GEOLOGY. 177 



the various branches of the Kagera, i.e., between 

 the Congo and Nile ultimately. 



Their appearance is throughout very uniform, 

 and resembles an intricate maze of deep and 

 narrow valleys, often 1,000 feet below the level 

 of the hills. 



The lowest rock is usually a black or glistening 

 shale, or ranging from this to a well-cleaved Killas. 

 Above this follows — ( L 2) a series of red or brown 

 sandstones ; (3) a coarse schistose sandstone ; (4) 

 a white granular quartzite. 



These rocks were so much folded and usually 

 at such a steep dip that I was unable to form any 

 idea of their thickness. The coal, which has been 

 said to exist in Karagwe, will, I suspect, turn out 

 to be a black shale, corresponding to the lowest 

 rock. 



Dr. Gregory considers it probable that these 

 are part of the series described by Mr. Joseph 

 Thompson about Lake Bangweolo, and by M. 

 Cornet, from the upper basin of the Congo. They 

 are not by any means promising, geologically. 



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