Unearthing Hidden Diamonds: Subterranean Detection via Microbial DNA in Soil

Scientists have developed an innovative approach for locating underground kimberlite, a type of rock closely linked to diamond deposits, by examining the microbial DNA present in topsoil. This method serves as a non-intrusive means of detecting minerals situated deep beneath the earth’s crust, and is more accurate than established geochemical testing. With wider implications for mineral discovery, this method has the potential to transform the future landscape of the mining industry.

Additionally, DNA sequencing techniques can contribute to the identification of minerals vital for transitioning to sustainable energy sources.

Through the analysis of microbial DNA in surface soil, researchers have pinpointed the location of underground kimberlite, the geological formation that houses diamonds.

These so-called ‘biological markers’ allow for the identification of subterranean minerals located several tens of meters beneath the surface without necessitating drilling operations. The scientific team posits that this is the inaugural application of contemporary DNA sequencing of microbial ecosystems in mineral prospecting.

Pioneering Methodologies with Substantial Prospects

The study, released recently in the journal Nature Communications Earth and Environment, introduces an innovative instrument in the realm of mineral discovery. According to co-author Bianca Iulianella Phillips, a doctoral student at the University of British Columbia’s Department of Earth, Ocean and Atmospheric Sciences (EOAS), a comprehensive set of such tools could offer substantial cost and time savings for mineral prospectors.

This methodology augments a somewhat restricted arsenal of available techniques for locating subterranean ores, which currently includes preliminary ground scans and elemental analyses of overlying geological layers.

Phillips remarked that this method emerged out of the need for enhanced subterranean imaging with superior sensitivity and resolution, and it holds promise for application in scenarios where existing methods prove ineffective.

During laboratory experimentation, researchers observed that the introduction of kimberlite into soil led to shifts in the microbial communities present. This change in the microbial makeup served as an indicator for the existence of subterranean mineral deposits, referred to as ‘biological markers’ in soil.

Practical Applications and Encouraging Results

By utilizing these ‘indicator’ microbes and their DNA patterns, the researchers examined surface soil at a North-western Territories exploration site where the presence of kimberlite had previously been verified through drilling. Out of 65 potential indicators, 59 were found in the soil, with 19 appearing in high concentrations directly above the subterranean ore. Additional indicator microbes were also identified.

Subsequently, they employed this suite of indicators to assess surface soil at another North-western Territories site, successfully delineating the spatial dimensions and precise location of kimberlite deposits located deep underground. The findings demonstrated that indicators from one site could be used to predict kimberlite locations at other sites. Future expeditions could amass a database of such indicator species to evaluate unknown locations for potential kimberlite deposits.

Microbial Exactitude Versus Geochemical Testing

In a comparative evaluation against geochemical analysis—a method involving soil elemental tests for subterranean mineral identification—the microbial approach demonstrated higher precision in locating underground ores.

Dr. Rachel Simister, the lead author and a postdoctoral researcher at the University of British Columbia’s Department of Microbiology and Immunology (M&I), noted, “Microbes are superior geochemists in comparison to humans, and their population is vast. While elemental options may be exhausted, microbial options are essentially limitless.”

Expanding Scope and Commercial Viability

Emerging from collaborative efforts involving Phillips, Dr. Simister, Dr. Sean Crowe, and the late Professor Peter Winterburn, this technique could expedite the identification of new kimberlite formations. Kimberlite rocks are not only potential reservoirs of diamonds but also possess the capability to absorb and store atmospheric carbon.

Furthermore, ongoing studies suggest the method could be applicable for locating other types of metallic deposits, such as porphyry copper reserves.

Dr. Sean Crowe, a senior author, EOAS and M&I professor, and Canada Research Chair in Geomicrobiology, stated, “This technology could be crucial for sourcing minerals essential for the advancement of green economies.”

Dr. Crowe, Dr. Simister, and co-author Dr. Craig Hart are co-owners of a spin-off enterprise, Discovery Genomics, which offers these sequencing services to the mineral resource sector.

Dr. Crowe observed, “This is a noteworthy development because it signals an increasing awareness of the role microbes can play throughout the mining process, from discovery to processing and ultimately to site restoration. At present, the cost of microbial DNA sequencing is comparable to other mineral exploration methods, but that could change with broader industrial adoption.”

Reference: The research, titled “DNA sequencing, microbial indicators, and the discovery of buried kimberlites,” was authored by Rachel L. Simister, Bianca P. Iulianella Phillips, Andrew P. Wickham, Erika M. Cayer, Craig J. R. Hart, Peter A. Winterburn, and Sean A. Crowe, and was published on October 21, 2023, in Communications Earth & Environment. DOI: 10.1038/s43247-023-01020-z.

Frequently Asked Questions (FAQs) about microbial DNA in mineral discovery

More about microbial DNA in mineral discovery

• Nature Communications Earth and Environment Journal
• Overview of DNA Sequencing Technologies
• Mineral Exploration Techniques
• UBC’s Department of Earth, Ocean and Atmospheric Sciences
• Canada Research Chair in Geomicrobiology
• Introduction to Kimberlite Deposits
• Discovery Genomics Company Profile