﻿504 Geological Society. 



fipple-marked ; horizontal inland, but near the coast dipping sea- 

 ward with the overlying beds. A patch, much rippled and contain- 

 ing few pebbles or boulders, lies horizontal in the coast-belt (3) of 

 Zululand and Swaziland at least 1000 feet lower than the main 

 body seen along the terrace (2). No, 7 stretches from St. Johns 

 .River, through Pondoland and Natal to Zululand, thins out and 

 disappears near the Pongolo. Intrusive and flat diorites were 

 noticed in it. A definite list of the strata of this conglomerate, 

 where it is 138 feet thick in Zululand, is given ; and the authoj 

 does not regard it as of glacial origin. No. 9 is treated of in the 

 next paper. 



3. ' On the Occurrence of Dolomite in South Africa.' By D. 

 Draper, Esq., E.G.S. 



A peculiar calcareo-siliceous rock, near Lydenburg, described by 

 Messrs. Penning and Crutwell as ' Chalcedolite,' and a similar 

 rock mentioned by Mr. Penning, F.GS., as overlying the ' Black- 

 reef Series ' of the Megaliesberg formation, are recognized as a dolo- 

 mite. Mr. C. Alford, E.G.S. , has described a ' calcareous quartzite,' 

 as passing into dolomite and ultimately into chert, and known 

 as the ' Elephant-rock ' in Transvaal, sometimes cavernous with 

 underground waters. Erom his own experience Mr. Draper has 

 recognized the ' Elephant-rock ' in thePotschefstrooir,Lichtenburg, 

 Malmani, and Lydenburg districts as a real dolomite, with inter- 

 stratified siliceous bands, weathering into a brown earth like man- 

 gar ese oxide, and superficial siliceous debris. It has its place 

 between the Table-mountain Sandstone and the quartzite of the 

 Gats Rand ( = Zuurberg Quartzite of the Cape). It has auriferous 

 veins in Malmani and Lydenburg. Dr. Schrenck has noticed a 

 similar dark-blue dolomitic limestone in Great Namaqualand. The 

 deep water-holes in it in Malmani are comparable with those found 

 by E. Galton in West Central Africa. The great caves in Mashona- 

 land may belong to it. The extensive tufaceous deposits in Griqua- 

 land-West, the Transvaal, and Orange Free State were probably 

 derived from this extensive dolomite. 



4. ' Contributions to the Geology of British East Africa.' By 

 J. W. Gregory, D.Sc, F.G.S. 



The author describes moraines, striae, glacial lake-basins, perched 

 blocks, and roches moutonnees below the present limits of the glaciers 

 of Mount Kenya, which he maintains indicate the existence of a 

 1 calotte ' or ice-cap extending at least 5400 feet farthe" down the 

 mountain than the termination of the present glaciers, and possibly 

 farther, for in the belt of forest detailed observations could not be 

 made. 



He agrees that this more extensive glaciation was produced by a 

 greater elevation of Mount Kenya, and that any theory of universal 

 glaciation is unnecessary, and indeed opposed by many facts in 

 African geology. 



He discusses the probable influence of this former glaciation on 

 the meteorological conditions of the surrounding area ard the dis- 

 tribution of its flora and fauna. 



