316 Notices of Memoirs — The Oilfields of Egypt. 



himself in the Geological Magazine, 1 so that it will be unnecessary 

 in this notice to go into that branch of the subject in any detail. 



In dealing with the succession of deposits the author follows the 

 Lyellian method, beginning with the most recent. In this brief 

 summary we will reverse the process, though we do not wish to 

 suggest that this method should have been followed in the Report. 

 The oldest rocks consist of granite and of ancient volcanic and 

 sedimentary rocks, similar to those of the Red Sea Hills and the Sinai 

 Mountains, probably of Archaean, certainly of pre-Carboniferous age. 

 They form the cores of the asymmetric anticlines of the EshMellaha, 

 Zeit, and Araba Hills as described by Dr. Hume in the paper already 

 referred to. On the old floor formed, of these rocks were deposited 

 Nubian Sandstone, Cretaceous and Eocene strata. The succession is 

 the same as that occurring on the western side of the Red Sea Hills 

 and in Sinai, except that in the latter locality flat-bedded Carboni- 

 ferous strata intervene between the old floor and the Nubian 

 Sandstone. 2 The Cretaceous and Eocene rocks are seen only in the 

 hill ranges where their thickness is often greatly reduced by folding. 

 Their presence confirms the view generally held that these rocks 

 were originally continuous over the whole area. 



The Miocene rocks which follow rest on any of the underlying 

 series. Thus on Shadwan Island they rest on granite and in the 

 Zeit range on Lower Cretaceous strata. In the Esh Mellaha range, 

 some 20 kilometres to the west of the Zeit range, both the uppermost 

 Cretaceous and the Eocene rocks are present. It follows, therefore, 

 that the Gulf of Suez marks the position of the axis of a post-Eocene 

 and pre-Miocene anticline from which the sediment overlying the 

 granite must have been wholly or partially removed by deuudation 

 before the Miocene rocks were deposited. We may remark in passing 

 that in other parts of Egypt this interval is l-epresented, to some 

 extent at least, by the so-called petrified forests, the fluvio-marine 

 series of the Fayum, and other deposits of a continental type. 



Flint conglomerates and coral reefs occur at the base of the 

 Miocene. In the Zeit range conglomerates, resting on Cretaceous 

 strata, are immediately followed by a dark limestone containing 

 fossils which M. Fourtau has identified with forms " typical of the 

 Lower Miocene (Burdigalian) and of the Lower Helvetian (Lower 

 Middle Miocene) ". The limestone is succeeded by an important 

 series of Globigerina marls with Aturia aturi, Terebratula miocenica, 

 and a delicate Pecten fauna. Similar marls have been met with in 

 a boring at Rarquada between 1,169 and 1,181 feet where they are 

 underlaid by a limestone and a flint conglomerate, as in the Zeit 

 range. This boring terminated in sands which Dr. Hume identifies 

 with the Nubian Sandstone. The sands yielded oil. These fossili- 

 ferous strata are succeeded by deposits of clay, gypsum often 

 calcareous, dolomitic limestones and salt; their total thickness cannot 



1 "Some Notes on the Post-Eocene and Post-Miocene Movements in the- 

 Oilfield Eegion of Egypt " : Geol. Mag., January, 1917, pp. 5-9. The map 

 illustrating this paper should be referred to. 



2 See review of Dr. Ball's memoir on The Geography and Geology of West- 

 Central Sinai, Geol. Mag., February, 1917. 



