88 
THE GEOLOGY OE NELSON. 
similar disposition of strata is observed on the loftiest summit 
of Europe, namely, on Mont Blanc. 
In the mica-slate and clay-slate zone of the western ranges, 
we have the matrix of the gold. From the interest attaching 
to this subject, I may be allowed to repeat the limits of these 
cold-bearing formations. On the east these formations are 
bounded by the Tabaka valley ; on the west by the Aorere 
valley, so that its breadth is from fifteen to twenty miles, and 
includes the Anatoki and Haupiri ranges. In a southerly 
direction the same formations can be traced to the gorge of the 
Buller river. How much further it extends in that direction 
lias not yet been ascertained; but inasmuch as gold has been 
found at the northern extremity of the Southern Alps, and 
also in the gravels of the Mat aura, in the Province of Otago, 
towards the southern extremity of the backbone, it is not un¬ 
reasonable to infer that the same gold-bearing zone may extend 
continuously throughout the whole length of the Middle 
Island. 
Before speaking more specially of the gold-fields, I wish to 
correct some of the theories popularly current among the 
diggers, according to which gold is to be traced to the action of 
fire. The gold, in its original position, is in larger or smaller 
particles dispersed throughout the quartzose constituents of 
the mica and clay-slate formations. By the gradual wearing 
away of these rocks, through the action of the elements, 
extending over immense periods of time, large masses of debris 
have been formed, and nature itself has executed an operation 
of gold-washing, by collecting the heavier particles and depo¬ 
siting them in the gullies of the streams, or in the conglomerates 
covering the slopes of the hills. 
There are, therefore, two principal descriptions of diggings ; 
either “ river diggings,” in the beds of the streams, or “ dry 
diggings,” in the conglomerate and gravel accumulated on the 
slopes of the mountains. 
I will first describe the best-known and most worked of your 
gold-fields—namely, the Aorere and the Parapara gold-field. 
The Aorere and Parapara Gold Field .—You are all aware, 
that the gold in the Aorere valley is confined to the eastern 
