The valley having sunk to its present depression, the melting snows of Hermon probably began to pour into it, and as the chasm had now no outlet (the watershed of the 'Arabah on the south having been raised about 800 feet above sea-level), a large salt lake must have formed at its southern end; the history of the sheets of water then occupying the distance of 150 miles, appears to be recorded in the formations now found in the valley.
The present north shore of the Dead Sea is a shingly beach, with a ridge of pebbles at the top of a somewhat steep slope. Some thirty feet above the high-water mark a second similar beach may be seen inland; and about a hundred feet above the water is a third. There can be little doubt that we see in these raised beaches former limits of the lake. Above the beaches, some 300 feet higher than the water, there are flat shelves of marl with steep slopes much worn by water-action. These marls are deposited against the high Dolomitic cliffs, the tops of which are about the level of the Mediterranean. The shelves (the "Siddâ of the Arabs) have also been recognised as former shores of the sea, and this level may be called the Siddim level.
When the marl beds are closely investigated they are found to consist of very thin strata of various materials, mud, small pebbles, and shingle, in layer above layer, strongly impregnated with salt and bitumen. They have the appearance of being deposited in still, deep water, and the present bottom of the Dead Sea must be of much the same character. The whole area over which they occur, reaching up the Jordan Valley for about four miles, is so salt that no vegetation will grow upon it; thus there is every reason to regard these formations as once forming the bottom of a lake resembling the present Dead Sea.
But our observations were carried still farther. North of Jericho is a curious terrace, in form not unlike a croquet-ground on a large scale, called Meidân el 'Abd, "the open place of the slaveâ (or perhaps better "the barren plateauâ). The study of the Dead Sea beaches shows, by comparison, that this is another old shore-line of a former sea, and, a little south of it, there is a cliff of conglomerate, which has also the appearance of a shore formation. The line of this former beach runs south, to the marl deposits which have been formed at the foot of K[)u]r[)u]nt[)u]l; thus we find yet another level some 600 or 700 feet below the Mediterranean, forming the shore at a time when the plains of Jericho were under water, and when the Dead Sea must have reached to the foot of the S[)u]rt[)u]beh, or eighteen miles farther north than at present. The shelf on which Beisân stands looks like another similar shore-line, and thus, perhaps, the Beisân plain was also, at this period, under water.