Tent Work in Palestine: A Record of Discovery and Adventure

by C. R. Conder

The precise manner in which the slopes of the Palestine watershed fall towards the Ghôr differs in the different regions, but in principle it is the same throughout; there is everywhere a violent contortion of the strata, sometimes forming a fault or fissure running north and south, and sometimes a sharp dip down eastwards. We first studied the section above the Bukei’a, near Mar Saba, and here, as I have before noticed, there appears to be a well-defined fault. In the neighbourhood of Fusâil I found the rocks tilted up at an angle of 30°, and the same violent contortion has formed the great fissure of Wâdy el Hamâm, west of the Sea of Galilee. The Fâr’ah Valley is a great rent seemingly due to the same causes, and thus the whole of the geological evidence goes apparently to prove the occurrence of a violent and probably sudden collapse of the whole Jordan Valley commencing north of the Sea of Galilee.

This depression must have taken place at a comparatively late geological period; all the cretaceous rocks had been deposited before it occurred, for their strata all dip down east, on the west side of the valley. There are even the means of fixing the period pretty exactly, for there are marine formations deposited on the cretaceous rocks which seem to have no dip, namely, the coloured marls and bituminous limestones which occur at Neby Musa, and again at the edge of the plain of Beisân, in the first case 200 feet higher than the Mediterranean, in the latter, 200 feet below that level; these strata are, I believe, attributed to the Eocene period. It appears that even at an earlier epoch the region was bituminous: the latest of the cretaceous formations disturbed by the depression contain bitumen which seems to have been once liquid, and, near Masada, there are even black bituminous stalactites on the rock. The Eocene coloured marls contain innumerable fossils, and the formation appears to have been deposited under water. It is probable that in Eocene times the Dead Sea reached up nearly to Hermon, and to the Red Sea, with which the Mediterranean must have been then in full connection, as the Isthmus of Suez had not then been formed.

A further change was wrought still later, for the convulsions which were accompanied by the great outflow of lava which has covered so large a district west and north of the Sea of Galilee, and in the Lejja country, are, I believe, dated by geologists as of the Tertiary period, and in one place the lava appeared to me to overlie the coloured marls. The chain of Gilboa, Little Hermon, and Tabor, with the Galilean hills, have all been more or less affected by this volcanic disturbance, and perhaps the depression of the valley may then have increased still more.

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 “Sidd” 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 slave” (or perhaps better “the barren plateau”). 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 Kŭrŭntŭl; 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 Sŭrtŭbeh, 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.

From these observations we infer the gradual desiccation of the Jordan Valley; the Beisân Lake and the Jericho end of the Dead Sea having disappeared. Thus the present lake may be compared to one of the little pools on its own banks, left by the waves in the hollow of a rock, and gradually evaporating, surrounded by a crust of dry white salt. Into its thick oily waters—more than one-fourth part solid salt—the winter rains, and the streams from the salt springs, bring down all the chlorides which were once spread over the larger basin of the former great lake, and which are now accumulating in the smaller area, so that the sea seems to be almost in process of evaporating into a salt-marsh.

There is, however, a curious indication still to be noticed. Hitherto evaporation has been on the increase. Is this still the case? The fords near the Lisân, which used to be passable by donkeys, are said now to be much deeper than formerly, and Sheikh Jemîl, the most intelligent of the Arabs near Jericho, told me that in his father’s days the sea did not generally reach farther inland than the Rujm el Bahr, whereas now the connecting causeway is always under water. This represents a rise of some ten feet in the water-level. In fact, according to this statement, the sea has now more water in it than it used to have half a century ago.

If the theory of desiccation be correct, the idea that the Dead Sea was first formed at the time when the Cities of the Plain were overthrown is a fallacy. Geologists hold that the lake had reached its present condition before man was created, and thus the vale of Siddim is, no doubt, still represented by the district of the Sidds round the northern shores of the sea; for the four successive Dead Seas, which we have traced above, had all dried up before the days of Abraham.