Palaeoceanography of the Early Cretaceous of the high latitudes (NE Greenland).
Zusammenfassung der Projektergebnisse
The aim of the project was to understand the biostratigraphic framework of North-East Greenland and to reconstruct the paleoenvironmental, paleoclimatic and paleoceanographic conditions in North-East Greenland during the Ryazanian - Hauterivian. This time interval is of special interest due to i) the elswhere occurring stable isotope event (Weissert Event), ii) a potential cold snap, iii) the presence of carbonate rich rocks in Greenland. The major results of the current project are the following: A detailed bio- and chemostratigraphic framework for the Ryazanian - Hauterivian (Early Cretaceous) of North-East Greenland has been developed. This is based on ammonites, calcareous nannofossils and Sr-isotopy. The sequences are condensed, the entire Ryazanian – Hauterivian interval is represented by ∼28m of calcareous mudstones. - The Sr-data ask for a re-calibration of the hitherto used standard Boreal calcareous nannofossil biozonation scheme. The latter was based on the highly condensed Speeton section (GB). Our data indicate a stratigraphic mismatch in the previous standard zonation. - Stable isotope data based on belemnites (δ18O) clearly suggest a cooling trend for the late Valanginian, which is paralleld by similar trends in northern Germany and France. Our δ18OBel data suggest a temperature decline of approximately 1‰ δ18O or ~4°C for ~16° latitude (39°N, northern Germany; 55° N, North-East Greenland). - It is for the first time that the Valanginian Nannoconus demise can be documented in the Boreal Realm. Coeval to its decline in the Tethys and Pacific the nannofossil genus Nannoconus disappears in Greenland. The reasons for this are seen in a climatic deterioration in the late Valanginian. - Our findings show in addition to nannoconids Tethyan faunas (belemnites - Pseudobelus; ammonites – Lytoceras, Phylloceras; brachiopods – Pygope). The occurrence of these Tethyan elements suggests the existence of a proto Golf current in the early Valanginian, which allowed Tethyan biota to spread as far north as North-East Greenland.
Projektbezogene Publikationen (Auswahl)
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2012. Early Cretaceous palaeoceanography of the Greenland–Norwegian Seaway evidenced by calcareous nannofossils. Marine Micropaleontology 90-91, 72-85
Pauly, S., Mutterlose, J., Alsen, P.
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2012. Lower Cretaceous (upper Ryazanian - Hauterivian) chronostratigraphy of high latitudes (North-East Greenland). Cretaceous Research 34, 308-326
Pauly, S., Mutterlose, J., Alsen, P.
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2013. Depositional environments of Lower Cretaceous (Ryazanian–Barremian) sediments from Wollaston Forland and Kuhn Ø, North-East Greenland. Bulletin of the Geological Society of Denmark 61, 19–36
Pauly, S., Mutterlose, J., Alsen, P.
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2013. Palaeoceanography of Lower Cretaceous (Barremian - Lower Aptian) black shales from northwest Germany evidenced by calcareous nannofossils and geochemistry. Cretaceous Research 42, 28-43
Pauly, S., Mutterlose, J., Wray, D.S.
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Integrated stratigraphy of Lower Cretaceous sediments (Ryazanian–Hauterivian) from North-East Greenland. Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 437, 1 November 2015, Pages 85-97
Möller, C., Mutterlose, J., Alsen P.
