Three locomotives of the FCAB (Ferrocarrill de Antofagasta a Bolivia) are pulling an impressive, about 2300 ton train (lead/zinc/silver concentrates in containers) from the San Cristóbal mine in Bolivia towards the harbour of Mejillones north of Antofagasta, on the 1 meter gauge line crossing the Salar de Carcote on a dam. Salar de Carcote, also known as Salar de San Martín, is a salt flat which covers an area of around 108 km² and its surface elevation is 3690 meter a.s.l. In the background above the train, you can see the black Cerro Porunita, 3868 meter high. It is a cinder cone which rises 90 metres (300 ft) above the surrounding plain and has a diameter of 800 metres (2,600 ft). The cone was constructed by andesite pyroclastic material and features a summit crater. The cone was formed 3.5 million years ago and has been degraded by erosion since then. Pulling the train are locomotives Clyde Engineering GL26C-2 # 2005 (former Queensland Rail # 2107 built 1971), GL26C-2 # 2010 (former QR # 2118 built in 1972) and EMD GT22CU-3 (rebuilt GR12) # 2402 (former FNC Ferrocarriles Nacionales de Colombia # 410, former STF Sociedad de Transportes Ferroviarios # 1210, built in 1963).