Geology 



produced by glacier-ice alone, amongst the agents of 

 denudation. 



The gorge at the head of the fall doubtless repre- 

 sented the amount of cutting effected by Gold Creek 

 as we afterwards named this stream since the retreat 

 of the ice from this part of the main valley, and the fall 

 was the result of the rapid ice-denudation upon the main 

 valley, from which that of the tributary had been free. 



Before the glacial episode the gravels of the hanging 

 valley had probably been continuous with those of the 

 main valley below the moraine, and this theory gave us 

 renewed hope of again striking the gold-bearing beds 

 and possibly also of discovering the source of the quartz 

 pebbles, and hence, in all probability, that of the gold 

 itself. 



The gravels lay in great flats on both sides of the 

 stream, the course of which was winding. Here and 

 there were sills of rock in the stream track which in- 

 dicated that the rocky floor of the valley was at no great 

 depth, though for the most part gravel-covered. 



On the flanks of the valley were several terraces 

 of alluvial materials, the relics of ancient flood-plains, 

 formed at a time when the valley had not been cut 

 so deeply as now. 



As the bottom of these terrace gravels would, in all 

 probability, be above the water-level, we selected a site 

 for a trial shaft near the foot of one of the higher 

 terraces, the gravels of which had yielded a fair 

 " colour " in the pan. 



The process of excavation was tedious, as we had 

 to make a large open pit with sloping sides, there being 

 no trees in this upland valley from which to cut timbers 



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