Simple device helps identify mineral deposits

CO2 and oxygen in soil gases can indicate mineral deposits

Device uses sensors to test soil gases, the levels of which can indicate deeply buried mineral deposits. | Palmer

A simple device that measures CO2 and oxygen in soil could help geologists zero in on valuable but deeply buried mineral deposits, according to new research from Geoscience BC.

Research has shown that soil gases that are high in CO2 and low in oxygen are indicators of oxidizing sulphides in bedrock – an indication of mineralization.

Testing soil gases can be helpful to geologists when a potential mineral deposit is buried beneath sediments and glacial deposits, according to a new report from Geoscience BC, which ran field tests using a simple device developed by a BC Geological Survey scientist.

“Anomalous concentrations in these gases are believed to indicate the presence of mineralized faults concealed beneath glacial sediments,” the report states.

The device uses the same types of sensors that are used in breweries and greenhouses for detecting CO2 and oxygen levels, and has been adapted for testing soil in the field. The device has been tested at the Mount Milligan mine in B.C.

“The results from Mount Milligan Mine are very encouraging,” said Ray Lett, the BC Geological Survey emeritus scientist who developed the device and is lead author on the recent study.

“The correlation of carbon dioxide and oxygen anomalies with observed fractures and potentially mineralized faults, combined with the ability to give reliable, real-time data demonstrates a tangible benefit to the mineral exploration sector.”

“Soil gas testing can help geologists to identify potential mineral deposits when this mineralization is buried beneath sediments such as glacial deposits, and the new device saves the need to send gas samples to laboratories for analysis,” says GeoscienceBC.

"This research demonstrates an innovative and cost-effective technique to support exploration for critical minerals in areas of B.C. and beyond that may host undiscovered mineral deposits,” said Geoscience BC vice president of minerals Christa Pellett