Geologists Newmont exploring for gold on the coromandel peninsula and the gold fields look for the tale signs of historic volcanic and geothermal. Activity exploration is conducted for define mineral deposits, although it's one of the first steps towards developing a mine exploration in an area does not necessarily mean that mining will follow for every thousand prospects identified only one has the likelihood of becoming an operating mine.
Exploration mine involve geological mapping rock and soil geochemical surveys and geophysical surveys. These surveys provide information on the characteristics of the rocks their history ,strength, magnetic susceptibility, electrical resistivity and mineral content . These are all parameters which help identify areas of greater prospectivity where more detailed work including exploration drilling may be conducted.
Exploration drilling provides a wide range of information on some surface geology, wine space drilling can often show geologic trends which point to areas of Greater prospectivity. Most of the rigs used in this area a diamond drilling rigs, they use a diamond impregnated drill bits capable of boring through hard rock. The drill bit cuts a circular hole to produce drill core for analysis.
The drill bit has attached to the end of a string of hollow steel rods. The rigs engine spins the drill string as it is pushed into the ground. every three meters a new rod is added, as the drill string is spinning and penetrating the rock the chorus forced into the drill rod, if meet raw so this core is pulled out through the inside of the rods and placed in boxes ready for analysis by geologists.
In this region most holes are drilled to a depth of between 200 and 500 meters and due to the near vertical orientation of the quartz veins the holes must be angled to intersect the veins and maximize the information from the drill core, then taken back to a corset and laid out so geologists can record the rock type from surface to the bottom of the hole.
Drill sites are chosen and controls are in place to ensure that exploration drilling activities minimize the impact to the environment. the consent of landowners and occupies is required for any exploration drilling activities and this is formalized in an access agreement.
Drill rigs come in a wide range of configurations from large truck for track mounted to small skid mounted healthy portable rigs. The type of rig used depends on the location ease of access and depth of hole planned. Water is sourced from local streams or if necessary brought to the site. resource consents from the Regional Council are required to take water from streams.
Drilling fluids are added to the water at the rig, these are used to lubricate the drill bit and flush the rock cuttings out of the hole. The cuttings that come up out of the hole may look muddy and messy but they're captured in sumps at the drill site, where the rock cuttings settle out and the fluids harmlessly break down over time.
There are no discharges off the site . Drilling activities must also comply with all district and regional council regulations covering a range of potential environmental effects.
When the drilling program is completed the drillers cement up the hole before the rig leaves the site. the sumps are filled and all equipment is removed. the site is rehabilitated to the satisfaction of the landowner
Video Gold Exploration Activities In Newmont Waihi
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