PRESIDENTIAL ADDRESS SECTION B. 73 



It is a practical certainty, for example, that further workable 

 deposits of gold and asbestos remain to be found in the Ly den- 

 burg district, and that many occurrences of lead and zinc await 

 discovery in the Western Transvaal, while the possibilities of 

 gold mining in that region cannot by any means be said to have 

 been exhausted. 



In so far as the Central Transvaal is concerned, most of the 

 epigenetic mineral deposits occurring in the Transvaal system 

 appear to be related genetically to the Bushveld granite and allied 

 rocks, and it is the portion of the province falling within the 

 sphere of influence of the intrusive activity of the Bushveld 

 complex that thus holds out the greatest promise. 



As the province includes a considerable part of the Diamond 

 Belt, there is also a possibility of further discoveries of Kim- 

 berlite pipes and dykes within it. 



II. — The Griqualand West region, as already indicated, is 

 far less important. Its mineral products include asbestos, lime- 

 stone, lead, and alluvial diamonds. It also contains enormous 

 deposits of iron-ore that may some day be of great importance. 

 Potassium nitrate, which occurs as thin veins in and as an encrus- 

 tation on the shales and slates of the Pretoria series, and also in 

 angular fragments as a scree deposit, has a wide distribution to 

 the north and north-east of Prieska. The mineral is believed to 

 have been derived by a process of nitrification from the excreta 

 of rock-rabbits, bats, and the like. Up to the present efforts to 

 work the deposits have not met with success. 



Some very promising occurrences are said, however, to have 

 been discovered recently, and a company has been formed in 

 Johannesburg to exploit them. The results of its activities will be 

 awaited with interest. 



Further discoveries of lead, zinc, and asbestos may be 

 expected within the province. 



The Old Granite, Swaziland System Provinces. 



Under this heading are included four large disconnected 

 areas occupied by the rocks of the Swaziland system, or their 

 supposed equivalents, and old granite and gneiss intrusive in them. 

 The areas are numbered I, II, III, and I\' on the accompanying 

 map. 



I. — Embraces the whole of the Northern, North- 

 western, and B>astern Transvaal, Swaziland, and portion of 

 Northern Natal. 



II. — Includes portions of Griqqualand West, and of the 

 Ma f eking division of the Cape Province. 



III. — Includes an elongated tract of country in Natal 

 and Zululand, occupied partly by the granite and rocks 

 belonging to the Swaziland system, and partly by Table 

 Mountain sandstone, which it was found more convenient 

 to group with these rocks than with the Karroo beds. 



