FACTORS CONTROLLING MINERALIZATIONS OF SOME SHEAR ZONES IN GRANITES, SOUTH SINAI, EGYPT

The present study deals with the factors controlling the distribution of uranium, thorium and other elements in some shear zones of selected younger granites, south Sinai, Egypt.Four areas are selected for this purpose namely El-Regita, Ghazala, El-Rosis El-Rosis area is located to the southeast of the Katherina city and can be reached via Wadi Isbaiya while El-Regita area is located to the northeast of the Katherina Mountain and can be reached through Wadi El-Sheikh. Wadi Ghazala area is located in the sThe field and petrographic studies declare that El-Regita area is mainly covered by granodiorite and monzogranite where they intrude the neighboring rocks with sharp contacts. The monzogranite is medium to coarse-grained with pinkish colour and shows hypiTwo important shear zones are observed in the monzogranite of El-Regita area, namely El-Regita shear zone and the pegmatite shear zone. The trend of the former one is nearly N 70o W and has dimensions 600m X 3m. Cu-quartz stockworks are developed along thEl-Rosis area is mainly covered by granodiorite, syenogranite and alkali feldspar granite. The granodiorite is medium to coarse grained and exhibits granular hypidiomorphic texture. It consists essentially of plagioclase, K-feldspar, quartz, biotite, chlo