72 Transactions. 



The fault-lines in all the veins are gold-bearing, and often carry thin 

 stringers of quartz. Unless this is due to secondary enrichment, the filling 

 of the fissures must have extended over a considerable period of time. The 

 order of movement seems to have been : (1) Formation of radiating fissures ; 

 (2) formation of flat fissures or shear-planes, with disturbance of the radiating 

 fissures ; (3) final adjustment of the fissured area, with faulting of the flat 

 fissures. In other words, the evidence seems to indicate that the formation 

 of the radiating fissures was the cause of all the movements which followed, 

 these latter being due to forces called into play to readjust the strain on the 

 fissured area. 



The formation of the fault on the east flank of the range, which was 

 subsequent to and independent of these local movements, also doubtless 

 disturbed the veins, but it is not possible to say to what extent. 



Localisation of Ores. — A striking feature is the occurrence of the antimony- 

 ore limited to the extreme west of the fissured area, no more than a trace 

 of antimony being found in the sulphide minerals of the other veins. This 

 is evidently due to processes of ore-segregation beneath. 



Gold. — In the oxidized zone, which extends to a depth of about 60 ft., 

 the gold is free and easily extracted, and from a comparison of the very 

 high values which have been obtained on the surface with the much lower 

 value of the unoxidized ore it is evident that an immense amount of 

 secondary enrichment has taken place. 



The unoxidized ore is impregnated with a sulphide having by analysis 

 the empirical formula FeAsgSg, evidently a mixture of iron and arsenical 

 pyrites. J. S. Maclaurin recently made a series of extraction tests on 

 samples of quartz from the Carrick Range,* mth the following results : 

 Fire assay — Gold, 17 dwt. 8 gr. per ton ; silver, 3 dwt. 3 gr. per ton. " No 

 gold was visible in the stone, but panning-ofF showed a little free gold." 

 Amalgamation — Extraction, 55 per cent. Chlorination without previous 

 roasting, 33 per cent. Cyanidation, 62-7 to 72*3 per cent. Cyanidation 

 with subsequent amalgamation, 9r3 to 96"4 per cent. 



These results indicate that the gold is largely associated with sulphides, 

 partly as a coating, most of which amalgamation would remove, and partly 

 involved in the sulphides, which explains the small extraction from un- 

 roasted ore by chlorination. With a lens a little free gold can always be 

 seen in the quartz, and much more coating the sulphides in irregular strings. 



Stibnite. — This is highly crystalline, often shows a marked comb-structure 

 parallel ■with the vein- walls, and is rather quartzose and low-grade. It 

 occurs in bunches easily freed from the soft lode-formation (at least, in the 

 oxidized parts), but requires much dressing to make it marketable. 



Similar Groups of Veins. — The Old Man Range, near Alexandra, carries 

 on its flanks a number of small veins similar in character to those of the 

 Carrick Range. White's reef is the best -known. It is significant that a 

 small antimony-vein occurs at Alexandra, thus completing the parallel 

 between the two groups of veins. 



(4.) The Bendigo Veins. 



The veins of Bendigo lie on the north-w^est flank of the Dunstan Range, 

 three miles from the Clutha River. The country rock is a firm and highly 

 plicated quartz-mica-schist, lying almost horizontally. The veins, which 

 are small and narrow, occupy a series of well-defined parallel fissures running 



* Government Mines Report (Wellington, 1905), p. 9. 



