NEW ZEALAND COAL

Taranaki Daily News, 3 May 1933, Page 9

NEW ZEALAND COAL

SUPPLY FOR 110 YEARS “SCANTY RESERVES.” SURVEY BY DR. J. HENDERSON. “Assuming that the average consumption will be 2,500,000 tons per annum and that half the proved coal will be ultimately mined, New Zealand has sufficient proved coal to last but 110 years, a very short period in the life of a nation,” said Dr. J. Henderson, director of the New Zealand Geological Survey, when discussing the coal resources of the Dominion in-a.paper- he read at the last meeting of the-. Wellington Philosophical Society. His lecture constituted the presidential address for the society’s Dr. Henderson said that- since estimates of the amount of coal were prepared for the 1913 session of the International Geological Congress several important coalfields had been examined in detail, a great deal of stratigraphical and palaeontological work had been done on the formations containing the coal, and considerably more was now known of the ages and correlations of the different sets of coalmeasures. These investigations had brought out more clearly the difficulty of making satisfactory estimates of the amount of coal, and on the whole had shown that the “probable” and “possible” coal was less than was thought, • ; . .

VARYING ESTIMATES. The total output of coal since European occupation of New Zealand to the end of 1931 was nearly 76,000,000 tons. For the last 20 years the yearly output had been about 2,000,000 tons, rising in some years to 2,500,000 tons. In countries of regular and little disturbed coal-measures such ' as Europe, North America, South Africa, and New South Wales, in which seams maintained their thickness over hundreds of square miles the geologist could arrive at dependable estimates, but in New Zealand, where a thick seam might grade into shale or altogether thin out in a few chains, and where most of the coal fields were strongly faulted, the estimates of different geologists were likely to differ widely. Mr. Morgan had made an estimate of the bituminous coal in 1927, and making use of the latest . work available reduced the 394,000,000 tons of bituminous in an earlier estimate to 298,000,000 tons. If a smiliar reduction were applied to all coals his total of proved coal would be about 760,000,000 tons.

The estimate was for coal hi the ground and not for coal extractable under present conditions without financial loss. In other countries where mining conditions were more favourable than in New Zealand an extraction of 75 per cent, was in' general not considered bad practice. In New Zealand he doubted if more than half of the higher rank coal or more than a third of the lower rank coal was at present being extracted, the remainder being I either destroyed by fire or otherwise irretrievably lost. Thus, the North Auckland coalfield, which produced a good house and steam coal and where the seams were not unduly. thick, originally contained about 13,000,000 tons of coal. Of this about 5,000,000 tons had been mined and probably another. 2,000,-.

000 tons was extractable, making a total extraction of rather more than 50 per cent. ’

“At present,” Dr. . Anderson concluded: “We. use over- 2,000,000 tons a year. Population tends, to increase geometrically, and. coal consumption also tends to increase per head. Let us assume that. the average - consumption will be but 2,500,000 tons per annum, and that half the proved - coal will ultimately be. mined.. On this basis our proved coal .will last , but-110 years. This is a very short period in the life of a nation. Though . already, over ■ 90 years of age, we, as judged by our dependence on many essential imports and on the distress the recent cutting-off of external loans has produced, have not yet reached the self-supporting adult stage. When we do we may expect to consume more coal per head and so reduce the life of our all-too-scanty reserves.”