(Large-size)THE CARAVAN ROUTESTO THEOASISOFKHARGA
(Large-size)THE CARAVAN ROUTESTO THEOASISOFKHARGA
(Large-size)
THE CARAVAN ROUTESTO THEOASISOFKHARGA
The main roads from the oasis run to Assiut, Kawâmil near Sohag, Waled Hallaf near Girga,Karnak near Farshut, and to Rizagat, Esna, and Edfu, and their disposition may be seen on the accompanying plan.
The Assiut road, after leaving Kharga village, passes the hamlet of Meheriq and follows the line of wells to Ain el Ghazâl, which is the last place at which water-skins and tanks can be filled. From Ain el Ghazâl the most direct route ascends to the plateau by the Ramlia pass in the extreme corner of the depression, but the Yabsa exit is recommended as easier and very little longer. After crossing a tract of country with an abominably rough surface, the two tracks unite a few kilometres north of the depression, and about a day’s march farther on the Zarâbi road takes off on the right. The main road proceeds direct to Assiut, descending the scarp about 8 kilometres before the town is reached, a by-path to the little village of Dronka having branched off beforehand.
From the summit of El Yabsa a separate road proceeds direct to El Ghennaim, a village on the edge of the desert to the north-west of Tahta. By these roads the distances from Kharga village to Assiut, Zarâbi, and El Ghennaim, are 210, 200, and 180 kilometres respectively.
El Refûf, the pass by which the Sohag (Kawâmil) road leaves the depression, is situated at the head of a gully, and offers an easy ascent to the plateau. A few kilometres beyond, the road passes to the north of El Shugera, a prominent detached block perched on end at the foot of the southern slope ofa small limestone range. The road runs in a fairly steady direction 40 degrees north of east, striking the Nile Valley scarp 15 kilometres before Kawâmil, on the edge of the cultivated lands, is reached. About 33 kilometres before reaching the scarp a branch takes off and runs nearly due north to Guhêna, south of Tahta; this branch is, in fact, usually referred to as the Tahta road.
If the traveller, after leaving the Refûf pass, keeps to the south of El Shugera, he will find a branch road leading to El Tundaba, a deep shaft in the centre of the plateau, at kilometre No. 92 on the railway; a little farther east this track strikes the main road from the Abu Sighawâl pass. The shaft is sunk through a thick deposit of silt, which has filled a local depression in the plateau to some depth. The silt must be regarded as rain-wash from the surrounding country, possibly deposited in the time of prehistoric man. Flint implements are to be found scattered about, and from the presence of pottery and graves it would seem that the place had been inhabited in comparatively modern times. The pit was evidently sunk for water, although at the present time it is quite dry; given, however, a heavy thunderstorm within the catchment-basin, drainage-water would in all probability find its way to the bottom of the deposit, where it would be held up by the limestone, and might form a supply lasting possibly for many years.
The road leaving the depression by the Abu Sighawâl pass, and leading to villages in the neighbourhoodof Girga and Farshut, is reckoned the best and shortest route between Kharga and the Nile Valley, and, by making a very short détour, caravans have the advantage of being able to water at the old Roman fort at the base of Jebel Ghennîma, 27 kilometres after leaving the village. The ascent of the pass was formerly very rough going, but a good road with an easy gradient has recently been cut for the transport of heavy boring machinery into the oasis. From the top of the Abu Sighawâl pass a well-marked track crosses to El Refûf and connects with the Sohag road, and care has to be taken by travellers for Waled Hallaf, El Elwania and Karnak not to make the initial mistake of getting on to this track.
For the first few kilometres the main road from Abu Sighawâl runs very straight over a level plain, on which fossil sea-urchins are so abundant as to attract the attention of the most casual observer; it then ascends a low escarpment, the Nagab el Jellab. The somewhat rough limestone country beyond is known as the Mishâbit, and then El Botîkh, with its countless millions of spherical chert concretions, is crossed. Beyond El Botîkh the road passes an isolated limestone hill called El Mograbi, where tradition has it that a Mograbi Arab from the west and his stolen oasis bride were overtaken and decapitated by the Kharga people. A little farther to the east there is a bifurcation, but the branches soon rejoin, and after passing El Masaâd the plain is fairly level, though coveredwith very angular blocks of crystalline limestone and cherty concretions. Farther on are the rocks of El Buraig, where large quantities of broken pottery indicate the site of one of the many water-stations maintained by the Romans along this road. Garat el Melh is so called from the occurrence of salt in the limestones of this locality. A few kilometres to the east of Garat el Melh the road passes El Suâga, an artificial heap of stones to which every self-respecting Bedawi is careful to contribute; and a couple of hours beyond, a fairly conspicuous limestone hill, called Garat Radwan, is reached.
Shortly after passing Garat Radwan the most prominent landmarks met with on this road, in the form of two solitary crescent-shape sand-dunes, loom into sight; these are called El Ghart by the Arabs and are distant 55 kilometres from Abu Sighawâl. They form part of a belt of single isolated dunes which crosses this part of the desert in a N.N.W. and S.S.E. direction. The same line of dunes is passed by the railway at kilometre No. 100, and I have observed its continuation still farther north on the Sohag road, at a point 45 kilometres from the Refûf pass. These dunes mark the entrance to an area of very rough hummocky crystalline limestone known as El Zizagat, through which the track is not easily followed. On emerging from El Zizagat the road bears slightly to the north, and is here only a few kilometres south of El Tundaba. At this point it bifurcates,the northern branch proceeding direct to Waled Hallaf near Girga, the southern continuing over the easy level plains of El Ishab to the rocks of El Baglûli, and thence past those of Dilail el Kelb to the twin hillocks of Dubîya. Beyond El Dubîya the road crosses the shallow drainage-line of Rod el Ghanam, near the head of the Wadi Samhûd, down which it passes, and thence over the Nile Valley plains past El Hamera and Hagar Hawara to Karnak and Farshut.
It should be mentioned that at Rod el Ghanam, shortly before reaching the head of the Wadi Samhûd, a branch road takes off on the left-hand side and descends by a separate pass to El Elwania; and here again care has to be exercised to avoid taking the wrong branch, as the tracks cover a broad area, and the actual junction may be easily missed.
The Kharga-Waled Hallaf road, via the Abu Sighawâl pass, is the shortest route from the oasis to the Nile Valley, the distance being only 160 kilometres; that to Karnak, by the Wadi Samhûd, is somewhat longer, being approximately 174 kilometres.
The next pass of importance to the south lies east of the village of Bulaq, whence it takes its name. From the summit a road runs nearly due east, meeting a second, starting from Beris and gaining the plateau by the Jaja pass, after one and a half days’ march. From the cross-roads, ‘El Mafâriq,’ routes run direct to Farshut and Rizagat.From Beris to Farshut, by the Jaja pass, the distance is approximately 224 kilometres; from Kharga, by the Bulaq pass, the roads to Farshut and Rizagat measure about 203 and 198 kilometres respectively. Another road from Beris leaves the depression by a pass to the east of the village of Dush; this bifurcates about two days’ march from the latter, the left-hand track leading to Esna, the right to Edfu. Other roads lead from the south end of the oasis, via Nakhail, to Kurkur and Dungun, while the Derb el Arbaîn runs southwards to Selîma and thence on to the Sudan.
The road between the oasis and Assiut is best known as being the last and worst portion of the Derb el Arbaîn, or forty days’ road, which, starting from Darfur, was originally one of the main lines of communication between Egypt and the Sudan. It was along this desert route that great numbers of slaves and large quantities of merchandise, such as ivory, gum, and other products of the Sudan, were imported into Egypt from the south. After passing the last spring in the oasis, caravans had still a little over 200 kilometres to cover before reaching the Nile Valley, with a steep ascent to the plateau at the outset, and thence for a considerable distance over the very worst surface imaginable—loose sand full of sharp angular blocks and fragments of flint and cherty limestone. Little wonder that, overladen and fatigued by the long distance already covered, the camels died in great numbers on this last stretch of road. Along mostdesert routes the dried bones of camels are of fairly frequent occurrence, but on the Derb el Arbaîn, between Kharga and Assiut, the skeletons of these poor beasts are met with in groups of tens and twenties, and must number hundreds and thousands. In many instances the skeleton still lies undisturbed, in the position assumed by the luckless animal in its death agony, the long neck curved back by muscular contraction so that the skull lies in contact with the spine. When one sees these remains, half buried in the sand, the bones bleached snow-white by a pitiless sun, with still adhering fragments of skin and muscle dried hard as adamant, one cannot but feel pity for those patient ‘ships of the desert,’ wrecked almost within sight of port.
Cailliaud, in 1817, observed the arrival at Assiut of a large caravan from Darfur, consisting of 16,000 individuals. It included 6,000 slaves—men, women, and children. He remarks: “They had been two months travelling in the deserts, in the most intense heat of the year; meagre, exhausted, and the aspect of death on their countenances, the spectacle strongly excited compassion.”
The actual width of the plateau varies from 120 kilometres between Abu Sighawâl and the scarp above Waled Hallaf, to 200 kilometres between Beris and Esna. The maximum elevation above sea-level is about 550 metres on the latitude of Esna, and on the whole the plateau has a fairly general slope to the north. As already mentioned, several distinct types of country, depending on thenature of the rocks constituting the surface strata, are met with. Smooth, hard, level plains, formed of a superficial layer of weathered limestone covered by a brown veneer of insoluble flint and cherty fragments, alternate with bare rugged rock desert of hummocky limestone. The sombre level or gently undulating flint-covered plains, frequently spoken of as ‘serir’ by the Arabs, have ideal surfaces for travelling; the light-coloured hummocky country, often called ‘kharafish,’ is in its most developed form made up of innumerable elongated hillocks, every portion of the exposed rock-surfaces being deeply scored; the furrows are separated by upstanding edges, often so sharp and knife-like as to be capable of injuring the feet of man and beast. The hillocks are separated by deep troughs half buried in drift-sand, all lying parallel, in the direction of the prevailing winds, so that progress in a latitudinal direction through this type of desert is a slow and tedious undertaking. Both types of country are equally desolate and barren, scrub of any description being of the rarest occurrence, except after local thunderstorms. Another type of country, to which we have already briefly alluded, is the curious desert-surface called El Botîkh (the water-melons), which results from the weathering of certain bands of the Lower Eocene formation containing numbers of large globular concretions; these, it may be mentioned, often lie so thickly strewn on the surface as to actually obstruct the passing caravan.
Kharga is connected with the oasis of Dakhla to the west by two roads, the lower and more southerly, known as the Derb el Ghubbâri, being the one most frequently used. This road, by taking a wide sweep to the south, avoids the intervening plateau altogether, so that the fatiguing ascent and descent are avoided. After leaving Kharga village the route leads past a group of wells, known as Ain Khenâfish, distant some 6 kilometres; thence it lies over wide-stretching plains of sandstone, leading up to the more broken country formed by the foot-hills of the towering plateau, which is always plainly visible on the north side of the road. The distance to Tenîda, the most easterly of the Dakhla villages, is 143 kilometres by the Derb el Ghubbâri.
The alternative route by way of Ain Amûr is appreciably shorter, though, owing to the extra time involved in negotiating the steep passes to and from the plateau, there is little saving in time when travelling with a heavily-laden caravan. Compared with the lower road, however, this route is much more interesting and picturesque, and the presence of water at Ain Amûr, about half-way between the two oases, is a distinct advantage. The road from Kharga village lies over a broad plain, whose only features are occasional conical hills of dark ferruginous sandstone. It follows a W.N.W. direction, heading for the great indentation to the west of the Jebel Tarif range. After getting well into the recess, but when still some15 kilometres from its head, the road turns abruptly to the south, and winds its way up an escarpment littered with huge blocks of tufaceous limestone. Perched near the summit of the cliffs stands the solitary palm which marks the site of the water-hole, in the immediate neighbourhood of which grows a fair amount of prickly scrub. The remains of mud-brick buildings and a stone temple show that this place was formerly inhabited, and of some importance.
The ascent to the plateau from Ain Amûr needs care with laden camels. The road proceeds up a narrow defile, the actual track being very rough, and so confined that in places the packs are liable to be dragged off by the rocks on either side. Once on the plateau the going becomes first rate, the freedom of the surface from blown sand being very noticeable. This is due to the isolation of this portion of the plateau-massif, which is cut off from the main mass to the north by the deep recess, and is bounded by a low-lying plain to the south. After a distance of 33 kilometres has been traversed the road descends into a narrow valley opening on to the low country to the south, and proceeds in a westerly direction to Tenîda. The distance from Kharga to Tenîda by this route is 128 kilometres.
It is possible on leaving Ain Amûr to cross to the top of the indentation, and thence to proceed across the plateau almost due west, striking the road from Assiut, known as the Derb el Tawîl, at the top of the pass 25 kilometres from the villageof Belat. There is, however, no track, and the surface is covered with parallel north and south ridges of rock, the crossing of which is extremely wearisome. Both near the head of the Ain Amûr recess and in the extreme north-west corner of the oasis very old tracks trending in westerly and northwesterly directions are observable, and although unused at the present day, these may mark the positions of formerly frequented routes leading to the oasis of Farafra. At the present time that oasis is not in direct communication with Kharga, the routes used being from Manfalut in the Nile Valley, from Qasr Dakhl in the oasis of Dakhla, and from Ain el Hais in Baharia.
Before leaving the subject of roads we must briefly refer to the route taken by the railway. The line, which has a gauge of 75 centimetres, was built by the Corporation of Western Egypt, Limited, to develop their concessions in the oasis. It commences at Mouaslet el Kharga, a new station on the Egyptian State Railway near Farshut, and crosses to the border of the desert, a few kilometres distant, by way of one of the embankments separating two of the great irrigation basins of Upper Egypt. At the edge of the desert is the station of El Qara, the point of departure for the oasis. After skirting the margin of the Nile Valley cultivation for a short distance it heads straight for the Wadi Samhûd, by means of which the plateau is gained without encountering any very heavy gradients. From the top of the Wadi Samhûdthe line follows the Abu Sighawâl road for about 40 kilometres, after which it diverges a few degrees and proceeds to El Tundaba, the shaft already described, 92 kilometres from Mouaslet el Kharga. From El Tundaba the railway follows more or less closely the cross-track, sometimes called the Derb el Refûf, which joins the Sohag road at El Shugera, and, entering the depression by the Refûf pass, follows down the gully, and thence across the plain to the station of Meheriq. From Meheriq it proceeds nearly due south to the Corporation’s headquarters, and thence on to its present terminus a few kilometres from Kharga village.
THE RAILWAY DESCENDING INTO THE OASIS.
THE RAILWAY DESCENDING INTO THE OASIS.
THE RAILWAY DESCENDING INTO THE OASIS.
My friend Ball lays great stress on the tortuous nature of the roads between the oasis and the valley, and recommends the scientific traveller to steer an independent course. But after traversing the majority of the main caravan roads, and with a fairly intimate knowledge of the characters of the intervening areas, I must say that, in my opinion, it would be difficult to better them. These roads were not laid out yesterday, but result from the accumulated experience of centuries. The original tracks may have been tortuous enough, but they have become straightened out by the cutting off of corners here and there, until at the present day the roads fulfil the three most important objects in view—the ascent and descent to and from the plateau at the points offering the easiest gradients, and the crossing of the plateau itself as directly aspossible over the smoothest and most level ground available. The roads give a wide berth to the outcrops of rough limestone, and anyone who has done much cross-country travelling in the Libyan Desert will appreciate their doing so.
Nor can I concur with the same author in his opinion that the Bedawin of this side of the Nile have a poor knowledge of their beloved desert. It is certainly true that the Arab does, for very good reasons, prefer to travel on the beaten tracks rather than undertake exploratory missions as the crow flies, his main object being to get to his destination as rapidly and easily as possible. If by chance, however, rain should fall on any portion of the desert, the Arab will very shortly be found there, taking full advantage of what Allah has provided in the way of free grazing for his herds. My own experience has been that the Arabs have among them a fair proportion of men with an extensive knowledge of the western desert, and I have frequently been struck by their wonderful knowledge of the roads and the facility with which many of them can follow the tracks on the blackest of nights, as even in broad daylight the landmarks which a European could recognize on second acquaintance are few and far between. The average Bedawi cannot be said to have exceptionally long sight, but he is frequently possessed of a wonderful sense of direction.
Travellers in the Egyptian deserts are apt to underrate the intelligence of the Bedawin, owing to the fact that they unconsciously form their impressionsfrom the miserable specimens of humanity so frequently sent out by the actual owners of the camels to act as drivers and attendants to a hired caravan. In such caravans there is seldom more than one man who knows the particular roads to be followed; the rest are wretched underfed creatures, generally half-breeds, who for a mere pittance tramp day after day, uncomplainingly and shoeless, alongside the caravan. They are much to be pitied, and it would be as unreasonable to expect them to have any special knowledge of the desert as it would be to look for information regarding, say, the mountains of Wales among the poorer classes of a Welsh town.
I do not wish to minimize the value of cross-country traverses carried out with special scientific objects; they are, indeed, often necessary for topographical and geological purposes. I would, however, warn the enthusiastic tyro that, in the Libyan Desert, travelling as the crow flies is not always so simple and glorious an affair as it may seem when planning expeditions from a comfortable arm-chair; and if his object is to get a short cut he will probably have reason to bitterly regret the moment he left the beaten track. I have in mind more than one instance where mistakes of this kind have been made, mistakes which might easily have led to disastrous consequences. In long cross-country traverses an error in steering of only two or three degrees will in a few marches throw a caravan many kilometres out of its course, and guiding camelsover rough country by compass is by no means an easy undertaking. Moreover, easily distinguishable landmarks are rare, and the desert plains over wide areas maintain remarkably persistent characteristics. Quite recently I recollect an Englishman, whose Arab attendant had become suddenly incapacitated by an attack of fever or sunstroke, getting hopelessly astray between the edge of the plateau overlooking the oasis and rail-head, which was then only 20 or 30 kilometres distant, in consequence of his missing the bifurcation of the road at El Shugera, and proceeding, owing to this mistake, along the route leading to Sohag.
Along the caravan roads the sharp fragments of rock have been stamped underground or kicked to one side, but elsewhere they usually litter the surface, and are very trying to camels, whose pads, though soft and yielding, are easily worn by much travelling over rough country. This has more than once been painfully impressed upon me by the antics of my own riding camel, whose mode of progression at such times resembled more the dance of a fanatic on red-hot coals than the ordinary gait of a well-bred ‘hegîn.’ Over some areas, however, one can travel in a straight line without let or hindrance, and in such cases it is only necessary to lay out the course correctly in the first instance, and to have the courage of one’s opinion to stick to that course until the destination is reached. One must not heed the remonstrances of the less sporting members of the expedition, who will lose no opportunityof predicting disaster, and in this respect the new chum fresh out from home is generally the greatest offender.
One of the longest cross-country traverses I myself have undertaken in the Libyan Desert was from Farafra Oasis to Assiut. The only road between that oasis and the Nile Valley strikes the latter near El Qusîya, midway between the towns Manfalut and Derut, so that travellers who wish to make Assiut have an additional day’s march southwards alongside the margin of the cultivated lands. On gaining the summit of the pass above Bir Murr, on the east side of the Farafra depression, I abandoned the road and set a course direct for Assiut, steering and plotting my route by compass and plane-table, the distance being reckoned by measuring-wheel. The most satisfactory method of procedure on desert traverses is to lay out a line, representing the correct bearing of the destination, along the centre of the longer axis of the plane-table, and then to steer to any well-marked object lying on either side, but within reasonable distance, of the proper course. At every station the exact position reached is plotted, and steps are taken, when selecting the next point on which to march, to converge towards the correct course marked down the centre of the table.
On this particular traverse I was unaccompanied by Europeans or Bedawin, my camel drivers being fellahin from the Nile Valley. The surface proved excellent going, and the Abu Mohariq belt of dunes,190 kilometres from Qasr Farafra, was crossed without trouble. Eight days after leaving Farafra village we struck the escarpment of the Nile Valley, having covered nearly 300 kilometres, and found we were marching on a point only very little to one side of the town of Assiut. From this traverse it was possible to calculate the longitude of Farafra with fair accuracy.
The normal rate of travelling of camels carrying ordinary loads weighing from three to four hundred-weight is 4 kilometres, or about 2½ miles, an hour, ten hours being the usual day’s march of caravans when accompanied by Europeans. The native caravans, carrying dates and other heavy merchandise, usually traverse the plateau in three days and nights, doing stages of 60 to 70 kilometres at a stretch. By travelling very light with trotting camels I have, on more than one occasion, crossed from the oasis to the valley in between thirty and thirty-five hours, doing from 180 to 190 kilometres in two stages of about twelve hours each, with one stop only of nine or ten hours.
Dimensions of the Oasis-Depression — Jebel Têr, Jebel Tarif, and other Hills within the Depression — Aspect of the Oasis from the surrounding Escarpments — Geological Sequence — Nature and Thickness of the Strata — Geological History of the Oasis — Formation of the Depression — Difference of Level of Strata on either side of the Depression — The Great Longitudinal Flexure — Height of the Floor compared with Sea-Level — Altitudes.
Kharga, the eastern of the two southern oases, is a depression lying with its longer axis north and south, mostly bounded by steep and lofty escarpments, but open to the south and south-west, on which sides the country rises gradually from the floor of the oasis. The extreme length of the depression, from the northern wall to Jebel Abu Bayan, which for convenience may be regarded as the southern limit of the oasis proper, is 185 kilometres, or 115 miles. The general trend of the eastern escarpment is nearly due north and south, but that on the west is very irregular, while to the south and south-west there is no definite boundary. The breadth of the depression may therefore be said to vary from 20 to 80 kilometres.
The ranges of Jebel Têr and Jebel Tarif form isolated hill-massifs in the centre of the northern part of the depression, while Jebel Ghennîma and Jebel Um el Ghennaim are conspicuous outliers of the plateau on the east side. With the exception of these, the floor is destitute of anything beyond comparatively insignificant eminences, unless we include the small range of hills known as the Gorn el Gennâh, to the south-east of the village of Gennâh, which is noticeable more on account of its sharply-defined peaks than of its general elevation above the surrounding country. Referring to the two conspicuous peaks, Ghennîma and Um el Ghennaim—Jimmy and Jemima, as I have heard them dubbed—reminds me that on the Survey and on some of the older maps the names are reversed. I have questioned a number of natives regarding the names of these hills, and have invariably been informed that Ghennîma is the more northerly of the two.
The villages, wells, and cultivated lands lie within a north and south band, occupying the lowest portion of the floor, and following the general trend of the depression. They are, however, broken up by a broad area of barren desert into two distinct north and south groups, of which Kharga and Beris villages are the chief centres respectively. A description of these is reserved for a later chapter.
When a traveller, after crossing the broad monotonous plateau, at length reaches the scarp or wall of the oasis, and sees spread out before him a vastdepression, stretching in some directions as far as the eye can reach, in others to the opposite bounding walls dimly discernible on the far horizon, he can hardly refrain from speculating as to the causes which have given rise to such huge hollows in the plateau. When he descends to the cultivated portions of the floor of the depression, and sees those numerous bubbling springs, which alone make life possible in the midst of this otherwise deadly wilderness, his second inquiry is as to whence comes such abundance of water in one of the most arid regions in the world. These questions are worth asking, and, so far as the present state of our knowledge permits, it will be my endeavour to answer them. I propose, therefore, to briefly place on record such information and data as I have been able to gain, but as both topography and water-supply are intimately connected with the geology of the district, it will be necessary at the outset to devote a few pages to a consideration of the latter.
THE CHRISTIAN NECROPOLIS AND JEBEL TER.
THE CHRISTIAN NECROPOLIS AND JEBEL TER.
THE CHRISTIAN NECROPOLIS AND JEBEL TER.
The geological deposits found in the oasis of Kharga are tabulated on the following page, commencing with those most recently formed. The succession, as shown in the table, is that which obtains in the northern part of the depression, but as far as is known the same stages occur throughout the oasis, and do not vary either in thickness or in lithological characters to any great extent. Over large areas the lower-lying parts of the oasis-floor are formed of those beds which we have designated the Surface-water Sandstone, though in
places the still older underlying grey shales are exposed. The purple or red shales generally form the rising ground towards the escarpments, at the base of which are usually found the phosphatic beds, with hard, pronounced bands made up of fish-remains and phosphatic nodules. Above come the Exogyra Beds, with thick bands of limestone almost entirely composed of large oyster-shells. Rising up above these is the generally well-marked cliff of grey shales, capped by a snow-white chalk of much the same age geologically as the well-known chalk of the South of England. The summit of the chalk frequently forms a separate plateau, subsidiary to the high desert tableland, and separated from it by the cliffs formed of the massive Eocene limestones.
The total thickness of the exposed strata is about 435 metres, a figure obtained by actual measurement.Numerous borings show the thickness of the unexposed underlying Impermeable Grey Shales to be 75 metres, and the deepest borings yet made have pierced the still lower Artesian-water Sandstone to a depth of 120 metres, making a grand total of known deposits of 630 metres, or 2,067 feet. The depth to which the water-bearing sandstone extends is at present a matter of speculation; the point is of great importance in connection with the water-supply, though up to the present no borings of sufficient depth have been made to determine its thickness, nature, and relation to the underlying igneous rocks.
With the exception of a few isolated bosses of eruptive rock in the desert to the south of the oasis—indications of the granitic foundation which probably underlies the entire area—the geological deposits of the oasis-depression, and of the surrounding escarpments and plateaux, are entirely of sedimentary origin, that is to say, they were laid down on the shores and beds of pre-existing seas and inland lakes. The sand-dunes are, of course, an exception, having been deposited by the wind on the surface of the land. Although, geologically speaking, the oldest group of sediments with which we have to deal belongs to the later chapters of the earth’s history, many hundreds of thousands of years have elapsed since the sandstones and shales, now forming and underlying the floor of the oasis, were accumulated on the bed of a vast inland lake. This sheet of comparatively fresh water was theninvaded by the sea, which held sway in the region while the whole of the series of sediments, now exposed in the cliffs of the oasis and some 350 metres in thickness, were being laid down. In Middle Eocene times the sea commenced to retreat to the north, and the area under description became dry land with a continually receding shore-line. Since that time the forces of denudation have constantly been at work lowering the general surface of the plateau and excavating those depressions in which alone at the present day man is able to exist.
The Egyptian oases are deep and extensive depressions or hollows cut down nearly to sea-level through the generally horizontal rocks forming the Libyan Desert plateaux, and appear to owe their origin in great measure to the differential effects of subaërial denudation acting on rock-masses of varying hardness and composition. The surface-features or configuration of almost any land which has long been exposed to the powerful forces of erosion are more or less intimately dependent on the structure and lithological characters of the underlying rocks. On relative hardness, more than on anything else perhaps, depend the ultimate positions of mountains, hills, and plateaux on the one hand, of valleys, plains, and depressions on the other. Variation in the original conditions of deposition, at the time when the rocks now forming the Libyan Desert were laid down on the floor of the sea, has resulted in a preponderant development in some areas of soft clayey or sandy rocks (as comparedwith the hard limestones), and subsequent earth-movements have raised these beds more in some districts than in others. The result has been that wherever, during the gradual denudation to which the country since its elevation has been subjected, these soft deposits have become exposed on the surface, weathering has proceeded at a greatly increased rate, and eventually produced deep and broad depressions separated by high limestone tablelands.
(Large-size)SKETCH MAPSHOWINGTHEGEOLOGYAND THEANCIENT LAKESOF THEOASISOFKHARGA
(Large-size)SKETCH MAPSHOWINGTHEGEOLOGYAND THEANCIENT LAKESOF THEOASISOFKHARGA
(Large-size)
SKETCH MAPSHOWINGTHEGEOLOGYAND THEANCIENT LAKESOF THEOASISOFKHARGA
But for the presence of comparatively soft formations such as the Esna Shales, the Exogyra Beds, and the Nubian Sandstone, coupled with the facts that they have an unequal development in different areas, and occur at a greater elevation in some localities than in others, the great depressions of the Libyan Desert would not have come into existence, or at any rate would have been of comparatively little importance in the configuration of the country.
The oases are true depressions, completely or partially surrounded by high escarpments. The oasis of Baharia, for instance, is on all sides hemmed in by cliffs; on the other hand, Dakhla and Kharga are open to the south, but as the ground in that direction rises considerably, they, too, cannot be regarded as other than true depressions. We have no definite grounds for considering that the erosion of these depressions can have been the work of previously existing rivers, and there is no evidence to warrant us in assuming them to have been formed by local subsidence of portions of the earth’s crust.
What, then, were the agents of denudation and transportation which operated in the formation of these great depressions? Under the existing arid conditions the surface rocks, unprotected by vegetation, are rapidly disintegrated or weathered as the result of the great diurnal variations of temperature to which they are subjected (insolation). The weathered material, however, does not accumulate and form a protective soil-cap, but is carried away by the wind (deflation), the heavier siliceous grains effecting an immense amount of abrasion of the exposed rock-surfaces over which they are swept. Changes of temperature, sand, and wind are, indeed, the chief agents of erosion and transportation at the present day, and, given a sufficiency of time and a continuance of favourable conditions, we can confidently admit the combination to be capable of effecting a vast amount of earth-sculpture. But the formation, in this way, of huge hollows 300 to 400 metres deep, and the removal of material amounting to hundreds of cubic kilometres, would necessitate the assumption that the present rigorous desert conditions have obtained for a very considerable period.
Taking all the available evidence of which we are cognizant into consideration, we do not feel justified in assuming this to have been the case, especially when we recollect the frequent presence on the escarpments of thick deposits of calcareous tufa, which it is evident must have been laid down after the depression had been carved out to a considerabledepth. These tufas are almost certainly of Pleistocene age, though whether they date from the early or late part of that period has not been determined. In some localities they occur as thick, horizontally-stratified beds, and were evidently deposited on the bottoms of lakes; in other places they appear as fan-like cakes spread over the face of the cliff, and may have been formed by springs situated near the summits of the escarpments. The tufas frequently contain large numbers of fresh-water shells and an abundance of fossil vegetation, and, from the presence of casts of the leaves of such trees as the oak, one is led to refer the deposit to the more humid period which preceded the incoming of the modern desert conditions.
Although the evidence met with in the field is altogether against the idea that portions of the plateau have been bodily let down by subsidence, there are good reasons for believing that tectonic movements have played an important part in deciding the general shape of the oases-depressions. For instance, there is considerable parallelism between the general trend of the Baharia depression and the folds which pass through that region. As a result of those folds, it is not improbable that the hard limestone beds were to some extent broken up, and the soft underlying clays and sandstones raised as compared with their position on either side of the folded belt. In Kharga, similarly, the main axis of the depression is, as we shall show, distinctly parallel to the great north and south line of flexure, andthere is little doubt that a close connection exists between the two. On the other hand, I know of no folding in the case of Farafra, which appears to owe its existence solely to the fact that there was in that region an unusual development of shales at the base of the Eocene nummulitic limestones. Of the four Egyptian oases, perhaps Dakhla is the one most easily accounted for, as this depression may be regarded as simply due to the general northerly dip of the sedimentary formations, and the gradual weathering back (northwards) of the great argillaceous series (Exogyra Beds) capped by the White Chalk. The original limits of the latter may, indeed, never have been very far to the south.[3]
While all sedimentary strata—such as the limestones, sandstones, clays, and shales with which we are now dealing—were originally deposited either quite horizontally or inclined at only a very low angle, it by no means follows that this horizontality is maintained when the strata are elevated into dryland. Over the Libyan Desert as a whole the successive sedimentary formations dip steadily northwards, but at a very small inclination. This results in every stage having a wide outcrop, so much so that, if it were not for the cliff-sections of the Nile Valley and the oases-depressions, we should have to travel immense distances to obtain any idea of the true succession of rocks. This general horizontality of strata appears at first sight to be well maintained in the oasis of Kharga, as whether we stand on the summit of the eastern escarpment, on top of the great central hill-massif of Jebel Tarif, or on the plateau above Ain Amûr, we see everywhere horizontally-disposed beds of limestone forming the plateaux and upper portions of the cliffs, with parallel bands of sandstone, shale, and chalk outcropping on the slopes below.
A closer examination, however, will show that there is in reality a difference in level of more than 200 metres between the same beds on either side of the oasis; for the beds capping Jebel Tarif belong to the White Chalk of the Cretaceous system, and are therefore very much older than those of Eocene age forming the eastern plateau (see map and section). This great difference in vertical position is due partly to a steady dip from west to east, partly to a remarkable longitudinal flexure running north and south through the centre of the depression, and partly to a gentle fold near the base of the eastern escarpment. Along the actual line of flexure, which passes through Jebel Têr, JebelTarwan, Nadûra, Gorn el Gennâh, and Gertuma (S.S.E. of Bulaq), the different rock-stages are folded and fractured to a remarkable degree. Throughout the greater part of its course the flexure approximates to the type of disturbance known as a simple monocline, but in places, as in Jebel Têr, it passes into a syncline bounded by nearly vertical faults; while in others the beds are bent into almost symmetrical basins or centroclinal folds, typical examples of these structures being met with at points 6 kilometres south of Kharga village and 2 kilometres south-west of Qasr Zaiyan.
The importance of this line of folding and faulting must not be lost sight of, as although the dislocations produced are only actually visible in the case of the exposed upper beds of the oasis sequence, the earth-movements to which it owes its origin have had similar disturbing effects on the underlying and hidden water-bearing strata. Ball reported that the most striking evidence of faulting was between Jebel Têr and Jebel Tarif, and showed the fault as running for a short distance in a N.N.E. and S.S.W. direction, but, as already mentioned, the line of disturbance is coincident with the longer axis of the former range, so that the majority of the wells are on the west or upthrow side of the fault. The effects of this faulting and folding on the underground water-supply will be further alluded to in a later chapter.
In the early summer of this year (1908) I followed the line of flexure southwards in order to determinewhether it continued throughout the oasis. As far as the small eminence of Gala, about 10 kilometres south of Bulaq, it ran in an almost straight line, but south of that point its course took a distinct bend to the west, so that the fold was very soon lost in the great belt of sand-dunes. Beyond this point its continuation could, however, be inferred by occasional exposures of steeply inclined sandstones, the most southerly point to which it was actually traced being in latitude 24° 55′ N., about 15 kilometres S.S.W. of Ain Girm Meshîm.
(Large-size)GEOLOGICAL SECTION ACROSS THE OASIS FROM JEBEL TARIF TO THE EASTERN ESCARPMENT.
(Large-size)GEOLOGICAL SECTION ACROSS THE OASIS FROM JEBEL TARIF TO THE EASTERN ESCARPMENT.
(Large-size)
GEOLOGICAL SECTION ACROSS THE OASIS FROM JEBEL TARIF TO THE EASTERN ESCARPMENT.
Before concluding our remarks on the geology of the oasis we must not omit to call attention to the beautiful and varied fossil remains which are almost everywhere to be met with in the calcareous beds of the hills and escarpments. It is, of course, by the study and comparison of these organic remains that geologists are enabled to determine the relative ages of the beds in which they occur, and thus to correlate them with the rocks of other countries. The lower argillaceous and arenaceous deposits of the oasis are comparatively unfossiliferous.
From any of the points of vantage, such as are afforded by the higher hills within the depression, the general level of the floor of the oasis does not appear to vary to any great extent, but actual levelling shows that this is not in reality the case; and it is this variation of absolute level which is the primary cause of the very varying volumes of water yielded by the artesian wells in the different districts.
The average height of the centre of the depression in the neighbourhood of the village of Kharga is approximately the same as that of the Nile Valley plain in the latitude of Farshut.
Ball, by comparison of a series of aneroid barometer readings with the barometric records for the same period at the Cairo observatory, deduced the value of a point near Kharga village as 86 metres above sea-level, and used this as his datum in calculating the levels of other parts of the oasis. Previous aneroid determinations of the same point had been made by Cailliaud (104 and 118 metres) and by Jordan (68 metres). But even when the greatest possible precautions are exercised, aneroid determinations, especially when made with a single instrument, are necessarily unreliable, and still more so when used for calculating the levels of different points on a plain having only comparatively slight irregularities of surface.
Utilizing the figure obtained by the railway surveyors for a point near the termination of the line, we get values of 58 and 60 metres above sea-level for Kharga village and Bore No. 1 at headquarters respectively, and a bench-mark at the latter place, having a value of 60·1, is used as the datum from which all the heights given in this book are calculated. Unfortunately it is not possible, owing to the lack of sufficient check-levels, to state the limit of probable error, and it must therefore be understood that the value of our datum, which in the meantime may be accepted as the best obtainable, is subject to future revision.
From this central point (Bore No. 1) lines of levels have recently been carried in every direction by Mr. F. E. Apted and myself, with the result that it has been shown that the general level of the floor of the oasis rises steadily to the north and falls to the south. These levels have in all cases been checked, and may, using the datum mentioned, be accepted as fairly reliable, the closing errors on the different loops being generally within a very few centimetres. The altitudes of a few reference points in each district are given here.
The Government Survey maps show a portion of the oasis floor as lying below sea-level, the differenceof height between the Kharga village datum and a point just south of Qasr Zaiyan being given as 104 metres. Detailed surveying shows that this estimate is excessive, the true difference being about 37 metres only. Although no actual reading has yet been obtained below sea-level—the lowest being +2·6 metres at a point 3½ kilometres north-east of the northern end of the Gorn el Gennâh, or nearly midway between that hill and Ain el Tawîl—it is evident that in this district the floor is only very slightly higher than the sea, and it may be that at one or two points its level is actually lower.
South of Qasr Zaiyan no revision of previous levels has as yet been made. According to Ball’s figures, the village of Beris is approximately 10 metres lower than Kharga.
While discussing the subject of levels it may be useful to note the relative heights of the escarpments and hills within the oasis. The edge of the eastern plateau varies from 350 to 400 metres above sea-level, while the plateau to the north of Um el Dabâdib has a general level of about 400 metres. Jebel Tarif appears to be very slightly higher, while the highest peak on Jebel Têr is not much more than 300 metres. The altitudes of these points with reference to the village were mostly determined by Ball by trigonometric observations with an eight-inch theodolite, and can therefore be relied on as being accurate.
Population — Relation of Population to Water-Supply — Trade in Dates — Imports — Taxation on Date-Palms and Wells — Measurement of Wells — Revenue derived from the Oasis — Origin of Inhabitants — Kharga Village — Industries — Ancient and Modern Wells — Meheriq Village — Troubles with Sand — Migration of Villagers — Ain el Tawîl and other Hamlets — Gennâh Village — Famous Wells — Ain Estakherab — Ochreous Waters of certain Wells — Ain el Ghuâta — Bulaq Village — Doum-Palms — Tomb of Sheikh Khalid Ibn el Walîd.
Inpoint of population Kharga ranks second of the four great oases of the Libyan Desert. In 1897 the inhabitants numbered 7,856, and ten years later had increased to 8,348. The 1907 census showed the male to be slightly in excess of the female population, a result entirely owing to the preponderance of men in the northern part of the oasis. The present distribution of the inhabitants, according to the last census, is shown in the table on the following page.
In the oases of the Libyan Desert there is a very close connection between population and water-supply. No water is intentionally allowed to run to waste, every drop being utilized to raise
the crops of rice, dates, barley, and wheat, which form the staple food-supplies of the inhabitants. Cut off by a waterless desert, these people have little intercourse with the outside world, except for a few weeks in the early winter months, when they dispose of their surplus date-crop to the Bedawin traders who cross the desert with droves of camels from the Nile Valley. The dates are usually paid for in cash, ready-money being required in order to meet the annual taxes levied by the Egyptian Government. Practically the only food-stuffs imported consist of such commodities as tea, coffee, and sugar, which are used sparingly, and regarded as luxuries even by the better classes.
It is evident, therefore, that the inhabitants rely almost entirely for subsistence on the products they are able to raise by their own toil and industry. Owing to there being no rainfall, the acreage of land which can be put under crops depends absolutely on the amount of water available for irrigation by wells. The total yield of the latter has, we know, fluctuated to a considerableextent at different times, and one may surmise that, could figures be obtained giving the number of inhabitants and the volume of the water-supply for different periods during the last 5,000 years, a remarkably constant ratio would be observable between the two.
Taxes are levied by the Egyptian Government on both date-trees and wells. Over 60,000 adult palms exist in the oasis, each one being subject to a yearly tax of 1½ piastres (about 3½d.). The output or yield of a well is, for purposes of taxation, determined in a somewhat rough-and-ready manner by a method which appears to have been in use for a number of generations. Whenever a new bore is completed, or an old well requires remeasurement, all the most influential personages in the oasis, headed by the Omda or chief of Kharga village, armed with a number of primitive appliances, solemnly proceed to the spot.
After first ascertaining that the well has not been temporarily blocked by interested persons—even here in the remote interior of the desert there is an inherent objection to the paying of taxes—the bed and sides of the water-channel are made as smooth as possible for a distance of five or ten paces below the mouth of the well, so that the water flows away with an even ripple. A small pointed stick is now inserted in the centre of the bed of the stream, in such a way that the top of the peg is exactly flush with the surface of the water. Then the Omda, hitching up his flowing robes, steps into the stream,and, selecting a gauge of suitable dimensions, fixes it firmly in the bed of the channel, in such a position that the whole of the flow passes freely through, without raising or lowering the surface of the stream above, as indicated by the peg. The interior of the gauge, a roughly-made wooden frame, is intended to be a definite number of centimetres in length, but in many of those used there is a small error. As soon as the stream flows evenly over the gauge or weir, without its surface-level being altered, the depth of water is measured on a scale. The latter is wetted and plunged into a heap of dry sand before being used, the depth of water being indicated by that portion of the scale from which the sand has been removed by the immersion. Observations are made at both ends of the weir to insure any error due to want of horizontality of the frame being detected.
The actual discharge is reckoned in ‘qirats’ and eighths of a qirat (tumns), a qirat being a water-section of 64 square centimetres. For example, if the depth of water passing over a gauge having an internal length of 40 centimetres was found to be 8 centimetres, the water-section would amount to 40 × 8 = 320 square centimetres, which would be reckoned as a discharge of 5 qirats.
The Omda and his attendants carry out the operations with the utmost care and solemnity, and have the most touching faith in the accuracy of their results. Apart, however, from errors in the gauges and scales used, and from the want ofprovision of a free fall on the downstream side of the weir, the fact that the velocity of the stream is entirely left out of account is sufficient to give the qirat a very variable value, low for small and high for large streams, the result being that the small wells are being taxed at about 50 per cent. higher rates than the large ones. In order to ascertain the average value of the qirat for streams of different size, I arranged with Mr. Patterson, who at the time was the Government Representative in Kharga, to send the Omda to headquarters and instruct him to measure a number of new bores belonging to the Corporation of Western Egypt, as these bores, being cased and provided with proper outlet valves, lend themselves to exact measurement better than the majority of the native-owned wells. The Omda employed the ordinary local native method just described, while I, using a tank of known capacity and a reliable stop-watch, made direct measurements immediately afterwards. The results obtained show that below 2 the qirat has a value of 22 gallons a minute; from 2 to 4 of 26 gallons a minute; and from 5 to 6 of 38 gallons a minute.
The annual tax levied on the water amounts to 50 piastres (about 10s. 3d.) per qirat. If the average value of the qirat be taken at 25 gallons per minute, the tax works out at approximately 1s. for every 6,000 cubic metres of water. Looked at from another point of view, it may be considered that the tax amounts to about 1s. 6d. an acre, as with every qirat of water the native cultivator inthe oasis will annually raise about two acres of rice and five of wheat or barley.
The total revenue derived by the Government from the oasis, by taxes on date-palms and water, amounts to a little over £1,000 per annum.
My old friend Sheikh Mustapha, who for more than twelve years has been Omda of Kharga village, was very anxious to know the results of the comparative measurements made on the bores. He professed himself as surprised at the difference in the results, but emphatically refused to entertain the possibility of there being any error in his measurements, made by so old-established a method. Although he was far too polite to so express himself in words, I felt that the old gentleman had the utmost contempt for my method of well measurement.
With the exception of the Dakhla peasants, the inhabitants of the oases differ entirely from the fellahin of the Nile Valley. According to Brugsch, the original inhabitants were Libyan (Berber) tribes, but after annexation to Egypt, there was considerable immigration from Nubia and other parts of the Nile Valley. Nevertheless, in the oasis of Kharga the physiognomic type of the Berber race is still predominant.
El Kharga, the chief village of the oasis, containing about 4,500 inhabitants, is situated in a broad belt of cultivated lands and palm-groves running centrally down the depression from the southern extremity of Jebel Têr. The villageconsists of a picturesque compact conglomeration of houses, built of sun-dried bricks, and of every shape and size. The streets meander in a very remarkable manner, and are to a large extent in partial or total darkness, owing to their being for the most part roofed over and covered by upper storeys. Without the aid of a guide it is almost impossible to find one’s way through the intricacies of the underground passages, though no fears need be entertained on the score of being in any way molested, the inhabitants being most peaceably inclined. In some parts of the village the streets are actually cut through the solid rock. They are generally clean and cool even on the hottest and dustiest of days, and as a rule the few wayfarers one meets scuttle like startled rabbits into the dark recesses on either side, from the depths of which, and through chinks in the wooden doors and windows, they can gape in safety at the unwonted spectacle of European visitors.