Cordillera Occidental (Bolivia) in the context of Uyuni

The geology of Bolivia comprises a variety of different lithologies as well as tectonic and sedimentary environments. On a synoptic scale, geological units coincide with topographical units. The country is divided into a mountainous western area affected by the subduction processes in the Pacific and an eastern lowlands of stable platforms and shields. The Bolivian Andes is divided into three main ranges; these are from west to east: the Cordillera Occidental that makes up the border to Chile and host several active volcanoes and geothermal areas, Cordillera Central (in some contexts also called Cordillera Oriental) once extensively mined for silver and tin and the relatively low Cordillera Oriental that rather than being a range by its own is the eastern continuation of the Central Cordillera as a fold and thrust belt. Between the Occidental and Central Cordillera the approximately 3,750-meter-high Altiplano high plateau extends. This basin hosts several freshwater lakes, including Lake Titicaca as well as salt-covered dry lakes that bring testimony of past climate changes and lake cycles. The eastern lowlands and sub-Andean zone in Santa Cruz, Chuquisaca, and Tarija Departments was once an old Paleozoic sedimentary basin that hosts valuable hydrocarbon reserves. Further east close to the border with Brazil lies the Guaporé Shield, made up of stable Precambrian crystalline rock.

The Cordillera Central is a Bolivian mountain range that divides the three river basins in the country and also has the second highest peaks in Bolivia. It is rich in minerals and starts in the north with Chawpi Urqu and the three Palumanis that were in the south up to Zapaleri, forming a border with Chile and Argentina. The Cordillera Central is divided into three sections:

• The northern section or Cordillera Real, with Chawpi Urqu and Palumani, La Paz, Illimani, Illampu, Janq'u Uma, Mururata, and Huayna Potosí, with the latter six all being more than 6,000 meters high. This section is famous because the highest meteorological observatory in the world can be found on Chacaltaya. Some of the highest ski slopes in the world can be found here also.
• The central section contains Sumaq Urqu, with the Potosí mountain range and the Paso de Condor rail station, both situated at an elevation of 4,288 meters.
• The southern section is characterized by its high rate of mineralization and large deposits of tin. Its highest summit is Zapaleri on the border with Chile and Argentina.

The Cordillera Central lies between the Cordillera Occidental and Cordillera Oriental.