The scientists were able to extract the samples they are working thanks to the help of Canada’s First Quantum Minerals (TSX:FM), the company that owns the open pit mining operation. They describe the samples as pristine, as they had never been in contact with the atmosphere.

Using different microbiological techniques and detailed electron microscope studies, the experts saw that copper sulfides are precipitating in a relationship with colonies of sulfate-reducing microbes.

In a media statement, the researchers explained that they saw nanometer-sized crystals of covellite embedded in the polymeric compounds that encapsulate bacteria.

“These crystals coalesce, later forming the big veins. However, much more work is needed in order to know to which extent these processes are global and if microbes control most of the formation of the secondary copper deposits,” their press release reads.