سنگ‌نگاری و شیمی گارنت‌ها در کانسار اسکارن خوت، شمال غرب تفت، استان یزد

Khut skarn deposit, located in the 50 Km NW of Taft,has formedin the result of Khut granodiorite intrusion into the upper Triassic impure carbonate rocks.Field evidences and mineralogical studies show Khut skarn is calcic type and exoskarn is the major skarn zone in area which associated with ore mineralization.The microprobe analyses show that there are two major types of garnet at garnet-pyroxene skarn zone: (1) Anisotropic garnets with 51/76-63/17 mol% grossular and (2) Isotropic garnets with 17/77-28/10 mol% grossular. Petrographic observations of anisotropic garnets show marked zoning and sector twining.Study of garnet zonation with electron microprobe in Khut skarn show chemical variations in Ti, Al, Fe, Mn, and Mgvalues form core to rim. In various zones, variations of Al, Ti and Fe are repeated alternatively. Hence, garnet zonation is caused by alternative variations of Fe, Al and Ti in composition of the fluid phase. This indicates multiple pulses of hydrothermal fluid flow.