format version:	1.2
date:	04/01/2008
default chronostrat:	UNESCO
Standard Chronostratigraphy	:	Period	Epoch	Stage	GSSPs		International Commission on Stratigraphy (2006). Click <a href="http://www.stratigraphy.org/gssp.htm">GSSP</a> for official boundary (GSSP) definitions, status and nomenclature.
Period	block	90	USGS-Named
	TOP	0
	Quaternary	2.588		The Quaternary, formerly an era or sub-era, was assigned in rank by IUGS/ICS/INQUA in 2007 to be a period/system. It spans the past 2.6 myr according to the International Quaternary Association (INQUA).
	Neogene	23.03
	Paleogene	65.5
	Cretaceous	145.5	dashed
	Jurassic	199.6	dashed
	Triassic	251.0
Epoch	block		USGS-Named
	TOP	0
	Holocene	0.0117
	Pleistocene	2.588		formerly Late Neogene, now extended downward by IUGS/ICS/INQUA in 2007 enable the Quaternary to be inserted an official Period.
	Pliocene	5.333		was Middle Neogene, now Late Neogene
	Miocene	23.03		Early Neogene
	Oligocene	33.9		Late Paleogene
	Eocene	55.8		Middle Paleogene
Stage	block		USGS-Named
	TOP	0.0117		End of Younger Dryas from ice-core layers relative to AD2000. Submitted as GSSA by Holocene working group (currently in Quat Subcomm voting)
	Lt. Pleist.	0.126	dashed	Spans the last Interglacial and following glacial cycle.
	M. Pleist.	0.781	dashed	Ionian is the potential name for this Stage.
	Calabrian	1.806		Calabrian GSSP is the former Plio-Pleistocene boundary (Vrica)
	Gelasian	2.588		Gelasian stage is proposed to be transferred to Pleistocene series by IUGS/ICS/INQUA (submitted May 2007; but on-hold by IUGS until Jan 2009) to enable formalization of the Quaternary as an official system of the international scale.
	Piacenzian	3.600
	Zanclean	5.333
	Messinian	7.248
	Tortonian	11.608
	Serravallian	13.82		Ratified (2007) -- Mi3b isotopic event (global cooling episode) in upper magnetic polarity chronozone C5ACn. Above (13.65 Ma) is the lowest occurrence of nannofossil Sphenolithus heteromorphus (which was working base of Serravallian in GTS2004).
GSSPs	event	80	USGS-Named			The base of each unit of the geologic time scale is defined at a specific location and point (Global Boundary Stratotype Section and Point, GSSP), where it coincides with an array of paleontological, geochemical, paleomagnetic or other markers for high-resolution global correlation. The current status of currently ratified GSSPs and possible markers for the other geologic units are summarized at www.stratigraphy.org [Click <a href="http://www.stratigraphy.org/gssp.htm">GSSP</a> ]
EVENT
	GSSP	1.806		The base of the Calabrian Stage of Pleistocene Series [click <a href="http://www.stratigraphy.org/pliple.htm">GSSP</a> for graphics] is defined as the base of the marine claystones conformably overlying the sapropelic Marker Bed "e" in the Vrica Section, Italy.
	GSSP	2.588		The base of the Gelasian Stage, base of the Quaternary System/Period and associated base of Pleistocene (as revised in 2007 by IUGS/ICS/INQUA) [click <a href="http://www.stratigraphy.org/gelasian.htm">GSSP</a> for graphics] is defined as the base of the marly layer overlying sapropel MPRS 250, located at 62m in Monte San Nicola section, Italy. The astronomical age of sapropel MPRS 250 (mid-point), corresponding to precessional cycle 250 from the present, is 2.588 Ma, which can be assumed as the age of the boundary.
	GSSP	3.6		The base of the Piacenzian Stage [click <a href="http://www.stratigraphy.org/piacenzian.htm">GSSP</a> for graphics] is defined as the base of the beige marl bed of the small-scale carbonate cycle 77. It corresponds to precessional excursion 347 as numbered from the present, with an astrochronological age estimate of 3.600 Ma. The GSSP is located in the Punta Piccola section, Italy.
	GSSP	5.333		The base of the Pliocene Series and the Zanclean Stage [click <a href="http://www.stratigraphy.org/miopli.htm">GSSP</a> for graphics] is defined as the base of the Trubi Formation. The age of the Zanclean and Pliocene GSSP at the base of the stage is 5.33 Ma in the orbitally calibrated time scale, and lies within the lowermost reversed episode of the Gilbert Chron (C3n.4r), below the Thvera normal subchron.
	GSSP	7.248		The base of the Messinian stage [click <a href="http://www.stratigraphy.org/messi.htm">GSSP</a> for graphics] is defined at the base of the reddish layer of sedimentary cycle no. 15 at Oued Akrech, Morocco, NW Africa. This point coincides closely with the first regular occurrence of the planktonic foraminifer Globorotalia miotumida and the first occurrence of the calcareous nannofossil Amaurolithus delicatus, and falls within the interval of reversed polarity that corresponds to C3Br.1r. The base of the reddish layer and, thus, the Messinian GSSP has been assigned an astronomical age of 7.251Ma.
	GSSP	11.608		The base of the Tortonian Stage [click <a href="http://www.stratigraphy.org/tortonian.htm">GSSP</a> for graphics] is defined as the mid-point of the sapropel layer of basic cycle number 76 in the Monte dei Corvi Beach section, located on the Adriatic coast of central Italy, 5km SE of Ancona. This level has been assigned an astronomical age of 11.608 Ma. It coincides almost exactly with the Last Common Occurrences of the calcareous nannofossil Discoaster kugleri and the planktonic foraminifer Globigerinoides subquadratus, and is associated with the short normal-polarity subchron C5r.2n. This level coincides closely with oxygen isotope event Mi-5 and the associated glacio-eustatic sea-level low-stand of supercycle T3.1 and concurrent deep-sea hiatus NH4.
Geomagnetic Polarity	chron					GTS2004 composites [Cenozoic-Late Jurassic from chapter on geomagnetic polarity time scale; Late Triassic provided by Dennis Kent in June 2005 (after Kent and Olsen, 1999); and other periods after compilations in associated GTS2004 chapter].
C-Sequence
	TOP		0.000
	N	C1	0.781	C1n (Brunhes)
	R	C1	0.988	C1r.1r (Matuyama)
	N	C1	1.072	C1r.1n (Jaramillo)
	R	C1	1.173	C1r.2r
	N	C1	1.185	C1r.2n (Cobb Mountain)
	R	C1	1.778	C1r.3r
	N	C2	1.945	C2n (Olduvai)
	R	C2	2.128	C2r.1r
	N	C2	2.148	C2r.1n (Reunion)
	R	C2	2.581	C2r.2r (Matuyama continued)
	N	C2A	3.032	C2An.1n (Gauss)
	No data	No Data	83.300	Used as a filler in this example
Cretaceous Normal Super-Chron ("Cretaceous Quiet Zone")
	N	C34	102.000	C34n
	R	M"-3"r set	102.200	M"-3"r set
	N	(C34n)	108.000	(C34n)
	R	M"-2"r set	108.200	M"-2"r set
	N	(C34n)	118.500	(C34n)
Type Mississippian Lithostrat	facies	80	234/201/201	notitle		Generalized from Heckel et al., 2005; with additional correlations by Paul Brenckle, written commun., October 2006)
Morrowan
	TOP		312.18	Base of Atokan (same as middle of Russian Melekessian -- See note on Regional Stages)
	Sandstone	Caseyville	317.60	Base of Lane conodont zone 16. "According to the 'Handbook of Illinois Stratigraphy' published by the Illinois survey, the Caseyville Formation includes all of the Morrowan." (Paul Brenckle, written commun., Oct 2006)
	Gap		318.10	Base of Lane conodont zone 15 = base-Pennsylvanian (in gap)
Chesterian
	Gap		319.77	Middle of Lane conodont zone 12
	Claystone	Grove Church	320.10	Base of Lane conodont zone 12
	Limestone	Kinkaid	321.68	See note on Menard. Base of Foram Zone Mf17.
	Sandstone	Degonia	322.07	See note on Menard
	Clayey limestone	Clore	322.46	See note on Menard
	Sandstone	Palestine	322.86	See note on Menard
Ammonoid major marker	event		236/204/215			PERMIAN = Kozur (2003), Davydov et al., 2004, and Henderson (2005); CARBONIFEROUS = GTS2004 diagram (Davydov et al., 2004 and unpublished zonation table), DEVONIAN = Becker and House (2000)
FAD
	Pseudotirolites	251.70
	Paratirolites	252.23
	Iranites, Sinoceltites	253.52
	Araxoceras	256.44
	Anderssonoceras	257.10
	Roadoceras, Doulingoceras	260.40
LAD
	Cravenoceras	321.05
	Goniatites	323.25
	Climenida	359.20
	EXTINCTION of all Devonian ammonoids; except Cymaclymenia evoluta, striata, and involvens	361.19
	Spheno. brevispina	363.48
	Manticoceras, Beloceras, Gephuroceratidae, Beloceratidae, Tornoceratidae	374.50
	Koenenitidae	382.28
Sequences (SEPM Global or Tethyan)	sequence				off	Hardenbol, J., Jacquin, T., Vail, P.R., et al. (SEPM charts. 1998)
		MFS	0.00	Major	A major transgression-MFS is indicated for Today, which presumes continued melting of glaciers will exceed the Eemian previous maximum highstand.
	LGM	SB	0.02	Major	Last Glacial Maximum; Marine Isotope Stage (MIS) 2
		MSF	0.13	Major	Base of Eemian stage; MIS 5
	MIS 6	SB	0.14	Major	Peak of Illinoian/Saalian glacial; MIS 6
		MFS	0.24	Medium	Onset of main pulse of interglacial MIS 7 MSF after glacial MIS 8
	MIS 8	SB	0.27	Medium	Glacial MIS 8.
		MFS	0.42	Medium	Interglacial MIS 11 MSF after glacial MIS 10
	MIS 12	SB	0.44	Major	Glacial MIS 12 (approx.) is a major peak. Glacial MIS 10 and 14 are lesser shifts than MIS 12 or MIS 16, therefore are omitted here.
Phanerozoic T-R Cycles (SEPM; GTS04)	trend					CENOZOIC-MESOZOIC = Hardenbol, J., Jacquin, T., Vail, P.R., et al. (SEPM charts. 1998); PALEOZOIC = GTS2004 diagrams
		MSF	0.00	Major	A major transgression-MFS is indicated for Today, which presumes continued melting of glaciers will exceed the Eemian previous maximum highstand.
	LGM	SB	0.02	Major	Last Glacial Maximum; Marine Isotope Stage (MIS) 2
		MFS	2.92	Medium	SEPM chart displays as 3/4ths from base of Pia 1 sequence. Marine isotope curve suggests this is a very broad highstand, and spans most of "Sequence Pia 1". This highstand is termination of Pliocene transgressive trend; which is a "Medium" MSF on long-term trend.
	Me 2	SB	5.77	Medium	Middle of Nanno Zone NN11d (CN9d) = midway between LAD of nanno Discoaster quinqueramus and LAD of Amaurolithus amplificus. This lowstand is minimum of Late Miocene regression; which is a "medium" SB on long-term scale.
		MFS	10.51	Major	Middle of Sequence Ser 4/Tor 1. This flooding event is a major short transgression in Late Miocene; and indicated as "major" on long-term trend.
	Ser 4/Tor 1	SB	11.80	Major	0.1 myr above Base of Nanno Zone NN7 (CN5b; FAD D. kugleri -- which aslo coincided with Base of Foram Zone M11 =FAD G. nepenthes in Hardenbol chart; but this foram FAD is now placed 0.2 myr later). Maximum regression of Middle Miocene trend. Assigned as major SB for Long-Term trend.
High-Res Plio-Pleist	point				off	Miller et al. (Science, 2005) based on conversion of oxygen-isotope data. They have similar detail extending back to 9 Ma, and a generalized curve back to 170 Ma, but the time scales in their table are Berggren et al (1995) and Gradstein et al (1994), which significantly diverge from GTS2004 below 5.32 myr, therefore this older curve is omitted until conversions are available.
nopoints	line		-125	50
	0.000	-1.6
	0.005	-3.3
	0.010	-52.4
	0.015	-120.4
	0.020	-122.2
	0.025	-99.1
	0.030	-102.6
	0.035	-91.0
	0.040	-85.7
	0.045	-80.4
	0.050	-75.3
Range	range				off	No ranges in default dataset, so here is a sample column.
	donald	0
	donald	1	rare
	donald	2
	donald	3	frequent
	donald	4	flood
	mickey	3
	mickey	4	rare
	mickey	5	missing
	mickey	6	flood
	mickey	6	sample
	mickey	4.5	sample
	mickey	3.3	sample
	goofy	4
	goofy	6	abundant
	pluto	0	rare
	pluto	3	frequent
	pluto	5	flood
	minnie	5
	minnie	6	abundant
	scroodge	2
	scroodge	4	flood
	scroodge	6	frequent