Helicopter equipped with magnetometer maps underground regions of magnetic minerals

Geological survey expands in western B.C.

Helicopter magnetic survey locates minerals, natural gas and water at different depths in the Earth crust

The latest geophysical survey of B.C. will map the largest area so far, creating a three-dimensional image indicating mineral and water resources far underground.

Geoscience BC has received $5 million from the provincial government for the Search II project, to complete an aerial magnetic survey of a 24,000 hectares between Fort Fraser and Smithers, north of Tweedsmuir Provincial Park.

After 10 years and 135 projects, the non-profit Geoscience BC has produced new earth science data for about half of the province’s area. The aerial surveys use a magnetometer to record local disturbances in the Earth’s magnetic field caused by magnetic minerals in the upper regions of the crust.

Last year’s helicopter survey of the Chilcotin Plateau included collecting samples from the tops of spruce trees. The cuttings are analyzed for mineral content, providing information in areas with no roads and few lakes for float plane access by prospectors.

[Video of tree sampling below]

Magnetic surveys of northeast B.C. have located saline aquifers as well as gas pools in deep shale formations. They also detect shallower fresh-water aquifers.

Carlos Salas, Geoscience BC vice-president for energy, said the northeast survey covered Treaty 8 First Nations territories at their request, mapping water and mineral zones.

“Over the Doig River First Nation community we found what looks like a really good aquifer they will be able to use as a source for their community,” Salas said.

Dallas Smith, president of the Nanwakolas Council representing Central Coast First Nations, is a director of Geoscience BC. He said understanding the locations of groundwater and mineral deposits helps in making development decisions.

“We understand the depths of some of these things,” Smith said. “It makes it a lot easier to keep that in reality and not start doing what seems to happen in First Nations territories, when we kind of romanticize these issues a little bit.”

The latest aerial survey area contains the former Bell-Granisle copper-gold mines and the idled Endako molybdenum mine. It will map the area north of the Huckleberry copper mine and the proposed Blackwater gold mine southwest of Prince George.