Waw an Namus, Libya
Location: 24.9N, 17.7E
Elevation: 3936 ft (1200 m)
Waw an Namus is an exotic volcano deep in the desert of Libya. A low caldera
about 4 km in diameter is surrounded by a 5 - 10 km wide dark black deposit
of ash that stands out starkly against the yellowish desert. The few people
who have visited have been struck by its beauty: The Italian geologist
Angelo Pesce wrote that as seen from the rim, one is "overwhelmed by a
scene of rare beauty....Inside, the only thing one wishess is to be alone
and wander in admiration from one end to the other." But Pesce also complains
about the "veritable cloud of mosquitos, which not having many occasions
to feed on fresh blood warmly welcome visitors to their desert realm. The
Arabic word Namus means mosquito."
On the floor of the caldera is a 120 m high cinder cone, the apparent source
of the ash apron, and three small salty lakes. The facts that one lake
is warm, and the entire feature is not deeply eroded suggest that the eruptions
which formed it may have occurred within the last few thousands of years;
no historic eruptions are known.
No lava flows are present at the crater, but small rocks ejected from
the central cone include feldspatic basalts, dunite and fist-sized nodules
of green olivine. The dunite and olivine suggest that the magma that formed
the volcano rose swiftly from deep in the mantle. Pesce considers Waw an
Namus to be related to the extensive basaltic lava flow field to the north,
The older name for this feature is Uau en Numas.
Sources of Information:
Pesce, A., "Uau en Namus," South-Central Libya and Northern Chad, Published
by the Petroleum Exploration Society of Libya, 6th Ann. Field Conference
(Ed. J.J. Williams), 1966.
Dautria, J.M. and Girod, M., "Cenozoic volcanism associated with swells
and rifts," Mantle Xenoliths, John Wiley & Sons Ltd., pp 195-214, 1987.