UBC researchers analyze microbes in soil to locate diamond deposits deep below

An analysis of microscopic life in the soil above mineral deposits can provide an accurate indication of what lies below, researchers at the University of British Columbia have found.

Published this week in the journal Nature Communications Earth and Environment, the research details efforts to locate kimberlite – the type of rock that contains diamonds – at two sites in the Northwest Territories.

Bianca Iulianella Phillips, a doctoral student in UBC's department of earth, ocean and atmospheric sciences, co-authored the paper. She told CTV News the purpose of the research is to make it easier to identify mineral deposits concealed under large amounts of soil.

"We can't see the rocks themselves," she said. “They're covered by soil. So we need sensing techniques to be able to see through that material."

According to UBC, researchers tested soil samples from above a kimberlite deposit that had already been confirmed through drilling, and found that 59 of the 65 microbial indicators of kimberlite that they had identified in the lab were present.

"There are tonnes of microbes in soil, and we've actually found that there are different types of microbes – and different amounts of them – in soils above mineral deposits," Iulianella Phillips said.

The team also identified indicators at the first site to add to their dataset. Then, they tested a site where drilling had not yet been done and were able to confirm the location and topological outline of the kimberlite deposit tens of metres below the surface.

Iulianella Phillips said as undiscovered mineral deposits become rarer and more remote or well-hidden, more precise methods for detecting them will be necessary.

She said she's hopeful that microbiological analysis could become part of the standard toolkit for mineral exploration.

Right now, the technique has only been demonstrated in searches for kimberlite and porphyry copper deposits, but Iulianella Phillips believes it could be used to detect other types of minerals, as well.

"We've looked at, specifically, two different types of deposits," she said. "But theoretically, you should be able to, you know, go out and try this – we'd love to try this – with other mineral deposits."

With demand for renewable energy and batteries growing as society works to address and lessen the impacts of climate change, Iulianella Phillips said developing databases of the microbial signatures of more "climate-relevant" minerals is a key step for future research.

She said there are several potential benefits for mining companies that add microbiological analysis to their mineral exploration process. Such analysis could save companies time and money, and help them generate more precise results.

"Drilling is costly, it's time-consuming, and so you want to really know (what's there) before you start poking holes in the ground," Iulianella Phillips said.