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Regional Studies: Stratigraphy, Tectonics and Volcanism |
Centre for Palynological Studies, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
The acritarchs, dinoflagellate cysts, algae, pollen and spores from the Harwich Formation sediments in 28 sections from southeastern England have been quantitatively studied to assist in the stratigraphic correlation of sedimentary units. Application of published zonations based on dinoflagellate cyst zonations does not enable a subdivision of the Harwich Formation to be proposed; to address this problem, quantitative palynological data has been studied to define associations which have been grouped into association sequences. Thirteen subdivisions of the Harwich Formation palynofloras have been achieved, enabling an accurate correlation of units with an c. 38 500 year duration across southeastern England. This correlation has identified two major depositional sequences, deposited during separate periods of rising relative sea level during the 54.5–54.0 Ma period. Application of the association sequence technique to three equivalent sections from the North Sea Basin and one from the eastern margin of the Wyville-Thompson Ridge, has allowed a comparison of the southeastern England onlap model with depositional sequence models proposed for the outer Moray Firth by other authors. Correct identification of the relationship of the deposits in southeastern England to the Dornoch, Balder and Sele Formations of the North Sea, and identification of the stratigraphic level of tephra layers –17 and +19, enables comments to be made about the position of the Paleocene-Eocene boundary in the North Sea.
