Geochemistry and REE distribution of apatite from pyroxenite and carbonatite in the Lillebukt Alkaline Complex, Finnmark, Northern Norway

NGU Rapport 2010.004

This report presents a chemical analysis of apatite from pyroxenite in the Lillebukt alkaline complex together with older analytical data on REE in apatite from the associated carbonatite. Published REE data on apatite from Siilinjärvi are also presented.

The apatite shows a strong enrichment in REE, up to 3000-4000 times chondritic values for LREE. The total REE (including Y) in apatite from the pyroxenite is 3605 ppm and in the carbonatite 3416 ppm. However these values are not directly comparable since there is a difference in the number of analysed elements.

When compared, the apatites from carbonatite (Stjernøy and Siilinjärvi) show slightly lower LREE, elevated MREE and lower HREE than apatite from the pyroxenite.