CONTENTS.

PREFACE

CHAPTER I.

The Oasis of Baharia (or Northern Oasis), also known as the Little Oasis, lies between the parallels 27° 48′ and 28° 30′ of north latitude, and between the meridians 28° 35′ and 29° 10′ east of Greenwich, being thus situated in the Libyan Desert about 180 kilometres, or four to five days’ march by camel, west of the Nile Valley (Sketchmap, Plate II). Like the other oases of the Western Desert (Farafra, Dakhla and Kharga) to the south, Baharia is a large natural excavation in the great Libyan plateau; it differs, however, from those oases, which are open on one or more sides, in being entirely surrounded by escarpments, and the vast number of isolated hills within the depression form an unique topographical feature. In Baharia, as, with the exception of Dakhla, in the oases generally, the cultivated area bears only a very small proportion to the total oasis-area, the remainder of the floor of the natural excavation being barren desert. The oasis contains four principal villages, all situated in its northern portion, and it is in the neighbourhood of these that water, and consequently vegetation, is most abundant.

The early history of Baharia is shrouded in an obscurity greater even than that surrounding the history of Kharga. That it was inhabited at a very early date is shown however by a stela of the reign of Thothmes II (about B.C. 1600-1500) found there by Ascherson, by a tomb of the 19th dynasty (B.C. 1300) and fragments of two temples, one dating from the reign of King Apries (B.C. 588-570) and the other from the reign of Amasis (B.C. 569-526), discovered by Steindorff in 1900, and by the references to it in the Ptolemaic inscriptions of the temple of Edfu. The oasis of Baharia is referred to in the hieroglyphic inscriptions of its newly-discovered temples as “the northern oasis of Amenhotep,” and as “the oasis Huye”; by Strabo it is called δεύτερα “the second” and by Ptolemy ὄασις μικρὰ “the small oasis.” The Romans have left traces of their occupation of Baharia in an arch near the village of El Qasr[1] and other ruins, as well as in numerous wells and underground aqueducts, which latter are still used by the present inhabitants. Fragmentary ruins of churches and a Coptic village attest the fact of the occupation of the place during Christian times. At present Baharia, along with the neighbouring oasis of Farafra to the south, is administered as part of the Mudiria of Minia, and is fairly prosperous, though lacking in enterprise to an even greater extent than is shown by the two southern oases of Dakhla and Kharga.

The first European traveller to reach the oasis of Baharia appears to have been Belzoni,[2] who reached it from Beni Suef on May 26th, 1819, and after spending some eleven days there returned by the same route. Though his observations appear to have been correctly made, the description of his travels is largely coloured by imagination, and his map appears only to have been a rough sketch. He erroneously confused Baharia with the oasis of Jupiter Ammon, whose temple he imagined he had found in the remains of the Roman arch near El Qasr, the chief village of the oasis. It is hardly necessary to remark that the oasis of Jupiter Ammon is really that now known as Siwa, situated some 340 kilometres west-north-west of Baharia.

The earliest connected modern account of the oasis of any value is that of Cailliaud,[3] who with Letorzec visited the place in 1820 on his way from Siwa to Farafra, and during a stay of about six weeks examined and mapped some of its principal features. He drew attention to its antiquities and gave a careful description of the hot springs and ancient aqueducts, besides taking a number of observations of latitude and noting some of the topographical and geological features, such as the occurrence of volcanic rocks in the oasis. Cailliaud records his meeting in Baharia with Hyde, an English traveller, who, however, does not appear to have published any account of his wanderings.

In the winter of 1823-1824 Baharia was visited by Pacho in company with F. Muller. In an account of Pacho’s travels[4] published after his unhappy death, there is no reference to his observations in this oasis beyond an indication of his route on the map.

Wilkinson[5] visited the oasis of Baharia in 1825.

The Rohlfs’ expedition of 1874,[6] with the distinguished scientists K. von Zittel and W. Jordan as geologist and topographer respectively, added very considerably to our knowledge of Baharia, more especially in the way of fixing precisely the geographical positions and levels of its principal points. Zittel, however, did not visit this oasis, and in consequence its geological structure was not studied, the few references to it made in the publications of the Rohlfs’ expedition being based on an examination of specimens collected by Ascherson.

Probably the most accurate map hitherto existing of Baharia Oasis is that of Ascherson,[7] who spent nearly three months there in 1876. Ascherson, who entered the oasis by the road from the Fayum and returned to Samalut, chiefly directed his attention to botanical observations, but his memoir contains some valuable topographical and geological information which supplements that of previous and later observers in important measure; he has also the distinction of finding the stela of the reign of Thothmes III already referred to, and the remains of an Egyptian temple; the latter is probably identical with one of those discovered by Steindorff in 1900.

The short memoir by Capt. H. G. Lyons, R.E.,[8] published in 1894, brought together a number of observations on the geology of the Libyan Desert generally, and his discovery of fossils, referred to Exogyra Overwegi, for the first time established the Upper Cretaceous age of the clays and sandstones forming the floor and lower part of the scarp in the northern end of the depression.

In 1897 the Geological Survey carried out its examination, the results of which are set forth in the following chapters.

Since the survey expedition, Baharia has been visited by Steindorff,[9] who during his five days’ stay in the oasis made important additions to our knowledge of its antiquities. These will be further referred to in the chapter on the topography of the oasis.

CHAPTER II.

Crossing the Libyan Desert from Maghagha and Minia respectively, the two parties of the Geological Survey met at a joint camp close to Zubbo, one of the chief villages of the oasis. It was desirable to fix this meeting-point as a primary station for the subsequent plotting of the maps. Cailliaud[10] gave the latitude of Zubbo as 28° 21′ 47″, and its longitude as 26° 43′ 46″ E. of Paris, (equivalent to 29° 3′ 55″ E. of Greenwich). Jordan gave for Bawitti the position N. lat. 28° 21′ 12″, long. E. of Greenwich 28° 56′ 45″. Taking the difference of latitude and longitude between Bawitti and Zubbo as found by the Survey, viz., lat. + 55″, long. + 4′ 16″, we have as the equivalent of Jordan’s latitude for Zubbo 28° 22′ 7″, and for his longitude 29° 1′ 1″ E. of Greenwich. Thus, while there is a fair agreement between the two authors as regards latitude, there is a difference of 2′ 54″ in the values of the longitude.

The longitude is of course always the difficult matter in the geographical determination of places not easy of access. Cailliaud’s value rests on the method of distance and azimuths, both roughly determined only; Jordan, on the other hand, used the absolute though not very precise method of lunar distances measured with a sextant. The Survey parties depended entirely on direct measurement by means of measuring-wheels from known points in the Nile Valley; the values obtained in this way are tabulated below[11].

I.—Traverse from Maghagha to Zubbo.

II.—Traverse from Minia to Zubbo.

III.—Traverse from Zubbo to Minia, via the south end of the Oasis.

The arithmetic mean of these three determinations is 28° 56′ 55″; owing, however, to the breakdown of the measuring-wheel during the outward traverse from Maghagha, and the consequent necessity of estimating a part of the distance traversed by the time taken in marching, the different traverses are not equal in value, and the longitude finally adopted by the survey, as the best approximation after investigation of the various sources of error in the measurements, was 28° 58′ 34″. It would thus appear that Jordan’s position may be a little too far east, the difference amounting to 2′ 27″, or about 3½ kilometres, while Cailliaud’s value would place the position at a rather less distance west of that adopted.

The survey observations confirmed the accuracy of Jordan’s latitude (28° 22′ 7″), from which the value found by Cailliaud differs, as already remarked, only slightly.

The surveying operations within the oasis were based on a rapid plane-table triangulation from a measured base line within it, details being simultaneously sketched in, on a scale of ¹⁄₅₀₀₀₀. The site chosen for the base was a level stretch of ground extending between the camp at Zubbo and an isolated clump of date-palms to the north-east; the length of this line was found by repeated wheel-measurement to be 3·88 kilometres. The two parties ran off their triangulations from this base to the surrounding hills, and carried on the mapping southward by plane-table, taking stations chiefly on the hills and prominent points of the scarps, and not meeting again till Ain el Haiss, in the southern part of the oasis, was reached. Here a test was made as to agreement of the two sets of maps, only a small difference being found. The position of Ain el Haiss, as found by taking the mean of the two determinations, is latitude 28° 2′ 11″ N., longitude 28° 39′ 19″ E. of Greenwich; this places the spring about 4′ 18″ east of Jordan’s determination (lat. 28° 1′ 55″ N., long. 28° 13′ 47″ E. of Green.).

The two parties made a third connection at the extreme south end of the oasis-depression. Our observations for this point give its latitude as 27° 48′ 13″ N., and its longitude as 28° 32′ 19″ E. of Greenwich, placing it very near the position shown on Jordan’s map.

The plane-table method making use of the magnetic meridian, it was imperative to determine the amount of declination of the compass. This was done at one point only, viz., at the south end of the oasis, the value found (by observation of the transit of Polaris) being 4° 50′ W. The declination is fairly constant over the entire area, except near the eruptive dolerite masses, the magnetite in which causes a very sensible deflection of the needle; in the neighbourhood of these, however, the surveying was carried on independently of the compass. With regard to the yearly change of declination, we have as data the previous observations of Cailliaud, who found the declination at Zubbo in January, 1820, to be 12° 13′ W.; of Jordan, who obtained the value 6° 56′ W. in March, 1874; and of Capt. Lyons,[12] whose observations with a Bamberg declinatorium at Mandisha in April, 1894, gave the value 5° 8·9′ W. Tabulating these:—

In view of the magnitude of the diurnal variation, which may range up to 10′ of arc, and our present lack of knowledge of the distribution of this diurnal variation during the twenty-four hours, a comparison after so short an interval as that between the last two observations is not to be trusted. It would seem proved from the three foregoing observations that the yearly variation is at present decreasing, the mean from 1820 to 1874 being 6′·3 as against 4′·2 for the period 1874-1894. This decrease is also noticeable in comparisons of the declinations observed at different times in other parts of Egypt.

The altitudes above sea-level of the principal points, more especially in the eastern half of the oasis, were determined with a Watkin aneroid barometer, which had been compared with the Cairo standard mercurial barometer. A fairly long stay was made at the Zubbo camp, and the altitude of this point may be regarded as fairly accurately fixed by the observations tabulated below:—

Since 1 mm. of mercury corresponds at the mean temperature of observation (20° C.) to 11·4 metres of height, we have height of Zubbo camp above Cairo observatory = 8·32 × 11·4 = 94·7, or say 95 metres. Since the observatory is 33 metres above sea-level, the camp at Zubbo is 128 metres above sea-level. Jordan’s altitude for Bawitti, which probably lies at about the same level as Zubbo, is 113 metres, and when it is remembered that the point of the Survey’s observation lay not in Zubbo itself, but at the camp on elevated ground some 10 or 12 metres above it, the results show a very good agreement.

At Ain el Haiss three barometric observations were taken on different days; the comparison of these with the Cairo records would place this point 156 metres above sea-level. Jordan’s value is 122 metres, the number of observations on which this figure is based not being stated, it is difficult to say which of the two altitudes is the more probable.

At the remaining camps within the oasis, and at the camps en route between the oasis and Minia, corresponding observations were taken, the number of comparisons with Cairo varying from two to seven at an individual station. These observations being reduced and corrected by comparison among themselves gave the levels of the different camps with some degree of approximation to accuracy, and the altitudes of intermediate points were found by interpolation based on barometric readings. The resulting altitudes will be found on the map (Plate I); where no altitudes have been taken by the Survey, the values given by Ascherson on his map have been inserted.

The statistics relating to the oasis, and the methods of cleaning out wells, are based on information supplied by the Government officials at Bawitti, and may be taken as fairly reliable. The particulars regarding water-supply are of course based mainly on direct observation during the survey of the villages.

The botany of the oasis having been fully studied by Ascherson[13] no attempt was made by the Survey to collect or describe the plants met with. The abundant growths of the beautiful maiden-hair fern (Adiantum Capillus Veneris)[14] will not, however, fail to strike even the casual visitor to the old Roman aqueducts, which still serve as the principal water-channels of the oasis. Nor were the animals of the oasis made the subject of any detailed observations, although the existence of several of the species of lizards and snakes common to the Nile Valley was recorded, and specimens collected when easily obtainable.

Baharia is not rich in archæological remains, and, with few exceptions, even those existing were not examined by the Survey, though the positions of all ruins met with during the work were mapped. In a later chapter will be found a connected though brief account of all the antiquities noted, the publications of previous authors being referred to wherever the descriptions cannot be given from personal observations.

The principal point attended to in the topographical mapping by the survey was the accurate delineation of the bounding scarps of the oasis and of the large number of hills within it. These features, of which an accurate map was essential for any proper consideration of the geology, had been only rapidly sketched by previous travellers, and the precise shape of the oasis was still unknown. In the cultivated spots, on the other hand, much had been done by Cailliaud, Jordan and Ascherson towards mapping the detail. Hence, beyond re-determining the precise positions of the main points and the general limits of the cultivated areas, no attempt at detailed mapping in these areas was undertaken by the Survey parties, it being felt that it would be preferable in the limited time available to concentrate attention on the almost totally unknown features, so essential to any geological consideration, rather than to devote considerable time to the details of the inhabited spots.

Thus, while the field maps resulting from the survey represented the oasis for the first time in its true shape, and the hills within it in their true relative magnitudes and positions, they fell somewhat short of the maps of Ascherson and Cailliaud in the number of springs, ruins, etc., shown. The more important ruins overlooked by the survey have, however, been inserted approximately from existing maps, and the whole result (Plates I, III and VII), is an advance on the existing representations.

The geology of the oasis was very carefully investigated, this being a field in which comparatively little had been done, and a number of very interesting results were obtained. The principal points in this connection worthy of note resulting from the detailed examination of the scarps and hills are—

(i) The existence of a marked unconformity between the Upper Cretaceous and Eocene strata, thus confirming the unconformity between these two great systems which had been noted[15] earlier at Abu Roash; this unconformity has now been remarked in many parts of Egypt.[16] The palæontological proofs of this unconformity were obtained from the western scarp, the beds of the eastern side, though they show the same thickening, being much poorer in fossils;

(ii) The occurrence of an extensive series of Upper Cretaceous beds of Cenomanian to Danian age within the depression and forming a large part of the desert to the west;

(iii) The precise extent and relations of the dolerite capping some of the sandstone hills in the north of the depression;

(iv) The existence of well-marked folding having an important bearing on the origin of the oasis;

(v) The presence of ferruginous sandstone deposits of later origin than the primary formation of the oasis-hollow, though long anterior to the date when the work of excavation, which gave the oasis its present form, took place.

These points will be found discussed at some length in the chapter on the geology of the oasis.

CHAPTER III.

The roads traversed by the Survey parties between Baharia and other places are three in number, viz., from near Maghagha and from Minia in the Nile Valley, and from Baharia to Farafra Oasis. Other well-known routes run from the Fayum, from Bahnessa, Samalut (Ascherson) and Delga, in the Nile Valley, from Alexandria, via Mogara, and from Siwa (Jordan, Cailliaud). The Survey’s return traverse to Minia from the south end of Baharia did not follow any defined road, but kept on the open plateau on a course computed from the known positions of the points of departure and destination.[17]

Road from Feshn and Maghagha to Baharia.The road from Feshn and Maghagha to Baharia leaves the edge of the Nile Valley cultivation at Qasr el Lamlum Bey, which bears 51½° west of true north from Maghagha railway station, and is distant 15·4 kilometres. From this point the road is well-defined and easily followed right into the oasis. In the following description the distances are given from the edge of the Nile Valley cultivation.

The road at first leads over a strip of drift sand, half a kilometre broad, with short prickly scrub, passing a white mosque on the left and then turning off somewhat to a direction 26° south of west, and continuing in a straight line for 15 kilometres over an undulating gravelly plain. The high prominent cliffs, about 7 or 8 kilometres to the north-west, are the flanks of Jebel Muailla, and a valley known as Wadi Muailla leads through them to the Wadi Rayan in the Fayum depression.[18] At 19 kilometres the valley scarp, with a number of isolated peaks, is approached on the right, while ridges and low mounds form the plain below, well-marked lines of drainage running from here in a south-east direction towards the cultivation. At 23 kilometres the scarp runs back, enclosing a large bay, across which the road runs and ascends to the plateau beyond at 27·8 kilometres. Numerous isolated parallel sand-dunes in the form of small ridges are seen running out into the bay from the cliff at the far end, all lying slightly west of north and east of south, or parallel to the normal wind direction.

The escarpment bounding the Nile Valley at this point is only some 15 metres in height, being thus quite insignificant compared with the cliffs on the east side. The plateau here was found to be about 140 metres above the cultivation, the road having risen gradually throughout. The latter continues for about 1½ kilometres across the strip of plateau when it again descends, making a slight detour to the left for easy descent. It then continues 9° south of west, slightly winding, over gravelly undulating ground. At 31-32 kilometres a line of low hills is passed on the right, while a dark well-marked range lies 6-7 kilometres to the left.

A ridge of sandstone, known as Jebel el Ghudda, is passed on the right at 45 kilometres, from the end of which a small dune runs out; beyond, the plain resumes its monotonous undulating character, a low ridge being crossed at 61 kilometres. There, the road, consisting of a number of more or less parallel well-marked narrow paths worn by camels, which have a somewhat general habit of marching in line one behind the other, changes its direction to 36° south of west, falling gradually in level until a patch of scrub is reached 6½ kilometres further on. This scrub was dead at the time of the visit, and furnished a useful supply of fuel. From this point the course is 7° south of west (true), which direction is maintained for the next 42 kilometres over a remarkably monotonous undulating gravel-covered desert, the typical “serir” of the Arabs. At 92 and 93½ kilometres some more patches of dead scrub were passed on the right, while logs of silicified wood were noticed strewing the plain on the left. An Arab grave was met with at 96 kilometres, while skeletons of camels lie about near the roadside at frequent intervals; at 110 kilometres the eye of the traveller is relieved by a small grove of green thorny flat-topped acacia trees (Acacia nilotica, or “sunt” of the Arabs) with a patch of coarse grass; four gazelle (probably Gazella dorcas) were observed browsing on the scrub here.

The course now continues 12½° south of west, over gently undulating gravelly “serir”, until the eastern scarp of El Bahr is reached at 125 kilometres from the cultivation of the Nile Valley. The “serir” or undulating gravelly type of desert then ceases.

El Bahr is a depression, some 60-70 metres deep, cut out in white limestone rocks; its breadth at the point crossed by the road was 8 kilometres. Within it are several high prominent hills, one of which near the centre on the left side of the road is called Jebel Gar Marzak. The bottom of the depression was quite green with vegetation; sufficient water is said to fall every year to keep these plants alive, and in 1894 rain is said to have fallen to such an extent that a pool of considerable size was formed; the silt deposited by this is plainly visible at the present time. A good deal of blown sand occurs within the depression. El Bahr evidently corresponds to the Bahr Bela Ma, (river without water) figured on some authors’ maps, which has been frequently but erroneously referred to as an old river-course; although this idea was shown to be untenable by Zittel[19] and Ascherson[20] it has subsequently been maintained by non-scientific writers. No traces of any river deposit occur in the depression, which consists simply of a series of unconnected depressions, eroded by wind-borne sand.[21]

The track leaves the depression at 134 kilometres, rising over heavy sand; it then continues 3° north of west. The character of the desert has now completely changed, and instead of the smooth undulating gravelly “serir,” its surface is rough and hummocky, being formed of hard bare limestone, cut up into sharp knobs and grooved into furrows by the powerful action of wind-borne sand; it resembles closely the surface of the rough open sea. This type of desert is spoken of as “kharafish” by the Arabs. While the “serir” forms an ideal surface for travelling over, the “kharafish” is the worst imaginable, the innumerable hillocks necessitating incessant small deviations, while the hard rough surface is in some places very troublesome to camels; moreover, an extensive view is out of the question and no tracks are visible on the surface, so that the road is easily lost except where marked by frequent cairns built of loose stones.

Occasional patches of blown sand are here met with, and the first well-marked dunes were crossed at 141 kilometres. From here onwards for kilometres the whole area was more or less sandy with occasional narrow well-marked ridges or dunes, running almost due north and south, and varying in breadth from that of a single line to a number of parallel ridges side by side half a kilometre broad. The largest dune of this group at 146½ kilometres is known as Ghard el Shubbab. The steepest sides are those facing west where the angle may reach 30°.

At the particular locality crossed by this road the sand area is very easily crossed, a circuitous route being followed in order to take advantage of the flatter dunes with the easiest slopes when crossing the steeper ridges. Probably the road crosses at one of the easiest points. This remarkable line of dunes, known as the Abu Moharik, has its origin in the neighbourhood of the oasis of Mogara and runs southward, almost without a break, across the desert until Kharga is reached, whence with a slight break owing to the broken character of the ground it continues southward within the oasis-depression. The total width of the sand-belt on the road under description is about 6 kilometres.

At 153 to 156 kilometres a number of black conical hills, Gar el Hamra, are situate from 1 to 2 kilometres from the road on the south side. One or two more sand-dunes were crossed and then the road, maintaining its direction of 2°-3° north of west, lay over a more or less uneven dark-coloured limestone desert broken up into a number of small hills. At 169 kilometres a broad ridge of sand-dunes was encountered, running 18° west of true north. These light yellow dunes afford a beautiful and remarkable sight, running northwards away to the horizon over a dark brown-coloured desert in an almost perfectly straight line and with a sharply maintained junction-line between the edge of the sand and the desert surface adjoining.

Within a few hundred metres of the western side of the sand-dunes the road commences the descent from the plateau into the oasis-depression. The road enters at the most northerly extremity of the oasis, the descent being particularly easy at this point, passing the large dark-coloured hill, Jebel Horabi (or Morabi?), on the right almost immediately afterwards.

A fine view of the depression is obtainable from the top of the escarpment, a broad low-lying expanse, bounded by steep escarpments or walls, stretching away to the south, its monotony relieved by several large flat-topped hill-masses, near which, on the lowest portions of the floor, dark areas, the cultivated lands and palm-groves can be distinguished. The road crosses the depression in a south-westerly direction, passes a spring known as Ain el Gidr, the first watering place, and divides in front of the great hill-masses separating the two groups of villages, the eastern branch keeping close under the eastern scarp of Jebel Mayesra, to avoid a large area of soft salty ground, and leading to the villages of Zubbo and Mandisha, While the western branch continues its course to the cultivation surrounding El Qasr and Bawitti. The distance by this road from Qasr el Lamlum Bey to the village of Zubbo is 190 kilometres and to Bawitti 195 kilometres.

Geology of the Feshn-BahariaHaving now described the topographical features of this road, the chief geological characters may be noticed. The plain between the Nile Valley cultivation and the scarp of the plateau is covered with sandy gravel, partly downwash from the higher ground in Recent times, and partly the remains of definite gravel deposits belonging to the Nile Valley Pleistocene series.[22] The pebbles now found strewn over the plain consist chiefly of flints, doubtless derived from the Eocene limestones forming the deserts on both sides of the Nile Valley, and occasional pebbles of hard felspar porphyry which must have originally been derived from the igneous massifs of the Red Sea Hills. Both are well rounded, although the former are frequently broken up into angular fragments by temperature changes. White granular beds of gypsum, of various degrees of impurity, crop out on the plain in places, and in all probability there was in Pleistocene times an extensive deposit of this mineral all over the surface of the low-lying country. In the desert lying between the Fayum and the Nile Valley further to the north, these gypseous beds occur of great thickness and wide extent, and the deposits crossed on this road are doubtless part of the same series.

The cliffs of Jebel Muailla to the north are capped by a hard dark bed of limestone, which weathers with a vertical face, while the more gentle slopes, generally more or less hidden with sand, are doubtless formed of softer limestones, marls, and clays. During the survey of the Fayum (see foot-note, p. 17) the hills surrounding Wadi Muailla were found to be formed of Lower Mokattam beds (Middle Eocene) and the hills seen from this road are doubtless composed of the same beds. The ridges crossed at 20 kilometres are formed of hard, compact, close-grained crystalline limestone, covered with more or less gypsum and flint gravel; the limestone beds forming these ridges show dips which suggest the existence of a fault running N.E.-S.W., parallel to the trend of the cliff behind, and this may be part of the extensive faults and folds of the Nile Valley. In one small hill (22 kilometres) shales with Ostrea were noticed at the base, with occasional hard oyster-limestone bands; the upper part was formed of 10 metres of gravel consisting of well-rounded limestone pebbles. This superficial deposit must be classed as Pleistocene and may be a sea-beach, though no conclusive evidence was obtainable on this point. The escarpment passed at 23 kilometres is capped by a bed of white limestone, shales forming the slope, but was not examined at close quarters. The floor of the bay formed by the receding cliff shows outcropping brown limestone with Ostrea, and the escarpment on the far side is capped by a hard white crystalline limestone with much flint, the latter forming bands. On the surface is a thin calcareous gypseous gravel deposit, doubtless of the same age as the gypseous beds already mentioned as occurring on the plain below. The flanks of the scarp are hidden by downwash. The cliff bounding this strip of plateau, 1½ kilometres further on, is composed of the same beds, the limestone being here silicified, with large silicified Conidæ. With regard to the age of these limestones and clays they are probably equivalent to part of the Lower Mokattam series already mentioned as forming the hill-masses round Wadi Rayan, although no Nummulites gizehensis beds were observed in the sections examined. A conspicuous black knob among the low gravelly hills left two kilometres on the right at 32 kilometres, was found to be a neck of hard dark andesitic basalt, one of the few occurrences of igneous rocks in the Western Desert. Several other similar looking dark hills were in sight, but time did not admit of their examination. The dark well-marked range 6-7 kilometres to the left of the road is probably identical with a range of hills occurring 10 kilometres west of Bahnessa, which was mapped[23] during the survey of the Nile Valley in 1899, and found to consist of a mass of andesitic basalt similar to that forming the small neck on this road. Doubtless they are both parts of the same intrusion. The surface of the plain is still composed in part of gypseous deposits, with occasional outcrops of the underlying limestone, the surface being covered with a certain amount of loose sand with rounded flints and their broken fragments. In the neighbourhood of Jebel el Ghudda the plain consists of limestone with numerous individuals of the large Nummulites gizehensis, and are thus of Lower Mokattam age. Much of the limestone is crystalline. The hills of Jebel el Ghudda are formed by younger overlying beds consisting of hard silicified sandstones and grits (quartzites), which lithologically are very similar to the beds of Jebel Ahmar near Cairo, of Oligocene age. They may, however, belong to the Upper Eocene series, so well developed above the Upper Mokattam in the escarpments to the north of the Fayum, as this series contains similar beds with similar silicified wood. They enclose bands of coarse conglomerate and have a peculiar blackish burnt colour. Occasional patches of these grits are here and there met with right up to the depression of El Bahr, and the silicified wood passed at 92 kilometres belongs to the same series of beds. From the scrub area at 93½ kilometres till the road approached El Bahr there was hardly a sign either of the grits or of section anywhere met with on this road. The depression is cut down through the upper series of sandstones and grits into the fossiliferous white limestones and sandstones below. The eastern scarp showed the following beds:—

The floor is covered in places with numerous weathered out individuals of N. gizehensis and large oysters. Some of the hills occurring within the depression showed brown siliceous limestone overlying white limestones with beds containing Nummulites gizehensis, Ostrea, etc., below. In some of these hills the beds show evidences of folding, which like that within the Baharia Oasis may have partly caused the formation of the depression by bringing the softer beds to the surface within the reach of the agents of denudation. On ascending the western scarp, beds with Ostrea, Turritella, etc., were crossed, and near the top thick yellowish sandstones crowded with Ostrea occur. Two of the species of Ostrea were afterwards examined by Dr. Blanckenhorn, one of which he regarded as nearly related to O. Fraasi, and the other as a new species with affinities to O. Hess, May-Eym.

Probably the whole of these fossiliferous beds belong to the Middle Eocene Mokattam Series; the lower beds with N. gizehensis, are certainly Lower Mokattam, and probably the upper, although the latter may represent the base of the Upper Mokattam. Whether the upper bed of sandstone capping the eastern scarp belongs to the same series or is equivalent of the silicified grits with silicified wood passed further back is open to some doubt.

Beyond the Bahr the desert is formed of a hard limestone much cut up by the action of wind-borne sand as already mentioned. This limestone is very unfossiliferous, occasional obscure nummulites seen on fractured or smooth surfaces being the only indications of its Eocene age.

The conical-peaked hills of Gar el Hamra on the left of the road at 151 kilometres were so striking that a detour was made specially to examine them. They were found to be composed of black ferruginous silicified sandstone or quartzite at top, with false-bedded sandstones below. They overlie nummulitic limestones forming the surrounding plain, and are not improbable Post Eocene lacustrine deposits, similar to those within Baharia Oasis (see pp. 60-62).

From here onwards up to the oasis-depression the plateau consists of hard brown limestone, more or less silicified, and contains nummulites and oysters. The Eocene strata, thus extend right up to the escarpment of the depression on the north side of the oasis. The geological structure within the depression will be found discussed in Chapter V.

Road from Minia to Baharia.Road from Minia to Baharia.—The cultivated land extends for some 9 or 10 kilometres west of Minia town, and at the time of the Survey expedition (early in October, 1897) this area was mostly covered by flood-water. Boats were therefore taken to the edge of the desert, and the march west was commenced from Nasl Nadiub Lengat, a small village on the cultivation-limit in lat. 28° 6′ 24″, long. 30° 39′ 45″ E., bearing from Minia railway station 9° north of west, distance very nearly 10 kilometres. The road westward being ill-defined, and the party knowing that any course followed a little north of west would surely lead to the oasis, no attempt was made to follow the track precisely, the course being rather chosen to take advantage of commanding points so as to map as much topography as possible en route. As will be seen further on, however, the road was struck some distance before reaching the oasis, and was thence followed to Zubbo.

On leaving Nasl Nadiub Lengat the course first taken was about 32° north of west. The desert here rises very gradually from the flood-level, (i.e. about 40 metres above sea-level), there being no cliff bounding the Nile Valley on the West at this point. For about 6 kilometres the ground was sandy, with occasional patches of flood-water and some grass; then came a stretch of level gravelly ground, and at 11½ kilometres some low sand-dunes were crossed. The course was now changed to about 3° south of west, and at 14 kilometres a descent was made from the gravel-plain into a limestone-depression, with gravel-capped eminences on either side. At 22 kilometres the gravel-strewn plain was again come on, a few low mounds, also gravelly, being passed at 31 kilometres, and camel-tracks, doubtless part of the Minia-Baharia road, being noticed coincident with the survey line at 37 kilometres. Continuing following these tracks, another camel-road was found to branch off at 46 kilometres to the north-west. The march was continued along the same track going a little more south of west, over a monotonous gravelly plain, with limestone showing through it in small patches, till at 78 kilometres from Nasl Nadiub Lengat a conspicuous though small mass of fissile gritty limestone was come on, which afforded a good survey-station. North and west of this are low gravel-covered hills. Turning a little north of west, a large extent of low table-like hills was seen on the south. At about 90 kilometres low plateaux of limestone, capped by gravel, closed in so as to form a defile about a kilometre wide, through which the line of survey passed, and at 98 kilometres a large sandy and gravelly depression, bounded by limestone scarps and containing numerous large limestone hills, was entered. Within the depression the course followed was about 30° north of west, so as to map roughly the escarpments on either hand. About 10 kilometres from the point where the depression is entered a long stretch of heavy sand was crossed beyond which tracks going west were come on, and the edge of the limestone plateau on the left curved round so as to cross the road. Ascending this low scarp at 116 kilometres, the course lay over white limestone, with sharp angular flints on its surface, and low limestone hills on either side. At 124 kilometres the broad belt of sand-dunes, the Abu Moharik, was reached. The dunes, which are of considerable height, run nearly north and south, and have a total width of some 4 kilometres; they formed the most serious obstacle of the entire journey. Beyond the dunes is a hard limestone plain, crossed by a low ridge (forming part of a higher plateau) at 136 kilometres. Beyond this ridge are low limestone-hills on either side, the floor being generally of hard white limestone. At 151 kilometres an oval depression in the limestone plateau, with its longer axis (about 4 kilometres) running W.N.W., was entered; this depression is full of hills of white chalk, which also forms the floor here. Ascending the opposite scarp of the depression at 159 kilometres, a narrow strip of higher plateau of much harder limestone was crossed, the edge of the scarp of the oasis of Baharia being reached at 160 kilometres, after marching for 57 hours from Nasl Nadiub Lengat. Up to this point there had been a gradual rise of the ground, from 40 metres at the Nile Valley to 265 metres above sea-level at the edge of the oasis.

The descent into the oasis is not difficult, the scarp being sandy and the fall gradual. At about 4 kilometres W.N.W. from the edge of the scarp is the first well or spring of the oasis, Ain Gelid (lat. 28° 19′ 28″ N., long. 29° 8′ 40″ E. of Greenwich), a small pool surrounded by grasses and with a tree growing near it. The barometric observations gave for this point the level 134 metres above sea, so that the total drop from the edge of the scarp is about 130 metres. From Ain Gelid the village of Zubbo bears about 15° north of west, and is some 17 kilometres distant, but owing to the hills between the two places necessitating a slight detour, the actual distance to be traversed is a few kilometres greater.

Geology of the Minia-Baharia Road.The road from Minia to Baharia shows essentially the same geological features as the one from Maghagha already described. The gravel which strews so large a portion of the road to the east is mainly composed of quartzite and flint pebbles, of a prevailing brown colour. Some of the rounded flints show a concentric structure, and are evidently segregation-nodules derived from chalk-beds; a very fine specimen of these, measuring some 20 c.m. in diameter, of almost perfectly spheroidal form, was obtained. The gravelly covering is frequently very thin, the limestones underlying it showing through in numerous places. No evidences of the precise age of this gravel have come to the authors’ knowledge, but it is certainly Post-Eocene. It appears to be the same formation which is found covering the edge of the plateau west of Girga[24] and south of Assuan (east bank) and at various other points of the Nile Valley. It overlies beds of every age from the Nubian Sandstone to the Lower Mokattam.

The limestones which underlie the gravel near the Nile, and which are well exposed in the depression crossed 14 kilometres from the edge of the cultivation, are crowded with nummulites of various species, N. gizehensis and N. curvispira being specially common; these rocks belong therefore to the Lower Mokattam Series (Middle Eocene).

The limestone underlying the gravel further west (from about 30 to 80 kilometres west of the cultivation-limit) is only seen in small patches; it varies in character, being in some places loose and tufaceous in texture, and in others gritty and fissile, passing into a calcareous grit. The mass of gritty limestone at 78 kilometres, noted above, is about 6 metres in length by 2 metres high and broad; it shows a peculiar stalagmitic structure, the layers always parallel to the free surface. Several smaller masses found around all show a similar structure, and where the rock is exposed on the floor concentric fissuring is frequently seen. The sand which strews the surface here is largely calcareous, being doubtless in part derived from the gritty limestones.

The eastern part of the low hills lying to the left of the track at about 85 kilometres from the cultivation-limit show the following section (total height about 13 metres):—

On the western part of the hills the gravel covering is absent, the succession here seen being:—

No fossils were seen in these beds except the nummulites in the gravel, which prove the latter to be at least in part derived from Eocene deposits.

The hills left of the road a little further on show the following section:—

On entering the depression at 98 kilometres a band of earthy reddish limestone with Bryozoa is crossed, this bed appearing to overlie the fissile sandy limestone already mentioned. From here a good view of the numerous limestone hills is obtained, the top beds of hard limestone showing out sharply from the lower sand-covered slopes; the beds show a stratigraphical depression here in addition to the eroded surface depression. The floor of the depression is covered with sandy gravel and Ostrea shells; an examination of the left scarp, about 3 kilometres after entering the hollow, showed the following succession of beds (total height of section 20 metres):—

One of the hills within the depression, to the left of the track about 6 kilometres further on, showed in a face of about 28 metres the following beds:—