THE GEOLOGICAL HISTORY OF THE COLONY 441 



covered the ground. The bones now found in the 

 Karroo belonged to bodies that were carried down by 

 rivers or drifted from the shores of the lake. 



The Karroo area, and with it probably the whole of 

 the folded belt, must have sunk to allow the accumula- 

 tion of the thousands of feet of sandstone and shale 

 that we see in the Karroo formation. Occasionally 

 perhaps wide stretches of mud or sand lay exposed for 

 a time above the water, to be submerged again and 

 buried under similar sediment. Such flat islands can 

 now be recognised where the slight unconformities in 

 the Ecca and Beaufort series mentioned in chapter v. 

 are found. 



The duration of this slow depression was unequal in 

 different parts of the Colony ; it was less along the 

 southern and south-western area, where the Cape 

 formation was thickest, than to the north. Probably 

 while the upper part of the Beaufort series was being 

 laid down, the folding began that eventually produced 

 the great southern mountains. It is not yet known 

 exactly when this process began, or when it reached its 

 maximum, but there is little doubt that it was in pro- 

 gress during the later portion of the Karroo period. 

 The numberless places along the southern edge of the 

 Karroo where the Lower Karroo beds can be seen rest- 

 ing conformably upon and involved in the folds that 

 affect the Witteberg, Bokkeveld and Table Mountain 

 series, as well as the occurrence of the Dwyka and 

 Ecca beds at Worcester, and the outliers on the north- 

 ern edge and in the heart of the folded belt, prove con- 

 clusively that the main part of the disturbances took 



