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



quartz occurs and is generally easily detached from the other part 

 of the flattish veins. The narrow vein is said to be barren, or 

 nearly so, and highly charged with pyrites for about two or three 

 feet above the flattish veins. Both the narrow vein and its 

 containing wall are tinged green, the latter for about an inch, 

 but this green tint shades gradually away from the vein inwards ; 

 arsenical pyrites occurs both in the narrow vein and its walls for 

 about the same distance as the green tint, and in particularly large 

 quantities for some distance above the flattish vein. Both the 

 flattish veins (viz., those with a low angle of dip) and the narrow 

 veins are heaved by a system of lodes that dip in an opposite 

 direction to the former, and intersect them. These latter are of 

 a loose barren character and of from a foot to three or four feet 

 thick. 



Sections across parts of the held shew the general mode of 

 occurrence as described (vide Figs. 25 and 26). A somewhat 

 similar phenomenon, I believe, exists at Ballaarat, in Victoria ; 

 the small vein being there known as the indicator vein, and 

 is followed for its accompanying rich shoots of gold. 



The flattish veins seem to have been formed upon joint planes 

 of the country rock. The black places on diagram (Fig. 25) show 

 the parts of the flat veins that are richest. All the quartz in this 

 field is strongly charged with both sulphurous and arsenical 

 pyrites, particularly arsenical, which exists in very perfect cubical 

 crystals. Some of the alluvial gold was in very large pieces, as 

 much as lOOlbs. in weight of the precious metal having 

 been obtained in one lump on more than one occasion. The 

 piece of gold and quartz that the blackfellow found, and which 

 led to the opening of the field, weighed over lOOlbs., and 

 most of this was gold. It is said to have been found lying near 

 the outcrop of the main vein upon the small rise to the right in 

 the diagram (Fig. 25). 



The Hill End reefing field is situated some distance from 

 Hargraves, and some extraordinarily rich patches of auriferous 

 quartz have been obtained from the reefs in that place. A 

 description of a portion of that field is thus given by Mr. E. 

 Pitman, Associate Royal School of Mines, London, and now 

 Chief Mining Surveyor of the colony of New South Wales : — 



" Hawkin's Hill, which has become famous on account of the 

 "enormous yield of gold obtained from its veins, is composed of 

 " beds of the altered conglomerate above referred to, dipping to the 

 " eastward. Thin layers of dark slate, with some chlorite slate, 

 "occur at intervals in the conglomerate, and carry lenticular veins. 

 " of quartz, with pyrites and potash mica (muscovite). In some 

 " places the mica was found to entirely replace the quartz, and 

 " here the gold was found to be exceedingly rich. The veins are 



