Māori use of stone
Although Māori did not use metals, stone was widely used for tools, weapons and ornaments. Suitable local rocks were used in different areas, but some types of stone were widely traded or taken as spoils of war:
- pounamu (nephrite and bowenite), found mainly on the western side of the South Island near Hokitika
- obsidian – the best-quality material coming from Tūhua (Mayor Island)
- adzite (also called baked argillite) from D’Urville Island and other localities in east Nelson.
Archaeological evidence shows that these rocks were widely distributed around New Zealand by 1400 AD, within 150 years of Māori settlement. Former quarries have been identified where blocks of adzite and obsidian were excavated and fragments trimmed to a convenient size.
The search for minerals
New Zealand was colonised primarily for agricultural land rather than for its mineral wealth. As an increasing number of European settlers arrived after 1840, they started to search for metals (particularly gold) and coal. Gold rushes in the 1860s led to the migration of men to hitherto remote areas in Otago, the West Coast, and Coromandel.
In 1870 when James Hector, the director of the New Zealand Geological Survey, described the minerals and mining industry in New Zealand, gold, silver, copper, lead and iron had all been discovered, and small-scale mining was under way. Occurrences of chromium, zinc, antimony and other minerals were known. All the main goldfields and coalfields had been discovered, and coal was being mined in many areas around the country.
In addition to metallic minerals, kauri gum or resin lying on the ground in Northland was collected, and later buried gum was mined.
Development of a mining industry
Most of the gold won in the 1860s was found in rich, surface gravels, and was worked by individuals or small groups using simple equipment. The richer and most accessible ground was quickly exhausted, and larger-scale mining started in the 1870s. Alluvial gold was sluiced and dredged, and hard-rock gold and coal were worked in underground mines. This required substantial capital, and many speculative mining companies were set up, both in New Zealand and overseas. High returns were obtained from the more successful mines.
The merits of gum digging
‘Gum digging has always been a standing resource for the industrious unemployed, and has enabled Auckland in times past to tide over periods of commercial depression with comparatively little difficulty. It has also been of vast benefit to hundreds of settlers with small capital.’ 1
Production of gold varied, but peaked about 1905 and then gradually declined. In contrast, coal production grew steadily to 1 million tonnes in 1900, doubling to 2 million tonnes in 1910, and stayed around that level for the next 70 years. A significant part of the mining revenue before the First World War came from kauri gum, but this declined as the resource became worked out.
Changes after 1945
The total value of mining output (excluding oil and gas) increased steadily after the Second World War, and exceeded $1 billion for the first time in 2004. The increase was due to changes in mining technology and in the products produced, and to increases in export markets.
- Non-metallic minerals – industrial development within New Zealand since 1950 has led to construction projects needing large amounts of non-metallics, especially aggregate.
- Iron – large reserves of black ironsands on the west coast of the North Island have been known about for 150 years, but it was not profitable to smelt the sand to produce iron and steel until the 1960s. Now New Zealand Steel produces iron and steel for domestic use and for export.
- Oil and gas – following the discovery of natural gas at Kāpuni in 1959, the offshore Māui gas field was found in 1969. Since then, there has been substantial exploration in the Taranaki region, with the discovery of a number of smaller oilfields and gas fields, and exploration continues.
- Gold – because the world price of gold was fixed, production gradually declined in the middle of the 20th century. Once the gold price was deregulated in the early 1970s, there was a marked increase in exploration and mining. In 2005 most production came from two large opencast mines at Waihī (Coromandel) and Macraes (Otago), with minor production from alluvial mining on the West Coast and in Otago using modern technology.
- Coal – production fluctuated between 2 and 3 million tonnes for many years. It increased after 1990 with the development of an export market for bituminous coal and passed 5 million tonnes in 2004.