CHAPTER XVII 

 CENTRE VALLEY TIN ORE 



ON our return journey we explored several tributary 

 streams on both banks of the river ; those on the right 

 bank were all cut in the Archaean gneiss and the country 

 which they drained consisted of rounded hills, heath- 

 covered and devoid of crags. From the top of one of 

 these hills we had a distant view of the volcanoes at the 

 head of West Valley in one direction, and of the glacier 

 we had just left on the other. From this elevated stand- 

 point we were also able to obtain a better view than we 

 had hitherto had of the great Granite Mountains to the 

 north of the river, and we determined to .make a 

 thorough investigation of these before returning to 

 Three Forks. 



Accordingly we recrossed the river and ascended the 

 tributary which joined it just below the upper lake. The 

 lower part of the valley was excavated in gneiss and 

 was, in many respects, similar to those of the tributaries 

 on the right bank. Some little distance up the valley 

 we came upon a great flat-topped terrace of gravel 

 through which the stream had cut a deep channel ; this 

 terrace was surmounted by a second, which in its turn 

 was followed by a third, though the last was smaller and 

 less marked than the two lower ones. 



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