Stable isotopes of strontium as a new proxy for continental weathering, pedogenesis processes and seawater temperature (TRION-project)

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General goals in the frame of the Trilateral ProgramThere is a general belief that scientific networking in a conflict region like the Middle East can support communication and understanding among the people and thus promote the efforts to achieve peace. The Trilateral Program of the German Science Foundation (DFG) aims to support such a process by involving Israeli, Palestinian and German scientists in joint scientific projects. In order to reach this ambitious goal in a sustainable way various aspects like joint student education and training, capacity building as well as public outreach efforts are needed to be addressed in the frame of the proposed TRION project.Scientific goals of the TRION II projectThe findings that there is natural and temperature dependent Sr isotope fractionation indicate that the origin of seawater Sr and its isotope composition is more complex than previously thought. In particular, we have to assume that weathered fractionated Sr from continental sources as well as fractionated Sr from hydrothermal sources together with the temperature dependent Sr isotope fractionation during carbonate precipitation/dissolution exerts control on the paired 87Sr/86Sr-d88/86Sr seawater ratios. Concerning the sources and sinks of Sr there is neither detailed information about the degree and mechanisms of Sr elemental discrimination and isotope fractionation in rocks and soils nor during marine organic and inorganic calcium carbonate (CaCO3) precipitation. However, the basic understanding of Sr elemental discrimination and isotope fractionation mechanisms are important in order to understand the Sr isotope balance in the ocean and may help to better elucidate the link between continental weathering and atmospheric pCO2 on geological time scales. Our goals within the TRION project were:Determine the mechanisms and degree of Sr isotope fractionation in continental rocks and soils being a major Sr source for the ocean.Determine the mechanisms and degree of temperature dependent Sr isotope fractionation during the precipitation of organic and inorganic marine carbonates being a major sink for Sr in the ocean