The PhD defence will be streamed directly using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.
Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants -> Raise hand'.
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Join the disputation
- Download Zoom
- Follow the Trial Lecture live: September 9th. at 14:00
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Tittle:
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Geologic and plate tectonic history of southern Norway: Precambrian to present.
Main research findings
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Pegmatites – related to granites or not?
Pegmatites are rocks rich in rare elements (e.g. Li, Be, Cs and Ta) and industrial minerals (e.g. quartz, feldspar and mica). This makes them interesting for economic reasons and for science. Even though pegmatites are well known, geologist still argue how they formed. Classically geologist argue that pegmatites are related to granites, while in recent years another theory suggest that they can form by direct melting of the rocks they are sitting in. In this thesis, I use mineral chemistry to classify pegmatites from south Norway and south-western Sweden, age dating to figure out how old they are and study their isotopic signature to figure out their source. The results show that these pegmatites are rich in Li, Sc and Ta but not in economic amounts. The age dating show that some of the pegmatites are older than their adjacent granites, while other are younger, and few have the same age. The isotopes show that some of the pegmatites have the same signature as the granites, while other have a different signature. From the results it can be concluded that the pegmatites formed mainly by direct melting of the rocks they are sitting in but also in relation to granites.
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Contact: Elisabeth Aronsen
Organizer: Natural History Museum
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