THE CENTRAL COEDILLERA OF COLOMBIA. 



145 



of Ruiz, the truncated cone of Tolima, and all the intermediate peaks are wrapped 

 in continuous fog 



Rising in terraces in the direction of the south, the various branches of 

 the Central Cordillera soon merge in the broad plateau of Antioquia, which 

 is carved into secondary mesas by the Nechi and its affluents. The Cerro 

 Grande, in a lateral ridge near the Magdalena, rises to a height of ô,3è0 feet, 

 while the Central Cordillera is dominated under the same latitude by Mount 

 Yarumal, whose twin peaks are respectively 7,470 and 7,230 feet high. In this 

 region the uplands broaden out considerably, descending in comparatively gentle 

 slopes down to the Magdalena. But westwards they fall abruptly, and beyond 

 the deep bed of the Cauca again rise rapidly in the escarpments of the Western 

 (Choco) Cordillera. 



In the midst of this chaos of crests in the district of Antioquia the chief 

 group is the Santa Rosa de los Osos (" Bear" Mountains), which in the San Jose 



Fiff. 5'i. — Mesa de Hee^-eo and Ruiz Volcano. 

 Scale 1 : 1,350,000. 



. ; 



r'!^"'^ tç^^tk'; 



^^B''<?ll^'<^»lji\:3il_^'j^\ '^?f"/'jf^ ^^-sS«a!!5?=:^v\'v>^^*>' 





f^J à 



V/esto" L 



30 Miles. 



peak attains an altitude of 9,000 feet. The various branches converge south 

 of Medellin and of the Rio Force in the transverse crest of San Miguel, 9,025 

 feet high. 



The Alto Pereira, eastern limit of this rampart, constitutes the corner-stone of 

 a remarkable chain disposed in the direction of the south, and increasing in height 

 in proportion as it loses in breadth. On a pedestal of crystalline rocks, flanked 

 on both sides b}^ cretaceous formations, rise lofty pyramids of eruptive matter, 

 mountains piled up like " Pelion on Ossa." In this chain of volcanoes the first 

 crater is the huge Mesa de Herveo, 18,340 feet high, flanked by another some 

 3,000 feet less elevated. Vast buttresses disposed in terrace formation fill up the 

 whole space comprised between the Rios Magdalena and Cauca. 



Northwards the Mesa de Herveo is limited by a flooded depression, whence two 

 streams flow in opposite directions to the two parallel rivers. Southwards it is 

 followed by the snowy Ruiz (17,390 feet) and Santa Isabel (16,760). In 1839 

 11 



