Atypische tropische Karbonate als Klima-Archive

• Applicant: Professorin Dr. Hildegard Westphal
• Subject Area: Palaeontology
• Term: from 2005 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5452403

• Final Report Year: 2011

Final Report Abstract

The present study has strongly changed the understanding of carbonate production controls under eutrophic conditions. These findings have implications for the paleotemperature and paleodimatic interpretations of heterozoan carbonates. The main conclusions are: - The complex sediment distribution of the Golfe d'Arguin (N Mauritania) results from an important sediment reworking and transport that are primarily controlled by hydrological patterns such as the swell and wind-driven currents. - The modem sedimentation of the northern Mauritanian shelf shows that heterozoan carbonates not only form in cool and cold waters but are produced under eutrophic tropical marine environments. This outcome differs from classical carbonate grain association models based on water temperature. - Taxonomy and ecology are the keys to interpret the paleoenvironments of heterozoan carbonate production. Heterozoan carbonate associations yield a wealth of multiparameter environmental information that needs to be included into meaningful paleoenvironmental interpretation. While this finding is far from being new, it has gained new significance on the background of the common practice of focusing on temperature interpretations.

Publications

• 2009. Sediment partitioning and winnowing in a mixed eolian-marine system (Mauritanian shelf). Geo Marine Letters, 29, 221-232. Geo-Marine Letters, Vol. 29. 2009, Issue 4, pp 221–232.
  Michel, J-, Westphal, H., Hanebuth, T.
  
• 2010. Heterozoan carbonate sedimentation on a eutrophic, tropical shelf of Northwest Africa (Golfe d'Arguin, Mauritania). Dissertation, Universität Bremen: Geowissenschaften, 2010, 142 S.
  Michel, J.
  
• 2010. Heterozoan carbonates in subtropical to tropical settings in the present and past. International Journal of Earth Sciences, Vol. 99. 2010, Supplement 1, pp 153–169.
  Westphal, H., Halfar, J., Freiwald, A.
  
• 2011. Modern heterozoan carbonates from a eutrophic tropical shelf (Mauritania). Journal of Sedimentary Research, Vol. 81. 2011, Issue 9, 641-655.
  Michel, J., *Mateu-Vicens, G., Westphal, H.
  
• 2011. The mollusk fauna of soft sediments from the tropical, upwelling-influenced shelf of Mauritania (NW Africa). Palaios. Palaios, Vol. 26. 2011, issue 7, pp. 447-460.
  Michel, J., Westphal, H., v. Cosel, R.