Gebel Zabara, a mountain mass rising to 1,361 metres above sea-level, forms a southward extension of the Hangalia range. The cairn on its summit is in latitude 24° 45′ 21″, longitude 34° 41′ 53″. The mountain is drained on the north and east sides by feeders of the Wadi Ghadir, while its western flanks are partly drained by the Wadai el Nom. Gebel Zabara is chiefly composed of schists of various types. The ancient emerald mines of Zabara are in the north-east part of the mountain, about two and a half kilometres from its summit. A triangulation beacon marks the highest point of the mountain, but this was only used as an intersection point. I ascended some of the flanking ridges near the old mines; these consisted of splintery schists, and though the climbing is steep and rough (see [Plate IX]), the schists give a good foothold so that the ascent to the top is probably not very difficult. The ruins in the Wadi Zabara, near the old mines, are at 514 metres above sea-level; the climb from them to the summit is thus one of 857 metres. Due south of Gebel Zabara is a high ridge, the north-west end of which is 1,104 metres above sea-level; this ridge is the most conspicuous of a mass of high hills flanking Gebel Zabara to the south, which have not been seen except from a distance, but which are probably drained by the Wadi Nugrus.
Gebel Ghuel, which forms a northward extension of Gebel Hangalia, is likewise composed of schists. Its highest point, the south end of a conspicuous high ridge, is 1,104 metres above sea. Its eastern faces are drained by the Wadis Ghuel and Fegas, both tributaries of Wadi Ghadir, while its western flanks drain into the heads of Wadi Um Khariga. High hills flank the main ridge on both sides, especially the east, and through these the drainage channels form deep gloomy gorges. Wadi Ghuel contains important water holes.
Gebel Um Khariga is the name given to several high hill ranges on either side of the Wadi Um Khariga. Two of these ranges, one on either side of the upper part of the wadi, form like Gebel Ghuel north extensions of the high ridge of Hangalia; the western range can be crossed at a gap by an easy pass, 773 metres above sea-level, which separates the heads of Wadi Gerf from those of Wadi Um Khariga. These two ranges shut in the wadi on either side for some ten kilometres of its northward course, beyond which the country becomes more open and the wadi curves round to the north-east, passing the north end of a third range of high hills which is likewise called Gebel Um Khariga. This third range extends northward for about ten kilometres from Gebel Ghuel, from which it is separated by a pass forming a good road over the head of Wadi Ghadir. Its most conspicuous feature is a twin peak at its north end, 674 metres above sea-level. The main ridge is flanked by high hills, especially on the east side. Only the north and west flanks of this range are drained by Wadi Um Khariga, the eastern side being cut up by feeders of Wadi Sukari. Besides the pass separating it from Gebel Ghuel, there are two other passes, one round its north end into Wadi Sukari, and another at its south end between Wadi Ghadir and Wadi Sukari, so that a complete circuit of this range can be made by camels. Some of the hills composing the mass consist of highly magnetic schists, and compass readings in the region may be disturbed by many degrees.
PLATE IX.
Descending Gebel Zabara. (Schists).
Gebel Igli el Iswid is a rather rugged mountain mass rising among a sea of lower hills, thirty kilometres north of Gebel Nugrus. Its highest point, marked by a triangulation beacon, in latitude 25° 4′ 6″, longitude 34° 36′ 16″, is 975 metres above sea-level. The mountain forms a tripartite watershed between the basins of Wadi Um Khariga (draining the south slopes), Wadi Dabur (draining the north and west slopes), and Wadi Igli (draining the eastern face), each of which three wadis courses separately to the sea. In occupying the triangulation station on the summit, I placed my camp in a gully draining to Wadi Um Khariga, about two kilometres south-south-west of the summit at an altitude of 605 metres above sea. The climb of 370 metres to the top from this camp was not difficult, and occupied only a little over an hour and a half. The mountain consists of very hard grey siliceous rocks, which ring under the hammer, and are probably crushed and devitrified felsites (see [p. 281]). There are galts in some of the gullies draining from this mountain, hence it is sometimes called Igli el Rayani. At the time of my visit (December 1905) there was said to be a little water in a galt on the west side of the mass; but the rock basins in the gully which I ascended were empty.
Gebel Igli el Ahmar, sometimes called El Atshani, is a lower hill mass of granite some ten kilometres north-east of Igli el Iswid.
Gebel Atut is a high black conical hill thirty kilometres north-west of Gebel Nugrus. Rising considerably above the hills which immediately surround it, Atut is visible from a great distance from the west, and its conical form renders it easy of recognition. Its summit, marked by a beacon, in latitude 25° 0′ 56″, longitude 34° 23′ 49″, is 908 metres above sea-level and 300 metres above the branches of the Rod el Atut which encircle its base. A camp can be placed close to the foot of the cone, and the ascent is easily made in about an hour. The rock of Gebel Atut is olivine gabbro (see [p. 302]), of great hardness, and the whole surface of the mountain is formed of great blocks, rounded and boulder-like below, but angular higher up. The blocks have rusty-looking surfaces, but are perfectly sound rock inside, and they ring like bells under the hammer. The upper illustration on [Plate X] shows a view of the summit of Gebel Atut, from which its blocky nature will be evident. The view from Gebel Atut is a very extensive one. To the west and north (see the lower illustration on [Plate X]) one can see the peaks of Gebels Muelih, Haggar Dungash, Iteima, Abu Diab, and Hamrat Wogud; to the south-east are the masses of Migif and Nugrus, while eastward one looks over a great expanse of hills towards Gebels Dabur and Um Khariga, with the sea beyond.
The hills of Um el Huetat, the highest of which rise over 200 metres above the wadis round them, are situated about eight kilometres due west of Gebel Atut; they are composed of schists of various types, and contain some old mines, mostly in talc schist. They are drained by the Rod el Farag, a tributary of Wadi Gerf.