Coastal Cordilleras of the Andes

Coastal Cordilleras of the Andes 

a meridional chain of ranges extending along the coast of the Pacific Ocean in South America, through Colombia, Ecuador, Peru, and Chile.

In Colombia, the cordilleras—which, in the north, carry over into the mountains of southern Panama—are known as the Serranía de Baudó; the range is intensively dissected by rivers, has elevations up to 1,810 m, and is made up of Paleocene-Neocene sandstones and marls.

In Ecuador, the cordilleras consist of sandstone-limestone massifs (primarily Paleocene) of elevations up to 800 m.

In Peru, the cordilleras are expressed in isolated residual ranges up to 1,780 m, situated primarily between 14° and 18° S lat.

Only between 19° and 37°30’ S lat., in Chile, do the cordilleras constitute a single, although intensively dissected, range reaching 3,200 m in elevation; south of 41°31’S lat., the range dips, forming the island chain of the Chilean archipelago.

In Peru and Chile, the cordilleras are formed by Upper Cretaceous intrusions into Mesozoic and Paleozoic deposits; deposits of copper ores (El Tofo, for instance) are associated with it. From 36° S lat. to the Taitao Peninsula, the cordilleras consist primarily of ancient crystalline and metamorphic rocks. The terrain is extremely worn down in the desert region of Peru and northern Chile; in central Chile the cordilleras have gentle erosional forms and ancient glacial forms south of 44° S lat.