Aucanquilcha Volcano

The Aucanquilcha volcano is located in the Antofagasta Region of northern Chile, between the Loa River and the Bolivia border within the Alto Loa National Reserve. It is part of the Central Volcanic Zone of the Andes.

One of the most prominent volcanic edifices in the region, the stratovolcano has the form of a ridge with a maximum height of 6,176 m (20,262 ft). By elevation, Aucanquilcha is # 4 in the Antofagasta Region, #19 in Chile, and #44 in the Andes of Chile and Argentina.

Part of a large cluster of volcanoes between the Loa River and the Chile-Bolivia border, the Aucanquilcha volcano was formed from four units that erupted between 1.04 - 0.23 million years ago. Some fumarolic activity and sulfur deposits are present at the summit.

The volcanic cluster of which Aucanquilcha is a part contains about 19 - 20 volcanoes and covers a surface area of 700 sq km (270 sq mi); the group is surrounded on its northern, western, and eastern sides by salt flats and alluvial deposits. On its southern side lies the Cerro Chela volcano.

The volcano is currently not glaciated despite its height due to the aridity of the climate. However, the volcanic cluster was modestly glaciated during the Quaternary, as evidenced by glacial striations and moraines at elevations above 4,500 m (14,800 ft). There is evidence of past glaciers on the main volcano and its subsidiaries.

Sulfur Mining

Several sulfur mines lie in the Aucanquilcha complex. At an altitude of 5,950 m (19,520 ft), one mine opened in 1913 and remained in use from 1950 to 1992. It was the world's highest mine during that period.

The sulfur obtained at the mine was initially transported down the mountain with llamas. An aerial cable system extending for 22 km (14 mi) was completed in 1935 to lower the sulfur in buckets. Eventually, this was replaced by a road that switchbacked up to the summit and could support 20-ton mining trucks. Since the mine closed in 1993, much of the road has fallen into disrepair.

Alto Loa National Reserve

Alto Loa National Reserve is a natural protected area in northern Chile's Antofagasta Region. It is at a 3,000 m (9,800 ft) altitude with a total surface area of approximately 300,000 ha (740,000 acres). Created in 2005, it is Chile's largest natural reserve.

The nearest settlement to the reserve is the small village of Ollagüe, and the closest city is the mining town of Calama.

Alto Loa is the home of three salt flats: San Martín or Carcote, Ascotán and Ollagüe. The climate is desertic, with approximately 3 mm (.12 in) of precipitation a year and temperatures that generally range between 25 °C (77 °F) and 17 °C (63 °F).

The main aim of the reserve is to protect the source of the Loa River (4,277 m or 14,000 ft altitude) and the vegetal and animal species that depend on the river ecosystem in the desert region. Along with its native flora and fauna,

Alto Loa National Reserve hosts three salt flats:

• Salar de Carcote (or San Martín): a remnant of an ancient lake, it covers an area of around 108 sq km (41.6 sq mi), and its surface elevation is 3,690 m (12,106 ft)

• Salar de Ascotán (or Cebollar): with a surface area of 246 sq km (95 sq mi), the salt pan was formerly filled by a 270 sq km (104 sq mi) lake

• Salar de Ollagüe: located on the border between Chile and Bolivia, this salt flat has a surface area of 133 sq km (51.3 sq mi), of which the majority lies in Bolivia

Fauna species found here include the Guanaco, the Condor, the Viscacha, and the Cougar. Flora species include the Tabaquillo or Queñoa (Polylepis australis) and the Yareta or Llareta.

Another of the park's objectives is to support the social and economic development of the local native communities through the operation of tourist concessions in the reserve.