Figure F42. Phase diagram for the Fe-Ni-S-O system at 300°C and 2 kbar. Phase boundaries of Fe phases are marked by thick lines, those of Ni phases and Ni-Fe alloys are thin lines, and others are dashed lines. Fe phases: Hem = hematite (Fe2O3), Py = pyrite (FeS2), Mt = magnetite (Fe3O4), Po = pyrrhotite (Fe1–xS); Ni and Ni-Fe phases: Va = vaesite (NiS2), Pd = polydymite (Ni3S4), Mi = millerite (NiS), Hz = heazlewoodite (Ni3S2), Ta = taenite (TagFeNi), Aw = awaruite (Ni3Fe), Ka = kamacite (

Figure F42. Phase diagram for the Fe-Ni-S-O system at 300°C and 2 kbar. Phase boundaries of Fe phases are marked by thick lines, those of Ni phases and Ni-Fe alloys are thin lines, and others are dashed lines. Fe phases: Hem = hematite (Fe₂O₃), Py = pyrite (FeS₂), Mt = magnetite (Fe₃O₄), Po = pyrrhotite (Fe_1–xS); Ni and Ni-Fe phases: Va = vaesite (NiS₂), Pd = polydymite (Ni₃S₄), Mi = millerite (NiS), Hz = heazlewoodite (Ni₃S₂), Ta = taenite (TagFeNi), Aw = awaruite (Ni₃Fe), Ka = kamacite (

FeNi). Oxide/sulfide phase boundaries are simplified after Frost (1985); others are calculated with SUPCRT92 (Johnson et al., 1992). A. Fields mark oxide-sulfide assemblages observed in Hole 1268A, red arrow = inferred evolution path. B. Fields mark oxide-sulfide assemblages observed in Hess Deep and the Kane Fracture Zone (MARK) areas (Alt and Shanks, 1998, 2003).