PRESIDENTIAL ADDRESS SECTION H. 75 



of metals, such as ,^old, iron, and copper, while the pegmatites 

 that vein the schists of the Swaziland system, near the margins 

 of the granite intrusions, are favourable to the occurrence of 

 tin, molybdenite, and mica. 



IV. — This area is occupied by granite and gneiss, except 

 along its eastern margin, where there is a broad belt of metamor- 

 phosed sedimentary and igneous rocks, belonging to the Kheis 

 esries — correlated tentatively with the Swaziland system. 



The only important mineral deposits hitherto discovered are 

 the lenses of pyrite, in part cupriferous, that are being opened up 

 at the Areacheap Mine, tojhe north-west of Upington. 



Copper-bearing quartz veins occur in gneiss in the neigh- 

 bourhood of Pella on the Orange River, and copper in the form 

 of malachite, chrysocalla and copper glance is also found in 

 quartz veins on the farm Toekomst West, on the Molopo. about 

 five miles south of the Keetmanshoop railway. 



These occurrences, while not workable, serve to indicate that 

 copper is widely distributed. 



The greater part of the region is still a terra incognita in so 

 far as the prospector is concerned, and certainly seems to merit 

 more attention than it has hitherto received. 



The Copper Province of Little Namaqualand. 



This province, occupying a fairly considerable extent of 

 country in the north-western corner of the Cape Province, 

 embraces two distinct mineral areas,* namely, ( i ) a northern 

 region characterised by veins containing native copper and 

 copper sulphides in a gangue of quartz, carbonates, felspar, and 

 chlorite. None of these are being worked at the present time. 

 The Kodas and Numees Mines, situated in the mountainous 

 country near the Orange River, yielded considerable quantities 

 of high-grade ore in the seventies of last century. Transport, 

 however, offered insurmountable difficulties, and they were closed 

 down after a time. 



Both mines are said to contain considerable reserves of ore, 

 which will doubtless be exploited as soon as the area is rendered 

 more accessible by the constrijction of roads and railways, when 

 other workable deposits will also doubtless be discovered. 



(2) A southern region, embracing about 2,000 square miles 

 in the middle of the Namaqualand division, characterised by the 

 presence of dykes and irregular intrusions of a genetically con- 

 nected series of igneous rocks — ranging from mica-diorite at 

 Ookiep, through norite at Tweefontein, to hypersthenite at Naba- 

 beep — which contain as primary constituents varying amounts of 

 copper sulphides ; the country rock being gneiss. 



No fewer than 344 distinct intrusions have hitherto been 

 located and mapped, and others in all probability await discovery. 



* Rogers, A. W. : The Copper Deposits of Little Namaqualand, Proc. 

 Geol. Soc. S.A., 1916, pp. xxi-xxxiv. 



