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The sandstones are then covered by incrustation deposits, 
forming the Plain of Zara, where gush out the hot incrusting 
springs. 
They are seen again to the south of this plain and consti- 
tute the cliffs from this point to the Wady Mojib, there 
resuming their former horizontality. They appear covered in 
many places with saline incrustations and palm-trees are 
frequent wherever the sandstones are smoothed (or levelled.) 
The Wady Mojib runs in a narrow gorge, deep and tortuous, 
in the midst of rocks to which atmospheric denudation has 
given odd and picturesque forms, the sandstones here have 
most varied colours, yellow, red, and black, (from bitumen no 
doubt). This Wady is one of the lowest valleys in the district, 
and the River (Arnon) runs in the midst of sandstone rocks, 
from the heights of Schihan, 2629 feet above the Red Sea, 
(in its valley near which place according to M. Lartet’s map 
are large deposits from thermal and mineral sources as well as 
Gypsum). 
From Wady Mojib towards the Lisanthe Nubian sand- 
stone dips slightly towards the south, and disappears on 
approaching that peninsula. Further south again it rises and 
forms the foot of the Eastern Escarpments to the Southern 
Ghor. Here are beds met within it that are nearly black, 
which owe their colour to an excess of manganese that they 
contain. In the environs of Petra the Nubian sandstone 
attains its greatest development where it occupies the summit of 
Mount Hor, having been uplifted 5332 feet above the Dead 
Sea there. 
Mr Hudleston says:—“<I will now mention some of the 
‘characteristics of the Nubian sandstone. Firstly: it is the 
‘seat of considerable mineral wealth, especially near its junc- 
“tions with the older rocks. It is largely developed in the land 
“of Midian, where Burton speaks of the western wall of 
“Neyd Plateau as consisting of a sandstone remarkable for the 
“beauty of its brick red precipices and castellations. The 
“copper mines of Wady Nasb, and the turquoise mines of 
‘‘Sarabit el Khadim and other localities are associated with 
