Geology 



minute grains of platinum, but a most thorough ex- 

 amination of the rocks themselves and of the sands 

 derived from them failed to reveal further traces of that 

 valuable metal. 



Associated with the Dunite, the name given to the 

 olivine-chromite rock, was another highly basic rock, 

 Norite, and connected with this were mineral deposits 

 which might prove to be of considerable value. These 

 consisted of masses of Pyrrhotite, a sulphide of iron with 

 some nickel, Pentlandite, a sulphide of nickel with some 

 iron, and Copper Pyrites (CuFeS 2 ). 



There were several other varieties of basic igneous 

 rocks to be seen in the same district, and some of these 

 contained considerable quantities of magnetite and a 

 somewhat similar ore of iron containing titanium, 

 Ilmenite. 



These deposits should if they were sufficiently ex- 

 tensive be worth the attention of the iron smelters, but 

 so complicated was the structure of this part of the 

 country that the only way of working }t out in a satis- 

 factory manner would be by detailed mapping, and as 

 time did not allow of this the further investigation of 

 East Valley and its possible economic products was 

 postponed until a subsequent occasion. 



We next returned to Three Forks and spent some 

 weeks in advising the engineers as to which parts of the 

 gravels we considered most likely to yield well and upon 

 similar matters. This done we set out for Base Camp 

 en route for the oil-field, from which had come rumours 

 of some general success, though no particulars were 

 forthcoming. 



At Base Camp we met with the captain of our 



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