Textural assemblage relationships between Clintonite-spinel-garnet in the Central Iranian skarns as evidence of clintonite genesis

The Fesharak and Shirkuh skarns in the Cenozoic magmatic belt of Central Iran formed when the granitoid intruded into the Lower Cretaceous dolomitic-carbonates. The main mineralogical assemblage concerned is Clintonite-spinel-garnet in Fesharak and clintonite-spinel in Shirkuh. Clintonite is either adjacent to garnet and spinel, or it contains the inclusion of these minerals displaying a stable relationship with them. Resorbed boundaries as well as development of corrosion textures in these two minerals are textural evidences suggesting spinel and garnet act as the source of Al in the genesis of clintonites according to the following reaction: 7 Spinel + Grossular+ CaMg(CO3)2+SiO2+4H2O= 4 Clintonite +2CO2.