Mineralogy and Genesis of Joveinan Iron Skarn (Cenozoic Magmatic Arc, North of Isfahan)

Joveinan marbles and skarns are located at 5 km NE of Ghohrood, 140 km North West of Isfahan in central part of Urumieh- Dokhtar magmatic arc. Intrusion of Ghohrood granitoid into the Cretaceous carbonate rocks caused the contact metamorphism and formation of skarn mineral paragenesis wollastonite, pyroxene, garnet, actinolite, epidote, chlorite, calcite, quartz, magnetite and sulfides (iron and copper). Mineralogical studies and Paragenetic mineral relations confirm that the Joveinan skarn is polygenic in origin and evolved in two major stages, metamorphism and metasomatism (progressive and regressive). In metamorphism stage that occurred immediately after the granitoid magma emplacement within carbonate rocks, Joveinan marbles are formed. Metasomatism stage are occurred with generation of anhydrous calc-silicates minerals such as wollastonite, diopsidic-hedenbergitic pyroxene and ugrandite garnets. The main stage of retrograde metasomatic, alteration of first calc-silicate minerals of skarn (pyroxene-garnet), caused the formation of epidote, actinolite and chlorite. The association of wollastonite, magnetite and Andradite represents that skarn is produced in more than 550 ° C temperature range and low partial pressure of CO2. Joveinan skarn is a calcic skarn that has been formed at shallow depth by oxidative hydrothermal fluids and evolved in different stage.