Fluid inclusions in chromite from a pyroxenite dike of the Pindos ophiolite complex

Chromitite occurrences in the Pindos ophiolite complex are located in elongated dunite bodies hosted in harzburgite of the mantle sequence, and show a compositional variation from high-Al to high-Cr type. Although the majority of the chromite ores is characterized by paucity in fluid inclusions, abundant fluid inclusions were found in chromite hosted by a coarse-grained pyroxenite dike at the Spanos Valley, Pindos complex. Chromite occurs in highly variable proportion in an orthopyroxene matrix or as inclusions in orthopyroxenes. Its composition is homogeneous and has an average Cr/(Cr+Al) ratio 0.73.The investigation of chromitites revealed the presence of primary and secondary fluid inclusions. The primary inclusions are of following types: Three-phase solid-liquid-gas, three-phase liquid-liquid-gas, two-phase liquid-gas and one-phase octahedron crystal-shaped. The secondary fluid inclusions are two-phase liquid-gas and mono-phase fluid inclusions.The presence of fluid inclusions in chromite aggregates hosted in orthopyroxenite dikes, in combination with the trace element contents in chromite concentrates and the mineralogical composition of the dikes may indicate that an aqueous phase separated from the magma.