Has someone lost something?? CSAMT explained ...

Over two to three days during the next few weeks geophysicists working for Newmont Waihi Gold will be carrying out CSAMT-resistivity ground surveys along some Waihi streets.

You may see a group of two or three people wearing high visibility vests peering at the ground as they walk along roadsides - perhaps looking as though they are searching for small lost items.

The CSAMT survey is the same technique that was used to carry out three surveys over various parts of town from 2004 to 2006.

Resistivity (CSAMT) Survey

The survey team places a series of porcelain pots about the size of coffee mugs along the ground. Each pot is connected with a wire to the next one to form a chain about 100 metres in length, before being connected to an instrument box.

There is no electrical current in these wires or pots, the procedure is totally safe around people and pets, there will be no interference with electronic equipment in the home and the procedure will not impede access across driveways or streets.

Several kilometres away two electrodes are placed on the ground about 1500 metres apart and joined by a wire. The electrodes are usually made of a square metre of tinfoil and are placed just under topsoil. A small portable generator is connected to the electrodes and a current introduced to the system.

The connected electrodes set up an electrical field that can be measured for a considerable distance and depth. As the electrical field radiates from the source its intensity can be measured. Different ground types produce different readings. Clay is a very good conductor of electricity while quartz is very poor.

After information has been gathered the survey team moves on, taking with them the hand-held equipment they have used.

CSAMT

Above: The data is converted to an image where varying degrees of conductivity in an electrical field are indicated by colours. This is laid over an aerial photograph to identify areas where quartz is prevalent.

CSAMT

This is an abbreviation for Controlled-Source Audio-frequency Magneto-Tellurics, a type of geophysical resistivity surveying technique. CSAMT measures differences in resistance to electric current within rocks and provides information about the rock types that make up the area in the survey.

 

Site Visitors - TV One

Presenter John Hudson (centre) with his cameraman and producer at the Waihi Gold mill site last week. After completing a safety induction they were escorted underground at Favona to film scenes for the current affairs magazine programme 'Sunday'.

Site Visitors

By the time you read this TV One may have screened the current affairs programme 'Sunday' containing Waihi footage.

Presenter John Hudson visited Waihi on Monday last week, along with his producer Max Adams and cameraman Ken Dorman. They were filming to complete a story based on Energy and Resources Minister Gerry Brownlee's minerals stock take, a matter of national interest.

 

Aussie Dust

Every Friday Newmont Waihi Gold environmental technicians replace the filters in air monitors sited in several locations around town.

The air monitors are in raised positions such as lamp posts and they suck in air using a small motor similar to a vacuum cleaner. As the air passes through the filter it deposits dust particles. Typically the dust is greyish in colour. On Friday 25 September, two days after the Australian dust storm that affected parts of New South Wales and Queensland, our filters had a distinctly orange hue. We have it on good authority this was due to wind drift bringing the dust across the Tasman Sea to New Zealand.

Walkways Weed Spraying

From time to time during September and October Glyphosate and Brushkiller weed spray (with associated penetrants, surfactants and marker dyes) will be used to control weeds on and around the walkways associated with the Martha Mine pit rim and the Black Hill Reserve, Waihi.

For further information please contact:
Mark Samson, Sustainability Manager, 07 863 8192

DJSI (World)

For the third consecutive year, Newmont Mining Corporation is selected to be part of the prestigious Dow Jones Sustainability World Index. In 2007, Newmont became the first gold company to join the DJSI World.

DJSI World tracks the performance of 2,500 leading companies, worldwide. The index independently evaluates companies' long-term economic, environmental, and social performance.

Companies are selected based on a systematic assessment identifying the top sustainability leaders in 58 different industry groups. The methodology evaluates companies based on a variety of criteria, including transparency, corporate governance, risk and crisis management, environmental management and performance, community relations and development, energy consumption and climate change, biodiversity, human resources, stakeholder relations, and safety.