105 
valley and every creek contains gold of somewhat different ap- 
pearance. 1 While most of the gold is very pure , that of the Slate 
River, for example, has always a brown ferruginous coat. On the 
Apoos River the gold is accompanied by crystals of iron pyrites, 
which remaind behind in the process of washing; in other places mag- 
netic iron or titaniferous iron is found in company with gold. The 
fact that the heaviest gold is found in the upper parts of the streams 
points clearly to the mountains as the original source of the metal. 
But it would be improper to speak of an Aorere gold-field if 
the gold were confined to the deep and narrow gorges of the streams, 
cut down into the clayslate rocks. The whole region of the eastern 
side of the Aorere valley, rising from the river beds towards the 
steep sides of the mountains at an inclination of about eight degrees, 
and occupying from the Clarke river to the South, to the Parapara 
on the North , a superficial extent of about 40 English miles , is a 
gold-field. Throughout tills whole district, on the foot of the range, 
we find a conglomerate deposited on the top of the slate rocks, at- 
taining in some places a thickness of twenty feet. Pieces of drift- 
wood changed into brown coal, as well as the partial covering of 
the conglomerate with tertiary limestones and sandstones at Wash- 
bourne’s Flat indicate a probably tertiary age of this conglomerate 
formation. Where a ferruginous cement binds the boulders and 
the gravel together, this conglomerate is compact; in other places 
only fine sand lies between the larger stones. Quartz aud clay- 
slate boulders are the most commonly met with. This conglome- 
rate formation is not only 
cut through by the deep A 
Section through the Quartz Ranges, 
a. clayslate. b. auriferous conglomerate, 
c. alluvial sand. 
gullies of the larger streams, 
but in some places washed 
by the more superficial ac- 
tion of water, and is thus 
divided into parallel and rounded ridges, of which that portion of 
the district called the Quartz Ranges is a characteristic example. 
1 According to a test made at the mint office in Vienna, the Nelson gold 
averages 89 per cent fine gold, and 0,145 per cent fine silver. 
