Chalcophile and highly siderophile element behaviour in subduction zones: implication for global recycling of crustal 186Os-187Os signatures.

• Applicant: Professorin Dr. Ambre Luguet
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 263541474

In constrast to the widely investigated subduction-related recycling of lithophile and volatile elements, the behavior of chalcophile (Se-Te) and highly siderophile elements (HSE) in subduction zones remains poorly constrained but is yet contradictory. This project aims at obtaining the first comprehensive Se-Te-HSE and 187Os isotope dataset on a coherent sequence of blueschist and eclogitic paleosubduction rocks from the Aegean islands of Syros and Sifnos (Cycladic Blueschist Unit) in order to understand how these elements behave during prograde high pressure-low temperature subduction-related dehydration of the oceanic crust. These aims will be achieved by combining Se-Te-HSE-187Os analyses on whole-rocks, silicates and individual host minerals with piston cylinder experiments at pressures and temperatures mimicing the typical P-T path of subduction. The results will contribute to a better understanding of the terrestrial cycle of Se-Te-HSE and of the origin of small and large-scale 187Os-186Os heterogeneities in the Earth mantle, including signatures in oceanic island and mid-oceanic ridge basalts.

• DFG Programme: Research Grants
• International Connection: France, United Kingdom
• Participating Persons: Professor Dr. Kevin Burton; Dr. Jean-Pierre Lorand; Dr. Geoff Nowell