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The approximately 150 km2 Jijal complex occupies a deep-level section of the Cretaceous Kohistan are obducted along the Indus suture. The complex consists of mafic garnet granulites, and a > 10 km × 4 km slab of pyroxenites (diopsidite > websterite; ± olivine), dunite, and subordinate peridotite, all of which are devoid of plagioclase. These contain chromite either in lenses, layers, and veins or as disseminated grains. The chromite is mostly medium grained, subhedral to euhedral, shows pull-apart texture, and may contain inclusions of associated silicates. Chromite grains within thin sections of chromitite are generally homogeneous in composition, but dunite and pyroxenite samples commonly contain chromite grains of variable composition. The segregated chromite has higher Cr2O3 wt%, cr-number, and mg-number, and lower fe'''-number than the accessory chromite. These variations are mainly attributed to subsolidus exchange of Mg and Fe between chromite and associated olivine or pyroxene, and to inheritance from a magmatic source, but other factors may also be responsible. In general, the chromite grains are altered along margins and fractures to ferritchromit that is enriched in cr-number (and generally Fe3+, Mn, and Ti) and impoverished in mg-number compared with the parent grains. Chromian chlorite (clinochlore, penninite, with up to 7·3 wt.% Cr2O3) is commonly associated with the alteration, as is serpentine in most silicate rocks and some chromitites. The chlorite shows considerable compositional variation from grain to grain and in some cases within a single grain. Clinopyroxene is low-Al, -Na and high-Ca diopside. Orthopyroxene ranges from En91 to En82 and olivine from Fo98 to Fo84 (ignoring one analysis each). The mg-number of these minerals is higher in chromitites than in dunites and pyroxenites. Several aspects of the petrogenesis of the ultramafic rocks (e.g., the abundance of diopsidite) are not clear, but they seem to have passed through a complex history. The high cr-numbers (>60) in the chromite indicate that the rocks may have originated from some form of oceanic lithosphere-island are interaction. Petrography and mineral compositional data suggest that the rocks are ultramafic cumulates derived from an are-related (?primitive) high-Mg tholeiitic magma, possibly at pressures in excess of 8 kb. There also are small ultramafic bodies in the form of conformable layers and emplaced masses within the garnet granulites. These contain magnetite and pleonaste with < 10 wt.% Cr2O3, and less magnesian olivine and pyroxene than the principal ultramafic mass. These also have the characteristics of island are plutonic rocks, but it is not clear whether the garnet granulites constitute a continuous sequence of are cumulates with the principal ultramafic mass or the two are produced from different source magmas.