THomson.—Glacial Action in Otago. 329 
so hurriedly done, he does not at the same time, like nature, mix his earth 
with vegetable matter, and so replenish the plains with fertile soil capable 
of bearing fruit for the sustenance of man, but otherwise his sluicing avocations 
are the same in principle as glacial action. 
Now if we watch sluicing operations from the commencement to their 
conclusion, we will see a parallel to one of the most benign provisions of nature 
most closely carried out. Let us take a hill-side bordering on a flat, such as at 
Gabriel Gully, or Weatherstone’s ; we will see. that. the shingle is deposited 
from the sluice nearest the hill; then the gravel ; furthest off is carried the 
mud and silt. Thus, let a be the hill that is sluiced, 
and B the plain; first, the tailings are carried in the 
direction of AB, then, as the earth rises, the channel 
gets choked, so they are carried in the direction of 
в; this being filled up, then in the direction of f; 
then of d; then of 4; then of e; and so forth; 
spreading out the material in the form of a fan, in 
separate layers, these layers varying with the quality of the soil taken out of 
the hill. Thus, if z were blue it would be spread in a thin layer over the 
portions of the fan it was carried to; if y were red it would be spread out at 
other parts in the same manner; and, if z were white it would appear at its 
proper time and in its proper layer, and this might be done over a thousand 
times. 
. Thus the modern gold sluicer answers the enigma that puzzles the Taieri 
farmer, when he discovers trees so far below the present surface, by telling 
him that these trees grew at а time when the glacial sluicing operations were 
at z, and whose tailings уеге deposited far below those of z and у. 
If such be the process by which the gold miner, in his sluicing operations, 
spreads out débris, drift, alluvial sludge, or tailings, in strata all over the plain, 
such we may anticipate is the precise process by which the same matter is 
made to cover the plains of New Zealand, wherein terrene and mountain 
glaciers perform the functions of the sluicer. And we have only to look to 
the neighbouring Province of Canterbury to see the effects of the process 
developed in its most prodigious grandeur. I allude to the fan-like deposits of 
the Rakaia, Rangitata, and Waimakariri on the spacious plains of that part 
of the Middle Island. In Otago, except on the Waitaki, probably we have no 
such examples, though we have great numbers on a minor scale, which may 
be called lateral alluvials, brought out from the small gorges of the limestone 
ranges at Papakaio, Waikari, Kakanui, etc. But in all cases, whether the 
deposits have been the result of natural or artificial causes, whether great or 
small, they all appear to conform to one principle, and to adhere to one shape, 
vertically and horizontally. 
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