THE GEOLOGIST 



JULY, 1861. 



ON METALLIFEROUS SADDLES. 



By Dr. R. N. Rubidge, of Port Elizabeth, South Africa. 



In the number of your journal for October, 1860, I read with great 

 interest a paper by Dr. Watson " On the Metalliferous Saddles of 

 Derbyshire and Staffordshire.'' The Doctor says that, though well 

 known to the miners, he believes these saddles have not hitherto been 

 described by any geologist. If he will refer to the Journal of 

 the Geol. Soc, 1857, p. 233, he will find a paper "On the 

 Mines of Namaqualand," in which I think he will recognise 

 a description of these deposits under the name of " metallic axes." 

 With such modifications as the difference in the strata and their 

 metallic contents requires, his description would nearly apply to what 

 I said. 



The strata in which my axes occur are gneiss and gneiss-granite 

 with occasional beds of magnesian and micaceous rock at Springbok 

 Vontein and Concordia, and micaceous and calcareous rock, with 

 gneiss at Kodas. The saddles (a better name than mine) in all the 

 productive mines were folds in the strata, with fissures of various 

 sizes and directions intersecting them. The one was in some cases 

 more abundant in the planes corresponding to the original bedding 

 of the rock: this was strikingly the case at Concordia, where the 



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