Art. XXXVI.—On Alluvial Gold in the Province of Wellington.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 2, 1869, Page 160

Art. XXXVI.—On Alluvial Gold in the Province of Wellington. By J. C. Crawford, F. G. S. [Read before the Wellington Philosophical Society, July 17, 1869.] Having visited the operations at present going on in the upper part of the valley of the Kaiwarra stream, I find in that narrow valley, a greater quantity of gold washed out than could have been reasonably expected from the limited area from which it must have been derived. Taking the actual fact of the presence of gold, in appreciable quantities, in this small valley, into consideration, I am inclined to revert to an opinion, which I long ago expressed, and which is as follows: that considering the very high angle of inclination of the main chain of the island, consisting, in this part, of the ranges of Tararua and Rimutaka, with all the subsidiary ranges, that the tendency of the denudation of the valleys, would be to wash out gold, or other minerals, which might be thereby released, beyond the boundaries of the hills, and deposit them in the valleys to the east and west of the chain. If, on the east side, we consider the wearing away which has scooped out the valleys of the Tauherenikau, the Waiohine, the Waingawa, the Waipoua, and the Ruamahunga, we may reasonably expect, supposing the rocks are to any extent auriferous, and fall and force of water are sufficient, that gold must have been carried out and deposited somewhere in the Wairarapa valley. On the West Coast, in a similar way, from the valleys of the Wainui, the Waikanæ, the Otaki, the Manawatu, the Rangitikei, gold may have been deposited in the trough between the main ranges and the line of Kapiti and Mana. I put this statement theoretically: how to prove the theory to be fact, is the point to be decided. If we attempt to sink to any depth, on either side of the range, we shall probably soon require powerful pumping apparatus, and of necessity considerable capital would be required. It is possible that tentative explorations may be made, at the least difficult points, which, without going to much expense, may either lead to further trial, or to the abandonment of the idea. Supposing the land to have formerly stood at a higher level (at a comparatively recent period), there is a possibility that the Lower Hutt Valley, and even the bottom of this harbour, may have undergone the conditions necessary for the concentration of alluvial gold. My reasons for advancing the above theory are, the extremely steep incline of the chain on both sides, and the rapid fall of the rivers, the great general force of their currents, and the frequency of heavy floods, combined with the proved fact that gold is found, more or less, distributed within these ranges. It is possible that the above remarks may be found applicable to the valleys of the Wakamarina and the Pelorus, in the Province of Marlborough

To accompany Paper by F. W. Hutton on the Geology of the North Head of Manakau Harbour.