Terrestrische Ökosystem- und Klimadynamik während des "Paleocene-Eocene Thermal Maximum" (~56 Ma) in den hohen südlichen Breiten: Eine integrierte palynologisch/organisch-geochemische Studie des Profils von Margaret Point, Südaustralien
Zusammenfassung der Projektergebnisse
The Paleocene-Eocene Thermal Maximum (PETM; ~56 Ma) is characterized by geologically rapid global warming of ~5 °C over a few thousand years and provides an important paleoanalog for anthropogenic climate change. Current knowledge of terrestrial ecosystem response to the PETM is largely based on the mid-latitudes of the Northern Hemisphere. To more fully reconstruct global terrestrial ecosystem response to the PETM, we generated vegetation and biomarker proxy records from an outcrop section at Point Margaret in southern Australia (Victoria; ~60 °S paleolatitude) – a region for which limited data currently exist. We document a rapid, massive, and sustained vegetation turnover as a response to regional PETM warming of ~3–4 °C, abruptly transitioning from a warm temperate to a mesomegathermal rainforest similar to that of present-day northeastern Queensland (Australia). Within the vegetation-turnover interval, a fern-spore peak suggests a brief stage of disturbed vegetation cover. The onset of the vegetation change leads the characteristic PETM carbonisotope excursion by ~1–4 kyrs. The reconstructed ecosystem change at Point Margaret is much stronger than in other Southern Hemisphere records due to differences in biogeographical and paleoceanographic boundary conditions, highlighting both the regional specificity of terrestrial ecosystem response and the need for a greater geographic coverage to fully understand terrestrial ecosystem response to PETM climate forcing.
Projektbezogene Publikationen (Auswahl)
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Identification of the Paleocene–Eocene boundary in coastal strata in the Otway Basin, Victoria, Australia. Journal of Micropalaeontology, 37(1), 317-339.
Frieling, Joost; Huurdeman, Emiel P.; Rem, Charlotte C. M.; Donders, Timme H.; Pross, Jörg; Bohaty, Steven M.; Holdgate, Guy R.; Gallagher, Stephen J.; McGowran, Brian & Bijl, Peter K.
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Rapid expansion of meso-megathermal rain forests into the southern high latitudes at the onset of the Paleocene-Eocene Thermal Maximum. Geology, 49(1), 40-44.
Huurdeman, E.P.; Frieling, J.; Reichgelt, T.; Bijl, P.K.; Bohaty, S.M.; Holdgate, G.R.; Gallagher, S.J.; Peterse, F.; Greenwood, D.R. & Pross, J.
