REVIEWS. 



Topography and Geology of Northern Sinai. Petroleum 

 Eesearch Bulletin, No. 10. By F. W. Moon, B.E., F.G.S., etc., 

 and H. Sadek, B.Sc, F.G.S. Cairo : Government Press, 1921. 

 P.T. 50. 



TX7E owe this important scientific publication to the interest which 

 ^' the Government of Egypt has taken and is taking in the 

 development of the oil resources of the country. It records the 

 observations of two officers of the Geological Survey of Egypt ; 

 an institution which geologists of all countries will rejoice to see 

 continued and even expanded under the new regime ; for vast 

 tracts of the country still remain unexplored. The main objects 

 of the expedition were, therefore, to look out for evidences of oil, 

 to note the localities where, and the geological formations in which 

 they occur, and to determine the positions of anticlinals, domes, 

 faults, and other structures which must be located before the most 

 promising sites for borings can be selected ; in short, to make a 

 geological survey of the area with special reference to oil-problems. 

 The party entered the field in November, 1919, at Suez, arrived at 

 El Arish at the end of February, 1920, having walked well over 

 1,000 miles, and then returned to Egypt by way of the now celebrated 

 Gebel Maghara massif, reaching Ismailia towards the end of May. 



How little was previously known of the area is shown by the fact 

 that when the Geological map of Egypt (1 : 1,000,000) was 

 published in 1910, that portion of the Sinai peninsula which lies 

 north of lat. 29° 30' was left blank. Now, owing to the work of the 

 authors, we have, in this memoir, a map on a scale of 1 : 250,000 in 

 which 8,000 square kilometres of that blank area are covered with 

 colour, representing nine distinct formations : Alluvium and 

 Eecent ; Miocene in two divisions (Miocene and Gypsum) ; Eocene ; 

 Cretaceous in three divisions (Campanian and Maestrichtian or 

 Chalk), Santonian-Turonian-Cenomanian ; " Nubian " and Lower 

 Cretaceous ; Jurassic ; and igneous intrusions. The authors 

 correctly describe their work as a reconnaissance survey ; but owing 

 to the excellent exposures, the persistence of easily recognizable 

 lithological divisions, the generally favourable climatic conditions — 

 heavy rains, hail-storms, blizzards, and intense cold are not wholly 

 unknown as the authors have reason to remember — the close relation 

 between topography and geological structure, and the possession 

 of admirable field maps ^ (1 : 125,000), issued by the War Office in 

 1915, much more has been accomplished than would have been 

 possible in a country where these conditions do not exist. 



In addition to the map, the volume contains nine plates of sections, 



^ These maps, with the geological information, are published separately 

 (seven sheets, price P.T. 20 per sheet). 



