Martha Mine
The Martha Mine is a gold mine owned by OceanaGold since July 2015 in the New Zealand town of Waihi.
William Nicholl marked out a 5 acres (20,000 m2) claim, calling it "Martha" after a family member. Several smaller claims were later merged to form the Martha Company. By 1882 the first battery to break gold-bearing rock was in operation. The Martha Mine eventually grew into one of the world's most important gold and silver mines, after industrial cyanide processes made recovering gold from the low-grade ores easier. Waihi prospered with the mine, by 1908 being the fastest-growing town in the Auckland Province, three times the size of Hamilton.
In 1935 New Zealand gold output peaked during the depression, with two-thirds by the Waihi Company which was the largest of the four major companies. That year for tax reasons the Waihi Company was split into three, including the Martha Company which controlled the Martha Mine.
Underground mining ended in 1952, but not because the mine had run out of gold; current operation is evidence of this. Rather, a series of factors led to a decline in production. Chief among those was the international gold price, which was fixed at $US35 an ounce, limiting the revenue the mine could make. Other factors included the need for a substantial capital expenditure to update the machinery. Although the technology was available to do this, the money was not. Manpower issues also factored into the decision to close the underground mine. There had been two World Wars and the Depression of the 1930s, depleting manpower and creating a difficult economic climate.
It was not possible, given these factors, to profitably mine the lower grade ore.
In the 1970s and early 1980s the gold price increased. Exploration and prospecting work identified the economic resource that could be profitably exploited through a lower cost open pit approach. The mine was reopened, and continues in production today. In April 2015 and April 2016, large landslides occurred and stopped mining activities. Geological studies are carried out to find out, whether the mining can continue.
The "Cornish Pumphouse" was originally built in a different location next to the Martha Mine in 1904 to accommodate a large Cornish steam engine designed to pump water out of the mine. The building's design originated from one used in tin mines in Cornwall, England.
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