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Danian
(Cretaceous/Paleogene boundary):
The GSSP for the base of the Danian was defined in the El Kef
Section (Tunisia) and ratified by the IUGS in 1991. However, this
GSSP was not officially published in a prestigious stratigraphical
journal of wide distribution. Only a short note was published
in Episodes by Cowie et al. (1989), in a report on activities
of the ICS from 1984 to 1989. Since this time, some problems arose
because the detailed proposal was unknown to many scientists working
on the K/Pg boundary, new sections in Mexico were found and controversial
interpretations were proposed. Therefore, in order to resolve
these problems, the ICS has required the ISPS to finally publish
the proposal. The chairman of ISPS (E.Molina) in collaboration
with Tunisian colleagues visited the GSSP at El Kef again, in
order to put in place an artificial marker ("golden spike"),
and to request the Tunisian authorities to protect the site. At
the same time, the present status of the site has been documented
by a series of photographs. Finally, it was officialy published:
Molina E., Alegret L., Arenillas I., Arz JA., Gallala N., Hardenbol
J., Von Salis K., Steurbaut E., Vandenbeghe N. & Zaghbib-Turki
D. (2006). The Global Boundary Stratotype Section and Point for
the base of the Danian Stage (Paleocene, Paleogene, "Tertiary",
Cenozoic) at El Kef, Tunisia: original definition and revision.
Episodes, 29(4), 263-273.
[Download PDF]
GSSP for the base of the Danian Stage (K/Pg) at El Kef section,
Tunisia
Selandian and Thanetian:
The Paleocene Working Group was commissioned by the International
Subcommission on Paleogene Stratigraphy in 1993 to define Global
Stratotype Sections and Points (GSSP’s) for the bases of
the Selandian and Thanetian stages. After 14 years of research
the time was ripe to conclude the activities, and a meeting was
held in Zumaia, Spain, from June 19 to 20, 2007, to discuss the
stage GSSPs and to decide whether it is possible to reach a decision
on the Paleocene stages. The meeting was attended by 23 scientists,
including a majority of the scientists that participated in the
founding meeting in 1993 in Göteborg, Sweden (Schmitz, 1994).
In addition participated an important group of younger researchers
having taken up this research path later. After constructive discussions
during two days the attending scientists held a vote that gave
the unanimous result that the GSSP’s for the Paleocene stages
shall be placed in the Zumaia section in Spain. The Danian/Selandian
boundary is placed at the base of the Itzurun Formation in the
Zumaia section at San Telmo Beach. The Selandian/Thanetian is
placed at the base of magnetochron 26n in the same section. A
detailed voting document for the International Subcommission on
Paleogene Stratigraphy was prepared by Schmitz et al. The proposal
has been approved by the International Subcommission on Paleogene
Stratigraphy, by the International Commission on Stratigraphy
and has been ratified by the International Union of Geological
Sciences in September 23, 2008.
Upper Danian (right), Selandian and lower Thanetian (left)
at the Zumaya section, Spain
Selandian/Thanetian (left) and Danian/Selandian (right) boundaries
at Zumaya
Ypresian (Paleocene/Eocene boundary):
The Working Group has successfully completed its task and proposed
to place the GSSP for the base of the Eocene Series in the Dababiya
Section near Luxor in Upper Egypt. The GSSP is located at the base
of the Carbon Isotope Excursion which has been selected as the criterion
for the recognition of the Paleocene/Eocene boundary in 2002. The
proposed boundary section has a good chemostratigraphic (stable
isotopes) and biostratigraphic record. The "Benthic Foraminiferal
Extinction Event", the peculiar planktonic foraminiferal and
calcareous nannoplankton assemblages linked to the Initial Eocene
Thermal Maximum are well represented in connection with the Carbon
Isotope Excursion. The proposal for this GSSP has been accepted
by the Voting Members of ISPS and ICS. Finally, it have been ratified
by IUGS. A complete documentation of the proposed GSSP and the official publication by Aubry
et al. (2007) was published in Episodes.
GSSP for the Paleocene/Eocene boundary at Dababiya, Egypt
Lutetian:
The Working Group had investigated sections in Italy,
Israel, Tunisia, Morocco, Mexico and Argentina, but unfortunately
none of them was a good candidate. In Spain many sections were visited
and sampled in the Betic Cordilleras (Alamedilla, Agost, Fortuna,
etc.) and in the Pyrennees (Anoz, Campo, Gorrondatxe, Guetaria,
etc.). Most of these Pyrennean sections are not ideal and plagued
with hiatuses, restricted facies, tectonic complications and other
problems...
Lately, the research was focused on the study of the two more
suitable sections to define the Lutetian GSSP: Agost and Gorrondatxe
sections in Spain. The results of both sections show that the different events
traditionally used to place the Ypresian/Lutetian boundary, previously
thought to be almost simultaneous, actually occur at very different
levels. The more close events to the base of the original Lutetian
stage seem to be the first occurrence of the calcareous nannofossil
Blackites inflatus at the base of Subzone CP12b and the
first occurrence of the planktic foraminifera Turborotalia frontosa.
The integrated magnetobiostratigraphic studies carried out at the
Agost and Gorrondatxe sections provides conclusive evidence that
both sections are almost continuous and contain diverse and well-preserved
fossil groups. However, the Gorrondatxe section was considered to be more
suitable than the Agost section.
The GSSP for the base of the Lutetian Stage (early/middle Eocene boundary) was defined at 167.85 meters in the Gorrondatxe sea-cliff section (NW of Bilbao city, Basque Country, northern Spain; 43º22'46.47" N, 3º 00'
51.61" W). This dark marly level coincides with the lowest occurrence of the calcareous nannofossil Blackites
inflatus (CP12a/b boundary), is in the middle of polarity Chron C21r, and has been interpreted as the maximum flooding surface of a depositional sequence that may be global in extent. The GSSP age is approximately 800 kyr
(39 precession cycles) younger than the beginning of polarity Chron C21r, or ~47.8 Ma in the GTS04 time
scale. The proposal was approved by the International Subcommission on Paleogene Stratigraphy in February
2010, approved by the International Commission of Stratigraphy in January 2011, and ratified by the International
Union of Geological Sciences in April 2011. The official publication by Molina et al. (2011) is in press in Episodes.
Chairman: Eustoquio
Molina, Spain
Secretary: Silvia Ortiz, Spain
For
more information visit the Website
Bartonian:
The Working Group in charge of the search of this GSSP is directed by R.Fluegeman (Ball
State University). Until now, work has concentrated on sections
in the Caribbean and the southeastern U.S.A. No prospective candidate
sections have been found yet, but the section along the Contessa
Highway near Gubbio, Italy is the leading candidate for the GSSP
for the base of the Bartonian Stage.
Chairman: Richard Fluegeman,
USA
Priabonian:
The Alano di Piave section (Veneto region, NE Italy) is de leading
candidate for defining the GSSP for the Middle/Upper Eocene, equated
to the base of the Priabonian Stage. Calcareous plankton (nannofossils
and foraminifera) high-resolution quantitative biostratigraphies
have been completed and correlated to magnetostratigraphy and to
oxygen and carbon stable isotopes across the critical interval,
while dinocyst biostratigraphical and benthic foraminiferal studies
are close to completion.
During 2008 studies on the Alano di Piave section (Veneto region,
NE Italy), the potential candidate for defining the GSSP of the
Middle/Upper Eocene, equated to the base of the Priabonian Stage,
are basically completed. Calcareous plankton (nannofossils and foraminifera)
high-resolution quantitative biostratigraphies are now well correlated
to magnetostratigraphy and to oxygen and carbon stable isotopes
across the critical interval. Dinocyst biostratigraphical and benthic
foraminiferal studies are close to completion. A paper on integrated
multiple stratigraphies of the Alano di Piave section is in progress
and should be submitted soon for publication.
Chairwoman: Isabella Premoli
Silva, Italy
Rupelian (Eocene/Oligocene boundary):
The GSSP for this boundary was selected in the Massignano Section
(central Italy), ratified by the IUGS in 1992 and officially published
by Premoli Silva and Jenkins (1993) in Episodes.
The GSSP for the Eocene/Oligocene boundary at the Massignano
section, Italy
Chattian:
The paper on “Integrated stratigraphy of the Oligocene pelagic
sequence in the Umbria-Marche basin (Northeastern Apennines, Italy):
A potential GSSP for the Rupelian/Chattian boundary” by Coccioni
and others, was finally published on the Geological Society of America
Bulletin in April 2008. The paper synthetises the detailed biostratigraphic,
magnetostratigraphic, and chemostratigraphic studies, along with
geochronologic results from several biotite-rich volcaniclastic
layers, which provide the means for an accurate and precise radiometric
calibration of the Oligocene time scale. The interpolated ages for
the Rupelian/Chattian stage boundary, located in the upper half
of Chron 10n at meter level 188 in the Monte Cagnero section, and
corresponding to the O4/O5 planktonic foraminiferal zonal boundary,
are 28.36 Ma (paleomagnetic interpolation), 28.27 ± 0.1 Ma
(direct radioisotopic dating), and 27.99 Ma (astrochronological
interpolation). These ages appear to be slightly younger than those
reported in recent chronostratigraphic time scale compilations.
At the end of the article the authors designated the Monte Cagnero
(MCA) section, out of the three sections studied, as the best GSSP
candidate for the Rupelian/Chattian boundary.
Coccioni R., Marsili A., Montanari A., and Others, 2008. Integrated
stratigraphy of the Oligocene pelagic sequence in the Umbria-Marche
basin (northeastern Apennines, Italy): A potential Global Stratotype
Section and Point (GSSP) for the Rupelian/Chattian boundary. GSA
Bulletin, v. 120; no. 3/4, p. 487–511, 17 figures, 4 tables.
doi: 10.1130/B25988.1.
The formal proposal to be submitted to the Subcommission is in preparation.
Chairwoman: Isabella
Premoli Silva, Italy
b) Other Working Groups and Regional Committees:
Paleogene Planktonic Foraminifera Working Group
Chairwoman: Birdget Wade, USA
Secretary: Helen Coxall, UK
Paleogene Larger Foraminifera Working Group
Chairman: Lukas Hottinger, Switzerland
Paleogene Deep-Water Benthic Foraminifera Working Group
Chairman: Michael Kaminski, UK
Secretary: Laia Alegret, Spain
Paleogene Calcareous Nannofossils Working Group
Chairwoman: Simonetta Monechi, Italy
Working Group on Paleogene Stratigraphy of the North Pacific
Chairman: Yuri.B.Gladenkov,
Russia.
Regional Committee on North-European Paleogene Stratigraphy
Chairwoman: Gitte Vestegaard Laursen, Norway
Secretary: Rui.da-Gama, Netherlands
South American Regional Committee on Paleogene Stratigraphy
Chairman:Juan Carlos Silva. Colombia
Secretary: Carlos Jaramillo, Panama
For more information visit the website:
http://striweb.si.edu/jaramillo/committee/index.html
Russian Paleogene Commission
Chairman: Mikhail A.Akhmetiev
Secretary: G.N. Aleksandrova
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