Annual Report 2011 of the Rupelian/Chattian Boundary Stratotype Working Group

The formal proposal of the GSSP for the Rupelian/Chattian boundary at the Monte Cagnero section (Umbria-Marche basin, NE Apennines, Italy) is in progress under the leadership of R. Coccioni and A. Montanari, two of the co-authors of the published paper in which the proposal was put forward.

Report by Isabella Premoli Silva, Chairwoman.

Annual Report 2010 of the Rupelian/Chattian Boundary Stratotype Working Group

The formal proposal of the GSSP for the Rupelian/Chattian boundary at the Monte Cagnero section (Umbria-Marche basin, NE Apennines, Italy) is in progress under the leadership of R. Coccioni and A. Montanari, two of the co-authors of the published paper in which the proposal was put forward. The following paper was published:

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.

Report by Isabella Premoli Silva, Chairwoman.

Annual Report 2009 of the Rupelian/Chattian Boundary Stratotype Working Group

The formal proposal of the GSSP for the Rupelian/Chattian boundary at the Monte Cagnero section (Umbria-Marche basin, NE Apennines, Italy) is in progress under the leadership of R. Coccioni and A. Montanari, two of the co-authors of 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", published on the GSA Bulletin v. 120 in 2008.

Report by Isabella Premoli Silva, Chairwoman.

Annual Report 2008 of the Rupelian/Chattian Boundary Stratotype Working Group

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. The formal proposal to be submitted to the Subcommission is in preparation.
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.

Report by Isabella Premoli Silva, Chairwoman



Annual Report 2007 of the Rupelian/Chattian Boundary Stratotype Working Group

Tasks of the Italian scientific community were to search for GSSPs of the Lower-Upper Oligocene Transition. Investigations on both transitions have been undertaken by a number of researchers from several Italian Universities (i.e. Padua, Ferrara, Urbino, Milan) and CNR Institutes as well as from some European and USA Universities and Institutions of the “ALANO NET” and by the numerous scientists of the OLIS Working Group coordinated by Coccioni (University of Urbino).
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 accepted for publication (after several revisions) on the Geological Society of America Bulletin in September 2007. Following this acceptance the formal proposal designating the Monte Cagnero (MCA) section as GSSP for the Rupelian/Chattian boundary, out of the three sections studied, is in preparation.

Report by Isabella Premoli Silva, Chairwoman

Annual Report 2006 of the Rupelian/Chattian Boundary Stratotype Working Group

A revised version of 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 re-submitted to the Geological Society of America Bulletin in January 2006. This version was returned to the first author at the end of August for a second revision which is presently underway. The new further revised manuscript will be re-submitted to the GSA Bulletin by next November in the hope it will be accepted for publication.
This long revision process delaied considerably the preparation of the formal proposal designating the Monte Cagnero (MCA) section, out of the three sections studied, as GSSP for the Rupelian/Chattian boundary.

Report by Isabella Premoli Silva, Chairwoman.

Annual Report 2005 of the Rupelian/Chattian Boundary Stratotype Working Group

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, submitted to the Geological Society of American Bulletin for publication, was peer-reviewed. The first author and few co-authors are presently preparing the final manuscript to be resubmitted to the GSA Bulletin for acceptance.
The revision of the manuscript delaied considerably the preparation of the formal proposal designating the Monte Cagnero (MCA) section, out of the three sections studied, as GSSP for the Rupelian/Chattian boundary.

Tasks of the Italian scientific community were to search for GSSPs of the Middle-Upper Eocene and Lower-Upper Oligocene Transitions. Investigations on Middle-Upper Eocene and Lower-Upper Oligocene Transitions. tasks of the Italian scientific community, have been undertaken by a number of researchers from several Italian Universities and CNR Institutes (i.e. Padua, Ferrara, Urbino, Milan), as well as from some European and USA Universities and Institutions of the “ALANO NET” and by the numerous scientists of the OLIS Working Group coordinated by Rio (University of Padua) and Coccioni (University of Urbino), respectively.

Report by Isabella Premoli Silva, Chairwoman.

Annual Report 2004 of the Rupelian/Chattian Boundary Stratotype Working Group

Investigations on the Lower-Upper Oligocene Transition are the subject of a paper, submitted to the Geological Society of American Bulletin, 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, and presently under revision after peer reviews.

Complete and continuous sequences of fossiliferous marine rocks covering the Oligocene Epoch and exposed on land are rare, making it difficult to define cause-and-effect relationships of palaeoenvironmental changes in an accurate and precise chronostratigraphic framework. One exception is represented by the pelagic succession of the Umbria-Marche Apennines (central Italy) where a complete and continuous sequence of marly limestones, calcareous marls, and marls allows a detailed bio-, magneto-, and chemostratigraphic study of this Epoch. In addition, this sequence contains several biotite-rich volcaniclastic beds which provide the means for an accurate and precise radiometric calibration of the Oligocene time scale. The OLIS Working Group, including 24 scientists from several Universities and Institutions (Italy, The Netherlands, USA, Canada, France and Belgium), approached a detailed interdisciplinary stratigraphic study of the Oligocene with particular emphasis on the reconstruction of the events that characterize the Rupelian/Chattian boundary. One of the main results of such integrated stratigraphic analyses of the most representative Oligocene sections of the Umbria-Marche region is the interpolated age of 27.3 Ma (with a geochronologic uncertainty of 0.3 m.y.), for the Rupelian/Chattian boundary, located in the middle of chron C9n.2n at meter level 199 in the Monte Cagnero section, and corresponding to the P21a/P21b foraminiferal subzonal boundary. This age is approximately one million years younger than that reported in recent chronostratigraphic time scale compilations.

A formal proposal designating the Monte Cagnero (MCA) section, out of the three sections studied, as GSSP for the Rupelian/Chattian boundary is in preparation.

Investigations have been undertaken by researchers of the Universities of Padua, Ferrara, Urbino, Utrecht and Milan, and by the numerous scientists of the OLIS Working Group coordinated by Coccioni (University of Urbino), respectively.

Report by Isabella Premoli Silva, Chairwoman.