MINING FOR GOLD

New Zealand Herald, Volume LXXI, Issue 21758, 24 March 1934, Page 13

MINING FOR GOLD

PAST BENEFITS RECALLED NEED FOR NEW METHODS RELIABLE TESTS AND DATA SOURCES OF INFORMATION No; ii. New Zealand owes much of its development, progress and prosperity in the past to goldmining and this is especially true of the Auckland . province. It is therefore remarkable, at this period when prices for other primary products ■ are at depressed levels, and gold is bringing an almost unprecedented price, that more attention is not being paid to the winning of the precious metal. In fact, it would "seem that there every inducement to encourage the production of gold, but success in this direction cannot be gained by following the older and betterknown methods of uncovering the treasure which the Hauraki Peninsula must undoubtedly contain. The need for gold-seeking on a comprehensive scale and on sound lines has never been so pressing in the life of the country as at present. Not only is there the necessity for finding new outlets for the thousands of able-bodied men whose normal occupations have disappeared and for . the countless youths who, as a result of the depressed conditions of the past few years have never had any regular place in the industrial life of the community, but the influx of new money that a successful revival of the mining industry would bring to the Dominion would stimulate activity in all directions. Lower Grades Now Profitable

In the 'sixties the discovery of rich reefs oil. the Hauraki Peninsula led to a rush of eager gold-seekers. The country was rescued from its desperate and depressed condition, towns grew, commerce was established and manysided development took place. ■ Again in the 'nineties Auckland was a great gold-producing province and much of the remarkable development that has since taken place can be traced to the money which flowed from the goldfields. Yet. much of that, gold was won under conditions that to-day would be considered primitive. The most was made, of rich strikes but, because of the methods and equipment then employed, much rich ore had to be passed over as. being unpayable. To-day, with better .equipment and methods'devised in other countries and with the price obtainable for the fine gold, this ore and much of still lower grade could be wprked profitably. That the early miners searched the country thoroughly no one can doubt who knows of their energy and methods. It cannot be assumed, however, that they uncovered all the golden stores or left no rich reef untouched.. Discoveries since th| old armies of prospectors dis-. banded are proof ' against such •an assumption, for rich finds have been made in the oldest" and most closelyworked fields and' even in" the mo?.t honey-combed of mines. ' '" I Closer Exploration. Needed ::

It was said recently by an experienced mining engineer that the gold-seeker of to-rday cannot expect to ■ find gold in the same manner as was done in the past.,He has to search more diligently, work harder, use better methods and drop a lot of the old ideas. He supported this statement by showing that gold had been found in places where the old miner would not have Relieved that it could have existed. v

Mining methods changed in the course of the years. In practically; all mining countries attention is ■'being .directed to the development: of ; lowgrade reefs. New methods of treatment and engineering have rendered possible the exploitation of ore bodies that previously were _ considered worthless, so that goldmining to-day may be truly classed as an industry. It is therefore clear that. something more must be done to explore" the potentialities of the gold-bearing areas of the province. Something has already been done in this direction, but the immense extent of auriferous country in the Auckland Province makes it extremely unlikely that the area has been adequately prospected. , Preliminary Search

Extensive preliminary work, utilising the best talent available, and involving tests over a wide area to establish the existence of average values, is necessary before the establishment of the largescale plant required to treat the ore is contemplated, In the aggregate a very large'area or auriferous territory in the Auckland Province is held by companies and syndicates, but few of them can even % contemplate operations on the scale suggested. The first stage in the campaign to revive this important industry 6nould be a scientific survey of the Hauraki field. This would involve co-operation between the holders of claims and the Government through its various departments capable of giving assistance. In this connection the possibility of carrying out a geophysical;survey similar to that recently done by the Department of Scientific and Industrial Research in the South Island should be considered. It is'reported that the use of geophysical methods —really the application of scienqe to prospecting—in the South Island in determining the presence of ore bodies has met with much success and it is felt that the • Hauraki area presents an admirable field for a test of this nature. Sites for Boring

Of more pressing urgency, however, is the need for definite tests by boring at selected points to determine the exact formation of the country at depths which' have' not been investigated. At Thames the dip of the strata would suggest that valuable information could be secured by boring at the southern end of the borough. At Coromandel, on the other hand, the trend of the reef system has led experienced miners to suggest that bores should be put down in the tidal flats between the Haura'ki Company's property near the Coromandel "Wharf and Preece's Point. There is also a wealth of almost priceless information in the bulletins issued by the New Zealand Geological Survey. Little attention seems to have been paid in the past to the conclusions reached by Mr. Colin Fraser in the No. 4 Bulletin of 1907., dealing with the Coromandel area, and the No. 10 Bulletin, of 1910, which covered the Thames field. Now that attention is being paid to the possibilities of rich deposits at lower levels than those previously worked there is a keen demand for copies of these exhaustive reports, and few are available. It has been suggested that the Mines Department should have them reprinted" and even have them brought up to date from the data in the departmental files. From present indications these bulletins "will soon play an important part in the planning. of the development of the Hauraki goldfield.