The classical problem of the nature and age of the Rupelian-Chattian (Early-Late Oligocene) unconformity in its type region is here approached using organic walled dinoflagellate cyst (dinocyst) correlations between the North Sea Basin and well-calibrated central Italian (Tethyan Ocean) sections. Useful Oligocene dinocyst events are the last occurrence of Enneadocysta pectiniformis (∼29.3 Ma), and the first occurrences of Saturnodinium pansum (∼29.4 Ma), Distatodinium biffii (∼27.9 Ma) and Artemisiocysta cladodichotoma (∼26.7 Ma). The latter event marks the earliest Chattian. The improved correlations indicate that the Rupelian-Chattian (R-C) boundary is associated with the so-called 'Oligocene Glacial Maximum'. This phase of important global cooling and glacio-eustatic sea level fall is genetically related to the unconformity between the classic Oligocene stages. Subsequent global warming (so-called 'Late Oligocene Warming Event'), induced a major sea level rise, leading e.g. to the time-transgressive deposition of the typical basal Chattian glauconitic sands. The oldest of the Chattian units have a GPTS age of∼26.7 Ma. It further appears that a hiatus of ∼500 kyrs spans the classic Rupelian-Chattian unconformity.
CITATION STYLE
Van Simaeys, S. (2004). The Rupelian-Chattian boundary in the North Sea Basin and its calibration to the international time-scale. Geologie En Mijnbouw/Netherlands Journal of Geosciences, 83(3), 241–248. https://doi.org/10.1017/S0016774600020308
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