99-30 



10003 



80-17 



+ 



7-24 

 - 26-37 



1. Unaltered rock. — - — 



2. Altered rock. — 19-13 



3. Altered rock, recalculated on a basis of constant alumina. 



4. Gains and losses of altered rock. 



The considerable loss of silica in the wall-rock is characteristic 

 of the veins throughout Otago. The notable loss of lime and 

 addition of carbon-dioxide and potash indicate that the mineralis- 

 ing solutions carried alkaline tungstates and carbonates. Re- 

 action with the wall-rock resulted in the addition of carbon- 

 dioxide, and in exchange between lime of the rock and potash 

 of the solutions, with the formation of scheelite in the lode. 



The next group of analyses indicates the processes at Macrae's 

 (samples from Golden Point). 



— 50-35 



