Gold-Deposits of New Zealand Considered in Relation to the Comparative Quantities of Reef and Alluvial Gold on the Various Goldfields of the Colony Vo (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 edition. Excerpt: ... case ceasing to be productive at a considerable distance from their sources in the Spencer Mountains. This secession of the gold is not due to the want of grinding and sorting of rock material in the beds of these streams, as they have volume and distance from their sources quite sufficient for that purpose, and their beds have lodgment areas as favourable for the retention of gold as the localities farther down stream where it is actually found. It is remarkable that over the area on the south side of this part of the Buller Valley all, or almost all, the gold comes from gravels resting on rocks that are unfavourable for the occurrence of gold-bearing quartz reefs, the country-rock being mainly of Cretaceous age; the other rocks are granitoid gneiss, the first being without reefs, and the last, though not incapable of carrying auriferous reefs, does not seem to do so. At the base of the Cretaceous formation there is a great development of conglomerates and pebble-beds known to be auriferous, the denudation of which seems to have supplied to the river-beds and the adjacent terraces the greater part of the gold which they contain; and, although around the sources of the Glenroy and the Alford Rivers and towards the eastern end of the Victoria Range of mountains quartz reefs are known to occur, none of these have been proved gold-bearing, and none of them are worked. In this district appears a condition of things that more to the south characterizes all the goldfields from the Big or Brown Grey to Ross--viz., that all the rivers, as they are followed inland towards the mountains of the main water divide, cease to carry gold almost immediately on their entering the mountain region. There is seeming exception to this rule in Reefton...