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Sie sind hier: Startseite Das Institut Bereiche Geochemie/Petrologie Arbeitsgruppen Experimentelle Petrologie Forschung Sulphide-melt/silicate-melt partitioning of Highly Siderophile Elements

Sulphide-melt/silicate-melt partitioning of Highly Siderophile Elements

The Highly Siderophile Elements, (HSEs - Pt, Ir, Re, Os, Ru, Rh, Pd, Au), have received growing attention from geochemists over the past 15 years, because of their unique and specific geochemical properties. These properties, specifically the pronounced affinity for metal (siderophile=”iron-loving”) yield potentially the most powerful geochemical tracers of fundamental processes such as core–mantle differentiation, core–mantle interactions through time and the late accretion histories of planetary bodies. The HSE abundances in the mantle are consequently very low, but their abundances may provide valuable constraints on mantle differentiation processes and/or planetary accretion processes.

Our current understanding of the crystal/silicate-melt and silicate-melt/sulphide-melt partitioning of HSEs is extremely limited. From basic thermodynamic considerations, the behaviour of these elements should depend on variables such oxygen and sulphur fugacity, as well as the most conventional variables such as composition, temperature and pressure. More experimental work is then necessary to fully grasp the behavior of HSE during a variety of mantle processes at high-temperature. Key to understanding the behaviour of the HSE during a variety of upper mantle processes is the role of sulphides and other mantle phases in the partitioning of these elements.

BSE image Pt solubility

Backscatter electron image of experiments where Pt solubility in sulphide melts was investigated. White blocks are the remnants of the Pt wire used in these experiments, the dark grey matrix is Fe1-xS and light grey are PtSx sulphide. (© Raúl Fonseca)

Contacts: Prof. Christian Balhaus and Dr. Raúl Fonseca