I'd I'olo;/!/ uiul (rfohHjji of Qaeeiisfotrii. 143 



rions. tiDiii veil ildwii the uully ritilit up to the outcTDp of thr I'cofs 

 on One Tire Hill. The dislritt Mining Surveyor in ISTl) ii'ixuts 

 the tindinu' of a rieh spniineii of (piartz (8-3 ozs. (J dwts. ijross 

 wciiiht. ")() t)zs. fine) six iiu-lics lielow tlii' surt'aee leef. and un- 

 doutedly derived from this I'eef. The nuggets found ni'aiest the 

 reefs are generally mixtures of tjuartz, linionite and gold, and show 

 little signs of rounding. ('obl)ler's gully has yielded the largest 

 nuggets, and there is every i-eason to believe that tlioy have 1)een 

 derived from the Swedish reef, which has been shown to l)e a 

 nuggety reef, and much of the gold olitained fiom it would be 

 best described as nuggets. For instance, a specimen of ipiartz 

 from tliis reef, having a maximum dimension of 3 inches, was 

 found to yield 48 ounces of gold.l Mr. Hirt, who has had a very 

 intimate acquaintance with this field, told the writer in private 

 •c-onversation that a nugget 40 ozs. in weight, and associated with 

 quartz and limonite, was got from a dei^th of nearly 100 feet in a 

 claim on the Homeward Bound line of reef. It will be agreed, I 

 think, that the evidence allows of no other conclusion than that the 

 nuggets have been derived by the breaking doAvn by denudation of 

 the former upward extension of such reefs, as the Swedish at One 

 Tree Hill. 



F. — Future possibilities, Secondary enrichment . etc. 



Oram's is the only reef on this field developed at greater depths 

 than 300 feet, and the majority of the workings have not penetrated 

 below the ground water level. Notwithstanding the shallowness of 

 the workings, there is apparently nothing to show that the values 

 have not been maintained in depth, as is seen from the figures 

 given above for Oram's reef. Of the geological factors that may 

 have influenced the values near the surface, secondary enrichment 

 is the most important. The recognition of its effect on auriferous 

 quartz veins, is frequently difficult, and this is especially so in 

 Victoria. Victorian gold is generally of a high degree of fineness, 

 and usually free from sulphides of the base metals w^hich are easily 

 leached, and either oxidised or redeposited at lower levels as secon- 

 dary sulphides. Further, most of these mines were developed before 

 secondary enrichment was studied, and practically no facts relevant 

 to the question are now obtainable from the records. The yields 

 from various depths aid us little, as is seen from the tabulated 



1 Vide, supra, p. 36. 



