i88i] A JOURNEY IN THE HEjAZ 539 



first part of the plateau is named our Wady appears 

 as a great gorge, with huge hills towering over it in the 

 distance. Northward, in the mountain line, another 

 opening was pointed out to me, where the road from 

 Wady Leimoon and from Medina comes in. So far as I 

 can learn, both the branches of Wady Marr (the Zeima 

 Valley and Wady Leimoon) are, so to speak, outlets of 

 this sandy lake, enclosing between their courses an island 

 of mountain. The formation of the plateau is easily 

 understood, and follows a type constantly repeated in 

 the granite of the Upper Hejaz. Near the coast the 

 hills are trap and basalt, with an occasional patch of 

 granite or quartzose rock breaking through in the valleys. 

 But from Sola the granite begins to preponderate, and 

 the plateau of the Beheita is wholly composed of dis 

 integrated granite in the form of gravel. The isolated 

 hills which rise from it are granite peaks. The rock has 

 the same character as at Sola ; it is full of cavities, and 

 easily broken up by fierce atmospheric agencies. The 

 tops of the hills are entirely resolved into loose blocks 

 of fantastic form and great size, some rising like lofty 

 obelisks, others overthrown and piled in confused masses 

 one above the other. Disintegration has gone so far 

 that the accumulated debris has covered all but the 

 summits of the granite eruption, and the original contours 

 have been levelled by the spreading sand. The highest 

 points are still hills ; the lower ones are mere piles of 

 detached rocks. The plains of the Upper Hejaz, through 

 which I passed, are all of this type groups of granite 

 hill -tops, levelled and connected by the accumulation 

 of gravelly debris. The original aspect of such a tract, 

 before the hollows were filled up, can still be seen in the 

 region south of Mount Kara, which is simply a forest of 

 granitic aiguilles. As the granite contains the elements 

 of a fertile soil, these plains afford good pasture after rain, 

 and they are generally pretty thickly dotted with acacias 

 samur and talk. Indeed, the finest trees I have seen in 



