Der Basaltvulkanismus des Djebel Haroudj Ostfezzan/Libyen

A geological map of Djebel Haroudj is presented which shows the distribution of volcanoes and six major basalt flows over an area of approximately 45,000 square kilometres. Differences between the flows are based on age rather than petrographic composition. The oldest flows most probably erupted in the late Pliocene, though it is possible that locally flows of Miocene or even Oligocene age are present. The middle flows most probably occurred during the Pleistocene. The absence of erosional forms and drainage indicates that the youngest flows are of post-pluvial, Holocene age. The zones of volcanic activity at Djebel Haroudj are related to three major tectonic elements of very different ages (see alsoKlitzsch 1966 a): the early Paleozoic southern Haroudj uplift, the western edge of the Mesozoic Tibesti-Sirte uplift, and the south-eastern prolongation of the Hon graben fault system of late Cretaceous to Tertiary age.