Investigators

Anton Eisenhauer, GEOMAR, Germany
Jonathan Erez, HUJI, Israel
Isabelle Taubner, GEOMAR, Germany

Goal

Determining the degree of temperature dependent Sr isotope fractionation during organic precipitation of marine carbonates

Summary

The temperature dependency of δ^88/86Sr in aragonitic corals (δ^88/86Sr ~ 0.033±0.005.T(°C)-0.94) has been shown to be more sensitive than that for inorganic aragonite (Fietzke & Eisenhauer, 2006). This difference clearly shows that results from inorganic precipitation experiments cannot unambiguously be transferred to organically precipitated carbonates due to the “vital effect” inherent to the calcifiers´ physiology. In particular, latter difference between inorganic and organic precipitation and the more sensitive reaction of Sr in organically precipitated CaCO₃ will be examined and tested in great detail. For these experiments we will select tropical corals (aragonite) from the Red Sea. These experiments will be performed in collaboration and leadership of Prof. Dr. J. Erez, Hebrew University, Jerusalem, Israel. Under his leadership corals and foraminifera will be collected at the Gulf of Eilat/Aqaba and then cultured under controlled laboratory conditions at the Hebrew University of Jerusalem, Israel. The results of the planned experiments will be important for the paleo-sciences because corals are important carrier of paleo-proxy information in the marine realm. Note, that the corals will be cultured as a function of the same parameters as in the inorganic experiments (water temperature, pH, precipitation rate and ionic strength) that will be performed at Graz University of Technology, Austria.