Figure 2. (a) T-P and (b) T-fO2 fields of magnetic mineral (titanomagnetite) formation in basalts (after [Lykov and Pechersky, 1976, 1977]). Broken lines delineate the crystallization regions of weakly magnetic Mg-Al ferrospinels (also shown by the symbols 1); 2 - bold dots are the points of titanomagnetite crystallization.