Production and Resources
General:The production of metallic ores has clearly decreased in recent years. That of fuels is increasing slightly, however, and the recent discovery of the gas-oil field in Taranaki is of major importance. The production of industrial minerals is expanding rapidly -both in tonnage used and in the uses found for old and new minerals. Kauri gum was once a major export, and second only to gold in total export value (£25 million). In 1963 it yielded only £12,000 and is likely to become even less important in the future.
There are no known major reserves of any metal ores apart from iron and perhaps aluminium, although further exploration and prospecting in such areas as Northland and the western half of the South Island (especially Nelson and Fiordland) may lead to new discoveries. Reserves of the fuels and of industrial minerals are adequate or large, except for feldspar, mica, phosphate, and sulphur. The quality of some others, such as oil shale, asbestos, bentonite, diatomite, fuller's earth, magnesite, and talc is such that care is required in prospecting, working, and utilisation.