Suiumaiy of Geological Observations. 



Towards 9,000 feet the persistently humid climate gives rise to the zone 

 of the cryptogams, and to the bogs that constitute one of the characteristic 

 features of Kuwenzori. From this altitude, we may say right up to the 

 glaciers, the ground is everywhere uninterruptedly covered with a boggy peat- 

 turf layer which not seldom reaches or exceeds a thickness of 20 inches. On 

 this substratum is developed a vigorous vegetation of mosses, hepaticfe 

 (liverworts) and lichens, which spread a thick mantle over the protruding 

 rocks, the erratic boulders and the trunks of the trees, whether living or fallen 

 with age, and for ceiitnrics accumulating on the surface of the ground. 



Over this overlying stratum of liog and vegetable detritus there is l>ut 

 a slight How of water, absorbed as it is as by a huge sponge. The surface 

 layer thus forms a protecting carpet for the rocks which, when they can be 

 seen underneath, appear to he relatively intact, escaping as they do in great 

 measure from the erosive phenomena. 



Beyond the boggy zone the surface action of the meteoric agents comes 

 again into play, but it must act very slowly in consequence of the abundant 

 vegetation of the crustaceous lichens covering the rocks. The nature of these 

 rocks, largely constituted of amphibole and quartz, also explains the slighter 

 action of atmospheric deiuidation which has freer play in the gneiss and 

 mica-schist zone. 



Attention may again l>e called to the characteristic protrusion of the rocks 

 composed of more resisting elements. This fact is apparent in the beds of 

 garnet-l)earing rocks, where the large crystals of garnet protrude with an 

 almost variolar or pitted aspect. The phenomenon is typical also in the mica- 

 schist zone on the western slope of Mt. Baker, where the mica-schist is 

 associated with al^undant quartz in lenticular veins and thin layers which 

 everywhere form protuberances, sometimes even very conspicuous on the 

 surface of the ground. 



Lastly, in the higher zones to the modifying and erosive action of the 

 atmosphere is added the extremely potent factor of frost and thaw. In this 

 case, wherever the underlying rocks are not protected by the masses of ice, we 

 find long stretches of ground covered with loose chaotic and shifting detritus 

 analogous to what is noticed on the crests and higher slopes of our Alpine 

 heisrhts. 



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