Al Haruj al Aswad

Haruj is a large volcanic field spread across 42,000–45,000 km2 in central Libya. It is one of several volcanic fields in Libya along with Tibesti, and its origin has been attributed to the effects of geologic lineaments in the crust.

It contains about 150 volcanoes, including numerous basaltic scoria cones and about 30 small shield volcanoes, along with craters and lava flows. Most of the field is covered by lava flows that originated in fissure vents; the rest of the flows originated within small shield volcanoes, stratovolcanoes and scoria cones. Some of these vents have large craters. Volcanism in Haruj blocked ancient rivers and led to the formation of Lake Megafezzan.