446 THE STORMBERG SERIES 



was going on the upper parts of the Karroo formation 

 were being laid down in the north-east, possibly also far 

 to the north and north-west of the existing boundary of 

 the Stormberg series. The time represented by these 

 rocks witnessed a great change in the inhabitants of the 

 land round the Karroo lake. G-lossopteris and many of its 

 fellow-plants of the earlier period died out and were 

 replaced by a new vegetation of which Thinnfeldia, 

 Taniopteris, Baiera and Callipterldium are the best-known 

 members. The fauna likewise changed, Dicynodon and 

 its congeners disappeared to make way for more highly 

 organised reptiles. 



Below the Molteno beds there is no direct evidence 

 of a diminution in size of the water basin in which the 

 Karroo formation was deposited, but the coarse sand- 

 stones in the Molteno beds and the overlying strata, the 

 coal seams and the occasional thin conglomerates in the 

 Molteno beds, all point to the proximity of land during 

 their deposition. 



The Molteno beds thicken southwards, and it is pro- 

 bable that the land at that time lay south and south- 

 east of the area at no very great distance. 1 



The varying position of the base of the Drakensberg 

 series proves that the Cave sandstone was subjected to 

 denudation before the volcanic outbursts commenced, 

 but there is also evidence in the interbedding of the two 

 groups of rock that the denudation was local, and that 

 the Cave sandstone continued to be formed after the 

 earliest activity of the volcanoes. The outpouring of 



1 Schwarz, T. P. S. 8. A., xiv., 1903, p. 98. Du Toit, T. P. S. S. A., 

 xvi., 1904, p. 53. 



