472 GEOLOGY OF CAPE COLONY 



steeply folded Table Mountain sandstones. The strata 

 are traversed by auriferous quartz veins carrying pyrites, 

 galena, blende, and sometimes siderite. The gold ob- 

 tained is all alluvial and is only found in very limited 

 quantities. 



In the Prince Albert Division on Spreeuw Fontein 

 and the neighbouring farms gold in the form of dust 

 and nuggets has been obtained for many years past, and 

 from 1891-98 part of the area was proclaimed a public 

 gold-field. The rocks which belong to the lowest Beau- 

 fort beds are gently folded and are traversed by quartz 

 veins. The gold is found in loose pieces of quartz on 

 the surface, but directly the reefs are sunk upon all 

 traces of the precious metal disappear. The limonite 

 pseudomorphs after pyrites in the sedimentary rocks 

 often contain specks of gold. The gravels were rich in 

 some places, and crystals of gold were even found in the 

 hollow parts of fossil reptilian bones. Prof. Schwarz l 

 considers that the source of the gold was in the Zwart- 

 bergen to the south, and that the metal was subse- 

 quently deposited in the gravels on a peneplain, the 

 relics of which are seen in the flat-topped gravel-capped 

 hills in the neighbourhood. Through the action of 

 solutions, probably ferric sulphate derived from pyrites 

 in the rocks, the gold was dissolved and the nuggets and 

 crystals were formed in the spaces between the gravels 

 and in cracks in the underlying strata. The contrast 

 between the enormously rich fragments of vein quartz 

 occasionally picked up on the surface and the barren 

 vein quartz below the surface is very remarkable, but 

 1 T. S. A. Phil. S., xv., p. 54, 1904 ; and G. M. t p. 377, 1905. 



