THE VEGETATION OF NATAL. 2!55 



I. THE EEG-IONAL FACT0K8. 



(1) GEOLOGICAL STRUCTURE AND SOIL CONDITIONS. 



The general physical features of Natal are as follows : On 

 the west it is bounded by lofty ranges of the Drakensberg, 

 which form the escarpment of the high inland plateau. The 

 highest peaks rise to an altitude of over 10,000 ft. on the 

 borders of Basutoland, and consist chiefly of volcanic 

 amygdaloid rock of considerable thickness. Below these are 

 the Cave Sandstones, the Red Beds and the Molteno Beds of 

 the Stormberg Series. The lower ranges and foot-hills of the 

 Drakensberg are formed by the sandstones and mudstones of 

 the Beaufort Sei-ies. Passing from these downwards towards 

 the coast, the whole succession of the Ecca Series is laid bare, 

 consisting of sandstones and shales cut through everywhere 

 by doleritic trap rocks. The Upper Ecca beds are the coal- 

 bearing sandstones of Natal. Below the Ecca beds lies the 

 Dwyka Conglomerate which marks the base of the Karoo 

 System. These formations cover by far the greater part of 

 Natal and Zululand. 



Below the Dwyka Conglomerate comes the Table Mountain 

 Sandstone, and below this again are the metamorphic rocks 

 of the Swaziland System, exposed along the valleys of the 

 Tugela and other rivers of Zululand, and also appearing in 

 the south-east corner in the Lower Umzimkulu district. The 

 Swaziland complex forms a sort of central core which is 

 flanked on both sides by the Table Mountain Sandstone. A 

 belt of these metamorphic rocks runs parallel to the coast 

 east of Camperdown, but it is only in the deeply cut river 

 valleys that such rocks are seen further inland. The belt is 

 invaded in places by large granitic intrusions, and the whole 

 of this strip of country is of a very broken character. 



The overlying Dwyka Conglomerate and Ecca Beds reappear 

 in a narrow strip along the coast line of Natal proper; while 

 alono- the flat coast of Zululand from the Umlalazi River 



