BARITE MINERALIZATION IN THE SOUTH UM-MONQUL AREA, NORTH EASTERN DESERT, EGYPT

The barite mineralisation in the north Eastern Desert of Egypt is host ed by Pan-African dacite, dacite porphyry and granite. The host rocks are variably altered by potassic, phyllic, phyllic-argillic, propyliti c and advanced argillic alteration. The barite mineralisation is in ve ins trending east-northeast - west-southwest and dipping 65 degrees-80 degrees to the southeast. The veins are mainly of barite with subordi nate quartz, accessory magnetite and specularite with minor sulphides (chalcopyrite, pyrite, covellite, enargite, bornite and pyrrhotite) an d traces of Au. The barite mineralisation is associated with advanced argillic alteration, which resulted from interaction of the host rocks with acid sulphate fluids. It is envisaged that these fluids were rel eased from high level intrusives similar to Cu bearing porphyry rocks. (C) 1997 Elsevier Science Limited.