planned for 2007
Episodes 14 (2), p.139-140, 1991
Tonian System
1000
-
Defined chronometrically
Base = 1000 Ma
-
Ratified 1990
Episodes 14 (2), p.139-140, 1991
Mesoproterozoic Era
Stenian System
1200
-
Defined chronometrically
Base = 1200 Ma
-
Ratified 1990
Episodes 14 (2), p.139-140, 1991
Ectasian System
1400
-
Defined chronometrically
Base = 1400 Ma
-
Ratified 1990
Episodes 14 (2), p.139-140, 1991
Calymmian System
1600
-
Defined chronometrically
Base = 1600 Ma
-
Ratified 1990
Episodes 14 (2), p.139-140, 1991
Paleoproterozoic Era
Statherian System
1800
-
Defined chronometrically
Base = 1800 Ma
-
Ratified 1990
Episodes 14 (2), p.139-140, 1991
Orosirian System
2050
-
Defined chronometrically
Base = 2050 Ma
-
Ratified 1990
Episodes 14 (2), p.139-140, 1991
Rhyacian System
2300
-
Defined chronometrically
Base = 2300 Ma
-
Ratified 1990
Episodes 14 (2), p.139-140, 1991
Siderian System
2500
-
Defined chronometrically; but will be replaced by GSSP
Base = 2500 Ma
-
Ratified 1990. GSSP replacement planned for 2007
Episodes 14 (2), p.139-140, 1991
ARCHEAN Eon
Neoarchean Era
2800
-
Defined chronometrically
Base = 2800 Ma
-
Subcomm. decision 1996, but not submitted to ICS
Informally in Episodes 15 (2), p.122-123, 1992.
Mesoarchean Era
3200
-
Defined chronometrically
Base = 3200 Ma
-
Subcomm. decision 1996, but not submitted to ICS
Informally in Episodes 15 (2), p.122-123, 1992.
Paleoarchean Era
3600
-
Defined chronometrically
Base = 3600 Ma
-
Subcomm. decision 1996, but not submitted to ICS
Informally in Episodes 15 (2), p.122-123, 1992.
Eoarchean Era
~4000
-
Base is not defined
Oldest preserved rocks on Earth's surface
-
Subcomm. decision 1996, but not submitted to ICS
Informally in Episodes 15 (2), p.122-123, 1992
HADIAN Eon
~4650
-
Base is not defined
Formation of planet Earth. Informal term
-
-
-