The Soih of the Auriferous Districts. 



Ill 



The argillaceous granitic soils, and those last described, are either 

 grey or ci-eam-coloured soils. They occur over vast areas, in the valleys 

 in granitic and gneissose country, and as wide-spread coverings to the 

 more or less unaltered rocks in districts where the country is quartz- 

 porphyry or i'elsite. The main difficulty in the successful cultivation 

 of these classes of soils is the retention of their fertility and increase 

 in their powers of retaining water. This can only be done by careful 

 tilla:,'e, in which every care is directed to the conservation of their 

 contents of humus. 



The basic rocks, which occur extensively in the gold-bearing 

 districts, upon decomjiosition give rise to ochreous and to red and deep- 

 red coloured soils, the topmost layers of which are not unfrequently 

 more or less bleached by the action of percolating waters charged with 

 organic acids arising from the decaying vegetable matters of the 

 forests. They usually contain considerable proportions of ironstone 

 gravel, in fact in some places the proportions of ironstone gravel is so 

 high as to render them more or less unproductive or practically useless 

 for purposes of cultivation. Their mean compositions are given in the 

 followins; table : — • 



COMPOSITIONS OF THE DRIED FINE SOILS. 



