Mantle sources under the Eastern Finnmark Region (EFR) appears to have inherited small scale heterogeneity from Precambrian geodynamics. Compositions varying from depleted and slightly enriched (similar to N-MORB and E-MORB), to enriched (similar to OIB type), are present in the EFR. Geochemical trends also indicates that some mantle sources has been to some extent influenced by subducting sediments, ...