CONTRIBUTIONS TO THE GEOLOGY OF BENGUELLA. 507 



C. Oendolongo Mountain*. 



A change in the structure of the country at length appears at km. 275. The 

 Oendolongo Mountains to the west have a stratified aspect and the railway is ballasted 

 with ferruginous sandstone. From the crossing of the Catumbella River at km. 275 

 to Quingenge, at km. 297 (44f>0 feet), the line slowly rises up the valley of the Cuati, 

 from the head of which it passes to that of the Cuiva River. The railway is near 

 the junction of granitic country to the north, with the stratified and volcanic rocks 

 which form the Oendolongo Hills to the south. Granite hills are conspicuous to the 

 north, and numerous granite bosses occur close to the railway. 



An excursion from Quingenge to the Cuati showed that the granites outcrop 

 immediately on the northern side of the railway near Cruz's. A mile further north 

 the white granite lias been replaced by bluish-gray dioritic granite. A quarter of a 

 mile further north the ground is strewn with blocks of rhvolitic tuff resting on granite, 

 which continues as far north as the bank of the Cuiva River, where the granite is 

 especially siliceous. Across the river the granite forms the Ilala (or Uhilala range) 

 to the north-west, and the Binda range to the north. South of the Cuati River, to 

 the north of Quingenge Station, the rock is gneissoid and is seamed with epidote veins. 



Continuing eastward along the railway, the sandstones recur after crossing the 

 Cambuacambula stream at km. 298^ ; but after km. 300 the railway is again on 

 granite, of which there are numerous outcrops along this part of the Cuiva valley. 

 Some of this granite is fine-grained, like that to the east, of the Agricultural Station 

 at Quingenge ; granite continues along the line to Cuma (km. 317, 4708 feet) and 

 beyond it. At km. 327^ the railway crosses a felspathic sandstone, which forms a 

 spur from the southern hills, and a synclinal in the hill face to the south of km. 323 

 is probably in rocks of the same series. The granite reappears at km. 328 from 

 beneath red sandstones, which form the hills to the south and probably also the table- 

 topped hills to the north. The railway crosses the Cuiva and thence follows its 

 tributary, the Chicanda River, which is crossed at km. 344 near a granite tor. The 

 railway shortly afterwards reaches the sedimentary rocks that form the mountainous 

 country around Lepi (km. 367, 5371 feet), but granite outcrops continue to the three 

 tors south of Lepi, which, being the most easterly in the district, form an important 

 landmark. 



The Oendolongo Mountains (fig. 5), which rise to the south of the railway, form 

 the first break from the monotony of granite to the east of Mount Sahoa. The 

 mountains extend from the Upper Catumbella River on the south-west to the 

 Chicanda River on the south-east. They present a bold scarp face to the north-west, 

 parallel to the railway line, and from their high north-western summit of Kanomba 

 (7250 feet) the mountain face turns abruptly to the south-east. The western corner 

 of this mountain mass consists of well-stratified quartzites, which are well exposed 

 about Babaera, where they are exposed around the station of Senhor Ferreira and 



