Trou au Natron

[6] Trou au Natron is located just south-east of Toussidé, the westernmost volcano of the Tibesti Mountains.

[2] Four smaller volcanic cones, made of scoria or andesitic tuff sit on the floor of the caldera.

[2] Because of its irregular shape, it has been theorized that the caldera was formed as a result of multiple massive explosions, each of which deepened the enormous pit.

[2] During these explosions, chunks of debris up to 5 m3 (180 cu ft) in size may have been hurled up to 10 km (6.2 mi) from the crater.

[4] Much of the surface of the caldera is lined with a white crust of carbonate salts such as sodium carbonite and natrolite.