ORIGIN AND MODE OF OCCURRENCE OF GOLD-BEARING VEINS. 143 



One of these I examined is in altered slate near its junction 

 with a granite containing much black mica. It contains calcite 

 as well as quartz, and in many places the calcite occupies the 

 whole of the vein. Both the quartz and the calcite contain gold 

 and iron pyrites with some galena, and often enclose portions of 

 country rock. Some of the patches of auriferous vein-matter 

 have given tons that yielded at the Sydney Mint as high as 600 

 ounces to the ton. Five tons of stone treated at that place gave 

 over 2,600 ounces of gold. The lode, however, varies much in 

 richness, the intervening quartz and other lode matter between 

 the patches sometimes only equalling 5 dwt. to the ton. It also 

 varies much in thickness from a few inches to about three feet, 

 and it strikes across the bedding of the slate obliquely. The gold 

 is chiefly in a free state, and the quartz has a bluish tint. 



The Gold Veins of New Zealand. 



The most important gold fields in this Colony are situated at 

 Reefton and the Thames. 



At Reefton, and within twelve miles radius from that town, a 

 great number of reefs have been worked, some with good and others 

 with unpayable results, and although the conditions have been 

 somewhat similar throughout, the reefs themselves have varied 

 a good deal both in size, productiveness, and distribution of the 

 stone and gold. A sketch section Fig. 32a, across the field shows 

 that several series of formations occur, in only one of which have 

 reefs been hitherto discovered. 



These gold bearing rocks, which are of lower carboniferous age, 

 consist of fine grained silky slates, interstratified with sandstone 

 and are folded into anticlinals and synclinals, the sides of which 

 dip at angles of 60° and less from the horizontal, and they are 

 traversed by dykes of diorite and reefs of quartz. The diorite, 

 however, is seldom associated with the reefs themselves where 

 worked, but the most productive country has been the slate 

 band referred to. 



Most of the reefs here are steep, underlying from 60° to vertical, 

 and in one case at least, the Welcome Mine at Boatman's, not 

 only does the gold occur in shoots, but the stone itself is found 

 under the same conditions. This mine has been worked to a 

 considerable extent, some 500 feet in depth, and the quartz is 

 frequently three feet in width, but pinches out in every direction 

 and then makes again, a series of blocks of quartz occurring, 

 which although following the same line are almost disconnected 

 from one another, and there have been times in the history of 

 the mine when neither quartz or gold were to be seen in the 

 levels. Notwithstanding this fact, there is distinct evidence to 



