1870.] GRIESBACH GEOLOGY OF NATAL. 71 



are everywhere of very limited extent and thickness, and the so- 

 called " reefs " everywhere thin out rapidly towards the base ; and, 

 lastly, there is no extensive aUuvinni anywhere in these districts 

 which yields gold. 



It is a weU-known fact that gold has actually been exported from 

 the east coast for centuries by the Portuguese in large amounts ; and 

 the question may be put, Whence does this gold come ? Gold 

 is there ; but the question is, Would it pay white labour or not ? 

 The Portuguese trader in Quillimane has perhaps one thousand or 

 more slaves, which cost him only a trifle, as they live by their wives' 

 labour ; when the dry season sets in, the QuiUimane traders send 

 their slaves to their work ; they are supplied with old flint-guns, and 

 sent into the interior to hunt elephants. Some are sent to trade, 

 and a great part to the diggings ia the rivers which flow into the 

 Zambezi, near Tette, and in those running from the south to the 

 Zambezi, coming from the fabulous country of Manico. There the 

 wives work at fields of rice, which support them sufliciently, whilst 

 the men wash the gold from the rivers in small kalabashes in quite 

 a primitive manner. As the gold itself has no value to them, they 

 bring it faithfully to their masters, who reward them with beads 

 and white Salempore (calico). In this way the master gains a good 

 deal, as all the gold he receives is a clear profit. If he has only 

 150 slaves engaged in the diggings, and he receives only 1 ounce 

 per head in the season, he makes a profit of <£581 5s. ! Of course 

 white labourers would never find it practicable to undertake gold- 

 washing there under such circumstances. 



b. Copper is already well known in many districts of South Africa, 

 and is also worked. I found copper at several localities in Natal ; 

 but nowhere, I should think, would it be found practicable to work it. 

 Near the Ifami river, south of Durban, a highly decomposed gneiss 

 occurs which shows traces of copper at the surface. It is situated 

 just along a fissure in the gneiss, and it possibly might lead to a 

 richer point ; but this is not probable. In the Insiswa Mountains, in 

 Kafflrland, richer copper-ores have been known for a very long time, 

 but have never been worked out. This locality is situated at the above- 

 mentioned line of greenstone, which strikes from south to north, 

 near the base of the Karoo beds. It is remarkable that along this 

 greenstone line copper is found. Thus, for instance, it occurs near 

 the Tugela valley, in greenstone whieh intersects the granite. 



EXPLANATION OF PLATES II. & IIL 



PXATE II. 



Geological Map of the Colony of Natal. 



Section from the Bluff, Port Natal, to the Mont anx Sources in the 

 Draakensberg. 



PiATE III. 



Fig. 1. Ammonites umholazi, Baily : a, dorsal view ; i, sutures. 

 Fig. 2. Ammonites remhda, Forbes ; a, section ; 6, sutures. 

 Fig. 3. The same, young individual. 

 Fig. 4. Anisoceras rugatum, Forbes. 



