284 PROCEEDINGS OF SECTION C. 



No. 83 (c). Representing seven and a-quarter inches of dark 

 grey shales. 



Gold a trace. 



Silver 3 dwts. 22 grs. 



No. 84 (d). Representing five inches of shale, 



Gold a trace. 



Silver 5 dwts. 21 grs. 



No. 85 (e). Showing flakes of native copper and representing 

 three inches of clay shale. 



Gold a trace. 



Silver 4dwts. 13 grs. per ton. 



With regard to these samples Mr. Dixon states — " The first of 

 these only gave the exact button of silver due to that present in 

 the litharge used. On parting the other buttons a minute speck 

 of gold was left in each case, but quite unweighable, therefore less 

 than^thirteen grains per ton in each." 



No. 93. Representing four inches of cupriferous shale core 

 from Heathcote Boi'e, from a depth of 1,065 feet below 

 the surface. 



Silver 13 dwts. 1 gr. 



No. 94. Cupriferous reddish-grey shale from Holt-Sutherland, 

 from 1,787 feet, representing two and three-qnarter 

 inches of core. 



Silver 7 dwts. 20 grs. per ton. 



Gold a trace. 



No. 95. Representing one and three-quarter inches of cupri- 

 ferous shale core from Holt-Sutherland. 



Silver 11 dwts. per ton. 



Gold a trace. 



" No. 95 contained more gold than the others, but still unweigh- 

 able." 



A considerable amount of the iron present is in the form of 

 magnetite as proved by powdering the rock and extracting the 

 the magnetic iron with a magnet. I was unable to determine 

 whether metallic iron was present, but this may be decided subse- 

 quently when a larger body of the rock is obtainable for treatment. 

 A great deal of the silica is undoubtedly free, as grains of quartz 

 can easily be detected by the naked eye, and this probably accounts 

 for the silica being in excess of the proportion required by the 

 alumina to form kaolin. 



The combined water is probably chiefly present in the clayey 



material of the rock, and kaolinised felspars in the basalt lapilli. 



The magnesia and lime present are in much smaller proportion 



than I expected, judging from the amount of epidote and secondary 



hornblende visible under the microscope. 



