MOROCCO. 359 



direction. Older eruptive rooks: that is, porphyrite, diorite, and 

 granite, which seem to be entirely lacking in the Sahara Atlas of 

 Algeria, ar(> liere ih(> most prominent, as is proved not only by the 

 mountains tluMuselvcs but also by the composition of the accumula- 

 tions of detritus at the mouths of the valleys. This recalls the 

 ancient denuded mountain ranges of the Iberian table-land. The 

 crumpliugs in tlie Moroccan Atlas seem to have begun and ended 

 sooner than in the other Atlas ranges; that is, at the end of the 

 Cretaceous period. 



According to J. Thomson, the same Cretaceous strata that lie flat 

 and undisturbed in the A' orland are abruptly uplifted and form an 

 essential feature of the Moroccan Atlas. Then these mountains would 

 be older tiian the liif Mountains, the Tell Atlas, and Sahara Atlas 

 of Algeria. Paleozoic rocks are probably another large element in 

 their structure. The process of upheaval was by far more intense, 

 so that e\'en to-day much higher ridges (3,000 to 4,000 m.) and peaks 

 (4,000 to 5,000 m.) appear here than in the more recently formed 

 ranges. The breadth of the range (about 200 km.), comprising a 

 number of separate folds wdiich constitute three parallel belts, the 

 Great Atlas, the Anti-Atlas, and the Middle Atlas, is also much 

 greater. The height of the ridges is every wdiere considerable. Deep 

 indentations do not occur in them. South of Marrakesh (the city of 

 Morocco), lie three passes, the first 3,000 to 4,000 m. high, the second 

 lying to the northeast of the first, 2,500 m.,the third, to the southwest 

 in the direction of the ocean, 1,000 to 2,000 m. The range thus forms 

 a high wall, difficult to cross, about 1,000 km. long, separating the 

 desert from the Vorland. Thus the Moroccan Atlas forms a moun- 

 tainous regi(m nearly as great in extent as the Alpine country be- 

 tween Nice and Vienna. Though in general, and not only on the 

 side toAvard the Sahara, the whole range shows signs of comparative 

 drought, which accords with its latitude and its situation in a dry 

 /one. It receives so much snow during the winter that its peaks, cov- 

 ered with snow until late in the summer, which glisten down upon 

 the dry, sun-scorched plain, and the streams in spring and early sum- 

 mer, fed by the melting snows, provide a quantity of water for irri- 

 gation. 



7'he i)re vailing drought, increased by an almost complete destruc- 

 tion of the woods, the cold, and the covering of snow in winter, the 

 rarity of wude valley plains, which, moreover, where they exist, are 

 capable .of culture only wnth the aid of artificial irrigation in sum- 

 mer—all these factors make the Moroccan Atlas less suited to habi- 

 tation than one would expect. The population is limited to the chief 

 valleys and thus only up to a slight elevation. Proper conditions are 

 also lacking for cattle raising and mountain grazing. The region 

 offers no allurements to the conqueror. Consequently, the Berlwr 



