Isotopic evidence of cool winter conditions in the mid-Piacenzian (Pliocene) of the southern North Sea Basin
Valentine, A.; Johnson, A.L.A.; Leng, M.J.; Sloane, H.J. (2011). Isotopic evidence of cool winter conditions in the mid-Piacenzian (Pliocene) of the southern North Sea Basin. Palaeogeogr. Palaeoclimatol. Palaeoecol. 309(1-2): 9-16. dx.doi.org/10.1016/j.palaeo.2011.05.015
In: Palaeogeography, Palaeoclimatology, Palaeoecology. Elsevier: Amsterdam; Tokyo; Oxford; New York. ISSN 0031-0182; e-ISSN 1872-616X, meer
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| Trefwoorden |
Phanerozoic > Geological time > Cenozoic > Tertiary > Cenozoic > Neogene > Pliocene > Piacenzian
Bivalvia [WoRMS]; Dinoflagellata [WoRMS]
Marien/Kust |
| Author keywords |
Palaeoclimate; Pliocene; Mid-Piacenzian; Sclerochronology; Oxygenisotopes; Bivalves |
| Auteurs | | Top |
- Valentine, A.
- Johnson, A.L.A.
- Leng, M.J.
- Sloane, H.J.
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| Abstract |
Oxygen isotope thermometry of Aequipecten opercularis and Atrina fragilis bivalves (which demonstrate all-year growth), provides quantitative evidence of cool-temperate winter conditions (below 10 °C) during deposition of the mid-Piacenzian Oorderen Sands and time-equivalent strata in the southern North Sea Basin (SNSB). Isotopic summer temperatures (seafloor) are within or only marginally above, the cool-temperate range (upper limit 20 °C). The occurrence of warm-temperate dinoflagellate cysts alongside (and presumably contemporaneous with) the bivalves, indicates the development of a correspondingly warm surface layer in summer (encystment allowing the dinoflagellates to survive cool winter conditions).This evidence of greater surface seasonality than now is consistent with greater global warmth and a reduction in the vigour of the Gulf Stream/North Atlantic Drift (GS/NAD), leading to a reduced supply of winter heat. This reduction in GS/NAD strength may be linked to breaching of the emerging Isthmus of Panama. |
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