ON THE CLIMATE OF EGYPT IN ANCIENT TIMES, 91 



Pliocene formation — the Pliocene age was probably still 

 more continental than the Miocene Period. 



After this came the great Pleistocene submergence (about 

 20,000 years ago) when the Red Sea and Mediterranean 

 again intermixed freely for a short geological period, while 

 the present valley of the Nile (without any Nile) was a long 

 fiord of the sea stretching as far hiland as the rocky barrier 

 at Assouan, and being gradually deepened by the erosive 

 action of the sea.* The raised beaches near Cairo belong to 

 this period." The scattering of boulders from the eastern 

 crystalline mountains over the Libyan Desert seems to imply 

 the action of floating ice in some part of the Pleistocene 

 Period.' The softer parts of the Miocene sandstone must 

 also have been wasted away at this time. 



This submergence was succeeded not long after by a re- 

 elevation partially restoring the conditions of the first con- 

 tinental period, and finally connecting Asia and Africa by a 

 permanent isthmus. 



A divergence is now manifested between the fauna of the 

 Mediterranean and Red Sea ; the fauna of the Mediterranean 

 taking the type of the Atlantic, and that of the Red Sea the 

 type of the Indian Ocean,^^ showing a complete change 

 between the climates of these two regions. 



The oldest part of the isthmus is the Miocene bed at 

 Shaloof, about 13 miles from Suez, and only 6 to 9 feet above 

 the level of the Red Sea. This bed is covered in part by 

 the old Blue Nile deposit of the Pliocene, or as some geo- 

 logists contend of the later Pleistocene, both these having 

 been continental periods with an abundant rainfall. The 

 highest parts of the isthmus are at El Gisr to the north, and 

 Serapeum to the south of Lake Timsah. These elevated 

 portions of the isthmus are composed of the Old Nile deposits. 



Thus the ancient Blue Nile built up a considerable portion 

 of the isthmus at a time when the climate Avas warmer than 

 at present ; for this limestone stratum extending from El Gisr 

 to Shaloof, and stretching to a considerable distance east 

 and west, contains freshwater shells that are now confined 

 to the Upper Nile, and that have somewhat of a modern 

 character as compared with what we might expect in a 

 Pliocene bed. 



* The author has somewhat inverted the order of things in the above 

 statement. There could not have been a Nile valley before a Nile river ! 

 The Pleistocene Period began with a great elevation of the laud and sea 

 bed following the Pliocene submergence. — Ed. 



