Page:Mount Seir, Sinai and Western Palestine.djvu/106

78 the high plateau of Edom (L), the red sandstone formation (S) being interposed.

The great leading fracture above described frequently sends forth branch fractures to the right, which, in some cases but not always, follow the directions of the valleys. There are others also parallel to it; and amongst the most remarkable of these is one traversed by the Haj Road, on descending from the Tîh towards the head of the Gulf of Akabah, already described (Fig. 6, p. 68). This is the leading fracture on the western side, and enters the gulf near Ras el Musry. The ridge of reddish granite to the east of the fault is seamed by dykes of deep red porphyry and basalt, crossing each other at angles of about 60°, cutting the rock into “lozenge-shaped” sections, somewhat like the vertebræ of a backbone. The ridge stretches from Ras el Musry northwards for about ten miles. At its eastern base, by the waters of the gulf, was in all probability situated Ezion Geber, and it may be presumed that the name “the backbone of a giant,” was taken from the ridge which rose so boldly and massively behind the walls of the city.

When describing the coasts of the Gulf of Suez, I had occasion to refer to the evidence of the recent elevation of the sea-bed, so that gravel and sand, with shells and corals of species still living in the adjoining waters, are to be found at levels up to 200 feet above the present surface. This elevation is not local, and may be supposed to have influenced the whole region of Arabia Petræa, and therefore the shores of the Gulf of Akabah. Accordingly, accompanied by my son, I made careful search for shells in the gravels of the valley, and not without success. The bed of the valley, sloping from the sea-margin up to the base of the mountains behind Akabah, is formed of loose gravel, and in this we found, ere leaving our camp, examples of univalves, amongst which was a Murex, several bivalves, an operculum, together with pieces of coral. These occurred at a level of from 80 to 90 feet above the sea; but it could be seen that the gravel in which they occurred sloped upwards to the base of the ridge at a height of about 200 feet, so that the ridge must be considered to have once formed the rocky margin of the gulf itself. The following