The Andes Mountains are part of the Southern Cordillera formed by subduction zone volcanism at the convergent boundary of the Nazca Plate and the South American Plate. Aracar volcano (summit elevation 6,082 meters) is one of many volcanoes in the Andes Range. It is a steep-sided stratovolcano with a youthful-looking summit crater approximately 1.5 kilometers in diameter. It is located just east of the Argentina-Chile border. Well-preserved lava flows are found at its base. Very little is known about the volcano's age and history. Prior to a report of ash columns from the summit in 1993, the volcano was not known to be active.

The large whitish features are very common in the arid Andes; they are called salars. The term salar is used exclusively to describe the saltwater wetlands of the Puna (high Andes) and can refer to not only salt lakes but also temporary marshes, shallow lakes and lagoons, or simply salt crust. The nearby Salar del Hombre Muerto is being used for mineral production. The endeavor is expected to become one of Argentina's biggest mines, producing up to 20,000 tons of lithium carbonate and lithium chloride per year, to be extracted by pumping the area's lithium-rich saltbeds.