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



of New South Wales are chiefly, so far as has been determined, 

 upper silurian and devonian, and as the carboniferous rocks of 

 that colony immediately overlie these formations, and although 

 denuded from the portions where the auriferous veins shew are 

 still to be seen, in situ crowning many of the highest hills, and in 

 some places covering up many of the valleys, and lying in 

 isolated patches on their sides, it is quite evident that the same 

 amount of denudation of the palaeozoic rocks cannot have taken 

 place in that colony, since the deposition of the carboniferous 

 strata as in Victoria. This may be considered proved by the less 

 extent of the alluvial leads in New South Wales, for although a 

 certain amount of denudation of the reef bearing rocks is likely 

 to have occurred prior to the laying down of the carboniferous 

 strata, as seems to have been determined by the fact that some 

 of the lower conglomerates of those measures have been proved to 

 contain alluvial gold, still there is nothing to prove that such 

 denudation has been nearly so extensive in New South Wales as 

 in Victoria. 



It would appear that the New South Wales quartz veins have not 

 been worn away to as great an extent as those of Victoria, and 

 that in many parts of the latter colony the entire mass of the 

 upper silurian and devonian rocks have, with their contained 

 quartz veins, been broken up and swept away, and have served to 

 supply the truly rich and extensive alluvial leads that have been 

 such a wonderful advantage to that colony. 



A large portion of the carboniferous strata of New South 

 Wales has undergone little or no alteration, but in some parts 

 of the colony they seem to have been metamorphosed or altered to 

 some extent, and to have been much contorted by the intrusion 

 of igneous rocks, and in these places they have been found to 

 contain auriferous quartz reefs or veins. There is, however, a 

 doubt as to whether these altered strata are really carboniferous 

 or whether they are not devonian beds. 



I will now proceed to give a description of some of the principal 

 gold veins in New South Wales, choosing those that are 

 peculiarly characteristic of some mode of occurrence. 



The alluvial field of Hargraves was the second gold field 

 discovered in Australia, the Ophir being the first, and it is 

 said to have been discovered by a blackfellow, an aboriginal of the 

 colony, stating to those with him when taken to see the gold at 

 Ophir, which is situated some miles away from Hargraves, that 

 he knew where some of the same kind of stuff was, and he 

 brought them to what is nowknown as Hargraves, and there shewed 

 them on the surface a large lump of gold and quartz. This led to 

 the working of the field, and a great amount of precious metal 

 was obtained from a comparatively small area of ground. 



