Comparative study between zircons fromthe Rosetta beach sand and wadi al arishAuthor(s): EmadA.Hamouda, AtifA.El Nahas
Acomparative study between the zircons ofWadiAlArish and beach sand from the placer deposits along theMediterranean costs of Egypt (Rosetta) was done. More than two hundred zircon grains from each area were examined. The different features of zircon including; typology, internal structures, inclusions and EDX analyses were investigated. The microscopic investigation revealed that zircons from wadi Al Arish are markedly coarser than zircons from the Rosetta beaches. Zircons from Al Arish area have high elongated with pencil like crystals and typically displaying oscillatory concentric zoning. These zircons were probably derived from an igneous source. On the other hand, the zircons from Rosetta havemoderate elongation, weakly zoned, homogeneous or patchy, this indicates that they were derived from a metamorphic source. The grain size, typological distribution, inclusions and mineral associations clearly discriminate between zircon from the Rosetta beaches and Wadi Al Arish. These phenomena leads us to the conclusion that Wadi Al Arish is the main source for the placer deposits in Al Arish coastal area while beach zircon may be attributed to upper reaches of Nile. Zircons from both areas show the imprints for their provenances from host rocks. Granitoid rocks in southern Sinai are the main source for zircon of Al Arish, while the metamorphic zircon represents considerable amount in the Nile sources especially the Blue Nile.