Today I will introduce everyone to an amazing hole in Waihi. It is the Martha mine. The mine has a very long history from the discoverer John McCombie, dated back in 1878 to the current enterprise, Newmont.
Gold was first discovered on Pukewa (Martha Hill, Waihi) in 1878 by prospectors John McCombie and Robert Lee. The samples of rock they had sent to be assayed were not considered worthwhile, so they left the area. Their claim was taken over by William Nicholl in 1879. He pegged out five acres, named the claim 'Martha' after a family member, and later a few small claims amalgamated to form the Martha Company. By 1882 the first battery was in operation.
In 1890 the Martha Company and other claims were bought by the Waihi Gold Mining Company of London, who invested a great deal of capital into the mine.
At the time, trials were being carried out to find a more efficient way to extract precious metals from the quartz rock. By 1894, the Forrest / MacArthur process had been developed and the use of cyanide in the gold extraction process was adopted worldwide. This process enabled a higher percentage of gold and silver to be extracted from hard rock, making many operations viable that would otherwise have had to close.
The Martha Mine became one of the most important gold and silver mines in the world. By 1952, when the mighty Martha Mine closed, around 5.6 million ounces (174,160kg) of gold and 38.4 million ounces (1,193,180kg) of silver had been produced from 11,932,000 tonnes of ore.
Built around 1904, from a design used in the tin mines of Cornwall, England, the structure housed steam engines and pumping machinery. The pumps were needed to cope with the ever increasing quantities of water as the mine workings followed the gold-bearing quartz reefs to a final depth of 600 metres.
Constructed by Hathorn-Davey, the horizontal Cornish pump was the pride of the New Zealand mining industry. The pump had a stroke of 4 metres and continuously dewatered the mine workings at a rate of 7000 litres per minute via No 5 shaft, which was situated adjacent. No 5 shaft had a depth of 399 metres. In 2006, the cornish pumphouse was moved to the current situated location to preserve the historical building and you can view the process from here (http://www.marthamine.co.nz/corn_pump_move.html).
Mining did not end in 1952 because the Martha had run out of gold; the current operation is evidence of this. Rather, a series of factors led to a decline in production:
the international gold price was fixed at $US35 an ounce, limiting the revenue the mine could make
the machinery needed to be updated; although the technology was available to do this, the money was not
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 is being worked today. If you are interested in knowing how the exploration task is performed, view the video below.
Of course, don’t just take my words for it. Listen to what the local kids in Waihi have to say about their environment below.
Well. As part of the Martha mine closure plan, we will be viewing a lake in Waihi by 2020. There are a lot of signboards hung along the fence with questions and answers about the Martha mine as part of a public awareness effort executed with the mine closure plan.
Questions and answers listed below are taken from those signboards on the (Top Left) photo to the (Bottom Right) photo.
Q: Why is the mine named Martha?
A: William Nicholl (an early propector) named the mine Martha after a relative.
Q: When was gold first discovered here?
A: 1878, by John McCombie and Robert Lee.
Q: How does the ore get to the processing plant?
A: Via a 2.7km long, 1.3m wide rubber conveyor belt that passes through a tunnel in Union Hill.
Q: How deep is the final pit?
A: 250 metres from the highest point on the north wall.
Q: Will fish and birds live in the water?
A: Yes. The water quality will support a range of fresh water fish species. It is expected that water fowl will inhabit the area too.
Q: How long will it take for the lake to fill?
A: About 5 years by using water from the Ohinemuri River in times of medium to high flow. If left to fill naturally it would take about 25 years.
Q: Will you be able to swim in the lake?
A: Yes. The water quality must comply with Environment Waikato standards for recreational use.
Q: How will the lake fill?
A: A combination of groundwater rain water runoff and water pumped from the Ohinemuri River at times of peak flow.
I will attempt to recapture the Martha mine photos after 5 years later from now. Or should I call it as Martha Lake by then? It will surely become a great time capsule for Waihi in remembrance of their mining historical background. For those that are interested, check out the map below for details.
Reference(s):
NEWMONT. (n.d.). History of Martha. Retrieved on April 26, 2010 from http://www.marthamine.co.nz/orig_martha.html
YouTube. (Dec 28, 2009). Exploration_web.mov. Retrieved on April 26, 2010 from http://www.youtube.com/watch?v=bUr0H4pt_wI&feature=player_embedded
YouTube. (Nov 16, 2009.). Living Next To An Open Cast Gold Mine - Waihi Central School. Retrieved on April 26, 2010 from http://www.youtube.com/watch?v=Y3Ys4450ndE&feature=player_embedded
NEWMONT. (n.d.). The Cornish Pumphouse. Retrieved on April 26, 2010 from http://www.marthamine.co.nz/corn_pump.html
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