CHAPTEK XI. 



VOLCANIC PIPES YOUNGER THAN THE STORMBERG 

 VOLCANOES. 



IN many parts of the Colony there are remarkable pipes, 

 channels through which materials were thrown from the 

 lower region of the earth's crust to the exterior, and 

 now filled with substances of different kinds, sometimes 

 clearly of volcanic nature, but often of such peculiar 

 character that their volcanic origin is not obvious and 

 can only be surmised from the manner in which the 

 rocks occur. 



The first of these pipes to be discovered was the 

 Jager's Fontein Mine, in 1870, but those at Du Toit's 

 Pan, Bult Fontein, Colesberg Kopje (Kimberley Mine), 

 and De Beers were found soon afterwards. 1 These 

 discoveries were entirely due to the finding of dia- 

 monds, which had been met with by chance near the 

 Orange Kiver three years previously. It was, of course, 

 some time after the diamond mines were opened that 

 their nature was understood. 2 The earliest search for 



1 For an interesting and fully illustrated account of the early dis- 

 coveries and of the whole history of the diamond mines and their work- 

 ing, see The Diamond Mines of South Africa, by Mr. Gardner F. 

 Williams, 1905. 



2 . Cohen, Neiies Jahrb. f. Min., p. 857, 1872. This paper, or letter, 

 contains the first suggestion of the volcanic nature of the pipes. 



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