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Nickel mining in New Caledonia is a major sector of the New Caledonian economy. The islands contain about 7,100,000 tonnes of nickel which is about 10% of the world's nickel reserves. With the annual production of about 107,000 tonnes in 2009, New Caledonia was the world's fifth largest producer after Russia (266,000), Indonesia (189,000), Canada (181,000) and Australia (167,000). Nickel production in New Caledonia accounts for 7–10% the country’s GDP and is responsible for as much as 80% towards foreign earnings.〔(【引用サイトリンク】title=Mining in New Caledonia )〕 With the exclusion of tourism, nickel ore and derived metallurgical products represent about 97% of the total value of exports.〔(【引用サイトリンク】title=The history and economics of mining in New Caledonia )〕 ==History== New Caledonia has the longest history of mining in the Pacific islands. Nickel was found in New Caledonia in 1864 by the engineer Jules Garnier. It was distributed in the ore layers which cover about one third of the area of the main island of New Caledonia. The nickel concentration was inhomogeneous and also varied with the depth. Whereas its usual concentration was 2–5 percent, it could reach 10–15 percent in scattered deposits of green garnierite. Those areas were developed first using primitive manual extraction methods and were gradually depleted, resulting in the present average concentration of about 2.6 percent. This nickel is located at the depth of about . Shallower layers of also contain nickel, but at half of the concentration. They remain unexploited and constitute most of the nickel reserves of New Caledonia.〔 Wide-scale mining started in 1875 in Houaïlou and Canala communes. Early mining was done by hand and then gradually became mechanised. By beginning of the 20th century two large mines at Bourai and Thio were established. In the initial years, after nickel was discovered mining was done in about 330 mines. However, in 1981 there were only 30 functional mines as against 130 in the early 1970s. Because of the remote location of the islands, about half of the ore was smelted locally, despite the underdeveloped industrial infrastructure of New Caledonia. Another half was exported, mainly to Japan. The first nickel smelter was built in 1879 with two other added in 1910 and 1913. The smelted product contained about 70–80% nickel and was sent for refining to France. Because of low nickel content in the ore, local smelting resulted in vast amount of displaced rocks near the smelters that changed the local landscape.〔 The production of ore was nearly constant between 1875 and 1948, but then increased about 70 times reaching a peak of about 8 million tonnes in 1971. This rise followed by a decline, to about 4 million tonnes of ore in 1981, due to cyclones, reducing demand for the metal and increasing role of other world producers, such as Indonesia, Philippines and Australia. Correspondingly, the mined area decreased from and the number of people employed in the industry from about 6,200 to about 3,600. Nearly half of them worked at the mines and another half at the major Doniambo processing plant near Noumea.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Nickel mining in New Caledonia」の詳細全文を読む スポンサード リンク
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