The Oligocene represents an important time period from a wide range of perspectives and includes signifi cant climatic and eustatic variations. The pelagic succession of the Umbria-Marche Apennines (central Italy) includes a complete and continuous sequence of marly limestones and marls, with volcaniclastic layers that enable us to construct an integrated stratigraphic framework for this time period. We present here a synthesis of 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. From this study, 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. The Monte Cagnero section is a potential candidate for defi ning the Chattian Global Stratotype Section and Point (GSSP) and some reliable criteria are here proposed for marking the Rupelian/Chattian boundary according to International Union of Geological Sciences (IUGS) recommendations.
Integrated stratigraphy of the Oligocene pelagic sequence in the Umbria-Marche basin (Northeastern Apennines, Italy): A potential GSSP for the Rupelian/Chattian boundary / R.COCCIONI , S. MONECHI, A. BELLANCA , D.BICE , H.BRINKHUIS , N.CHURCH , A.DEINO , F.LIRER , A.MACALADY , P.MAIORANO , A.MARSILI , A.MCDANIEL , S.MONECHI , R.NERI , C.NINI , M.NOCCHI , J.PROSS , P.ROCHETTE , L.SAGNOTTI , M.SPROVIERI , et al.. - In: GEOLOGICAL SOCIETY OF AMERICA BULLETIN. - ISSN 0016-7606. - ELETTRONICO. - 120:(2008), pp. 487-511. [10.1130/B25988.1]
Integrated stratigraphy of the Oligocene pelagic sequence in the Umbria-Marche basin (Northeastern Apennines, Italy): A potential GSSP for the Rupelian/Chattian boundary
MONECHI, SIMONETTA;
2008
Abstract
The Oligocene represents an important time period from a wide range of perspectives and includes signifi cant climatic and eustatic variations. The pelagic succession of the Umbria-Marche Apennines (central Italy) includes a complete and continuous sequence of marly limestones and marls, with volcaniclastic layers that enable us to construct an integrated stratigraphic framework for this time period. We present here a synthesis of 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. From this study, 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. The Monte Cagnero section is a potential candidate for defi ning the Chattian Global Stratotype Section and Point (GSSP) and some reliable criteria are here proposed for marking the Rupelian/Chattian boundary according to International Union of Geological Sciences (IUGS) recommendations.
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
