Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/100

 Section (in ascending order) of the Escarpment of Tih, starting from the Plain of Ramleh.

feet. White, reddish, and purplish sandstones 300 A. Shaly beds 50 B. Coarsely bedded sandstone 20

C. Shales and sandy shales, with gypsum and some thin nodular limestones near the top 100

D. Hard, compact cream-coloured limestone 12

E. Hard limestone and shales, with a rubbly bed containing hippurites ; ferruginous sandy bed at top 100

F. Limestone and shales, with large Ammonites 100 G. Calcareous sandstone, with large nodules of alabaster 50 H. Tumbled stuff 40 K. Compact limestone, about 20 L. Tumbled stuff. 50

M. Limestones and marl, some chloritie and some with flint nodules ; a hard bed near the top 100

Total (A to M) 642

The above total (A to M) may be regarded as an approximation to the thickness of the Lower Cretaceous rocks, the 300 feet beneath being assigned to the Trias, as will bo shown further on. Fragments of several large Ammonites were found, mostly in a bad state from exposure to the weather, and too cumbrous to bring away ; so that only pieces of sufficient size to show the nature of the form and the pattern of the chambers were collected.

On the top of the escarpment the beds form a broad plateau, falling with the dip to the northward, and far away in the distance crowned by an escarpment of white beds, probably the representatives of the Gharandel and Taibe bituminous series. The highest point of the Tih plateau is 4630 feet above the sea-level, according to Russegger.

From the plain of Ramleh there is a descent of about 250 feet into Wady Baba, immediately to the south of which is the old mining region. This comprises, within an area of about twenty square miles, the copper-smelting station of Nasb, the old copper-mines of Wady Chaly, the quarries and temple of Sarabut el Khadem, and the turquoise-mines of Wady Maghara, forming by far the most interesting district, from an antiquarian and geological point of view, in the whole of the Sinaitic peninsula.

Nash. — In the cliff at the lower end of the Nasb valley, on the right-hand or western side, the red-sandstone series of Ramleh is seen to rest unconformably on a dark-green schistose gneiss and mica- schist, pierced by a great number of intrusive dykes, principally porphyries, with small oligoclase crystals in a dark-red or black base. The lower member of the series is a dark-red, soft sandstone, with marly partings ; it is very similar in character and general appearance to the Lower New Red Sandstone about Chester, and may be from 100 to 200 feet thick. This is succeeded by lighter- coloured rocks of a similar character, much false-bedded, and variegated with yellowish, brown, red, and purple bands, making a thickness of about