Petrography, Geochemistry and Petrogenesis of Panah-Kuh Skarn, West of Yazd

Panah Kuh skarn is located about 50 km northwest of Taft City in Yazd province. The intrusion of Panah- Kuh stock with granodiorite-quartz diorite composition into the limestone Jamal Formation has led to the skarnification in this area. Field and mineralogical observations show that Panah-Kuh skarn included two endoskarn and exoskarn zones. Exoskarn is calcic type and magnesian skarn which formed in contact with the marbles whereas endoskarn formed with restrict development into intrusion. Dominated minerals are garnet (andradite) and pyroxene (diopside-hedenbergite) in the calcic skarn and forsterite, diopside, serpentine and talc in the magnesian skarn. At least two paragenetic stages of skarn formation have been recognized. The early skarn formation (stage I) was dominated by anhydrous minerals such as pyroxene and garnet in the calcic skarn and forsterite and diopside, in the magnesian skarn. According to mineral assemblages which formed at this stage, it can be concluded that the temperature range was less than 500 0C. The hydrous skarn assemblage such as serpentine and talc (stage II) replaced early-formed skarn assemblages. The mineralogy and geochemical characters of Panah-Kuh skarn is consistent with deposition under oxidized conditions, formation at shallow crustal levels and similar to those of Fe bearing skarn system.