ORIGIN AND MODE OF OCCURRENCE OF GOLD-BEARING VEINS. 137 



But what chiefly concerns us in this place is the peculiar 

 formation of the quartz veins that exist in it, the denudation of 

 which has doubtless supplied the gold found in the alluvial. 



The alluvial was obtained from a gully situated near the top 

 of a high range, this gully being flanked on the one side by 

 silurian or devonian slates and shale, and on the other by a 

 sandstone formation, both strata being inclined at a very high 

 angle. 



Crossing this valley, but in an oblique direction, so as to cut 

 through most of the alluvial field, is a quartz reef averaging in 

 thickness from 8 to 10 feet in some places, and from 1 to 2 feet in 

 others, the thickest part being on a small rise near the centre of 

 of the field, and there the vein seems to consist of a large blow on 

 the surface with possibly two legs or branches which divide as 

 they go down. One of these legs dips easterly, and has been 

 worked for some distance from the surface ; it coincides with the 

 dip and strike of the shales which are about 90° from the horizontal 

 and north west respectively. 



Cutting across the field in a direction more or less oblique to 

 the main vein, are a number of flattish veins, and these are 

 inclined at so small an angle from the horizontal, and are in some 

 cases so near to each other that they actually lay under one 

 another, so that a vertical shaft of some hundred feet deep might 

 be expected to cut one after another as it went down. 



Parallel to the main quartz vein or reef, and at varying 

 distances from it and from each other, are small veins of quartz 

 that coincide with the strata, and are thus parallel with one leg 

 of the main reef. These veins are from one to two or three inches 

 thick, and are heavily charged with arsenical pyrites. They 

 strike the flattish veins as they go down, but do not cut them, 

 although they are found again continuing downwards on the same 

 course, immediately below the vein they strike, and continue 

 thus until they strike another vein. It is where these small 

 veins strike the flattish ones that the quartz in the flattish veins is 

 richest, — the immediate point of junction being rich beyond 

 all comparison with other portions of the deposit ; as much 

 as 700 ounces has been taken from immediately beneath one of 

 these junctions, and so rich was the quartz in this place that the 

 700 ounces were taken from only a few feet along the vein and 

 were all crushed out of the stone with an ordinary pestle and 

 mortar by hand labour. It is not, however, always directly under 

 the small vein that the extraordinarily rich quartz is formed, but 

 in a space from about six to twelve inches to one side or the other 

 of this vein (vide Figs. 27 and 28), and a shallow gutter, or 

 sometimes a ridge, seems to run along the flattish quartz veins, 

 •and it is in this gutter, or on this ridge, that the highly auriferous 



