Geology of Colombia
Geology of Colombia refers to the geological composition of the Republic of Colombia that determines its geography. The territory of Colombia covers vast areas within the South American plate, where most of the emerged land is, the Caribbean plate and the Nazca plate.
Emerged and Submerged zones
Colombia is formed by two great territorial zones, one submerged in the Pacific Ocean and the Caribbean sea covering a total area of 828,660 km² and the second is the emerged land which is formed by the Andes mountain range and the Llanos plains that are shared with Venezuela and cover an area of some 1'143,748 km².
Emerged zone
In the emerged zone the region is washed by numerous rivers that include the Meta, Vichada and the Inirida rivers which contribute to other major rivers like the Orinoco River, Vaupés River, Caquetá River, Putumayo River and Apaporis River. This region of the LLanos plains is also divided into three subregions;
Northern plains
the northern area characterized by its wavy plains similar to a savanna and located between the Andes mountain range and the Guiana Shield formed during the Tertiary mostly covered with sand and clay, while the rivers contributed with sedimentary elements from the Andes during the Quaternary.
Macarena mountains area
The second region is located in the central area of the Llanos plains with a more wavy topography and formations elevated like the Alto del Vaupés or the Serranía de la Macarena mountain range, isolated in the middle of the plains and towards the Guyana Shield.
Southern area
The southern area is made up by most of the Putumayo and Amazon River basins, while the topography is flatter that the other two regions, this area is covered by dense jungle and makes up most of the Amazon Region of Colombia.
The Andean region
The Andean Region of Colombia is the other emerged area of the two areas that compose the geology of Colombia. This area originated after a complex geological development that started in the Paleozoic era when the Nazca plate collapsed with the South American plate pushing it under the Caribbean plate that created volcanic islands off the Pacific coast off Colombia and the isthmus of Panama. The Colombian Massif, near the border with Ecuador formed and split into three mountain ranges; Cordillera Central (central mountain range), Cordillera Oriental (Eastern mountain range) and the Cordillera Occidental (Western mountain range), each product of three different formation processes and divided from one another by valleys.
The Cordillera Oriental was the most recently formed mountain range of the three, developing by the end of the tertiary period and consisting mostly of sedimentary elements. The formation of the Cordillera Oriental covered the continental platform with pelagic sediments with Precambrian and Paleozoic metamorphic rocks bases. The area of the Bogotá Savanna and the highland of Cundinamarca and Boyacá tableland. To the northeast the volcanic metamorphic formed massif in Santander and Norte de Santander formed the Andes in Venezuela and the mountain ranges of Perijá and Motilones, between the border of Colombia and Venezuela during the Pleistocene and added sedimentary rocks during the Mesozoic.
The Cordillera Central formed from the Guyana shield during the Paleozoic era with intrusions from granite and metamorphism. To the west presents basic volcanic rocks from the end of the Cretaceous period and diorite intrusive rocks from the Tertiary. To the west there are metamorphic Paleozoic rocks and two major massifs in Ibagué and the Serranía de San Lucas. Another important formation is the Baudó Mountains to the west of the country.