304 



METEOROLOGY AND GEOLOGY 



Notes on the Collections of 



EOCKS AND MINEEAL SrECIMENS FROM THE UGANDA 



PK()TECT( )KATE 



made by sir harry johnston, messrs. george wilson, racey, wm. grant. c. w. 

 hobley, v. w. isaac, and others. 



By Messrs. Jj. Fletcher and G. T. Prior, of the Mineralogical Department, 

 British Natural History Museum. 



The rock specimens include examples of the Archaean gneisses, schists, and granites, 

 which constitute the main mass of the Uganda ])lateau : specimens of these rocks 

 come from the Busoga, Bukedi, Elgon, and Unyoro Districts, from Ruwenzori and 

 the Nile Province. Besides these basement rocks, there are specimens of ferruginous, 

 schistose, and slaty rocks from Unyoro, possibly belonging to the Paheozoic Karagwe 

 series ; coarse ferruginous sandstones and quartzites from the shores of Lake Victoria 

 Nyanza and Lake Naivasha, and from Ankole ; and volcanic rocks (chieHy jthonolites) 

 from the Elgon and Baringo Districts, the Kam.'isia hills. Lake Nakuro, and the Nandi 

 District. 



Of minerals of economic value, the collection contains specimens of iron ore, 

 graphite, and diatomaceous earth. The iron ore includes specimens of magnetite from 

 Budolo hill, Masaba (Elgon); Nagarive hill, Bukedi; and Jinja, Busoga; and of 

 ironstone (limonite chieHy), from Bukonge and Jinja in Busoga, from the Bugaya islands, 

 Buvuina, Kavirondo Bay, Ankole, and Unyoro. Graphite is present in small amount 

 on specimens from Unyoro (Chief Byabaswezi), and the diatomaceous earth occurs 

 8 miles west of the Katonga River, and also on the shore of Lake Nakuro. As to 

 the occurrence of gold, all that can be said is that no visible gold could be found 

 upon any of the numerous specimens of quartz in the collection. 



The Catalogue of Specimens proceeds in geejuraphical order froin East to West. 

 MAU, NANDI, AND BAPJNGO DISTPxICTS. 



Locality. 



Cliffs on north-west coast of Lake Nakuro 

 Hill facing Lake Nakuro, south of railway station , 

 Hill north of railway station. Lake Nakuro . 

 Hill north east and o miles from Lake Nakuro 



Shore of Lake Nakuro 



Seget Valley, Nandi District .... 

 Sigowet hills, „ .... 



Naii.e. 



Kenyte. 



Tuff. 



Glassy lava (Kenyte). 



Scoria. 



Diatomaceous earth. 



Phonolite. 



Bed of Seget Piver, Nandi District . 

 Kamiisia hills, below ravine . . . . 



Baringo District, Eldama l»avine 



Lake Naivasha 



Bed of Nyando River, Nandi District 

 Bed of Lower Kedowa River . . . . 

 LTpper waters of ,, . . . . 



Nyando Valley, 10 miles west of Port Ternan 



Red jasper, quartz, chalcedon, 



calcite, and i)honolite. 

 Basalt, scoria, and i)honolite. 

 Obsidian tuft", sandstone. 

 Nephelinite. 



Limestone from concretionary 

 blocks in alluvial deposits over- 

 lying granite and gneiss. 



