People at Fort Hoofddijk

Cornelia Köhler
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European Graduate College EUROPROX Project II-13
Mrs. C. Köhler
Paleomagnetic Laboratory
Fort Hoofddijk
Universitšt Bremen
Department of Earth Sciences, 
Utrecht University 
Budapestlaan 17, 3584 CD Utrecht 
The Netherlands 
Phone: +31 30 253 5481

Usually at:
Faculty of Geosciences (FB 5)
Bremen University
Bremen, Germany

Phone:  +49 421 218 8956 
E-mail: ckoehler@uni-bremen.de

Research
Publications
Homepage at Europrox
 


Research of Cornelia Köhler

Hematite based reconstruction of Saharan aridity and dust flux to the Mediterranean Ocean during middle to late Miocene tectonic and climatic events
Project partners:
Bremen: Tilo von Dobeneck, David Heslop, Ulrich Bleil
Utrecht: Cor Langereis, Fritz Hilgen, Wout Krijgsman
.
While the Miocene biostratigraphy of Central Mediterranean sediments has been studied in rather detail, the continental influences, in particular, the Saharan dust records of this period have not been fully investigated. It is therefore promising to apply the above proposed rock magnetic and voltammetric techniques for characterizing and quantifying hematite and goethite also to some selected Miocene time slices, in combination with state-of-the-art environmental magnetic methods. 

Satellite image of the Sahara
Trubi marls at Punta di Maiata, Sicily
For an early time slice at around 13 - 14 Ma encompassing the closure of the Indian Ocean gateway, suitable marine land sections crop out in Malta (Blue Clay Formation), at the Tremiti Islands (Cretaccio Formation) and in south-eastern Sicily (Tellaro Formation). All three sections show lithological cyclicity, partially overlap and confine an interval of about 3 million years from 13.5 Ma (earliest Serravallian) to 10.5 Ma (early Tortonian). The astronomical calibration based on abundance fluctuations of Globigerinoides spp. and CaCO3 content provides an absolute age for several calcareous nannofossil and planktonic foraminiferal bioevents throughout the interval. 

For a second time slice at around 7 - 8 Ma enclosing the Tortonian saliniy crisis, the Metochia section on Gavdos (off Crete), the northern Italian marine Monte dei Corvi section and the Sicilian Monte Gibliscemi section seem appropriate. While the organic-rich sapropel layers are probably too intensely overprinted to yield information on iron oxide mineral content, the more oxic marl layers will be preferentially investigated. Dated samples from all these sections are available at our Dutch partners, but some additional field work may be appropriate at a more advanced stage of this study.

publications Publications of Cornelia Köhler
2008
  • Köhler, C.M., Heslop, D., Dekkers, M.J., Krijgsman, W., van Hinsbergen, D.J.J. and von Dobeneck, T. (2008). Tracking provenance change during the late Miocene in the eastern Mediterranean using geochemical and environmental magnetic proxies, Geochemistry, Geophysics, Geosystems, in  press