[2] The highest summit Cerro Falso Azufre lies at the western end in Chile, which has mostly generated pyroclastic material from craters.

[2] Falso Azufre with a base surface of 387 square kilometres (149 sq mi) is one of the biggest volcanoes in the area.

The presence of two oppositely curved vent alignments gives the complex an arc-like shape which reaches heights of about 5,900 metres (19,400 ft) above sea level.

[5] The rocks contain hornblende and pyroxene with a total content of 58-61% of SiO2[6] and form a potassium-rich calc-alkaline suite.

[7] A number of dates have been obtained on Falso Azufre; with the exception of the oldest ones on the Kunstmann edifice (3.5 to 2.9 million years ago) Falso Azufre has only yielded ages of less than one million years, with older dates found in the western part of the volcano and the younger dates of less than 400,000 years ago in the eastern part;[3] the absolutely youngest date was obtained on a lava flow linked to Dos Conos; 160,000 ± 80,000 years ago.