Scotland
Nick Mappin
Nick is a fifth-year Integrated Master’s student at the University of St Andrews, with a particular focus on igneous petrology and ore geology. His research looks into a nepheline syenite deposit in the north of Norway, which is mined for nepheline and feldspar, for use in glass and ceramics. He is establishing what the controlling factors are on the ore quality and how and why the ore spatially varies throughout the deposit.Fluid interaction in nepheline syenite, Stjernøya, Norway, and the implication for ore quality.
Fluid interaction in nepheline syenite, Stjernøya, Norway, and the implication for ore quality
The Nabarren nepheline syenite deposit is an intrusive body in the south of the Lillebukt Alkaline Complex, Norway. It comprises two predominant, syenite types, subdivided based on the accessory mafic mineralogy: biotite- and pyroxene-nepheline syenite. Sibelco operate an open pit and underground mine, exploiting nepheline and feldspar, for use in glass, ceramics, and paint fillers. Past studies conclude that biotite-bearing nepheline syenite has a reduced ore quality, however, the cause of the degradation is unknown. Contaminated carbonatite dykes are heterogeneously distributed throughout the deposit. Field evidence, cathodoluminescence, and petrography reveal a strong mineralogical alteration and ore quality reduction surrounding the dykes. Metasomatism or magmatic interaction between carbonatite and syenite is interpreted to cause this change. This presentation explores the processes liable for the ore quality variation and how ore beneficiation and mine operations can be enhanced.