Laguna Colorada (caldera)

22°15′S 67°30′W^[1] Laguna Colorada is an ignimbrite shield^[1] of the Altiplano-Puna volcanic complex^[2] at an altitude of 5,000 metres (16,000 ft)^[3] in the Potosi Department^[4] of Bolivia.^[5]

Laguna Colorada is a c. 40-kilometre-wide (25 mi) ignimbrite shield that was formerly also known as Panizos (not to be confused with Cerro Panizos). The shield is not clearly associated with a caldera but appears to contain a sag structure.^[1] The ignimbrite field is bordered by the Laguna Colorada to the west, Cerro Torque in the north, and Quetena to the east;^[5] Laguna Colorada is also the origin of the name of the shield.^[1] Likewise, the Tatio formation at El Tatio originates from eruptions at Laguna Colorada;^[6] however, the 700,000-year-old Tatio ignimbrite is considered to be separate.^[1] An older ignimbrite was erupted 2.21 ± 0.05 million years ago.^[7]

An ignimbrite is associated with Laguna Colorada. This ignimbrite was erupted 1.98 million years ago and has a volume of 60 cubic kilometres (14 cu mi) dense rock equivalent,^[3] covering a surface of about 1,100 square kilometres (420 sq mi). Several fall deposits occur both within and below the ignimbrite.^[1] This ignimbrite is also known as the Tatio ignimbrite and given a volume of 150 cubic kilometres (36 cu mi) dense rock equivalent,^[8] or the Aguadita tuffs.^[1] The ignimbrite is one of the youngest in the region and keeps a noticeable texture in high-altitude images.^[5] Deposits perhaps correlated to this ignimbrite have been recovered in the Quebrada de Humahuaca region.^[9]

The active geothermal fields of El Tatio and Sol de Manana are located around the Laguna Colorada system.^[10] As of 2018^[update], a pilot geothermal power project was underway at Laguna Colorada.^[4] An electrical conductivity anomaly beneath Laguna Colorada has been interpreted either as new magma or hydrothermally altered material.^[11] Recent^[when?] satellite imagery has shown that Laguna Colorada is subsiding at a rate of 4 millimetres per year (0.16 in/year), with the subsidence encompassing the area of the Laguna Colorada ignimbrite and covering a diameter of 20 kilometres (12 mi).^[3]