الفهرس 
Geological settingOnly 14 pages are availabe for public view
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Abstract
The g r a n i t i c rocks i n the Urnm Rasein area can be subdivided i n t o two main groups according t o the f i e l d r e l a t i o n s and geochemical c o n s i d e r a t i o n i n t o the Urnm Rasein older g r a n i t e and Abu Hireig younger g r a n i t e . - The Urnm Rasein older g r a n i t e s a r e f u r t h e r subdivided i n t o t h r e e d i f f e r e n t v a r i e t i e s according t o the degree , of the deformation, mineral composition and r e l a t i v e ages i n t o t h e Urnm Rasein gneissose t o n a l i t e , Urnm Rasein gneissose trondhjemite and the Urnm Rasein trondhjemite. The Abu Hireig younger g r a n i t e is represented by one small rnonzogranitic p l u t o n . The r e s u l t s of modal and chemical analyses of the g r a n i t i c r o c k s , show t h a t the Urnm Rasein gneissose t o n a l i t e f a l l s within the t o n a l i t e f i e l d , the Umrn Rasein gneissose trondhjemite and the Urnm Rasein trondhjemite l i e within trondhjemite f i e l d , whereas the Abu Hireig monzogranite lies within the monzogranite f i e l d . The chemical c h a r a c t e r i s t i c s show t h a t the Umm Rasein older g r a n i t e possess a sodic c h a r a c t e r , whereas the Abu Hireig monzogranite possesses a potassic c h a r a c t e r . The Umm Rasein gneissose t o n a l i t e has an intermediate d i f f e r e n t i a t e , whereas Umm Rasein gneissose trondhjemite, trondhjemite and Abu Hireig monzogranite have an acid d i f f e r e n t i a t e . The Umm Rasein older g r a n i t e show calc-alkaline c h a r a c t e r and the Abu Hireig younger g r a n i t e shows a l k a l i n e c h a r a c t e r . from the f i e l d r e l a t i o n s , state of deformation and chemical s t u d i e s , t h e g r a n i t i c rocks of Urnm Rasein area a r e arranged chronologically as follows: Younger g r a n i t e . Abu Hireig rnonzogranite. (Youngest ) Older g r a n i t e . Umm Rasein gneissose ionalite. (Oldest Umm Rasein gneissose trondhjemite. Umm Rasein trondhjemite. The Ummm Rasein older g r a n i t e believed t o be formed by the p a r t i a l fusion of the mantle wedge, with l i t t l e c r u s t a l m e l t c o n t r i b u t i o n they can grouped as G1 (Hussein e t a l . , 19821, G r A g r a n i t o i d s ( E l Shatoury e t a l . , 1984) and I type g r a n i t e ( I s h i h a r a , 1977). Abu Hireig younger g r a n i t e on the other hand have been formed by p a r t i a l melting of the lower c r u s t w’ith some addition from the mantle by c o l l i s i o n . They can grouped as G I1 (Hussein et a l . , 1982), G r B g r a n i t o i d s ( E l Shatoury, 1984) and S type g r a n i t e ( I s h i h a r a , 1977)