arkL dataset view

This page allows you to view all the information for a dataset, or subdataset, i.e. for a set of events and the intervals that they define, including the definitions of the basal events and the data used to set their age. The intervals table can show two levels of intervals, such as zones and sub-zones, or stages and sub-stages. The events table shows all the events in the dataset, including for example taxon events not used as markers of the base of intevals. page. On this page codes such as TAsZ (Tethyan Ammonite subZone) which are added to interval and/or event names to make them unique are shown. To see the data as it appears on TSC, and without those codes use the column view page

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s and epochs in the chronostratigraphy dataset↑

interval	duration	interval notes	sub-interval	duration	notes	basal event	base age	pup	within_intv	offset	offset from	event notes	compilation notes	stage
long Rhaetian	8.1530					base Sagenites reticulatus / Paracochloceras suessi TAZ	209.5130	0		0.0000	FAD Misikella posthernsteini (sensu lato)	DOTTED -- Onset of Cochloceras genus is coincident with FAD of conodont M. posthernsteini (option 1 for base of Rhaetian (low in Chron E17r) used here). Cochloceras suessi is also used for the lowest Zone of Rhaetian; but Jenks et al (2015) scale used here.		Rhaetian
short Sevatian	4.5190					base Sevatian	214.0320	0	Sagenites quinquepunctatus TAZ	0.0000		LATE Norian. Assigned as base of Sagenites quinquepunctatus in common usage (e.g., Jenks et al., 2015) However, to avoid a Very Short Sevatian IF the Austrlia GSSP candidate is accepted that has truncated the former upper part of that Sevatian, Kozur (2003, and written to Jim Ogg, 2006) proposed incorporating the next lower ammonoid zone of Halorites macer.		Norian

Events in the chronostratigraphy dataset↑

id	Event	type	stage	age	placement	TSC notes	compilation_notes	abv term	stage
5881	top Holocene		Holocene	0.0002	preset age: The system seems to have a problem with setting top Holocene to zero, as a get around I have set it to 0.0002 - ie, 200 years ago, which is also the approximate base of the Anthropocene		We are using this event, top Holocene, as the top event for all intervals extending up to the modern area.		Holocene
5882	base Holocene	stage_base	Holocene	0.0118	preset age: Base Holocene = End of Younger Dryas cold interval. Age relative to AD2000 from from ice-core layers at Greenland GSSP = 11.784 (11.8) ka.	Base Holocene = End of Younger Dryas cold interval. Age relative to AD2000 from ice-core layers at Greenland GSSP = 11.784 (11.8) ka.			Holocene
5883	base Lt. Pleist. ("Tarantian")	stage_base	Lt. Pleist. ("Tarantian")	0.1300	preset age: Base = Eemian Interglacial interval. Ca. 130 ka (Head and Gibbard, 2015); was 126 ka in GTS2012.	Tarentian (Tarantian) is the equivalent name for this "Lt. Pleistocene" interval after its marine formation near Taranto, Italy, which spans the last Interglacial and following glacial cycle. Base = Eemian Interglacial interval. Ca. 130 ka (Head and Gibbard, 2015); was 126 ka in GTS2012.			Lt. Pleist. ("Tarantian")
5884	base Chibanian	stage_base	Chibanian	0.7730	base C1n (Brunhes)	Named Chibanian after the GSSP at Chiba section (east-central Japan; ratified January, 2020). GSSP level is base of tephra with U-Pb zircon date of 773.7 (+/-7.2) ka; which is essentially at Matuyama/Brunhes polarity chron boundary (base of Chron C1n). Ionian is an equivalent name for this "M. Pleistocene" interval. Base = base of Brunhes Chron			Chibanian
5885	base Calabrian	stage_base	Calabrian	1.8000	preset age: The Calabrian begins with "base of a claystone unit conformably overlying sapropel marker bed "e" in the Vrica section of Calabria in southern Italy = MIS 64/65 transition in oceans. This is at or near the top of the Olduvai (C2n) Normal polarity chron. An age of 1.806 Ma for mid-point of underlying sapropel was previously used for the GSSP age also; but Cita et al (2012; Episodes for re-ratification) noted the offset, therefore recommended a 1.80 age.	Calabrian (former base of PLEISTOCENE pre-2009) -- The Calabrian begins with "base of a claystone unit conformably overlying sapropel marker bed "e" in the Vrica section of Calabria in southern Italy = MIS 64/65 transition in oceans. This is at or near the top of the Olduvai (C2n) Normal polarity chron. An age of 1.806 Ma for mid-point of underlying sapropel was previously used for the GSSP age also; but Cita et al (2012; Episodes for re-ratification) noted the offset, therefore recommended a 1.80 age.			Calabrian
5886	base Gelasian	stage_base	Gelasian	2.5800	preset age: Major expansion of N.Hemis. glaciation begins near Gauss/Matuyama boundary [accepted in 2009 for base of "Quaternary", hence base of revised "Pleistocene"]. NOTE: Was at 2.588 Ma, which is mid-point of underlying Sapropel, which Rio et al (1998) had recommended to also be age of base-Gelasian. However, Gibbard and Head (2009) noted the offset; therefore recommended 2.58 (not 2.59); which is used here.	Major expansion of N.Hemis. glaciation begins near Gauss/Matuyama boundary [accepted in 2009 for base of "Quaternary", hence base of revised "Pleistocene"]. NOTE: Was at 2.588 Ma, which is mid-point of underlying Sapropel, which Rio et al (1998) had recommended to also be age of base-Gelasian. However, Gibbard and Head (2009) noted the offset; therefore recommended 2.58 (not 2.59); which is used here.			Gelasian
5887	base Piacenzian	stage_base	Piacenzian	3.6000	preset age: Zanclean/Piacenzian boundary = cycle near base of Gauss Normal; working definition of Langereis and Hilgen, 1991	Zanclean/Piacenzian boundary = cycle near base of Gauss Normal; working definition of Langereis and Hilgen, 1991			Piacenzian
5888	base Zanclean	stage_base	Zanclean	5.3350	0.1000 Ma offset from base C3n.4n	PLIOCENE -- Base of Pliocene is traditionally placed at base of Trubi Formation (base of Zanclean Stage) representing restoration of marine conditions in the Mediterranean following the late Miocene (Messinian) dessication. This event occurs 5 precession cycles (100kyr=5x20kyr) below the Thvera (C3n.4n) Polarity Subchron, or at 5.32 Ma [Hilgen and Langereis, 1993, "A critical re-evaluation of the Miocene/Pliocene boundary as defined in the Mediterranean", Earth Planet. Sci. Lett., 118: 167-179].			Zanclean
5889	base Messinian	stage_base	Messinian	7.2460	preset age: Base of Messinian (Top of Tortonian) is linked to the FAD of Globorotalia conomiozea (Foram) in the Falconara section in Sicily (e.g., Colalongo et al., 1979); and this datum is within polarity chron C3Br.1r in Crete with an astronomical chronology age of 7.1 Ma to this level (Krijgsman et al., 1994) (summarized in Berggren et al., 1995). Radiometric dating yields 7.26 +/-0.1 Ma (Vai et al., 1993), which is almost within the magnetostratigraphic estimate.	Base of Messinian (Top of Tortonian) is linked to the FAD of Globorotalia conomiozea (Foram) in the Falconara section in Sicily (e.g., Colalongo et al., 1979); and this datum is within polarity chron C3Br.1r in Crete with an astronomical chronology age of 7.1 Ma to this level (Krijgsman et al., 1994) (summarized in Berggren et al., 1995). Radiometric dating yields 7.26 +/-0.1 Ma (Vai et al., 1993), which is almost within the magnetostratigraphic estimate.			Messinian
5890	base Tortonian	stage_base	Tortonian	11.6250	preset age: Base of Tortonian Stage = Midpoint sapropel 76 in the Monte dei Corvi section, Italy (Hilgen et al., 2003); originally 11.61, now re-tuned as 11.625 Ma.	Base of Tortonian Stage = Midpoint sapropel 76 in the Monte dei Corvi section, Italy (Hilgen et al., 2003); originally 11.61, now re-tuned as 11.625 Ma.			Tortonian
5891	base Serravallian	stage_base	Serravallian	13.8200	preset age: Base-Serravallian GSSP (ratified 2007) = major Mi-3b cooling = Seq Boundary TB2.5 = Hardenbol’s Ser 1. Astronomical-tuned age is 13.82 Ma. Above (13.65 Ma) is the lowest occurrence of nannofossil Sphenolithus heteromorphus (which was working base of Serravallian in GTS2004).	Base-Serravallian GSSP (ratified 2007) = major Mi-3b cooling = Seq Boundary TB2.5 = Hardenbol’s Ser 1. Astronomical-tuned age is 13.82 Ma. Above (13.65 Ma) is the lowest occurrence of nannofossil Sphenolithus heteromorphus (which was working base of Serravallian in GTS2004).			Serravallian
5892	base Langhian	stage_base	Langhian	15.9940	base C5Br	Base of Langhian = base of Chron C5Br in GTS2004			Langhian
5893	base Burdigalian	stage_base	Burdigalian	20.4480	base C6An.1r	Base-Burdigalian -- Current working group (cited in Lourens et al., GTS2004) adopted age of FAD of nanno H. ampliaperta, as calibrated at Ceara Rise.. Berggren et al (1995) assigned base of Burdigalian to FAD of foram "Globigerinoides" altiaperturus. Base of Burdigalian (working version) = approx. base of Chron C6An.1r (used here) or of Chron C6An.1n			Burdigalian
5894	base Aquitanian	stage_base	Aquitanian	23.0400	base C6Cn.2n	Base of Miocene (base of Neogene Period) = base of Chron C6Cn.2n. The GSSP of the Oligocene/Miocene boundary is defined as 35m level of Rigorosa Formation in the Lemme-Carrosio sections of NE Italy, corresponding also to the FAD of Foram Globorotalia kugleri (base of Foram Zone M1) (Berggren et al., 1995; Steininger et al.,1997, Episodes). There might be a very minor offset between the Foram and the Magnetic markers?		base Miocene	Aquitanian
5895	base Chattian	stage_base	Chattian	27.2862	@ 0.15 up in C9n	Base of Chattian (Early/Late Oligocene boundary ) GSSP is local higest common occurrence of planktonic foraminifer Chilogeuembelina cubensis at Monte Cagnero, Italy (although this highest-common is diachronous among ocean basins); with published placement at 15% up in Chron C9n at the GSSP (used here; with cycle-mag scale of Palicke for GTS2020). This constrasts with the interpreted astronomical interpretation of 27.82 Ma "option 1" (Coccioni et al., 2018) or 27.42 Ma "option 2". Previous working version had been base of Chron C10n.1n (same as GTS08). [NOTE: Base is potentially at ~70% up in "undifferentiated Chron C10n" in the GSSP in Italy (Coccioni et al., 2008), which would project as equivalent to C10n.1n.4.] Potentially at 2/3rds up in undifferentiated Chron C10n in candidate GSSP in Italy (Coccioni et al., 2008). Assigned in GTS08 as base of Chron C10n.1n = Foram Zone P21a/P21b boundary (=LAD of common Chiloguembelina occurrence => last occurrence defines top of Rupelian, rather than an FAD defining base of Chattian) following Berggren et al. (1995). Ideally, this level would be at the base of polarity chron (C9r or C10n.1n), which provides a global marker.			Chattian
5896	base Rupelian	stage_base	Rupelian	33.9049	@ 0.87 up in C13r	Eocene/Oligocene boundary is defined at Massignano (central Italy) at the LAD of Hantkenina spp. and calibrated to magnetics, plus dated by ash beds as ca. 33.7 Ma. Base of Rupellian is at Chron C13r.87 (to round to even 33.90, instead of 33.89 of Westerhold 2014). Essentially, the "top of Eocene" is defined by a LAD, rather than a "base of Oligocene" (e.g., using an FAD).			Rupelian
5897	base Priabonian	stage_base	Priabonian	37.7100	preset age: astronomical age of 37.71 Ma based on email/table by Palicke (3Sept2019, citing Galeotti et al., 2019	Base of Priabonian = submitted Priabonian/Bartonian GSSP (Tiziano Bed) awaiting ICS/IUGS ratification. Has astronomical age of 37.71 Ma based on email/table by Palicke (3Sept2019, citing Galeotti et al., 2019; Agnini et al. (submitted)). GTS2016, following Wade et al. (2012) and Priabonian Working Group (2014 status report) had placed at the sudden successive (15 kyr separation) in the extinctions of muricate planktonic foraminifera families of Morozovelloides and Acarinina (was alternative version following Wade et al., 2012, and Priobonian working group 2014), then at Alano (candidate GSSP section in Italy), it was temporarily using the RARE FAD of C. oamaruensis. Proposed GSSP level is 10% up in C17n.2n (similar age)			Priabonian
5898	base Bartonian	stage_base	Bartonian	41.0300	base C18r	DASHED -- Base of Bartonian (working version) assigned as base of Chron C18r. The base of Bartonian is typically correlated to a level within Nanno Zone NP16, and closely associated with LAD of Reticulofenestra reticulata (Leg 320-321 cite same chron-age scaling as chron-age scaling as Berggren et al. (1995); = ca. C19r.7. Berggren et al. (1995) equate to the TOP of polarity chron C19n (base of C18r), implying an age estimate of 41.25 Ma.			Bartonian
5899	base Lutetian	stage_base	Lutetian	48.0680	-0.8100 Ma offset from base C21	Base of Lutetian (GSSP ratified Feb 2011) is base of nannofossil Blackites inflatus at Gorrondatxe section in Spain. This level is 39 precession cycles above base of Chron C21r at Otsakar section near GSSP one (therfore near C21r.7) (= 0.81 myr above using 20.7 kyr average precession at ca. 48 Ma as advised by Heiko Palicke email to J.Ogg 5Sept2019). NOTE: Using Lutetian GSSP proposal’s assignment of "uncertain = R" at top of C21r (as they indicate with their labeled C21n/C21r level), then this was lower -- 40% up in C21r -- age from spline-fit with cycles. Therefore, this is about 0.78 myr above the GTS04 working placement as base of C21r (following Berggren et al’95) [NB base C21r= base C21]			Lutetian
5900	base Ypresian	stage_base	Ypresian	56.0010	-1.1000 Ma offset from base C24	Base of Eocene is 1.142 myr after beginning of Chron C24r, or ca. Chron C24r.36 (actually C24r.37 using revised C24r-duration of 9Mar2012) = decision of Paleogene-chapter group for GTS2012. BUT, rounded here to 1.1 myr, following Palicke’s 3Sept’19 email to Robert Speijer and J.Ogg [NOTES: This is NOT tied proportionally within Chron C24r; but some indicate it as C24r.36 (e.g., used in Agnini et al’07 for calibrating nannofossil datums near boundary). Age used here is from U-Pb => 0.05 myr lower. Base of Eocene is 0.94 myr (0.98 in another table) above top C25n according to cycle stratigraphy.]			Ypresian
5901	base Thanetian	stage_base	Thanetian	59.2370	base C26n	Base of Thanetian (Ratified by ICS/IUGS (Spring 08): Base of magnetic polarity Chron C26n = same as temporary assignment in GTS2004 (GSSP in Zumaya, Spain), as in Berggren et al., 1995			Thanetian
5902	base Selandian	stage_base	Danian	61.6630	-0.6150 Ma offset from base C26	Ratified by ICS/IUGS (Spr’08): Onset of a carbon isotope shift and sea-level drop (Exxon/Hardenbol sequence boundary "Sel1"); near diversification of the Fasciculith group of calcareous nannoplankton, preceding the lowest Fasciculithus tympaniformis (base of nannoplankton zone NP5). Approximately 30 precession cycles (ca. 0.615 myr using 20.5 kyr) above the base of magnetic polarity Chron C26r at GSSP in Spain. [Was 32 precession cycles in original proposal, but was re-studied => 30 cycles. Final GSSP definition is about 0.6 myr younger than GTS04 provisional version (which was base of Chron C26r) at 62.3 Ma.]			Danian
2961	base Danian	stage_base	Danian	66.0400	preset age:	GSSP: The base of the Cenozoic Era, Paleogene System, Paleocene Series and Danian Stage [click GSSP for graphics] is defined at the reddish layer at the base of the 50cm thick, dark boundary clay in a tributary of the Oued Djerfane, west of El Kef, Tunisia, where it coincides with the Iridum Anomaly fallout from a major asteroid impact.Maastrichtian/Paleocene boundary = 66.0 Ma (radiometrics in GTS2012) = C29r.45 (Husson et al.; 2011 from cycles); GTS04 was C29r.5 (Hubbert, but basal Paleogene may have missed a cycle?) = 65.5 Ma. Was C29r.7 = 65 Ma = age calibration point of Cande and Kent (1995), who didn’t have any compensation for K/T condensation.; but later cyclostrat seems to imply nearly in middle of C29r			Danian
2962	base Late Maastrichtian		Maastrichtian	69.9100	base Hoploscaphites birkelundae WAZ	Not defined. Uppermost ammonite zone of Early Maastrichtian is Baculites clinolobatus in U.S. western-interior => base of H. birkelundi is base-""Late"". N. Europe ’Neubergicus/Tridens’ zone considered equivalent to Early Maastrichtian substage.			Maastrichtian
2963	base Maastrichtian	stage_base	Maastrichtian	72.1700	preset age:	GSSP: The base of the Maastrichtian Stage [click GSSP for graphics] is defined at level 115.2 on platform IV of the geological site at Tercis les Bains (Landes, France).The ratified GSSP boundary is in an abandoned quarry near the village of Tercis les Bains in southwest France, at 90 cm below a coincident lowest occurrence of Pachydiscus neubergicus and Hoploscaphites constrictus ammonoids. Chron equiv = C32n.2n.82 (7/8ths up); used to fit GTS2020 assigned age of 72.17 [Not sure how that 72.17 was derived]			Maastrichtian
2964	base Late Campanian		Campanian	76.3800	preset age:	Base of Late Campanian usage in N.Amer. Western Interior usage is base of Didymoceras nebrascense ammonite zone (with age as shown here). In northwest Europe usage, the base of a Late Campanian is traditionally marked by the extinction of the belemnite Gonioteuthis quadrata, which would correlate to base of the Baculites sp. (smooth) zone of N.Amer. Western Interior; or about 3 myr lower (or ca. 1 myr above base of Middle Campanian in that regional usage).			Campanian
2965	base Middle Campanian		Campanian	80.6400	preset age:	Base of Middle Campanian usage in Western Interior is base of Baculites obtusus ammonite zone.			Campanian
2966	base Campanian	stage_base	Campanian	83.6500	preset age:	potential GSSP may coincide with extinction of pelagic crinoid Marsupites testudinarius.Base-Campanian is the extinction of crinoid Marsupites testudinarius (provisional boundary marker); which is near base of C33r (alternate definition). Age from Gale-Gradstein spline fit of 83.6 Ma is about 0.5 myr older than base of C33r of 83.07 ?0.15 (Ramezani et al.; Songliao basin).			Campanian
2967	base Late Santonian		Santonian	84.5400	base Sphenoceramus lundbreckensis WInoZ	Base of Upper Santonian is commonly placed at lowest occurrence of stemless crinoid Uintacrinus socialis (coeval with base of Sphenoceramus lundbreckensis inoceramid zone), and this level is near the FAD of nannofossil Arkhangelskiella cymbifomis. Base of Late Santonian in N.Amer. Western Interior usage is base of Clioscaphites choteauensis ammonite zone (Cobban et al., 2006); which leaves nearly no time for M. Sant.			Santonian
2968	base Middle Santonian		Santonian	85.3000	base Clioscaphites vermiformis WAZ	Base of Middle Santonian is Clioscaphites vermiformis ammonite zone in W. interior.			Santonian
2969	base Santonian	stage_base	Santonian	85.7000	base Cladoceramus undulatoplicatus WInoZ	GSSP: Base of the Santonian coincides lowest occurrence of Inoceramid bivalve Cladoceramus undulatoplicatus Base of Inoceramid Cladoceramus undulatoplicatus			Santonian
2970	base Late Coniacian		Coniacian	87.5000	base Magadiceramus subquadratus WInoZ	Base of Late Coniacian in N.Amer. Western Interior usage is lowest occurrence of the inoceramid bivalve Magadiceramus subquadratus (Kauffman et al., 1996).			Coniacian
2971	base Middle Coniacian		Coniacian	88.0900	base Volviceramus WInoZ	Base of Middle Coniacian is lowest occurrence of the inoceramid bivalve genus Volviceramus; which is at base of Scaphites ventricosus ammonite zone in N.Amer. Western Interior usage.			Coniacian
2972	base Coniacian	stage_base	Coniacian	89.3900	0.0000 Ma offset from base Cremnoceramus deformis erectus WInoZ	potential GSSP may coincide with lowest occurrence of Inoceramid bivalve Cremnoceramus rotundatus (sensu Troger non Fiege). Age corrected from 89.27 in GTS04, according to correction by Ireneusz Walaszczyk, chair of that working group.Base-Coniacian (candidate definition) is lowest occurrence of inoceramid bivalve Cremnoceramus deformis erectus. This correlates approximately with base of Scaphites preventricosus ammonite zone in Western Interior. Age is extrapolated as 89.77 ? 0.34 by Siewet et al., 2011 (Table in her thesis to Ogg on 19 Aug 2011); revised to 89.75 ?0.38 in Sageman et al. 2014. [NOTE: GTS04 had a higher placement relative to ammonite zones; corrected in GTS07]			Coniacian
2973	base Late Turonian	-	Turonian	90.2700	base Scaphites whitfieldi WAZ	Many options; but put here as base of ammonite Scaphites whitfieldi zone in the North American Western Interior; although Gale et al. (2020) suggest probably the first occurrence of the widespread inoceramus species I. perplexus (but he omitted from his GTS2020 age-correlation charts), which is close to a small positive carbon-isotope positive excursion, the Caburn Event			Turonian
2974	base Middle Turonian		Turonian	92.9000	base Collignoniceras woollgari WAZ	Base of Middle Turonian in N.Amer. Western Interior usage is base of Collignoniceras woollgari ammonite zone, approximately 5 meters above the GSSP defining the base of the Turonian Stage in the Rock Canyon Anticline section near Pueblo, Co.			Turonian
2975	base Turonian	stage_base	Turonian	93.9000	base Watinoceras devonense WAZ	GSSP: The base of the Turonian Stage [click GSSP for graphics] is defined as the base of Bed 86 of the Bridge Creek Limestone Member at the western end of the Denver and Rio Grande Western Railroad cut near the north boundary of the Pueblo Reservoir State Recreation Area, west of Pueblo, Colorado, USA. The GSSP coincides with the first occurrence of the ammonite Watinoceras devonense, is in the middle of a global positive excursion in carbon 13 isotopes, and is bracketed by widespread bentonites that have yielded age of 93 to 93.5 Ma.The base of the Turonian Stage is at the base of Bed 86 of the Bridge Creek Limestone Member, west of Pueblo, Colorado, USA. The GSSP coincides with the first occurrence of the ammonite Watinoceras devonense, is in the middle of a global positive excursion in carbon 13 isotopes, and is bracketed by widespread bentonites that have yielded age of 93.79 to 93.96 Ma; and cycle-extrapolated as 93.90 ?0.15 myr (Meyers et al., AGU, 2010; and submitted to Geology, 2011). Cycle-strat duration = 0.35 myr (Meyers et al., EPSL, 2011 in press); contains bentonite dated as 93.79 ?0.26 Ma in upper part of this zone.			Turonian
2976	base Late Cenomanian		Cenomanian	95.4700	base Dunveganoceras pondi WAZ	The replacement of ammonites of the genus Acanthoceras by the genus Calycoceras is commonly used to mark the base of the Upper Cenomanian. the placement will probably be at the base of of the Calycoceras guerangeri Zone, which is just slightly higher than the base of Dunveganoceras pondi ammonite zone in N.Amer. Western Interior usage (used here for the age).			Cenomanian
2977	base Middle Cenomanian		Cenomanian	96.2400	base Cunningtoniceras inerme TAZ	The sudden entry of the ammonite genera Cunningtoniceras and Acanthoceras is a major biostratigraphic event. Base of Middle Cenomanian is base of Cunningtoniceras inerme in Tethyan scale; which is considered to be coeval with base of Conlinoceras tarrantense ammonite zone N.Amer. Western Interior usage.			Cenomanian
2978	base Cenomanian	stage_base	Cenomanian	100.5000	0.2500 Ma offset from base Mantelliceras mantelli TAZ	GSSP: The base of the Upper Cretaceous Series and Cenomanian Stage [click GSSP for graphics] is defined at 36 meters below the top of the Marnes Bleues Formation on the south side of Mont Risou, east of Rosans, Haute-Alpes, France. This level coincides with the first appearance of the planktonic foraminifer Rotalipora globotruncanoides Sigal, 1948, and can be placed in the context of a series of secondary marker levels based on nannofossils, planktonic foraminifera, ammonites and an ornate Carbon-13 curve.Base Cenomanian placed as 0.25 myr OLDER than the computed 100.25 Ma base for ammonite subzone Neostingloceras carcitanense s.z. (Europe) [=base M. mantelli TAZ]; based on Ar-Ar ages by Obradovitch (adjusted for GTS2012 FCT standard)			Cenomanian
2979	base Late Albian		Albian	107.5875	base Dipoloceras cristatum BAZ	Base of Late Albian is Base of Diploceras cristatum ammonite zone. Basal ammonite zone of Late Albian is Mortoniceras inflatum in England.			Albian
2980	base Middle Albian		Albian	110.2200	base Lyelliceras lyelli BAZ	The traditional base of the Middle Albian is placed at the lowest occurrence of the ammonite Lyelliceras lyelli. Basal ammonite stage of Middle Albian was Hoplites dentatus in England.			Albian
2981	base Albian	stage_base	Albian	113.2000	base Microhedbergella renilaevis pfZ	GSSP (Kennedy et al., 2014) is FAD of planktonic foraminifer Microhedbergella renilaevis in middle of Kilian organic-rich layer in SE France and associated negative excursion in C13. Working definition for GTS2012 was the first appearance datum (FAD) of Praediscosphaera columnata (subcircular) following usage in Piobbico core and U-Pb dated (113 Ma) event in Boreal realm (Germany). GSSP is essentially base of Kilian event	Equation leads back to FAD of Microhedbergella renilaevis (p. foram)		Albian
2982	base Late Aptian		Aptian	118.7623	base Epicheloniceras martinoides BAZ	Base of Late Aptian is base of Epicheloniceras martinoides (formerly martini) ammonite zone (Kilian group, 2011, who urged that use of French Bedoulian/Gargasian be discouraged (although that regional boundary is near that same level).			Aptian
2983	base Aptian	stage_base	Aptian	121.4000	base M0r	potential GSSP may coincide with base of magnetic polarity Chron M0r.Current working definition for Base of Aptian is base of polarity chron M0r			Aptian
2984	base Late Barremian		Barremian	124.4007	base Toxancyloceras vandenheckii TAZ	Base of Late Barremian was base of ’Emiriceras’ barremense ammonite zone in south-east France; but revised ammonite zonation implies that this is middle of Toxancyloceras (formerly Ancyloceras) vandenheckii zone; therefore, the base of Toxancyloceras vandenheckii is used here for """"Base of Late Barremian			Barremian
2985	base Barremian	stage_base	Barremian	126.5007	base Taveraidiscus hugii TAZ	potential GSSP may coincide with lowest occurrence of ammonite Spitidiscus [now Taveraidiscus] hugii - Spitidiscus vandeckii group. Base of Barremian (base of Spitidiscus hugii ammonite zone). In GTS2012 it as assigned as Chron M5n(0.8)			Barremian
2986	base Late Hauterivian		Hauterivian	129.9391	base Subsaynella sayni TAZ	Base of Subsaynella sayni ammonite zone in Tethyan zonation; but other more global events (e.g., a nannofossil) are being considered.			Hauterivian
2987	base Hauterivian	stage_base	Hauterivian	132.6000	preset age: Gale-Gradstein GTS2020 FIXED base-Haut as 132.6; therefore NO TIE used here.	potential GSSP may coincide with lowest occurrence of ammonite genus Acanthodiscus (especially A. radiatus).The base of the Hauterivian (base of Acanthodiscus radiatus ammonite zone of Tethyan realm) is considered to be near the beginning of chron M10n (e.g., Weissert and others), as supported by later studies (e.g, McArthur et al., 2007, Palaeo-3), and consistent with the cycle-scaled duration of the Valanginian. Assigned as base M10n. In GTS04, the base of the Hauterivian Stage was assigned, based on the reported occurrence of its earliest ammonites, to near the beginning of magnetic polarity chron M11n (Channell et al., 1995, EPSL). However, the GTS04 authors and reviewers were not aware that this published correlation had been revised. Earlier version -- Valanginian/Hauterivian boundary is within M10Nr or within the adjacent normal-polarity chrons; tentatively assigned to middle of M10Nr.			Hauterivian
2988	base Late Valanginian		Valanginian	135.3985	base Saynoceras verrucosum TAZ	Base of Saynoceras verrucosum ammonite zone			Valanginian
2989	base Valanginian	stage_base	Berriasian	137.7000	base Calpionellites darderi subzone	potential GSSP may coincide with lowest occurrence of calpionellid Calpionellites darderi (base of Calpionellid Zone E); followed by the lowest occurrence of ammonite ""Thurmanniceras"" pertransiens.T. pertransiens/T. otopeta boundary is in lower-middle M14r in southern Spain. Shorter in duration in GTS2004, even with this transfer of an ammonite zone. This reflects the postulated faster spreading model (and dropping of U-Pb date of 137 reported for uppermost Berriasian), hence Pacific anomalies represent shorter time.	It seems that the T. otopeta TAsZ has been moved from the Valanginan to the Berriasian to which makes some of the older notes confusing. In addition the stage base in the Stage Summary/Cret output/TSC is different to that on the CRET Macro sheet Base Calp darderi (137.7 Ma) CalpZ vs 0.3 M14r (137.44 Ma)		Berriasian
2990	base Late Berriasian		Berriasian	139.9200	base Fauriella boissieri TAZ	Base of Subthurmannia boissieri ammonite zone [=Fauriella boissieri]			Berriasian
2991	base Middle Berriasian		Berriasian	141.3760	base Subthurmannia occitanica TAZ	Base of Subthurmannia occitanica ammonite zone			Berriasian
608	base Berriasian	stage_base	Berriasian	143.1000	preset age: NEEDS CHECKING. This age possibly can be derived rather than preset, but the logic here is convoluted.	Base-Berr = base of Calp B option . GSSP Not yet defined. Lower option is Base of Calp. alpina zone (Calp. B) -- current (Sept 2015) preference by working group	There are at least two alternative versions of the base Berriasian (J/K boundary). On TSC 143.1 Ma = base C. alpina CalpZ. On CRET Macro 142.307 = base M18r		Berriasian
609	base Late Tithonian		Tithonian	145.0465	base Micracanthoceras microcanthum TAZ	Late Tithonian = base of M. microcanthum			Tithonian
610	base Tithonian	stage_base	Tithonian	149.2374	base M22An	GSSP not yet defined. Set here as Base of Chron M22An, which is nearly coeval with base of H. hybonotum ammonite zone at Crussol Mountain, France			Tithonian
611	base Late Kimmeridgian		Kimmeridgian	152.0351	base Aulacostephanus mutabilis BAZ	Late Kimmeridgian (Boreal usage; shown here) = Base of A. mutabilis ammonite Zone. Tethyan usage is base of A. acanthicum Zone, about 0.3 myr higher.			Kimmeridgian
612	base Kimmeridgian	stage_base	Kimmeridgian	154.7780	base Pictonia baylei BAZ	candidate GSSP: Base of P. baylei ammonite zone (Isle of Skye), using lowest occurrence of P. flodigarriensis ammonite (not yet ratified) which is essentially coeval with Base of Chron M26r at the GSSP. Same as base of redefined E. bimammatum zone in Poland magstrat reference section.Base of Kimmeridgian (International)			Kimmeridgian
613	base Late Oxfordian		Oxfordian	157.9601	base Perisphinctes cautisnigrae BAZ	Base Lt.Oxf. (Boreal usage) = base P. cautisnigrae, as used here. In Tethyan usage, it "was" higher" (base of P. bifurcatus); but new base-Kimm (Boreal) assignment implies that this version is truncated (very brief)			Oxfordian
614	base Middle Oxfordian		Oxfordian	159.1001	base Perisphinctes plicatilis TAZ	M.Oxf. = base P. plicatilis ammonite zone			Oxfordian
615	base Oxfordian	stage_base	Oxfordian	161.5301	base Quenstedtoceras mariae TAZ	Base of Q. mariae ammonite zone using base of woodhamense horizon at Dorset. GSSP is not yet decided, but this level at Redcliff (England) candidate has been correlated to 25% up in Chron M36Br of Deep-tow extension to M-Sequence.			Oxfordian
616	base Late Callovian		Callovian	162.6309	base Peltoceras athleta TAZ				Callovian
617	base Middle Callovian		Callovian	163.4719	base Reineckeia anceps TAZ	Middle Callovian base in Sub-Mediterranean province is placed at the base of the Reineckeia anceps Zone. In the Sub-Boreal province, the substage boundary is placed at the base of the Kosmoceras jason Zone. These two levels are considered approximately coeval.			Callovian
618	base Callovian	stage_base	Callovian	165.2900	base Bullatimorphites bullatus TAZ	Base of B. bullatus ammonite zone. GSSP is not yet decided. In magnetostratigraphy from the Albstadt-Pfeffingen GSSP candidate (Swabia, Germany), this level is the base of a brief normal-polarity zone, which is interpreted to be the base of marine magnetic anomaly M39n.3n in the Deep-Tow extension to M-Sequence (using mid-depth projection)			Callovian
619	base Late Bathonian	-	Bathonian	165.8274	base Hecticoceras retrocostatum TAZ	DASH due to Different Versions: In the Sub-Mediterranean province (Tethyan province), a Middle/Upper Bathonian boundary is assigned to the base of the Hecticoceras (Prohecticoceras) retrocostatum Zone. In the Northwest European province (Boreal province), a substage boundary is commonly assigned to the base of the Procerites (Procerites) hodsoni Zone, which is a significantly older level (Groupe Français d’Étude du Jurassique, 1997).			Bathonian
620	base Middle Bathonian		Bathonian	166.9661	base Procerites progracilis TAZ	Middle Bathonian = base of Procentes progracilis ammonite zone			Bathonian
621	base Bathonian	stage_base	Bathonian	168.1690	base Zigzagiceras zigzag TAZ	GSSP: Base of Z. zigzag ammonite zone at Ravin du Bès-Bas Auran (France). In magnetostratigraphy of Spain, this level is the base of a normal-polarity zone, which is interpreted to be the base of marine magnetic anomaly M42n.1n in the Deep-Tow extension to M-Sequence (using mid-depth projection)			Bathonian
622	base Late Bajocian		Bajocian	169.7385	base Strenoceras niortense TAZ	Late Bajocian = base of Strenoceras niortense ammonite zone			Bajocian
623	base Bajocian	stage_base	Bajocian	170.9000	base Hyperlioceras discites TAZ	GSSP: Base of H. discites ammonite zone at Cabo Mondego (Portugal). In combined magnetostratigraphy of Spain and Switzerland, this level is in the uppermost part (ca. 80% up) of a reversed-polarity-dominated zone, which is interpreted to be marine magnetic anomaly M44n.1r in the Deep-Tow extension to M-Sequence (using mid-depth projection)			Bajocian
624	base Late Aalenian		Aalenian	171.5000	base Graphoceras concavum TAZ	Late Aalenian is the Graphoceras concavum Zone			Aalenian
2134	base mid-Aal R		Aalenian	172.6600	@ 0.05 up in Ludwigia murchisonae TAZ		part of a confused interval, needs checking		Aalenian
625	base Middle Aalenian		Aalenian	172.7000	base Ludwigia murchisonae TAZ	Middle Aalenian comprises the Ludwigia murchisonae and Brasilia bradfordensis Zones			Aalenian
626	base Aalenian	stage_base	Aalenian	174.7000	base Leioceras opalinum TAZ	GSSP :Base of L. opalinum ammonite zone at Fuentelsaz (Spain).			Aalenian
627	base Late Toarcian	-	Toarcian	179.8244	base Haugia variabilis TAZ	DASH -- Late Toarcian substage boundary not standardized. Base of the Haugia variabilis ammonite zone is used here. But an alternate three-substage division (e.g., Groupe Français d’Étude du Jurassique, 1997) groups the Haugia variabilis and underlying Hildoceras bifrons zones into a Middle Toarcian, and places the limit of an Upper Toarcian at the base of the Grammoceras thouarsense Zone.			Toarcian
628	base Middle Toarcian		Toarcian	181.1677	base Hildoceras bifrons TAZ		JRY - definition does not seem clear		Toarcian
629	base Toarcian	stage_base	Toarcian	184.2001	base Dactylioceras tenuicostatum TAZ	GSSP: Base of D. tenuicostatum ammonite zone; with GSSP in either Portugal (2012)			Toarcian
630	base Late Pliensbachian		Pliensbachian	188.0001	base Amaltheus margaritatus BAZ	Late Pliensbachian (Domerian) = base of Amaltheus margaritatus ammonite Zone			Pliensbachian
631	base Pliensbachian	stage_base	Pliensbachian	192.9001	base Uptonia jamesoni TAZ	GSSP: Base of A. bucklandi ammonite zone at East Quantoxhead (England).			Pliensbachian
632	base Late Sinemurian	-	Sinemurian	196.3729	base Asteroceras obtusum TAZ	Late Sinemurian (Lotharingian) = base of Asteroceras obtusum ammonite Zone			Sinemurian
633	base Sinemurian		Sinemurian	199.4600	base Arietites bucklandi TAZ				Sinemurian
634	base Hettangian	stage_base	Hettangian	201.3600	base Psiloceras tilmanni TAZ	GSSP: Lowest occurrence of the ammonite Psiloceras spelae at Kuhjoch (Austria).			Hettangian
8870	base Rhaetian	stage_base	Norian	205.7402	0.0000 Ma offset from FAD Misikella posthernsteini (sensu stricto)	DASHED -- Misikella posthernsteini (sensu stricto in taxonomy of Marun et al., 2015) is the proposed marker for base-Rhaetian Pignola-Abriola (southern Italy) GSSP canddiate is the FAD of Misikella posthernsteini (sensu stricto) as recognized and calibrated by Maron et al. (2015) as being in the lower part of reversed-polarity zone they suggests is about 20% up in Chron E20r.2r of Newark polarity scale (made "21% here to round to 205.7 = UPb age +/-0.15). This is preceded by transitional forms of Miskella that call M.posthernsteini sensu lato (hence a lower FAD at the Austrian GSSP candidate that uses that level).			Norian
8871	base Sevatian		Norian	214.0320	base Sagenites quinquepunctatus TAZ	LATE Norian. Assigned as base of Sagenites quinquepunctatus in common usage (e.g., Jenks et al., 2015) However, to avoid a Very Short Sevatian IF the Austrlia GSSP candidate is accepted that has truncated the former upper part of that Sevatian, Kozur (2003, and written to Jim Ogg, 2006) proposed incorporating the next lower ammonoid zone of Halorites macer.			Norian
8872	base Alaunian sensu Kozur		Norian	215.2920	base Halorites macer TAZ	Alternative for base of Alaunian is base of Halorites macer ammonoid zone by Kozur (2003, and written to Jim Ogg, 2006). However, Jenks et al. (2015) assign as base of the next higher ammonoid zone (S. quinquepunctatus), which would result in a Very Short Sevatian IF the Austrlia GSSP candidate is accepted that has truncated the former Sevatian.			Norian
8873	base Alaunian		Norian	217.4915	base Cyrtopleurites bicrenatus TAZ	MIDDLE Norian. Assigned as base of Cyrtopleurites bicrenatus Ammonoid zone (Tethyan).			Norian
8874	base Norian	stage_base	Norian	227.3000	base Guembelites jandianus TAZ	EARLY Norian. DASHED. Assigned here with age from Pizzo Mondello using base of Metapoly. primitius conodont, assuming same as base of Tethyan Guembelites jandianus ammonoid zone, pending decision on GSSP..			Norian
8875	base Tuvalian		Carnian	233.6000	-3.4000 Ma offset from base Carnian	Age of 233.55 from independent Carnian ammonite-subzone scaling method fits the Cycle-Mag from S.China plus most of Carnian Pluvial event. Decided to FIX in GTS2020 as a rounded 3.4 myr above base of Carnian (as used in Wendy Zhang’s Carnian Fig.9 age model); and DASH base-Julian at this level.			Carnian
8876	base Carnian	stage_base	Carnian	237.0000	preset age: Fixed at 237 Ma "GSSP is one ammonite subzone just above a level dated at 237.77 +/- 0.14 Ma" (Mietto et al., 2012)	Main marker for Carnian GSSP. Fixed at 237 Ma "GSSP is one ammonite subzone just above a level dated at 237.77 +/- 0.14 Ma" (Mietto et al., 2012, Carnian GSSP report in Episodes). No subzonal divisions => scaled as "1.2 subzonal units" in relative duration because it was equivalent to lowest subzone of Trachyceras Zone, and to enable T. aon to move down for obtaining 1.3 myr duration for late Julian Reversed-zone. Ladinian ’Daxatina canadensis’ ammonite zone (uppermost Ladinian) is also the lowest subzone of the Trachyceras zone that extends into the Carnian. It is upgraded to a Zone in some schemes (e.g., Spitsbergen). This zone is equivalent to upper half of ’Frank. regoledanus’ zone of Krystyn (1983).			Carnian
8877	base Longobardian		Ladinian	239.4800	preset age: Wotzlaw et al., 2018, -> U-Pb-dated limits of 239.48 +/-0.5	base of Late Ladinian or Longobardian substage is traditionally assigned as base of Protrachyceras longobardicum Ammonoid zone in Tethyan realm.			Ladinian
8878	base Ladinian	stage_base	Ladinian	241.4600	preset age: Direct radiometric dating and cycle-strat near GSSP in Italy (Wotzlaw et al., 2018, J.Geo.Soc.) = 241.46 +/-0.28	Base-Ladinian (GSSP) now = base of E. curionii Zone. U-Pb estimated age from Wotzlaw et al., 2018 U-Pb on boundary.Direct radiometric dating and cycle-strat near GSSP in Italy (Wotzlaw et al., 2018, J.Geo.Soc.) = 241.46 +/-0.28 = control on scaling of Anisian-Ladinian. E. curiionii spans two subzonal units in relative duration.			Ladinian
8879	base Illyrian		Anisian	243.3285	@ 0.10 up in MT5r	10% up in Magchron MT5r of Hounslow-Muttoni (2010; used here). NOTE: EXACTLY SAME RESULT (!!) as the GTS2012 scaling using Four subzonal units in relative duration. Zone has alternative zone/subzone divisions (e.g., Table 2 in Kozur’03; and I’ve used Bachmann-Kozur’04 here => middle subzone is "two" subzonal units).			Anisian
8880	base Pelsonian	-	Anisian	244.2388	@ 0.20 up in MT4n.2n	DASHED --About 20% up in MT4n.2n in magnetic-polarity compilation by Hounslow-Muttoni (2010), for which MT4n duration is scaled with cycle-magstrat at Guandao (Mingsong Li, 2015, in prep; used here). Two subzonal units in relative duration.			Anisian
8881	base Bithynian	-	Anisian	244.9834	base MT3r.3r	Base of Bithyrian = within MT3r; put at base of MT3r.3r (1/3rd up in CG11r of Szurlies’07) = uppermost Rot. 1.5 subzonal units in relative duration (no subzone divisions). Applied zonation of Kozur (2003) to Bithynian, which uses lower two zones of Boreal, then what had been subzones of Kocelia super-zone for upper two divisions.			Anisian
8882	base Anisian	stage_base	Anisian	246.7000	base Chiosella timorensis TKCdontZ	FAD of Ch. timoresis would be the base of Anisian at the suggested placement of a GSSP at Wantou.			Anisian
8883	base Spathian	-	Olenekian	248.0958	base Novispathodus pingdingshanensis TKCdontZ	DASH -- Approx. conodont Placement (base of Novispathodus pingdingshanensis at Chaohu; Li et al., 2016). Base Spathian (LATE OLENEKIAN) is not formally defined. Base of Spathian in Boreal ammonite zonation is about 70% up in Hounslow-Muttoni LT5n-7n (= a single CG8n; 85% used here to better fit Chaohu); and this fits cycle-scaling relative to base-Triassic in S.China’s conodont-version [DONE INDEPENDENTLY HERE]. Szurlies (2004) has the conchostracan-version at about 75% up in his Magzone CG7n (which may be a small gap) = base of Detfurth cycles in Germanic system. GTS04 -- Computed Smithian duration (as shown in cell) was from 8 conodont units (of 28): Sweet & Bergstr?m (1986) obtain 7 time units for their "Smithian", and I’ve added another 1 unit for lower N. pakistanensis conodont zone (see below) => 8 units. Base-Spathian is FAD of Ns. triangularis in their scheme, and this has been retained here.			Olenekian
8884	base Olenekian	stage_base	Olenekian	249.8750	base e5.2 ChL	Base of Olenekian (base of Smithian substage) -- Assumed coincidence of Chaohu conodont marker for GSSP candidate and Tethyan ammonite zone usage (base of Flemingite, which is nearly same level at Chaohu). Chaohu 405kyr cycle-strat suggests the conodont-based candidate GSSP level is the base of "e5.2" of Mingsong’a band-pass version for 100kyr cycles (Mingsong Li to JOgg Aug2015) = 249.9 Ma (Li et al., 2016, EPSL); but this assumed constant rates within 405kyr cycles; plus bases of Szurlies cycles are defined differently than Chaohu cycles. At Chaohu GSSP candidate, this is just below (ca. 0.05 myr?) the base of Hounslow-Muttoni magnetozone LT3n (CG6n of Szurlies 2007) => base-Induan (as used at Chaohu) would be near the base of Germanic cycle s3.3.			Olenekian
8885	base Dienerian	-	Induan	250.4955	@ 0.25 up in CG5n	LATE INDUAN. DOTTED -- Base of Dienerian (traditionally base of Proptychites candidus Boreal ammonoid zone) is assigned from a potential conodont marker as ca. 25% up in LT2n of Hounslow-Muttoni’10 = middle of Szulies Magzone CG5n (sn2 of Szurlies’03) (GR2 of Ogg). GTS04 -- Computed "GSSP-based Griesbachian" duration from 3 conodont units (of 28): Sweet & Bergstr?m (1986) obtain 3.5 time units for their "Griesbachian" (base-Dienerian = base N. kummeli), of which FAD H.parvus (=I.isarcica) occurs 1 unit above former Griesbachian base (=base O.concavum). In their scheme, revised Griesbachian would be 2.5 units. However, Orchard-Tozer indicate that base-Dienerian is slightly above base Ns. dieneri, whereas Sweet and Bergstr?m had had placed this Ns. dieneri 0.1 unit below base of their Dienerian. Therefore, considering units/ammonte zone, I assigned this to be 0.5 units below actual Dierian base => Griesbachian spans 3 units, and Dienerian is shortened (at base) by 0.5 unit.			Induan
8886	base Induan	stage_base	Induan	251.9000	preset age: Radiometric age on GSSP = Control Age !	Radiometric age on GSSP = Control Age ! Burgess, Bowring and Shen apply EarthTime standards to GSSP at Meishan to bracket between ash beds at 251.94 +/-0.04 and 251.88 +/-0.3.			Induan
10372	base Triassic	stage_base	Induan	251.9000	preset age: Radiometric age on GSSP = Control Age !	Radiometric age on GSSP = Control Age ! Burgess, Bowring and Shen apply EarthTime standards to GSSP at Meishan to bracket between ash beds at 251.94 +/-0.04 and 251.88 +/-0.3.			Induan

Dataset References ↑

Column mock-up

This column mock-up plot is a simple plot of the data to allow visual comparison with the output from TimeScale Creator

The data plotted here are the columns from the chronostratigraphy dataset for the interval 0.0002 - 251.9000 Ma

Name:	chronostratigraphy id:1 sort: 1	Dataset type: Data types:
TSC_source_notes:	International Commission on Stratigraphy [http://www.stratigraphy.org/. Details on boundaries/GSSPs are at Geologic TImeScale Foundation [http://timescalefoundation.org/gssp].
compilation_notes:
Cenozoic notes & compilation notes
Cretaceous notes & compilation notes
Jurassic notes & compilation notes	jj
Triassic notes & compilation notes
Permo-Carboniferous notes & compilation notes
Devonian notes & compilation notes
Silurian-Ordovician notes & compilation notes
Cambrian notes & compilation notes
refs to add:
Linked refs:	Gale 2016;Gale et al. 2020;Gale et al. 2020;
Interval Colour:
Event Colour:
Added abbreviations:
interval types:	period;epoch;stage;substage	Main initerval type:
prefix(es):

View a dataset or subdataset chronostratigraphy/all