Stijn De Schepper Ph.D
Phone +49 (0)421 218 3974
Postdoctoral researcher at the Historical Geology and Palaeontology Research Group of the Geosciences Department at the University of Bremen (Germany) and the International Graduate College – Proxies in Earth History (Europrox). Europrox is an interuniversity initiative with the main aim to understand the history of natural variability of biological and physical processes and their impact on climate and oceans.
Stijn's research at Europrox focuses on establishing environmental proxies based on dinoflagellate cysts. The validity and utility of dinoflagellate cyst indices as proxies for sea-surface temperature are tested via direct calibration to isotope records. The period of interest is the Pliocene and Pleistocene, where specific time-intervals are selected for detailed study in order to improve understanding of climate variability and associated variations in the palaeoceanography of the North and South Atlantic Ocean.
PhD Dissertation title
Plio-Pleistocene dinoflagellate cyst biostratigraphy and palaeoecology of the eastern North Atlantic Ocean and southern North Sea Basin.
Supervisors: P.L. Gibbard (University of Cambridge) and M.J. Head (Brock University, Canada).
This study provides an independently calibrated high-resolution dinoflagellate cyst biostratigraphy for Plio-Pleistocene (4.0–0.5 Ma) deposits recovered from eastern North Atlantic Deep Sea Drilling Project (DSDP) Hole 610A. The age model, which is largely tied to marine isotope stratigraphy and magnetostratigraphy, has been revised for the lower part of the hole using new data on the range of the calcareous nannofossil Reticulofenestra pseudoumbilicus.
The present study has yielded a rich and diverse dinoflagellate cyst record, which includes several range bases and tops within the studied interval. The highest and/or lowest occurrences of 23 species were recognised in DSDP Hole 610A and calibrated to the newly defined age model using graphic correlation. A dinoflagellate cyst biozonation with eleven interval zones and one acme subzone have also been erected.
The first signs of intense climatic cooling occur at Marine Isotope Stage (MIS) M2 (3.3 Ma, Pliocene), where ice-rafted detritus is recognised in Hole 610A for the first time. Within a short interval spanning this event, dinoflagellate cysts and the _18O-record from the planktonic foraminifer Globigerina bulloides have been examined from the same samples in order to obtain a directly calibrated dinoflagellate cyst-based temperature index. Several other environmental indices (e.g. productivity, flux or transport indices) were calculated from the dinoflagellate cyst record as a means to interpret the palaeoecological variability within MIS M2. Multivariate and cluster analysis were applied to distinguish between cold, warm and intermediate assemblages. Palaeo-autecological data on individual extinct species were also obtained using multivariate analysis.
The same palaeoecological techniques have then been applied to the entire Plio-Pleistocene section. A cooling of the climate is reflected by a decrease in the number of species, which starts from c. 3.0 Ma onwards. Heat transport to the north via the North Atlantic Current (NAC) is apparently reflected also in the abundance of Operculodinium centrocarpum sensu Wall and Dale (1996). At around 2.85 and 2.7 Ma, peaks in this species' abundance may reflect increased NAC heat transport associated with the closure of the Isthmus of Panama.
The most significant changes in the dinoflagellate cyst flora occur in the Gelasian Stage, coincident with the intensification of the Northern Hemisphere glaciations. In this interval, the cool-tolerant Habibacysta tectata is the dominant species, reflecting an important ocean-wide reorganisation. A possible explanation could be the cessation of warm surface-water transport to northern latitudes via the NAC and an associated halt in deep-water production in the Greenland–Norwegian Seas.
Biostratigraphic data collected from the North Atlantic has been successfully applied to the Pliocene deposits of the southern North Sea Basin. Here, the Tunnel-Canal Dock (Antwerp, northern Belgium) section yielded diverse dinoflagellate cyst assemblages. Dinoflagellate cysts, and also pollen, clearly indicate a Pliocene age from both biostratigraphic and palaeoecological evidence. The study firmly places the Kattendijk Formation within the Zanclean Stage, whereas the Lillo Formation belongs to the Piacenzian Stage of the Pliocene. Additional sequence stratigraphic evidence has placed even more accurate age constraints on these lithostratigraphic units. Palaeoecological information from dinoflagellate cysts shows that deposition of both Pliocene units occurred in progressively shallowing neritic environments under (warm-)temperate conditions, prior to cooling associated with the onset of the Northern Hemisphere glaciations.
Finally, taxonomic progress on dinoflagellate cysts, acritarchs and marine incertae sedis from the eastern North Atlantic and the southern North Sea Basin has resulted in the recognition of numerous new taxa from both regions.
- Neogene and Quaternary dinoflagellate cyst biostratigraphy.
- Combining palynology with isotope studies to reconstruct Pliocene and Early Pleistocene palaeoceanography for the Atlantic Ocean and to improve understanding of climate variability and variations in the thermohaline circulation.
- Understanding the mechanisms and consequences associated with the onset of the Northern Hemisphere glaciations at the Plio-Pleistocene transition.
- Establishing dinoflagellate cyst sea-surface temperature indices for the Pliocene and Quaternary. Reconstructing Atlantic sea-surface temperature, salinity, sea ice-cover and productivity during the Pliocene and Quaternary, when the important climatic shifts towards the glacial-interglacial oscillations occurred.
- Unravelling the environmental significance of extinct dinoflagellate cyst species, so they can be applied for quantitative environmental analysis in pre-Quaternary times.
- Silurian Chitinozoa biostratigraphy of the Brabant Massif.
Stijn holds a BSc and MSc degree in Geology (Palaeontology) from Ghent University, where he studied between 1996 and 2000. During the final year, he wrote his dissertation at the Research Unit Paleontology of Ghent University. The following year, he was a student at the University of Liège, where he obtained the Interuniversity Master's Degree in Plant Micropalaeontology and Palynology with greatest distinction. His dissertation "Pliocene organic phytoplankton from Doel, northern Belgium: biostratigraphy and palaeoecology" was based on a dinoflagellate cyst study from the Deurganckdok in Doel. In 2002, he was briefly employed as a geologist with a dredging company from Belgium.
Stijn was a PhD student in the Quaternary Palaeoenvironments Group from October 2002 to July 2006 and was funded by the Gates Cambridge Trust. He successfully defended his thesis this year and was awarded his PhD on Saturday 23 July 2006. He will continue as a Post-doctoral researcher at the University of Bremen, in Germany from October 2006.
De Schepper, S. and Head, M. J. (in prep.). Age calibration of dinoflagellate cyst and acritarch events in the Plio-Pleistocene of the eastern North Atlantic (DSDP Hole 610A).
De Schepper, S. and Head, M. J. (submitted). New dinoflagellate cyst and acritarch taxa from the Pliocene and Pleistocene of the eastern North Atlantic (DSDP Site 610). Journal of Systematic Palaeontology.
Louwye, S., De Schepper, S., Laga, P. and Vandenberghe, N., 2006. The Upper Miocene at the southern North Sea Basin, a palaeoenvironmental and stratigraphic reconstruction with dinoflagellate cysts. Geological Magazine.
De Schepper, S., Head, M.J. & Louwye, S., 2004. New dinoflagellate cyst and incertae sedis taxa from the Pliocene of northern Belgium, southern North Sea Basin. Journal of Paleontology 78(4), 625-644. Abstract.
Louwye, S., Head, M.J. & De Schepper, S., 2004. Palaeoenvironment and dinoflagellate cyst stratigraphy of the Pliocene in northern Belgium at the southern margin of the North Sea Basin. Geological Magazine 141(3), 353-378. Abstract.
Vandenberghe, N., Herman, J., Laga, P., Louwye, S., De Schepper, S., Vandenberghe, J., Bohncke, S.J.P., Konert, M., 2001. The stratigraphic position of a tidal clay deposit at Grobbendonk (Antwerp province, Belgium). Geologica Belgica 3/3-4, pp. 405-417. Imprinted 2000.
De Schepper, S., 2001. Mapping, lithostratigraphy and biostratigraphy with Chitinozoa from the Silurian type-sections in the Orneau Valley (Brabant Massif). Geologica Belgica 3/1-2, pp. 126-129. [Imprinted 2000].
De Schepper, S. and Head, M.J., 2006. Plio-Pleistocene dinoflagellate cyst biostratigraphy and palaeoecology of the eastern North Atlantic (Rockall Trough). The 2006 international workshop on dinoflagellates and their cysts: their ecology and databases for palaeoenvitonmental reconstructions (Copenhagen, 10–12 November).
De Schepper, S., Head, M.J. & Louwye, S., 2004. New dinoflagellate cyst and incertae sedis taxa from the Pliocene of northern Belgium, southern North Sea Basin. Polen, vol. 14. XI International Palynological Congress, Granada, Spain, 4-9 July 2004.
De Schepper, S., Head, M.J. & Louwye, S., 2003. Pliocene dinoflagellates from Belgium: sequence stratigraphic interpretations and a refined taxonomy. American Association of Stratigraphic Palynologists Annual Meeting 5-8 October 2003, St. Catherines (ON), Canada.
Louwye, S., Head, M.J. & De Schepper, S., 2002. Age and palaeoenvironments of a shallow marine Pliocene sequence in northern Belgium revealed by dinoflagellate cyst stratigraphy. Annual Meeting of the Palaeontological Association, Cambridge, UK, 15th -18th december 2002.
Louwye, S., Head, M.J. & De Schepper, S., 2002. Dinoflagellate cyst stratigraphy of a shallow marine Pliocene sequence in northern Belgium - southern North Sea Basin. Excursiegids Nederlands - Belgische Palynologendagen, 26 September 2002, 1p.
Louwye, S., Head, M.J. & De Schepper, S., 2002. Dinoflagellate cyst stratigraphy and palaeoenvironment of a shallow marine Pliocene sequence in northern Belgium (southern North Sea Basin). Joint meeting of the American Association of Stratigraphic Palynologists, British Micropalaeontological Society (BMS) and the North American Micropalaeontology Section of the SEPM, London, UK, 11-13 September, 2002.
De Schepper, S. & Louwye, S., 2001. Biostratigraphy with organic-walled phytoplankton and palaeoecology of a Pliocene sequence from northern Belgium (Deurganckdok, Antwerp area). 8th biannual joint meeting of the Regional Committees on Northern Neogene and Palaeogene Stratigraphy (RCNNS/RCNPS), p. 57.
De Schepper, S. and Head, M.J., 2006. New dinoflagellate cyst and acritarch taxa from the Pliocene and Pleistocene of the eastern North Atlantic (DSDP Site 610). The 2006 international workshop on dinoflagellates and their cysts: their ecology and databases for palaeoenvitonmental reconstructions (Copenhagen, 10–12 November).
De Schepper, S. and Head, M.J., 2005. Plio-Pleistocene dinoflagellate cyst biostratigraphy in the North Atlantic Ocean. Volume des Résumés, Joint Meeting APLF-TMS-LSPG, p. 41 (Paris, 3–7 October).
Louwye, S., De Schepper S., Laga, P & Vandenberghe, N., 2005.Late Miocene shoaling of the southern North Sea Basin, a palaeoenvironmental and stratigraphic reconstruction with dinoflagellate cysts, and comparison with the Mediterranean realm. 12th Congress of the Regional Committee on Mediterranean Neogene Stratigraphy, Abstract Volume, p. 153 (Vienna, 6–12 September).
Louwye, S., De Schepper, S., Laga, P. and Vandenberghe, N., 2005. The Upper Miocene at the southern North Sea Basin, a palaeoenvironmental and stratigraphic reconstruction with dinoflagellate cysts. Volume des Résumés, Joint Meeting APLF-TMS-LSPG, p. 78 (Paris, 3–7 October).
De Schepper, S., & Head, M.J., 2005. Plio-Pleistocene Dinoflagellate Cysts from DSDP Hole 610A, Eastern North Atlantic, and Biostratigraphic Application to Shallow Marine Environments. Geologic Problem Solving with Microfossils, Abstract Volume, p. 38 (Houston, Texas, 6–11 March 2005).
Workshops/Summer Field schools
- The 2006 international workshop on dinoflagellates and their cysts: their ecology and databases for palaeoenvitonmental reconstructions (Copenhagen, Denmark, November 2006).
- International short course on dinoflagellate cysts (Tübingen, Germany, May 2004).
- International short course on sequence stratigraphy given by Luis Pomar (University of the Balearic Isles) and Bilal Haq (National Science Foundation, U.S.A.) in Mallorca, Spain (June 2003).
- Two summer field school campaigns on neotectonics in the Altai Mountains of Central Siberia (Russia) and around the Yssik-Kul Lake in the Kyrgyz Republic in 1999 and 2000.