254 SOUDAH, OR BLACK MOUNTAINS. 



Ihe examination of caves and caverns, being an investiga* 

 tion, as appears from the preceding details, not only inti- 

 Inately connected v?ith the early history of man, and of hi» 

 condition in a low state of civilization even at the present 

 iay, but also with the geological history of our species, and 

 of that of several of the more powerful and interesting spe- 

 cies of the class of quadrupeds. 



In the route from Tripoli to Mourzouk, the first change 

 of rock met with by Dr. Oudney was at Benioleed,* where he 

 remarks there is a rich valley, the sides of which are of 

 lunestone hills 400 feet high, capped with greenstone and 

 amygdaloid. The Jibel Gulat, 600 feet high, one of the 

 highest hills he had met with since leaving Tripoli, is con- 

 siderably to the south of Benioleed. It is composed of marls 

 and limestones, containing fossil oysters and limpets, form- 

 ing a deposite which is said to resemble the tertiary rock 

 named calcaire grossiere of the Paris basin, which occurs 

 in Malta, Sicily, and on the north side of the Mediterra- 

 nean, on the shores of Italy and France. These limestones 

 continue onwards to the valley of Bonjeviff which was 

 found strewed with gypsum. Captain Lyon mentions gun- 

 flints as occurring in the road to Bonjem ; while Dr. Oud- 

 ney speaks of striped jaspers and cornelians, but does not 

 mention gun-flints. These rocks continue onwards to 

 Sockna. A short distance to the south of Sockna are the 

 Soudah or Black Mountains. These, Captain Lyon says, 

 rise to a height of 1500 feet, extend about 100 miles in 

 breadth from N. to S., and as far as the eye can reach from 

 E. to W. They are perfectly barren, of very irregular 

 forms, occasionally broken into detached masses, and some- 

 times rising into cones. They are composed of trap-rocks, 

 said to be of the nature of basalt. After crossing this 

 range, the route to Mourzouk leads across gravelly and 

 sandy tracts, with frequent appearances of dolomite lime- 

 stone, occasionally rolled masses of basalt, and agates, pro- 

 bably derived from amygdaloidal trap.t The road from 



* The inhabitants of Benioleed are Arabs. The water is excellent, 

 but some of the wells are UlO feet deep.— Lyon. 



t This is the northern boundary of the kinedom of Fezzan. There 

 are here some perfect remains of a Roman fortress, built by order of Sep 

 limius Severus. — Lyon. 



I At Sebha, a town of 800 inhabitants, the population is no longer 

 Ar^b, but black ; hence Captain Lyon, in his map, says, " Sebha,N. lat. 

 270 black population coniiuences =' 



