Arctic dinoflagellate migrations mark the strongest Oligocene glaciations
Van Simaeys, S.; Brinkhuis, H.; Pross, J.; Williams, G.L.; Zachos, J.C. (2005). Arctic dinoflagellate migrations mark the strongest Oligocene glaciations. Geology (Boulder Colo.) 33(9): 709-712. dx.doi.org/10.1130/G21634.1 In: Geology. Geological Society of America: Boulder. ISSN 0091-7613; e-ISSN 1943-2682, more |  |
| Keywords | Behaviour > Migrations
Geological time > Phanerozoic > Geological time > Cenozoic > Paleogene > Palaeogene > Oligocene
Temporal variations > Long-term changes > Sea level changes
| | Author keywords | Oligocene; dinoflagellate cysts; migration; global atmospheric cooling;sea-level change; Rupelian-Chattian boundary |
| Authors | | Top | - Van Simaeys, S., more
- Brinkhuis, H., more
- Pross, J.
| - Williams, G.L.
- Zachos, J.C.
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| Abstract | Here we report on mid-Oligocene globally synchronous Arctic dinoflagellate migration events, calibrated against chron C9n. We show that sudden appearances and marked abundance increases of the Arctic taxon Svalbardella at lower and middle latitudes coincide with the Oi-2b benthic δ18O glacial episode, dated as ca. 27.1 Ma. These unprecedented migrations are taken to indicate anomalously strong surface-water cooling during Oi-2b time, in turn associated with strong concomitant Antarctic ice-sheet growth and sea-level lowering. We estimate the duration of these unique Svalbardella migrations and the associated episode of profound cooling as  500 k.y. Our records suggest a close link between this distinct Oligocene glaciation episode, strong sea-level fall, and the classic lower-upper Oligocene, or Rupelian-Chattian, boundary, dating this boundary as ca. 27.1 Ma. |
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