BY W. H. TWBLVETREES AND W. F. PETTERD. 41 



•cally that of a zinc-copper nature ; at the Hercules the 

 zinc-lead impregnation is the most pronounced ; while at 

 the King River, the East Hercules, Red Hills, and others, 

 the ore is almost zinc free : and at the Mount Read Mine 

 almost all degrees of admixture may be obtained. A small 

 quantity of associated gold and silver is very general, and 

 in favourable localities for decomposition, where large 

 masses of gossan have formed, the precious metals have 

 been obtained in greater abundance, and have in one 

 instance been worked by methods common to the alluvial 

 gold-miner. In the workings of the Hercules and South 

 Hercules mines, bunches of crystallised carl)onate of man- 

 ganese of great beauty are occasionally met with, and in 

 . the schists of the East Hercules the ores of bismuth have 

 been detected, while in the vicinity of Lake Dora cobalt 

 minerals occur ; but the ores of these metals are not by 

 any means abundant, and are, as at present known, simply 

 curiosities of interest to the mineralogist, l)ut of no practical 

 value to the miner. 



The following is a list of the more important minerals 

 wdiich have been detected : — 



Arsenopyrite. Cuprite. Liinoi.ite. 



Absolite. Chalcocite. Malachite. 



Azurite. Erj^thrite. Psilonielane. 



Barite. Fluorite. Pyrites. 



Boruite. Galeiiite. Pyrolusite. 



BisiDuthinite. Goethite. Rhodochrowte, 



Cerussite. Gold. Siderire. 



Cbalcopyrite. Hematite. Sy)lialerite (Blende). 



Cobakite. Huascolite. Stibnite. 



Copper, native. Janiiesonite. ' Tetrabedrite. 



The Mount Read felsite does not appear to have yielded 

 sufficiently to the foliating force to provide planes along 

 which solutions could travel freely, or was not so easilj^ 

 attacked 1)}^ the latter : hence it contains no ore bodies. 

 This is not, however, a universal rule. At the Red Hills 

 an igneous rock, probably felsite, occurs, whicli has Ijeen 

 more strongly foliated, and, in a specimen received from 

 the Government Geologist (.s^v Report on Lake Dora Dis- 

 trict, 1898, p. xxi.,) we noticed a decided illustration of the 

 replacement process. A few felspai- crystals remained 

 unaltered, but the rest of the rock had been converted into 

 hematite. But at the Mount Read mines the ore is confined 

 to the argillitic schists. The question arises, whether the 

 proximity of the igneous rock l)ears any casual relation to 

 the ore in the schists — has the eruptive rock in any way 

 stimulated ore deposition ? An answer in the affirmative 



