MINING companies can more accurately pinpoint reserves of valuable minerals using a new water-tasting approach developed by CSIRO.
In work supported by the Minerals Research Institute of WA, CSIRO researcher Nathan Reid led a team of scientists analysing samples of groundwater from the Capricorn region in WA, where layers of sediment and weathering are believed to hide potential ore deposits from view.
They discovered broad ‘haloes’ of altered water chemistry around known deposits of gold, uranium, and other minerals where interaction with the ore systems had left distinctive traces in the water.
“Groundwater penetrates through covering sediments and interacts directly with the bedrock, dissolving trace amounts of the minerals present into solution,” Dr Reid said.
“By sampling those waters, our instruments can essentially ‘taste’ the geology they have come into contact with.
“Where the underlying rocks contain a valuable ore deposit, the chemical flavour of that mineralisation extends much further than the concentrated mineralisation itself – just like a teaspoon of salt can make a whole glass of water taste salty.”
These haloes of altered water chemistry could help geologists identify areas where other ore deposits might still lie hidden below the surface, helping to focus mineral exploration in the right areas.
Chemical anomalies identified in groundwater from sediment-covered areas of the study region have already stimulated further exploration investment from companies seeking to identify undiscovered mineral deposits.
MRIWA CEO Nicole Roocke said the work demonstrated the exciting mineral exploration potential remaining in the Capricorn.
“We anticipate this innovative approach to mineral exploration will stimulate renewed interest in many similar areas of WA where we know richly endowed geology lies buried below younger rocks,” she said.
