Coussi

Coussi is a dormant stratovolcano located in the Tibesti Mountains of northern Chad. It is the highest point in both Chad and the Sahara Desert, reaching a summit elevation of 3,415 meters (11,204 feet). The volcano's name likely originates from the local Teda language.

Coussi's summit features a large, complex caldera, approximately 15 kilometers (9.3 miles) wide and 19 kilometers (12 miles) long. Within this caldera are several nested calderas and lava domes, indicating a complex history of eruptions and collapses. Tarso Toussidé, a much younger volcano, lies to the west.

The volcano is primarily composed of trachyte and phonolite, volcanic rocks rich in alkali feldspars. Its formation is linked to the African Rift System, a zone of tectonic activity that has shaped much of eastern and northern Africa. The remote location and harsh desert environment have limited detailed scientific study of Coussi, and significant gaps remain in our understanding of its volcanic history and potential for future activity. The area around Coussi is extremely arid, with minimal rainfall, contributing to the stark and dramatic landscape.