CHAPTEK XIV. 



ECONOMIC GEOLOGY. 



ALTHOUGH but little has been written concerning the 

 mineral resources of the Cape Colony, the subject is one 

 that can only be briefly and inadequately touched upon 

 here. 



Asbestos. White asbestos (chrysotile) has not yet been 

 found in any quantity. Blue asbestos (crocidolite) is 

 being mined with success at various places in Prieska and 

 Hay. The mineral is found in layers interbedded with 

 the hard banded jaspers and ironstones of the Griqua 

 Town series, the fibres being more or less perpendicular 

 to the bedding planes. The fibre varies in length up to 

 three inches, but it is usually much below that length. 

 The mining is very simple. In many places the asbestos 

 has suffered oxidation and silicification, and has been 

 changed to the hard brown mineral commonly, but 

 wrongly, known as crocidolite. 1 The amount available 

 must be immense, for the mineral has been observed 

 in the Lower Griqua Town beds at numerous localities 

 from the Orange River northwards to the border of 

 the Bechuanaland Protectorate. 



1 For an account of the mode of occurrence, etc., see G. C., x., pp. 

 158-161. 



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