Above the Qasr el Sagha series, and well marked off from them both lithologically and palæontologically, is found a great thickness of variegated sands, sandstones, clays and marls, the “Fluvio-marine Series” (Jebel el Qatrani beds), divided near the summit by one or more thick intercalated lava sheets, the latter forming a convenient junction line. This series of variegated beds is of Upper Eocene—Lower Oligocene age.
No Miocene strata have been recognized within the area, but further north, as at Mogara, Lower Miocene deposits occur;[34] and it is probable that there is a continuous series of lithologically similar beds from the summit of the Fayûm escarpments (Lower Oligocene) to the Mogara Miocene.
The Pliocene is probably represented by the great terraces of gravel—raised beaches—which are such a marked feature in the geology of the district. Fossiliferous Pliocene deposits have also been recorded from the south part of the area by Schweinfurth.[35]
Pleistocene and Recent are abundantly represented by lacustrine clays, both ancient and modern, alluvial land and blown sand, the formation of which deposits is continuing at the present time.
The following table will show the sequence of strata and the classification adopted in the present memoir:—
Table showing Succession and Classification of Strata in the Fayum.
| Approximate average thickness in metres, northpart of Fayum. | ||||
|---|---|---|---|---|
| RECENT ANDPLEISTOCENE | Alluvial soil, clays, sands,etc. | |||
| Blown sand. | ||||
| Lacustrine clays, extending to about 23metres above sea-level. | ||||
| (MIDDLE?)PLIOCENE | Gravel Terraces (?Pleistocene). | |||
| Shell-borings on rocksurfaces. | ||||
| 50 | Fossiliferous deposits of Sidmant. | |||
| LOWEROLIGOCENE | Tongrian | Fluvio-marine Series (Jebel elQatrani beds). | ||
| 30 | Sandstones andsandstone-grits with silicified trees and | |||
| Basalt sheets, interbedded andcontemporaneous. | ||||
| UPPER EOCENE | Bartonian. | 250 | Variegated sands, sandstones, clays andmarls, with limestone-grits and thin bands of limestone. The upperbeds contain Unio sp., Lanistes bartonianus, Blanck.,Turritella pharaonica, Cossm., Potamides scalaroides,Desh., P. tristriatus, Lam., Pleurotoma ingens,May.-Eym. In the lower beds are large numbers of silicified treesassociated with vertebrate remains including ArsinoitheriumZitteli, Beadn., A. Andrewsii, Lankester,Palæomastodon Beadnelli, Andr., P. minor, Andr.,Mœritherium Lyonsi, Andr., M. trigodon, Andr.,Megalohyrax eocænus, Andr., M. minor Andr.,Saghatherium antiquum, Andr. and Beadn., S. minus,Andr. and Beadn., S. magnum, Andr., AncodusGorringei, Andr. and Beadn., Geniohyus mirus, Andr.,G. fayumensis, Andr., G. major, Andr., Phiomiaserridens, Andr. and Beadn., Pterodon africanus, Andr.,P. macrognathus, Andr., Eremopezus libycus, Andr.,Testudo Ammon, Andr., and frequent crocodilian and chelonianremains. | |
| MIDDLE EOCENE | Parisian. | Upper Mokattam | 155 | Qasr el Sagha Series (Caroliabeds). |
| Alternating limestones, marls, claysand sandstones with Qerunia (Hydractinia)cornuta, May.-Eym., Astrohelia similis, Felix.,Echinolampas Crameri, Loriol., Ostrea Reili, Fraas,Ostrea elegans, Desh., Alectryonia Clot-Beyi,Bellardi, Exogyra Fraasi, May.-Eym., Caroliaplacunoides, Cantr., Cardita fajumensis, Oppenh.,Macrosolen Hollowaysi, Sowerby, Turritellapharaonica, Cossm., T. carinifera, Desh., Mesaliafasciata, Lam., Rimella rimosa, Sol. The vertebrateremains include Mœritherium Lyonsi, Andr., M.gracilis, Andr., Barytherium grave, Andr., Eosirenlibyca, Andr., Zeuglodon Osiris, Dames, GigantophisGarstini, Andr., Pterosphenus Schweinfurthi, Andr.,Psephophorus eocænus, Andr., Thallassochelys libyca,Andr., Podocnemis antiqua, Andr., P. Stromeri, v.Rein., Stereogenys Cromeri, Andr., S. podocnemioides,v. Rein., Tomistoma africanum, Andr., with siluroids andPropristis Schweinfurthi, Dames. | ||||
| Lower Mokattam | 50 | Birket el Qurûn Series(Operculina-Nummulite beds). | ||
| Sandstones and clays, withsandy limestones, and one or more well marked concretionarysandstones weathering into large globular masses. | ||||
| Nummulites Fraasi, de la Harpe, N.Beaumonti, Operculina discoidea, Schwag., Qeruniacornuta, May.-Eym., Plicatula polymorpha, Bell.,Pectunculus pseudopulvinatus, Orb., CarditaViquesneli, d’Arch., Cardium Schweinfurthi, May.-Eym.,Venus plicatella, May.-Eym., Macrosolen Hollowaysi,Sow., Lucina pharaonis, Bell., Tellina scalaroides,Lam., Clavellithes longævus, Sol., Voluta arabica,May.-Eym., Turritella pharaonica, Cossm., T.carinifera, Desh., with Zeuglodon Osiris, Dames, andZ. Isis, Beadn. | ||||
| Ravine Beds. | ||||
| 70 | White marls and marly limestones withgypseous clays; Nucularia sp. Leda sp.,Corbula aff. pixidicula, Desh., Lucina sp. (?pharaonis), Tellina tenuistriata, Desh., ZeuglodonIsis, Beadn., and scales and teeth of fish. | |||
| Wadi Rayan Series (Nummulitesgizehensis beds). | ||||
| 130 | Limestones, marls, clays, etc., withNummulites gizehensis, Ehrbg., N. curvispira,Carolia placunoides, Cantr. |
Section X.—MIDDLE EOCENE (PARISIAN).
A.—Wadi Rayan Series.—(Nummulites Gizehensis Beds).
(A.I.e. Schweinfurth, I.b. Mayer-Eymar,[36] Lower Mokattam of Cairo).