Prehnite as an indicator mineral in the Wadi Nasb uralitized gabbro, South Sinai, Egypt

We report the first finding of prehnite in the southern Sinai peninsula, in a uralitized gabbro developed at the contact of the appinitic gabbro of the Wadi Nasb mafic intrusion (WNMI) with younger granitic intrusions. Subsolidus reactions with hydrothermal fluids caused the gabbro to gain Al2O3 and CaO while losing SiO2, Fe2O3, TiO2, P2O5, Ba, Nb, Zr and Y. Uralitization proceeded through two stages of alteration and mineral replacement. The...