الفهرس Only 14 pages are availabe for public view
 |  | from | 191 |  |  |
| | | from | 191 | | |
Abstract
The study area is located in the south eastern part of Sinai Peninsula between Nuweiba and Taba Cities along the gulf of aqaba. It is bounded by latitudes 29º 17` – 29º 24` N and dissected by longitude 34º 44` E and covers about 120 Km of Pan-African basement rocks in Sinai. The detailed mapping of the Precambrian rocks within the area revealed the following rock units, beginning with the oldest; metagabbro-diorit complex, migmatites, gneissose granites (gneissose quartz monzonite and gneissose monzogranite), volcanic rocks (Dokhan type), younger granite. Most of these rock units are intruded by numerous dykes with variable amount of attitude and magnitude.
The metagabbro-diorite complex are exposed in the middle of the eastern part of the map area. They are represented by metagabbro and metaquartz diorite. The magma type of these rocks is range from calc-alkaline to tholeiitic. Tectonically, they developed in volcanic arc setting.
The gneissose granites occupy the extreme southern part of the study area. They comprise gneissose quartz monzonite and gneissose monzogranite. The magma type of these rocks is mainly calc-alkaline. The tectonic setting of these rocks is mainly volcanic arc environment.
The volcanic rocks are occupy limited exposure at the middle of the western part of the studied area. They are represented by lithic crystal tuffs and crystal tuffs. Geochemically, these rocks were derived from calc-alkaline magma. Tectonically, the volcanic rocks were extruded in volcanic arc setting.
The younger granites constitute the major part of the map area. They comprise monzogranite and syenogranite which can not separated in the map. Geochemically, these rocks were derived from calc-alkaline magma. Tectonically, the investigated younger granite developed in within plate setting.
Dykes of different types; acidic and basic are encountered within most rock units of the map area. The basic type is the most common. Their crosscutting relationship and trends indicate, that the oldest is acidic type and the youngest is the basic.
Radiometrically, the studied Dokhan volcanics are relatively more enriched in contents of the radioactive elements; U and Th than other types of the investigated rock units.
Studied the relation between lineaments structures and uranium-thorium concentration was showing that, the structure lineaments play limited role in both distribution and concentration of uranium and thorium in the studied rock units.