Response of terrestrial environments to short-term climate perturbations: Low-latitude signals during the mid-Cretaceous super greenhouse world (ODP Leg 207, Demerara Rise)
Zusammenfassung der Projektergebnisse
The main project results comprise: • the development of a new approach of evaluating the thermal alteration of sporomorphs based on a mid-Cretaceous succession from ODP Site 1276 (Newfoundland margin). Although originally not in the focus of the proposed project, these efforts resulted in a publication on a new approach of visually assessing sporomorph colours to determine thermal alteration. • the confirmation of a significant cooling connected to the formation of OAE 2 that likely acted as a consequence of atmospheric CO2 drawdown resulting from the burial of organic matter. • the detection of a strong increase in the latitudinal SST gradient in the proto-North Atlantic during OAE 2 formation, suggesting a strong coupling between pCO2 and latitudinal thermal gradients under greenhouse climate conditions. • the finding of a a decrease (as opposed to a traditionally expected increase) in terrestrial input coinciding with OAE 2 formation at ODP Site 1276 (Newfoundland Margin). • the generation of a marine palynomorph dataset across the OAE 2 interval at Wunstorf, N Germany, with the dinocyst signal suggesting pronounced changes in sea-level and surface-water salinity. Hence, the project yielded answers to the questions (2) [testing the hypothesis of a significant pCO2 drawdown connected to OAE 2 formation] and (3) [assessing terrestrial input into the marine realm during OAE 2 formation] as formulated in the original proposal. Unfortunately, the project failed in providing answers to the originally formulated research questions (1) [Identifying potential terrestrial climatic perturbations connected to OAE 2 formation] and (4) [Identifying potential leads and lags between environmental signals from the terrestrial and marine realms during OAE 2 formation].
Projektbezogene Publikationen (Auswahl)
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2005. Terrestrial response to short-term climate perturbations: Low-latitude signals during the mid-Cretaceous supergreenhouse world (ODP Leg 207, Demerara Rise). Scientific Program and Abstracts, Seventh Symposium on the Cretaceous, 05.-09.09.2005, Neuchâtel, Switzerland, p. 192- 193
Schellenberg, F., Pross, J., Erbacher, J., Friedrich, O.
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2005. Thermal alteration of terrestrial palynomorphs in sediments intruded by igneous sills (Newfoundland Margin, ODP Hole 1276A). ODP Leg 210 Postcruise Meeting, 22.-28.08.2006, Briançon, France
Schellenberg, F., Pross, J., Pletsch, T., Ligouis, B.
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2007. Thermal alteration of terrestrial palynomorphs in mid-Cretaceous organic-rich mudstones intruded by an igneous sill (Newfoundland Margin, ODP Hole 1276A). International Journal of Coal Geology 70, 277-291
ross, J., Pletsch, T., Shillington, D.J., Ligouis, B., Schellenberg, F., Kus, J.
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2010: CO2-driven cooling and increased latitudinal temperature gradient during the mid-Cretaceous Oceanic Anoxic Event 2. Earth and Planetary Science Letters 293, 97-103
Sinninghe Damsté, J.S., van Bentum, E., Reichart, G.J., Pross, J., Schouten, S.
