Mineralogy, geochemistry and economic potential of Baqi-Abad skarn (south of Taft)

The Baghi-Abad skarn deposit is located south of Taft, Central Iran. Shirkuh granitoid batholite, marble and skarns are the most unit rocks in this area. The outstanding metamorphic zones are pyroxene-plagioclase skarn, melilite-fasaiite zone and finally spinel-clinopyroxene zone. The last zone of metamorphic halo is brucite marble. After this zone, marble limestone and then limestone of Taft Formation can be seen. The metamorphism and metasomatism caused by intrusion of the Shirkuh granitoid into the cretaceous carbonate rocks caused formation of calcite, wollastonite, clinopyroxene, garnet, vesuvianite, epidote, quartz and titanite. The main texture of these rocks is granoblastic, replacement and reaction, and poikiloblastic. Investigations confirm that the Baghi-Abad skarn is polygenetic in origin and evolved in two major stages, metamorphism and metasomatism (progressive and retrogressive). Prograde metamorphism characterized by anhydrous calc-silicates minerals such as wollastonite, diopside, pyroxene and garnets. The retrograde stage is revealed by the alteration of the calc-silicate minerals, the first skarn (clinopyroxene-garnet) and were formed epidote, vesuvianite. The Baghi-Abad skarn is a calcic- dolomitic and polygenic skarn and based on chemistry of clinopyroxene and garnet is comparable with Sn-W-Zn world mineralized skarns.