Disputas og prøveforelesning: Øyvind Sunde
Øyvind Sunde ved Naturhistorisk museum vil forsvare sin avhandling "Mineralogy and geochemistry of pegmatites in the Larvik Plutonic Complex, Norway" for ph.d.-graden.
Tid og sted for prøveforelesning
Fredag 27.september kl. 10:15 på Tøyen Hovedgård vil kandidaten holde prøveforelesning over emnet:
Mineralisation associated with pegmatites.
- Professor Frances Wall, University of Exeter, United Kingdom
- Dr. Erik Jonsson, Sveriges Geologiska Undersökning, Sverige
- Professor Hans Arne Nakrem, Natural History museum, University of Oslo
Leder av disputasen
Kort presentasjon av avhandlingen
Peculiar rocks consisting of large and rare minerals are known as nepheline syenite pegmatites and can be found in larvikite (national rock of Norway!) around the Larvik area. Detailed chemical analyses of a mineral called wöhlerite, which is rare on the global scale but common in the pegmatites, reveal a close relationship of the pegmatites to the host larvikite. These pegmatites have a unique internal structure of mineral distribution, and may be distinguished based on their mineral assemblages. Boron isotopic composition of tourmaline and hambergite reveal that external fluids have interacted with the early melt. Such boron isotope data is particular interesting for the research community, because they represent a unique geochemical system where boron isotopes are poorly studied. Furthermore, this study developed hambergite as a new host for boron isotopes.
Studies of how these pegmatites form is important scientifically to develop our understanding of these geological systems, and commercially because this group of rocks are potential sources for important strategic elements.