Appendix C. 



the inouiiiaiu is essentially constituted of gneiss, the hiotitc variety and uikivriine 

 being common on the lower parts of the mountain. This gneiss, associated 

 with wka-xchMts, may be traced from Ibanda liy the Mahoma Valley, not only 

 up to the crests of the mountain, liut probably also extends to the south and 

 west of the range. 



It should be mentioned that in Mt. Lnigi di Savoia there are lai'ge dikes of 

 macroscopic pcf/iiiati/e i-ich in <iarnd and tounwdine, haplite and micro-granite in 

 the neighl)Ourhood of Stairs Peak ; diabase, which crops out at Sella Peak, where 

 it aliounds in fulgurites ; diorite, epidosyte and crystalline chalk, which seems to 

 point at contact between the gneisses and the amphibolic schists. 



^It. Speke. — The prevailing rock appears to be a granitoid gneiss with 

 biotite and abundant cpidole ; with the gneiss would appear to be associated 

 diorite, amphiboUte and micro-granite. 



Mt. Emin. —Yields qnarizitt' and a diorite analogous to that of -Mt. Stanley. 



Mt. Geshi. — The dominant rock again appears to be ainphihoUc schist in 

 association with quartzite and epidosyte. 



In the Bujuku Valley the prevalent form appears to be of a type analogous 

 to that occurring on Mt. Speke. This valley, as well as that of the Mubuku, 

 would seem in its upper reaches to open out in contact with gneiss and 

 amphibolic rocks. 



Teetonic Structure. — The tectonic feature by which the Kuwenzori ^lassif is 

 outlined and clearly characterized is represented by two great zones of fracture. 

 One lying to the west is of vast size, having given rise to the Semliki Valley, 

 and in this direction completely isolated the enormous mass of the Kuwenzori 

 Kange. The other (eastern) zone of fracture is less marked, but well outlined 

 by the volcanic formations, in which are included those of Fort Portal. 



In relation with the two main zones of fracture, others occur in the interior 

 of the range, and these are disposed in two difl'erent directions, one west and 

 east — that is to say, normal to the chief trends — the other, on the contrary, 

 running in parallel lines from south to north. To these lines of iinier fracture 

 are due several valleys and many of the secondary glens, which tend to give 

 their characteristic isolation to all the principal heights. 



The stratigraphic disposition is regular. As we ascend the Molniku 

 Valley, we everywhere notice in the gneiss and mica-schist beds an incline from 

 east to south-east. This incline is, on the whole, maintained in Mt. Baker, 

 and is clearly seen, for instance, in Cagni Peak. In Mt. Luigi di Savoia the 

 east-south-east slope recurs, with a tendency to the south which farther on 

 becomes due south. In Mt. Stanley the south-east tends to change to west 

 or north-west, although the south-east to east incline reappears in the Bujuku 



390 



