The following section was measured on the mainland[54] opposite the island Geziret el Qorn.
| Top. | Metres. | ||
|---|---|---|---|
| 1. | Gypseous clays, separated by a band ofbrown sandstone crowded with white well-preserved shells, includingnumerous individuals of Plicatula polymorpha, Ostrea,Turritella and Lucina pharaonis. Large vertebrae ofZeuglodon Isis occur on this horizon further to thenorth-east | 8 | |
| 2. | Sandstones and gypseous clays. Althoughhere the sandstones are not hard or predominant, this bed isequivalent to the hard sandstone full of borings capping the plainbetween the ruins of Dimê and the top of the escarpment overlookingthe lake. Further north this bed often contains numerous Caroliaplacunoides and Ostrea | 3 | |
| 3. | Gypseous clays | 3 | |
| 4. | Clays, brown sandstones, and occasionalbeds of limestone, often very fossiliferous, containing OstreaReili, Carolia placunoides, Cardita Viquesneli,d’Arch., Lucina sp., Turritella pharaonica,[55]Clavelithes longævus, Qerunia cornuta, etc.,etc. | 10 | |
| 5. | Clays with fossils as in last bed, cappedby hard band of shelly sandstone | 3 | |
| 6. | Alternating yellow-brown sandstones andgypseous clays | 10 | |
| Total thickness | 37 | ||
| Bed with weathered-out sandstone concretions attop—upper bed of section at Geziret el Qorn.[56] | |||
At the western end of the Birket el Qurûn the series is well marked, the sandstone beds forming the steep face of the bold precipitous cliffs which are so marked a feature at this end of the lake. The group has a thickness of some 50 metres and is overlain by the lower beds of the Qasr el Sagha series; it is more convenient here to give the entire section of the cliffs down to the base of the series under discussion:—
| Top of Cliffs. | Metres. | |||
|---|---|---|---|---|
| 1. | Hard grey sandstone and shelly limestonepassing up into calcareous sandstone (forming surface of plaindipping north). | Lower part (42 metres) of Qasrel Sagha Series. | ||
| 2. | Impure sandstone with numerousfossils:—Qerunia cornuta, corals, Ostrea Reili, O.Clot-Beyi, Carolia placunoides, Plicatulapolymorpha, Cardita (? fajumensis) sp.,Clavelithes longævus, Serpula, etc. | |||
| 3, | 4. Clays with band of argillaceoussandstone. Septaria bed near base. Fish-remains. | |||
| 5. | Earthy limestone crowded with OstreaClot-Beyi, O. sp., Plicatula polymorpha,Pecten sp., Lucina sp., Cytherea sp.,Turritella sp., Nonionina sp., Oliva sp.,Pleurotoma sp., Vermetus sp., Nautilussp. | |||
| 6. | Thin-bedded clays, grey with yellowishband, sandy clays interbedded with soft whitish sandstones withsmall irregular concretions. Clays, gypseous and sometimescarbonaceous. | |||
| 7. | Shelly sandstone, hard on upper surfaceand very fossiliferous (forms similar to Bed 9). | |||
| 8. | Gypseous clays. | |||
| 9. | Thin (·25 to ·5 metre) hard darkreddish-brown, very ferruginous, concretionary-weathering sandstonewith nummulites and Operculina and well-preserved examplesof Qerunia cornuta, Pecten sp., Pectunculussp., Venus sp., Cardita Viquesneli, Astartesp., Macrosolen Hollowaysi, Lucina sp., Naticasp., Cerithium sp., Clavelithes longævus,Voluta sp., Dentalium sp. | 1 | ||
| 10. | Hard purplish clays | 7 | ||
| 11. | Soft yellowish sandstone withOstrea sp., Cardita ægyptiaca, Lucina sp.,Turritella sp., and sharks’ teeth. Upper surface tends tobecome dark, ferruginous, and concretionary | 1 | ||
| 12. | Purple clays, with strings of gypsum | 6 | ||
| 13. | Soft light-yellow sandstones with hardershelly bands and occasional concretionary beds, forming verticalcliff-wall | 17 | ||
| 14. | Grey and brown clays | 18 | ||
| Ravine Beds. | Total | 50 | ||
In the cliffs west of the end of the lake the upper bed No. 9 continues highly fossiliferous and yields the most perfectly preserved molluscan remains to be found in the Fayûm and probably in Egypt.
A few kilometres east of the end of the lake a band of large globular concretions occurs in the thick brown sandstone forming the vertical face of the cliff. In many places the effect of weathering of these rocks is of some interest, numerous “earth-pillars” having been formed; these are largely the result of the action of blown sand, assisted by rain, the concretions being left capping pillars of brown sandstone, the sides of which are sculptured by the wearing action of sand. The curious perforate or cellular appearance which the weathered surfaces of this sandstone assume after long exposure are particularly noticeable in this neighbourhood and in the Zeuglodon Valley further west.
In the well-marked hill distant 17 kilometres to the north-east of Gar el Gehannem, the soft fossiliferous sandstones of this series are crowded with Operculina, Nummulites, and many species of mollusca beautifully preserved.
At Gar el Gehannem the series is seen ([Fig. 2] and detailed section [page 36]) forming part of the slope of the hill, underlain by the Ravine beds, and capped by part of the Qasr el Sagha series. It here consists of yellow sandstones divided by a bed of clay; the sandstones are often crowded with nummulites (of two species); also Operculina (discoidea?), echinids, Balanus sp., Ostrea Reili, O. Fraasi, Carolia placunoides, and species of Pecten, Pinna, Cardita, Teredo, Turritella, and Cerithium.
Fig. 5.—Section of cliffs, western end of the Birket el Qurun.