Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/105

 plain of Ramleh continues, and, near the bend of Wady Saaou, forms a square edge, so that the drifted sand of the plain pours down like water over a weir, and forms great heaps on either side.

Sarabut el Khadem, Wady Chamile, &c. (see Pl. I. fig. 4). — The ruins of Sarabut el Khadem are on the high sandstone-plateau, 2290 feet above the sea-level. There are ten sculptured stones upright, which are, I am informed, of the period of the 18th Dynasty. Below the temple or necropolis, whichever it may be, are two small quarries in the red sandstone, whence have been derived the blocks upon which the hieroglyphics were sculptured. Great numbers of flint flakes are found all over the plateau and in the quarries, where they are associated with stone hammers of a double conchoidal form. The iron and manganese bed crops out at the top of the hill, overlying some shaly beds containing a little green carbonate of copper, probably the same as those seen in the mine at Wady Khalig. The limestone-beds are also seen capping many of the smaller hills on the plateau. About 15 feet below the limestone, turquoises are found in a bed of ferruginous sandstone, which has been followed to a certain extent in two caves of ancient date, as evidenced by the hieroglyphics near the entrance. The workings are still kept up in a small way by the Bedaween. The turquoises occur principally in the joints traversing the sandstone, and are apparently rare and small, though of good colour.

From Sarabut el Khadem Wady Saaou runs in a south-easterly direction for about four miles to the height of land which divides it from Wady Chamile. The valley is about 1/2 or 3/4 of a mile broad, with alluvial terraces covered in part with blown sand. The cliffs are everywhere formed by New Red Sandstone above gneissic rocks, and on the right-hand side (going up) they rise to a considerable height, probably exceeding 4000 feet in the peak of Gharabi aleady mentioned. This, together with many of the neighbouring hills, is capped by a thick bed of markedly columnar lava. Close to the top of the pass, which is 2100 feet above the sea-level, the same rock breaks through the soft sandstones, and forms a dyke about 50 feet thick. Here it is much decomposed, forming earthy spheroidal masses, the original character of which can scarcely be made out by inspection. Dykes of a very similar kind are found in the valley going up to the plain of Ramleh on the north. The course of these dykes is about south-east, or parallel to the direction of the valleys.

After crossing into Wady Chamile, which also runs in a south- easterly direction, the sandstones become softer, the valley widens, and is fairly well covered with grass and scrubby bushes. This continues for about three or four miles, when the sedimentary rocks come to an end, only a few small and scattered outliers being visible on the tops of the gneissic hills. About this point the valley turns round to the south-west, and becomes narrow and very tortuous between steep wall-like cliffs of granite, with many hard red porphyritic dykes. Although perfectly dry in the summer months, there is abundant evidence of the effect of great floods of water coming down occasionally at other times of the year ; and the risk of such