Page:Africa by Élisée Reclus, Volume 1.djvu/395

 similarly disposed in pyramids grouped symmetrically round the central cone. These uplands, which do not exceed 1,000 feet in altitude, and which are indebted for their imposing appearance to their abrupt walls falling precipitously down to the Gulf of Suez, form the northern extremity of the granitic system. Farther north, nothing occurs except limestone rocks or sand dunes. Both slopes of the range are also overlaid with layers of more recent formation. On the east side cretaceous taluses are found in many places resting on a granite foundation, and

several of the headlands along the coast belong to these cretaceous formations. Here also occur deposits of sulphur, as well as naphtha springs and beds of bitumen. Basaltic eruptions occurred at some remote period in the Jebel range, and these lavas are visible as far as the neighbourhood of Ismailia.

On the coast the prevailing rocks are sandstones and limestones of contemporary formation, in which are embedded fossil shells and polyps. Some more recent sandstones and limestones of like origin are entirely formed of these animal remains.

As on the Arabian seaboard, a gradual movement of upheaval has been observed