الفهرس | Only 14 pages are availabe for public view |
Abstract The Um - Ara gaanite pluton pertains to the group of younger granite of the basement complex of Egypt. It covers about 210 km and comprises the following tow main varieties : 1) Coarse - granite monzogranites, covering 90% of Um - Ara granite pluton and forming moderate to high hilly country. They are highly wethered, fractured and jointed. 2) Fine -grained alkali feldspar granites cover 10% of Um - Ara granite pluton and cropping out at the northern and northwest parts of studied area. The petrochemical characteristics of the fine - grained radioactive granites are summerized as follows: * Both FAM and KCN diagrams indicate that these granites have alkaline affinities. *The alkali - silica diagram adopted by Irvine and Baragar (1971) shows that, these granites may have been crystallized from a soda rich magma. * The relation between agpaitic coefficient and silica indicates, however, the miaskitic nature of the granites. |