ORIGIN AND MODE OF OCCURRENCE OF GOLD-BEARING VEINS. 141 



The South Australian Company's Reef varies in thickness from 

 about two feet to ten or twelve or even more. It has yielded 

 over half-an-ounce of gold to the ton of quartz on all that has 

 been crushed, and is a very promising lode. It is also in diorite 

 country, and has been heaved on its strike. The gold in this 

 vein, particularly in some of the thickest parts, confines itself 

 sometimes to about a foot or so of the quartz, either on the foot 

 or hanging Avail, but in the lower levels is more regularly 

 distributed through the reef. 



About eleven miles from Temora Gold Field, at a place called 

 Sebastopol, is a quartz vein in talcose or micaceous schist, 

 combined with chlorite schist. This lode lias yielded some steady 

 returns of a payable kind with ordinary appliances in years past, 

 and is now about to be worked with, more modern machinery so as 

 to treat the pyrites contained in £he stone. The following is a 

 cross-section of this lode, and it is one of those lodes that coincides 

 very closely with the bedding planes of the strata, both in strike 

 and. dip ; for most of its course it varies very much in thickness, 

 being as much as fourteen feet in some places and not more than 

 two in others. It contains, besides gold, iron pyrites, and galena ; 

 cross- veins occur with it, and also parallel ones, all of which are 

 auriferous. (A cross-section of "Morning Star" Reef, Sebastopol, 

 is shown at Fig. 36). 



The Junee reefs, near the same locality, are in granite or at 

 the junction of slate and granite. Figs. 34 and 35 are cross 

 sections of two of those quartz veins. 



The Muttama Reefs, on the branch of the Southern railway 

 line to a place called Gundagai, are in a rock that appears to be 

 quartz diorite, and which is evidently a wide belt of that rock, 

 bounded on each side by slate. A description of them will serve 

 to show the fact of the gold occurring in oblique shoots that dip 

 in certain directions common to the district or locality. 



The formation of the district is, as has been said, a quartz 

 diorite, bounded upon both sides by altered slates, both classes of 

 rock carrying quartz veins. The hills, which are steep, have been 

 denuded to some extent, and are intersected by creeks along which 

 alluvial flats of greater or less richness occur. 



The slates are probably of silurian age, and from the nature 

 of the diorites it would appear that they are traversed by planes 

 which dip to the west at an angle of about 45° in the samo 

 direction as the slates, and this gives a somewhat stratified 

 appearance to them. At one place, near a reef called "The 

 Doctor's," the diorite is hard near the surface but soft underneath, 

 which also favours the supposition that the beds are stratified, as 

 alternate hard and soft belts of tufuceous rock and diorite — as at 

 the Thames in New Zealand — and the same belt of country, with 



