Figure 11. Helium isotope abundance in samples from Kola ultrabasic-alkaline-carbonatite Complexes: whole-rock abundances (gas extraction by melting). Samples from Seblyavr, Kovdor and Lesnaya Varaka show low 4He/ 3He ratios similar to or even slightly below the mean MORB ratio. 3He abundances in ultrabasic rocks and carbonatites from these massifs are higher than those typical for MORB and OIB glasses. Sources of data for helium isotope abundances in MORB (170 samples) and OIB (280): Hiyagon et al. [1992]; Honda et al. [1991, 1993]; Kaneoka et al. [1986]; Marty [1989]; Moreira et al. [1995]; Ozima and Zashu [1983, 1991]; Poreda and Farley [1992]; Poreda and Radicati [1984]; Sarda et al. [1985, 1988]; Staudacher and Allegre [1989]; Staudacher et al. [1986, 1989]; Valbracht et al. [1996].