Academic Commons

Articles

Toward a Revised Paleogene Geochronology

Berggren, William A.; Kent, Dennis V.; Obradovich, John D.; Swisher, Carl C.

New information has become available that requires a revision of Paleogene chronology incorporated in most current Cenozoic time scales. Age estimates for the limits of the Paleogene (the Oligocene/Miocene and Cretaceous/Paleogene boundaries) have not changed appreciably and remain at about 24 Ma and about 66 Ma, respectively. However, new radioisotope data indicate that boundaries of subdivisions within the Paleogene are generally younger than previously estimated, for example, the Paleocene/Eocene and Eocene/Oligocene, by about 2 to 3 m.y. We review the current status of magnetobiostratigraphic correlations and new radioisotope data, with particular reference to late Eocene~early Oligocene geochronology and provide a reassessment of the age of the Eocene/Oligocene boundary as 34 Ma. We anticipate that with concurrent work on a fundamental revision of the geomagnetic polarity sequence, a comprehensive and detailed new time scale for the Cenozoic will soon be developed.

Files

Also Published In

Title
Eocene-Oligocene Climatic and Biotic Evolution

More About This Work

Academic Units
Lamont-Doherty Earth Observatory
Publisher
Princeton University Press
Published Here
January 30, 2012
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.