Reports and Proceedings — Geological Society of Loiido)/. 231 



yet at this 570 foot level on the Winterbourne Bassett plain 

 implements and flakes are very scarce, while trimmed pieces are 

 Very numerous, although the level of the Winterbourne Stones is 

 300 feet lower. Many uf the latter, however, have been evidently 

 re-chipped, and are therefore of later date. The author concludes 

 that implements of at least three Palaeolithic periods are foiind at 

 Knowle, and these three periods may be compared with the Chellena, 

 Lower Acheulien, and Upper Acheulien of Professor Commont et 

 St. Acheul. Still older implements (possibly earlier Chelleen) seem 

 also to occur. 



2, "On the Karroo System in ^Northern Rhodesia, and its 

 relation to the General Geology." By Arthur John Charles 

 Molyneux, F.G.S. 



In 1903 (Quart. Journ. Geol. Soc, vol. lix) the author described 

 the occurrence of deposits, that have since been I'ecognized as of 

 Karroo age, in Southern Rhodesia. The present communication 

 traces their extension across the Zambesi, whei'e their boundary 

 follows the foot of the remarkable line of escarpments that divide 

 the plateau, nearly 4,000 feet in altitude, from the low-lying 

 (1,500 feet) regions of the Zambesi Valley. Karroo deposits also 

 form the floor of the peculiar trench-like valleys of the Luangwa, 

 Lukasashi, and Lusenfwa (or Luauo), the walls of which are similarly 

 steep, and of metamorphic rock gneiss, schist, and granite. 



The Luano Valley is described. Its northern precipice is known 

 as the Machinga (native meaning 'a fence'), and the Lusenfwa 

 and Molongushi Rivers are followed in their mature courses across 

 the flat plateau plains. They reach the Luano by waterfalls into 

 deeply incised gorges, cutting back 15 and 8 miles respectively 

 into the plateau. Rivers that join the Luano from the south, on 

 the contrary, descend into open valleys of Karroo floors, that are 

 divided one from the other by tongues from tlie southern highlands, 

 and suggest 'rolled-out' folds. 



Between the Kafue junction and Feira the Zambesi River also 

 occupies a trough valle^^ lined by steep escarpments ; that on the 

 south side rises 2,000 feet in less than a mile, being formed of 

 a flexure of altered sediments. The Danda flats show Karroo beds. 



The Lufua River runs parallel with the strike of the gneiss of 

 the locality, and crosses two synclinal basins of clastic deposits, 

 separated by Archtean ridges. The Losito has also a deep strike 

 channel. 



The Karroo deposits are grouped into basal conglomerates. Coal- 

 measures, Upper Matobola Beds, and Escarpment Series. No effusive 

 basalts were seen, but there is an area of Forest Sandstones near 

 the Losito-Zambesi confluence. In the Luano Valley the conglomerates 

 are made up of resisting quartz, quartzite boulders and pebbles, 

 all having dimpled or concave depressions on one or more sides ; 

 they possess no orientation, are unsorted, and exhibit a varying 

 matrix. Though they form the base of the Karroo System there 

 is no certain evidence of glaciation, but the beds seem to have 

 originated as scree deposits on an uneven floor. The grinding of 



