Page:Mount Seir, Sinai and Western Palestine.djvu/109

Rh There is a slight dip to the northwards, which ultimately brings the limestone down into the plain opposite Ain Gharandel. Henceforth there is a double terrace on the western side, and the strata stretch away indefinitely into the high table-land of the Till. At distant intervals these terraces are broken into by winding valleys, which give access to the interior of the table-land. On the eastern side the mountains of granite and porphyry behind Akabah, intensely red in colour, so as to give rise to the name of "Jebel el Nur" (or mountains of fire), gradually decline in elevation northwards, and several outliers of the Desert Sandstone are seen capping the higher elevations of the older rocks towards the head of the Wâdy Turbân. Soon afterwards, as we proceed northwards, the sandstone formation descends to lower levels, breaking off in abrupt walls and precipices in the districts of the Wâdies Gharandel and Dalâghah, and forming the escarpment of Jebel Haroun (Mount Hor), which towers conspicuously above all the other heights. Farther in the distance to the east, the light grey and brownish ridge of Jebel Zibbeyagh, forming the margin of the limestone table-land of Edom, may be seen at an elevation of about 3,000 feet above the plain. The limestone begins immediately east of the Wâdy Mâsa, behind Petra, forming the upper portion of the ridge east of this celebrated valley. In this district, however, the Desert Sandstone sometimes forms a double or treble escarpment, owing to the existence of large faults by which the strata are successively repeated, as shown in the view of J. Nachaleagh (Fig. 8).

This general succession, modified by changes in the dip, and by faulting, is continued all the way northwards to the eastern side of The Ghôr, and along the shores of the Salt Sea. At the base of the escarpment are the red sandstone cliffs, sometimes resting (as at Es Safieh) on a foundation of older crystalline rocks, and extending up the flanks of the escarpment to an elevation of 2,000 feet above the Salt Sea. To these succeed soft sandstones of variegated colours, probably belonging to the "Nubian Sandstone" formation surmounted by the Cretaceous limestone of the table-land, which stretches far away eastward into the Syrian Desert, the haunt of nomadic tribes.

The surface of the Wâdy el Arabah is variously covered by loam, gravel, and blown sands, which are often piled up in great dunes covering large areas, and form a great obstacle to travellers. Occasionally the limestone rock appears in isolated bosses or ridges, as is the case along part of the watershed about 45 miles north of Akabah. There are no continuous G