86 



SOUTH AMERICA— THE ANDES REGIONS. 



central nucleus of Mucuchies rising to an altitude of 13,520 feet. AU the upland 

 valleys between the crests, standing at an elevation of over 11,500 feet, have 

 assumed the aspect of paramos, that is, of irregular treeless plateaux clothed with 

 low herbage, mosses and lichens, exposed to the cold winds and icy fogs. 



The steepest slopes of this section of the Andes fall northwards down to the 

 plains encircling the shores of Lake Maracaibo. On this side an imposing aspect 

 is presented by the cretaceous cliffs rising abruptly above the fringe of leafy 

 woodlands, streams and morasses. The numerous rivers which have their source 

 in the sierra flow for the most part in a line with the mountain barrier, some 

 descending north-westwards straight to the Maracaibo lagoon, some south-east- 



Fig. 29.— SlEEEA DE MeEIDA. 

 Scale 1 : 600.000. 



'r^^^ ^J. 



>'0^' 



W. 



7rio- 



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VVest of Gr-eenwich 70'50 



12 Miles. 



wards to the Apure affluent of the Orinoco. But several rising in the very heart 

 of the Cordillera have to force their way through winding gorges down to the 

 lowlands. Thus some of the headwaters of the Apure first flow south-westwards 

 normally with the main axis of the system, and then trend sharply round to reach 

 the plains through deep ravines in the mountain barriers. One of these ravines, 

 lying entirely within Venezuelan territory, may be regarded as the natural limit 

 between the Sierra de Merida and that of Pamplona, in Colombia. Here the 

 political frontier is formed by the Rio Tachira and the breezy heights of the 

 Paramo Tama. 



Underground Forces. 

 No active volcanoes have been reported in the Venezuelan highlands, but evi- 

 dences of old eruptions have been observed, especially at San Juan de los Morros, 



