448 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [JunO 18, 



conical, with the apex cut off, forming a little plain sloping some- 

 what to the north. The southern slope of this cone is much steeper 

 than the northern. Several miles to the N.E. of the top, a great 

 conical peak rises to about 17,000 feet ; and ahout fifty miles to the 

 west of Kihmandjaro, a great conical mountain, named Meru, rises 

 from the great plain of the Massai to an elevation of perhaps 

 18,000 feet. 



As seen from the east, the snow forms only a thick cap to the 

 Kilimandjaro, with a broad tongue creeping down the south slope ; 

 and, when the sun is high, several long streaks of snow are seen 

 lying in small ravines descending from the cap. As seen from 

 Madjami, the snow partially covers the S.W. face of the dome (about 

 one-fourth the height of the mountain), but several large bare 

 patches of rock show out above the snow : the snow here seems to 

 lie at its steepest possible angle ; so that fresh snow, faUing on this 

 side, must at once slip down to the foot of the face of the dome. 

 On one evening, at Madjami, we saw three such slips of snow in 

 about an hour's time. On the eastern peak a few patches of snow 

 are seen when the sun is high. 



AU parts of the mountain we saw are composed of lava of sub- 

 aerial origin. From not reaching the top, and having seen only the 

 S.E., S., and S.W. parts of the mountain, I cannot speak with cer- 

 tainty of its structure ; but I think that the Kilimandjaro is the 

 north-eastern part of an old subaerial volcano, the south-western 

 and larger part having sunk down several thousand feet, and been 

 partially broken up by faults. The great fault separating these two 

 parts lies about N.W. and S.E., and forms a very steep, long, flat, 

 south-western face to the mountain; and a high, very rugged 

 mountain-mass lying a few miles to the north of Madjami may be 

 the relics of the top of the original mountain. 



The commonest rocks to the south and south-west of the moun- 

 tain are a vesicular porphyry, with crystals of glassy felspar, and a 

 fine, hard, stony, slate -coloured lava, slightly vesicular, and some- 

 times containing small black crystals. In the south-east of the 

 mountain there is much of a similar stony lava, only generally 

 more vesicular, and containing more of the small black crystals. 

 Near the foot of the mountain is much highly vesicular brown lava ; 

 and at the outer edge of the south-east slope several uniclinal ridges 

 of metamorphosed sandstone project through the lavas, which here 

 appear to have their original slope; the strike of these ridges is 

 about N. and S., and the dip E. at about 20°. 



The geological structure of the rest of the country through which 

 we passed seemed to be very simple. The strike of the whole is 

 about N. and S., and the dip easterly at various angles. Our route 

 lay through a great plain (comparatively a plain, but in reality it 

 rises and falls a little), which stretches far into the interior. It is 

 bounded on the south by the northern ends of the ranges of Usam- 

 bara, Pare, IJgono, Anusha, &c., and to the north by the southern 

 ends of the Endara and Bura, &c., and contains the mountains of 

 Kadiaro, Kilimandjaro, Meru, &c. Between the Kilimandjaro and 



