. Transactions and proceedings of the New Zealand Institute . r 1 oz. per ton, while at the foot of the winze theassay value is uniformly over 1 oz., and rich specimen-stone, particularlythe brecciated variety, may be picked up showing much coarse gold. Itis peculiar also that at this point the gold is often dark in colour andrusty. At No. 3 level, below it, and for some distance above it, the gold is prettyevenly distributed across the vein. Rising to No. 2 level, a barren blockof glassy quartz comes in, and the seamy gold-bearing quartz is pushedover to the two walls, and divided by clay par
. Transactions and proceedings of the New Zealand Institute . r 1 oz. per ton, while at the foot of the winze theassay value is uniformly over 1 oz., and rich specimen-stone, particularlythe brecciated variety, may be picked up showing much coarse gold. Itis peculiar also that at this point the gold is often dark in colour andrusty. At No. 3 level, below it, and for some distance above it, the gold is prettyevenly distributed across the vein. Rising to No. 2 level, a barren blockof glassy quartz comes in, and the seamy gold-bearing quartz is pushedover to the two walls, and divided by clay partings from the barren centreblock, which corresponds practically to a horse of country rock. Thisblock wedges out when followed in either direction along the strike, andit also has an easterly pitch or dip along the strike of the vein. Boththese features may be seen on the accompanying plan of the workings. 78 Tronsactinns. where it will be observed that in each level the foot-wall and hanging-wall seams have been driven on, leaving the centre block Shclfl Fig. W. -Mine-plan, Barren block. Thus in the wider portion of the vein the gold has been deposited in twoshoots along the walls. The gold-bearing quartz differs from the barren dogs-tooth quartz in being seamed and mottled wdth pyritic mullock,and under the microscope is finer in grain. These facts point to a certainamount of replacement along the walls, while the barren block has beenformed by simple deposition in an enlarged fissure. In places in Nos. 2 and 3 levels there occur pecuhar siliceous concretions(Plate II, 3), cavernous and irregular in form, with a fine chalcedonic are dark, and coated thickly with very fine pyrites. In appearancethey suggest clinkers in coal, or fossil forms. Associated Minerals.—The dominant sulphide is pyrite, in fine crystalsand grains. It is absent in the clear glassy quartz, and thickly distributedin the auriferous quartz. In the No. 3 level there wa
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