Appendix C. 



although some specimens present a typical graphic association of quartz with 

 microcliiie. 



In the LwamutukuzH, Muyongo antl Fort Portal districts I noticed in the 

 gneiss-granitic formation consideral)le intrusions of diabase rocks of grainilar and 

 sometimes coarse-grained structure. The specimens collected by us never 

 contain olivine, nor even the chloritic green pigment so common in the rocks 

 of this type in our lands ; characteristic is always the abundance of ilmenite, as 

 also the basic felspar often referable to anortldte. 



Thanks to the metamorphosis of the pyroxenes in amphiboles, which ma}^ 

 be easily followed in its various traiisitions, some of these dial)ases pass over to 

 epidiorite ; true diorite I did not come across in dfii, but believe that it occurs in 

 the Kaibo-Butiti district. Conspicuous also, between Fort Portal and Duwona, 

 is a thick bed of overlying Iii/jicrsthcne gabbro of coarse structure. 



Faiieo-oic. — The formations which represent the Pal?eozoic Age follow for 

 about 50 miles lietween Mitiana and Kasiba. Their eastern limit did not appear to 

 be very clearly marked, whereas the western is distinctly defined by the granitic 

 range which I have described as extending from Kasiba to Muyongo. It is in 

 fact against these very escarpments that the palaeozoic formations are inclined. 



The rocks met in the district are sandstones, arkoses, quartzites, qnartdte 

 breccias and various schists, micaceous or t ai co-micaceous. All these rocks, whose 

 clastic and metamorphic origin is readily recognized in the petrographic 

 laboratory, arc for the most part coloured a deep red, and correspond perfectly 

 to the rocks referred to the Palaeozoic Age, as descril)ed by observers in other 

 parts of Uganda, as well as in Congoland and South Africa. 



An exact determination of age is too often prevented by a total lack of 

 fossils. I think, however, that it may be useful to point out how some of the 

 schists met l)y me greatly resemble analogous formations of the Permian 

 Epoch in the Alps, and how, as we proceed westwards, the series seem dis- 

 tinctly to pass from the sandstones to the schists, thus suggesting a steady 

 increase of metamorphism in that direction. 



Rccenf fiiniiatinìis. — These are repi'esented by the concretionarij Uiiioidte (the 

 ironstone of English writers), and Iiy hitrrifc. 



The cone ret io nari/ liinonifc is (jiie of the characteristic formations of the 

 Lake Victoria region. 



Already on the east shore, and then in a typical manner on tlic west, in 

 the Entebbe district and beyond it, we may say as far as the Kasiba-Muyongo 

 granitic zone, the ground is covered with a concretionary limestone, at times 

 pisolitic (pea-like) or vacuolated, always very compact, colour shifting from a 

 bright I'cd to a biownisli-ycllow or dai'k lnowii. 



384 



