83 



vertical dip, and au easterly strike, and have had dykes and 

 masses of granite intruded into them. 



In the first-mentioned set of beds there arc numerous quartz 

 reefs and veins. Their general strike is in an east and west 

 direction, but they also intersect the country more or less 

 ineridionally. 



Xorth of Brady's Grully there are gravel and boulder drifts, 

 <3omposed chiefly of quartz. These occupy a raised tableland 

 adjoining the flats of Salt Creek. They exactly resemble the 

 Pliocene auriferous gravels of Barossa and Echunga, but so far 

 as they have been tested they have not been proved to be pay- 

 ^bly auriferous. 



The gold in Brady's, Groslin's, and other gullies is found in 

 the late tertiary and recent alluvial drifts and surfacing. In 

 Brady's Gully the auriferous deposit is spread widely over the 

 'flat, the depth of sinking varying in accordance with the thick- 

 ness of the alluvium, the most shallow parts being where the 

 present watercourse has eroded its upper portions. 



Owing to the prevalence of limestone and calcareous slate 

 beds, there is an abundance of travertine limestone in the soil, 

 •and found coating the rocks. In numbers of places this also 

 cements the gravel, and forms a calcareous conglomerate or 

 cement. This is frequently found to carry gold. 



"With regard to the origin of the gold, there is no doubt but 

 that many of the nuggets and the greater part of the finer 

 alluvial gold has been derived from quartz reefs. Specimens 

 have been found combining quartz and gold. It is also found 

 in iron oxide, but a matrix of ferruginous and travertine lime- 

 stone is most frequent. It is possible that from these vein- 

 stones the largest nuggets have been derived. 



These veins, being small and irregular, were probably diflS- 

 cult to discover. In many instances, possibly, they had been, 

 -entirely eroded at the same time as the formerly-existing 

 superincumbent strata which supplied the gullies with gold. 



Good reports have recently been received from the men 

 working the reefs, and rich specimens of gold have been 

 shown. 



In one reef — the Ironclad — carbonate of bismuth and lead 

 has been found associated with the veinstone and gold. Bis- 

 muth is a good indication of the presence of gold. 



