الفهرس 
Magnetization in rocksOnly 14 pages are availabe for public view
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Abstract
the granitic rocks investigated i n this thesis showed high and variable susceptibility and their anisotropy were due to shape alignment of magnetite grains. The high susceptibility has been explained as due to high content of magnetite and the inhomogeneuity is because rnagnetit e is spatially variable within the host s i l i c a t e s . In some granite s i t e s susceptibility w a s low although magnetite waa detected i n the IRM curves, which indicate the sensitivity of the technique to rocks which contain only very s m a l l proportions of magnetite. This low susceptibility at the margins of the pluton was consistent with the haematite content indicated the saturation magnetization curves. Both magnetite and haematite appeared i n some curves which would certainly indicate that haematite is much more developed i n quantity than magnetite. The susceptibility i n the granite rocks is higher than both the diamagnetic and paramagnetic susceptibility and most of the magnetic components are either ferrimagnetic or imperfect antiferromagnetic , the l a t t e r show parasitic ferromagnetisrn. The age of the ferromagnetic fabric (whetehr postdates the emplacement or is contemporaneous with it ) w a s d i f f i c u l t to be assessed, because both primary and secondary f a b r i c do e x i s t . However, i n Um Had Granite the magnetite appears t o have been formed primarily during a slow c r y s t a l l i z a t i o n of magma i n zero s t r e s s f i e l d . T h i s is also consistent with the petrographic description of the magnetite. In the Fawakhir pluton, the o r i e n t a t i o n of t h e f a b r i c , t h e r a t h e r high anisotropy as well as the trend of the f o l i a t i o n planes give an impression that the magnetic fabric s l i g h t l y postdates the emplacement of the pluton. On the other hand, the strong development of f a b r i c near the margins could indi c a t e a flow f a b r i c . However more concentrated p r o f i l e s would be necessary to define the nature of the Sabric and to determine the age of the ferromagnetic components carrying the magnetic f a b r i c . A1 though the degree of anisotropy was moderate formes of the g r a n i t e samples, i t tends to be strongly f o l i a t e d near the margins and only s l i g h t l y f o l i a t e d to l i n e a t e d i n t h e i r i n t e r i o r s . This behaviour is cons i s t e n t with the t y p i c a l g r a n i t e emplacement as it is expected to form pronounced compressional e f f e c t on the nearly enveloping rocks. Around the Urn Had and Fawakhir plutons the metamorphic rocks showed an orienta t i o n of the magnetic f o l i a t i o n planes paralleled the g r a n i t e contact, showing t h a t both the magnitude and orientation of the fabric was disturbed by the granite and a r e r e l a t e d to it. Sampling south of the margins of the Fawakhir Granite did not show an observable change i n the trend of fabric due to the granite emplacement and the orientation was not parallel to the granite cont a c t .