276 
PROFESSOR T. G. BONNET ON A COLLECTION OF 
Balfour on his way to the shore in Kurmeli Bay; but judging from the specimens 
which he has brought, I think it probable that some true granite is also associated 
with the gneissic series. The limestone, supported as usual by the latter, extends 
along the shore of Kurmeh Bay, and towards the eastern part it is cut (together, of 
course, with the older rocks) by basalt dykes. Felsite also occurs somewhere in this 
district, probably inland towards the south-east. 
Further east along this plain, in the vicinity of Kaclhab village, basalt dykes are 
seen cutting the limestone rock, and there are scattered boulders of granite or grani¬ 
toid rock, of red felsites and rhyolites, and of a hornblendic diabase. The cliffs by 
the sea between Kadhab village and Hadibu Plain are composed chiefly of the usual 
massive limestone, which rests on a green flinty shale or argillite. The lower part of 
the limestone is a breccia, in which are fragments of the subjacent rock, and bands in 
it even resemble the latter (possibly being composed of the same material redeposited). 
In this neighbourhood occurs a mass of a kind of kersantite, the presence of which may 
account for the peculiar “ baked ” aspect of the shale. 
Similar argillites occur along the line of strike in the valley to the south-east of 
Tamarida village, overlain as before by the limestone. They have a rather sharp dip 
to the south-south-w r est, and “ an imperfect vertical cleavage, or possibly, jointing.” 
Apparently beneath, but possibly intrusive in the argillites, are some compact pale 
grey felsites. 
Inland rises the fine Haggier range whose outlines somewhat remind us of the 
peaks of Sinai. The bulk of the specimens from this place are reddish or pinkish 
felspathic granites, not generally very rich in quartz and always poor in the third 
constituent, generally rather coarsely crystalline, to which we may give the name of 
pegmatite.* This is cut by veins of a more compact granite and by at least one dyke 
of mica-trap. It is possible that gneiss also is present in this region. About the 
margin of the range the limestone rests upon the granite, and contains detritus from 
the latter in its lower part. The approximately highest point of the range is a 
pegmatite. On the south side about Adona we have the same pegmatites with 
a more hornblendic granite, and intrusive dykes or veins of compact purplish quartz- 
felsite or rhyolite. 
Eastwards from Hadibu, on the way to Jebel Omhari, blocks of reddish felsite or 
rhyolite are shown on the plain, and the limestone is presently reached. The extreme 
north-west of the Girgha range is formed of pegmatites similar to those of the 
Haggier mountain, varying from coarse to fine in texture, and of a rather compact 
quartz-felsite ; the latter constitutes a considerable hill mass, and is probably intrusive 
in the former. There is also some intrusive diabase. 
Between Kami and the hamlet Ma-aber, on the Motaha, the rocks vary considerably. 
Granites of the usual type, compact reddish or greyish quartz-felsite or rhyolite alter- 
* There is some authority for applying this term (often used vaguely) to granites which consist almost 
wholly of quartz and felspar. Of these, “ graphic granite ” is a variety. 
