Pumphouse Progress
Fencing is nearly complete at the pumphouse. The fine weather has allowed hydroseeding to go ahead as scheduled. The sprayed area will 'green up' after the next rain. Planting around the area has also been completed so we are now up to finishing details and there is a bit more concreting to do. The building and grounds have been inspected by LINZ (Land Information New Zealand, the owners) and this will be followed by an application for a 'Change of Use'. We are nearly there!
The Newmont Waihi Gold freephone is attended 24 hours a day, seven days a week.
0800 NEWMONT
(0800 639 6668)
Searching for gold bearing deposits is a bit like all those investigative dramas that seem to feature every night on television. There’s the painstaking fieldwork, hours of lab analysis, the reference to previous cases, the assembling of all of the evidence, and finally a decision is arrived at based on an objective analysis of all the information available. The big difference is that searching for gold isn’t quite such a drama, and our geologists aren’t quite as good looking as those TV actors.
Join us for an episode of:
NWG: Gold Deposit Investigation
Geology boss Terry rubs a hand across his stubbled chin as he orders his teams out into the field. He's puzzled. He knows from the old timers that the Martha vein runs east to west and dips, but he's missing vital information. Where does it go outside the pit walls? How deep is it? Is it continuous or fragmented? How rich is it? If it does exist, what then? All these questions and no real answers yet. He really needed a good commercial break...
Actually, that's all very melodramatic. Terry already knows the broad answers to most of those questions, he and the team are now looking to firm up the data and increase levels of confidence, but you get the idea.
Newmont Waihi Gold continues to explore areas around the Martha open pit, paying particular attention to the Martha vein system as well as exploring for extensions of the Favona system.
The aim is to maximise the resource with the possibility of extending the life of the operation before it finally moves into closure. These investigations are conducted under the conditions of the company’s various Exploration Permits.
Geological results are just one part of the 'evidence gathering'. Good results in the field mean that the next set of questions comes into play. Is the resource economic to mine and how could that be done, if at all? What are the social, cultural and environmental factors that must also to be considered?
Right now the Exploration Department is methodically working through the region using a variety of techniques to determine if there are areas worth further investigation. A western drilling programme forms part of this work.
Last year drill rigs explored the area to the east of the open pit. You may remember that a rig was positioned on Waihi East School's playing field during the summer holiday.
Rigs have also operated in the Waitekauri Valley, Golden Valley, on Union Hill and on various sites on the edge of the Waihi basin and in the open pit itself. A rig was also placed in the old Mitre 10 yard.
In this latest round of investigations drill rigs will soon be operating on the western side of the open pit adjacent to Moresby Avenue. It is also likely that a rig will operate in the paddock on the western side of Moresby Avenue just north of Central School.
As in the past, we will take this opportunity to offer drill rig tours to the public. When we get a rig operating in an open space with easy access we will arrange weekday and weekend tours. If you haven't yet seen a drill rig in operation, you are invited to take this opportunity to come and see for yourself.
Far left, top: As during previous drilling programmes, members of the public will be given the opportunity to tour a rig and view its operation at first hand.
Far left, bottom: Drilling for core is one of a range of exploration data gathering techniques that provides a wealth of information about rock geochemistry, composition, orientation and occurrence.
Left: Drill rigs operating on the surface are fully enclosed to reduce noise. This rig can also operate underground.
Exploration
Drill rigs produce core samples that are analysed, logged and stored. This is just one of a range of exploration techniques that have been used in the region.
Soil Surveys
Sampling the geochemical composition of soil cover can assist in determining the type of rock below the surface.
CSAMT
Controlled Source Audio-Frequency Magneto Tellurics is a resistivity technique that measures differences in the electrical resistivity within rocks. Clay is a very good conductor of electricity while quartz is very poor. Used in conjunction with other techniques CSAMT can indicate rock types below the surface without the need to drill.
Aeromagnetic Surveys
Towed under a helicopter, a magnetometer measures the earth's magnetic field. Different rocks contain different amounts of the magnetic mineral magnetite. Epithermal gold and silver deposits are lower in magnetite and so show up as subtle variations.
Gravity Surveys
The strength of the earth's gravitational field relates to the density of the material it contains. Very slight variations in the gravitational field are a result of variable rock densities and topography. The mapping of gravity density can assist in the identification of andesites (a good host rock for mineralisation) and rhyolites (poor host rock).