Geological and other Reports
Wanganui, December 18, 1861
Sir,—Although I have few additional facts to communicate concerning the discovery of gold in this Province, yet I find that I have some arguments still in store to show the small chance there is of finding what are called dry diggings in these parts, and that the existence or absence of gold will not be proved until the results of deep sinking shall have been tried.
In many countries, such as Great Britain or Australia, for instance, the mountains slope gradually into the valleys, the valleys into the plains, without any distinct line of demarcation; so that it is difficult to say where one begins and the other ends, while in New Zealand (excluding the country covered by tertiary rocks) the prevailing character is, that mountain and valley, or plain, meet abruptly, and therefore that the horizontal strata which form the plain may require as deep sinking to bottom through them near the hill as at a distance from it, the bed rock of the valleys appearing frequently to be a tolerably level surface of strata with their edges uppermost. The beds of drift or of alluvium, which may lie on the sides of the mountain above the level of the valley, are few and unimportant, and hence the absence of dry diggings.
The more I see of the rocks of our main range, the more I am satisfied that they answer Sir Roderick Murchison's definition of gold constants. The direct evidence is small, but the circumstantial is almost conclusive. It being granted throughout that the stratified rocks answer the necessary conditions with regard to age, then the circumstantial evidence rests on the facts that the rocks of the page 5 range are dislocated, tilted, and upheaved at angles varying from 45° to vertical, and that they have evidently been altered to a great extent by the action of heat. There is strong presumptive evidence also that these effects have not been produced by comparatively modern lavas or traps, and therefore we may expect the true plutonic rocks to be close at hand, with almost as much confidence as if we found them on the surface—in addition to this, the rocks are every where traversed by diffused veins of quartz, and gold has been found in its detritus.
Having proved the gold constants by circumstantial evidence, it does not, therefore, follow that gold exists in payable quantities, or at all; but as I have already seen far more specimens of Wellington gold than I had seen of Australian in the year 1850, and which at that time led me to expect the discovery of the Bathurst diggings at no distant date, I have reasonably come to the conclusion that we have fair grounds for expecting to find the precious metal in payable quantities. Had no one attempted to dig in Australia it is probable that little more than specimens of gold would have been found there to this day, except perhaps the discovery of a few auriferous quartz reefs, which, wanting the skill and labour introduced by the diggings, would probably never have been worked.
It appears that gold has been found all along the West Coast—at all events at Terawiti, at Waikanae, and at Otaki; for that reason, and from the fact that New Zealand gold, like Australian, seems to prefer to lie to the westward, I should be inclined to recommend in preference a trial sinking on the West Coast, and particularly at Otaki, where the gravel seems to be more quartzose than the average; but otherwise, appearances are equally good in the Wairarapa; and the valleys and plains at Featherston, Greytown, or Masterton, look as “likely” for sinking as Waikanae, Otaki, or Rangitikei.
I find that the tendency of exploration is to go to the tops of the mountains to find the origin of the gold. Although this may result in the discovery of other minerals, and may be interesting to the geologist, it is not likely to be profitable to the gold miner.