48 MR. H. J. L. BEADNELL ON THE NUBIAN [Feb. I9O9, 



If confirmatory evidence of the intrusion of the granites were 

 required, it is I think indubitably furnished at the south-eastern end 

 of the hill, for here the limestone-beds of the E:cogyra-Senes, which 

 overlies the Nubian Sandstone, are themselves thrust up and dip 

 away from the igneous boss at inclinations of 10°, 20°, and 28° to 

 the south. In one spot, on the south side, the limestones dip 

 steeply against the granite at 25° north (see fig. 4, p. 47). Veins 

 of quartz are noticeable in the granites, which do not differ in any 

 important respect from those already described. 



Gf & H. — These are the most extensive exposures met with. 

 The two hills together have a length of 8 kilometres, and form a 

 prominent feature of the landscape to the south of the village of 

 Dush, from which they are distant only 22 kilometres. Like the 

 boss just described, H lies close against the Cretaceous escarpment. 



The foot-hills at the western extremity of Gr consist of beds of 

 coarse brown grit, dipping steadily away from the crystalline boss 

 at 25°. The actual contact of the sandstone with the igneous rock 

 is clearly exposed : the granite has a dull grey appearance (perhaps 

 due to kaolinization of the felspars) : its actual junction with the 

 sandstone is wavy, and well seen where the igneous rock has 

 been weathered away, leaving the tilted sandstones overhanging. 

 There is a good deal of quartz at and about the actual junction, 

 but more in the nature of angular lumps of irregular shape filling 

 cavities than waterworn pebbles, although there are small pebbles 

 in the sandstones themselves. I saw nothing, in fact, to favour 

 the view that the granite was in its present position before the 

 deposition of the sandstones. 



At the south-eastern corner of G, highly-tilted shelly limestones 

 were again observed, and across the space intervening between the 

 two hills more disturbed sandstones were met with. Again, at 

 the eastern end of H a mass of sandstone and altered shale occurs 

 dipping off the igneous boss at an angle of 30° south-eastwards. 

 A pebble-bed of white quartz is conspicuous here in the sandstones, 

 at least 100 feet above the beds that are in contact with the igneous 

 rocks. 



This concludes my remarks on the igneous exposures themselves, 

 which I have described in the order in which they were met with 

 and examined in the field. I venture to think that the disturbed 

 state of the strata in the immediate neighbourhood of the igneous 

 rocks, the marked alteration which they have in many cases under- 

 gone, as well as the nature of the actual contact where the latter 

 is visible, can only be satisfactorily accounted for on the supposition 

 that the granites have been intruded in a Aiscous state against and 

 into the sedimentary rocks. The lack of gravels or conglomerates 

 between the ordinary sandstones and the crystalline rocks, and the 

 entire absence of gently inclined, annularly contoured, overlapping 

 sandstones, such as one would expect to meet with if the sedi- 

 mentaries had been deposited on the flanks of a subsiding ridge or 

 island, appear to confirm this view. 



