82 Transactions of the Boyal Society of South Africa. 
Sand dunes are prominent features in the country south of Verneuk 
Pan and within 5 miles of it, and they certainly derive part of their 
material from it. How much of the sand is obtained in this way would 
be a difficult question to answer, even after a detailed investigation, for the 
Karroo strata, which furnish the sediments in the pan, are themselves 
made of the minerals which might possibly be contributed to the dunes by 
the ancient rocks of Kenhardt. 
The conclusion to which a brief study of Verneuk Pan and the 
surrounding country leads, then, is that great flat surfaces practically 
devoid of vegetation may be primarily due in this region to the extremely 
low grade reached by streams behind bars of hard rock, then to the 
consequent unfavourable conditions for plant-growth owing to the increas- 
ing brackness of the soil, and finally to the scope thus given to the wind to 
remove dust and sand from the bare ground. 
