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Indiana University Studies 



is due to the late formation of the Cordillera of Bogota which in 

 southern Colombia and northern Ecuador are piled up against 

 the Cordillera Oriental. In the center and south of Ecuador 

 others of the interandean parks are tapped by Pacific slope rivers, 

 the Tumbez, Rompida, Canar, Can Chan, and Chimbo. 



The Rio Patia in southern Colombia rises near Popayan, flows 

 between the eastern and western Cordilleras southwestward to 

 about 90 miles north of the Equator, then breaks thru the west- 

 ern Cordilleras and flows northwestward to empty into the Pa- 

 cific near Tumaco. A large southern tributarj^ the Guaitara, 

 rises between the two Cordilleras, 45 miles north of the Equator, 

 and flows between them to join the Patia, where it bends from a 

 southwest to a northwest flow. 



The Rio Mira, with a length of about 100 miles, flows north- 

 west, emptying into the Pacific at the northern border of Ecuador. 



The Esmeraldas, with a general trend nearly parallel to that 

 of the Mira, drains the parks about Quito and empties into the 

 Pacific approximately 60 miles southwest of the mouth of the 

 Mira, at 1° north. 



The rivers emptying directly into the Pacific between the Es- 

 meraldas and the Guayas are all small, the largest of them, the 

 Rio de Chone and the Rio de Portoviejo, are less than 40 miles 

 long, measuring from source to mouth. South of Portoviejo the 

 country is dry and the rivers are shorter still. In the area be- 

 tween Cuenca and the coast, the Atlantic slope streams, tributaries 

 of the Amazon, rise within about 35 miles of the Pacific coast. 



Wolf and Sievers make out that between Esmeraldas and 

 Guayaquil, coastal Cordilleras reach a height in places of 2,300 

 feet. In the north, about Esmeraldas and Manabi, they are of 

 late tertiary and quarternar\^. Southward about Portoviejo they 

 consist of older formations. The youngest land of Ecuador lies 

 between the coast Cordilleras and the western Cordilleras. Even 

 .as late as quarternary time the Guayas basin was a gulf reaching 

 :from Machala to the base of the Cordilleras. This gulf has been 

 largely filled by debris to form the present Guayas basin. The 

 chalk mountains of the coastal Cordilleras reach a height of about 

 £00 to 1,000 feet. The quarternary rolling land has an elevation 

 of 60 to 250 feet. Between the coastal Cordilleras and the west- 

 ern Cordilleras there are a number of characteristically lowland 

 streams with a north and south trend. 



Sievers, from whose Slid und Mittelamerica the above account 

 is taken, p. 459, says: 



