26 
PHYSICAL ASPECTS OF ADEN. 
south-east, and rises to a height of 1,218 feet. Jebel Ghudir runs along 
the southern coast, where its spurs produce deep indentations on the 
coast line. These small promontories are called, beginning from west : 
Has Alarga, Ras Mujallab Heidi, Ras Abu Kiyama, and Ras Salih On 
the easternmost promontory of the peninsula there rises the Jebel Ishan 
to a height of 697 feet. Along the Bandar Fukum, a bay formed by 
the peninsula and the continent, there stretches a chain of low hills,, 
called Jebel Fukum. 
The igneous rocks consist of basalt in almost all its forms, compact, 
black, grey peridotic ; rough, cellular, scoriaceous, variolitic ; teph- 
rine, with small crystals of glassy felspar, which forms some of the high 
peaks in the interior of the crater ; leucostine, which forms part of the 
lavigenous effusions in the north-west part of the peninsula, where the 
last vents of the volcano appear to have existed ; pumite and stigmite, 
simple, variolitic, and pisolitic, which form small deposits in various 
parts of the general mass, and semiopal and chalcedonies, which abound 
in the island of Sirah. To these may be added brown carbonate of lime, 
in columnar stratified crystalline deposits, with transverse wavy lines ; 
massive and fibrous gypsum ; and fluor spar in minute crystals of an 
amethystine colour on the surface of chalcedonies. 1 2 There are lavas 
containing crystals of anjite, and not unfrequently those of sanidine. 
The rocks exhibit every degree of vesicularity ; the vesicles are in some 
specimens globular, and in others flat and drawn out. In some places 
the lava is quite schistose, and might be easily taken for metamorphic 
rock. Volcanic breccias are also met with, as near the Main Pass, 
where fragments of dark green lava are embedded in a reddish matrix.^ 
Tufas are also present, but apparently to a limited extent. “ With 
reference to the Aden pumice, it was found that this differed from 
ordinary pumice in containing gypsum or hydrated sulphate of lime. 
In the specimens examined the quantity of this constituent was found 
to be 18*68 per cent.” 3 
The deposits of consolidated sea-sand occur more especially near the 
Northern Pass, towards the base of the volcanic ridges, raised sometimes 
15 or more feet above the level of the sea. The stratification is diagonal, 
and this arrangement has probably been produced by the drifting of 
opposing currents. The flat line of coast on the northern part of the 
promontory is evidently a raised beach, and the consolidation of the 
sand must be assigned to the action of a tropical sun upon the calcarious 
1 Carter, H. J. : 1. c., p. 85. 
2 Mallet F. R. : 1. c„ p. 4. 
3 Report of the Chemical Analyser to the Government of Bombay for the year 1872-73. 
