SOUTH AFKICA AND ITS DIAMONDS. 
175 
and carnelian, tlie peridot, mesotype, natrolite, calcite, and 
probably the rock-crystal and amethyst, have been derived 
from the veins, glodes, and kernels of the amygdaloidal and 
other trappean rocks in place — and we may add the garnet too, 
for I have a specimen of melaphyre (?) loaded with garnets, 
labelled “ from near the Orange Eiver ” — yet the lydite must 
have come from some old metamorphic rocks; and we may 
associate with it the hepatic mundic, the ilmenite, specular 
iron-ore, diopside, tourmaline, and most probably the diamond 
as well. 
Many of these specimens, not being waterworn, could not 
have travelled far. There are, however, two very probable 
local sources for them : namely, 1st, Outcrops of old rocks, still 
lower in the series than the Karoo beds which lie on the floor 
of the valley, pierced and covered by the greenstone and 
amygdaloidal lavas ; and such outcroppings are indicated here 
and there in the Orange Eiver Free States and the country to 
the west. 2nd, The blocks and smaller fragments of old 
rocks, constituting the materials of some of the Karoo beds 
themselves. 
We must further observe that, on the one hand, the great 
Draakenberg, based, no doubt, on old metamorphic rocks, such 
as Sutherland and Oriesbach have met with on the Natal side 
of that range,* has supplied, and may still supply, to some of 
its rivers the minerals of the older series of rocks, as well as of 
the Karoo beds and their dykes. On the other hand, the 
northern head-waters of the Vaal come direct from off old 
metamorphic rocks, and have some diamonds in their valleys 
before they reach that part of the Vaal which flows over Karoo 
strata . 
We may add that down all the valleys of the Orange Eiver- 
system ice may have played its part, as among the hills 
further south, and have carried blocks and crystals for miles, 
and left them to be detached, unharmed, by subsequent opera- 
tions of rain and rivers. 
Lastly, what are the metamorphic rocks of the Transvaal and 
the Upper Vaal, on the one hand, and of the base of the Draaken- 
berg, on the other? We know that “ Devonian ” schists, sup- 
porting an old sandstone, are present in the latter, and that 
similar rocks lie against still older mica-schists, marble, gneiss, 
and granite in the Oats Eand about the head-waters of the 
Vaal. And, further, we now know that the Karoo beds of the 
Stormberg, between Washbank and Queenstown, lie on the 
palaeozoic carboniferous strata containing Lepidodendron , Sigil- 
* With similar rocks on this eastern side of the range, probably diamonds 
may also be found in the alluvium of the valleys. 
