Composition of chromites in cordierite-and mica-bearing Cr-Ni ores from M laga Province, Spain

SUMMARY. An unusual paragenesis of chromite, nickeline, cordierite, and red-brown mica occurs in veins, pods, and schlieren i serpentinized ultramafic rocks at La Gallega nd Los Jarales in M~ilaga province, Spain. The chromites in this paragenesis are low-ferric, ferrous-rich aluminous chromites with exceptionally high vanadium content ranging between I'8 and 2"9 wt ~ V~Oa nd high zinc content ranging between o'5 and 1 "o wt ~ ZnO. A comparison of chromite composition with avail-able experimental data, together with paragenetical and textural evidence, suggests hat he chromite, cordierite, and red-brown mica crystallized at magmatic temperatures between approximately 13OO ~ and IOOO ~ at low oxygen fugacities and maximum pressures below Io kb, probably near 5 kb. SAMPLES of chromite-nickeline ores, collected from dumps at the abandoned mines of La Gallega near Ojdn and Los Jarales near Carratraca, M~tlaga province, S. Spain, show an unusual paragenesis with chromite, (Ni, Fe, Co)-arsenides and-sulphar-senides, cordierite, red-brown mica, plagioclase, chlorite, and serpentine. The ores typically form bronze-coloured rocks, consisting of fine-grained mixtures of chromite and Ni-arsenides, which occur associated with cordierite and the other silicates in schlieren, pods, and veinlets in serpentinized ultramafic rocks of the alpine typ