Pick axes and a diamondDiamond Geology and Exploration

Microbial community fingerprinting as a tool for direct detection of buried kimberlites

Wednesday, November 20, 2019 - 9:40am to 10:00am Theatre One
(Student abstract)


B. Iulianella Phillips (Presenting)
University of British Columbia
R.L. Simister
University of British Columbia
P.A. Winterburn
University of British Columbia
S.A. Crowe
University of British Columbia

Mineral exploration in northern latitudes is challenging in that undiscovered deposits are likely buried beneath significant glacial overburden. The development of innovative exploration strategies and robust techniques to see through cover is imperative to future discovery success.

Microbial communities are sensitive to subtle environmental fluctuations, reflecting these changes on very short timescales. Shifts in microbial community profiles, induced by chemical differences related to geology, are detectable in the surficial environment, and can be used to vector toward discrete geological features. The modernization of genetic sequencing and big-data evaluation allows for efficient and cost-effective microbial characterization of soil profiles, with the potential to see through glacial cover.

Results to date have demonstrated the viability of microbial fingerprinting to directly identify the surface projection of kimberlites in addition to entrained geochemical signatures in till. Soils above two kimberlites in the Northwest Territories, have undergone microbial community profiling. These community-genome derived datasets have been integrated with chemistry, mineralogy, surface geology, vegetation type and other environmental variables including Eh and pH. Analyses show significant microbial community shifts, correlated with the presence of kimberlites, with a distinct community response at the species level directly over known deposits. Diversity of soil bacteria is also depressed in the same regions of the microbial community response. The relationship between microbial profiles and buried kimberlites has led to the application of microbial fingerprinting as a method to accurately delineate potential ore deposits in covered terrain.

The integration of microbial community information with soil chemistry and landscape development coupled with geology and geophysics significantly improves the drill / no-drill decision process and has proven to be far more accurate than traditional surficial exploration methods. There is high potential for application as a field-based technique as microbial databases for kimberlites in northern regions are refined, and as sequencing technology is progressively developed into portable platforms.