BIOMINERALIZATION OF ZnS (sphalerite) AT THE TENNYSON MINE, WI
While SCUBA diver Tamara Thomsen Ebert was exploring the flooded underground tunnels associated with the abandoned Piquette Mine under Tennyson, Wi, she observed white biofilms among the prominent red-orange biofilms on the tunnel floor.
Image of the white biofilms before (above) and after (below) sampling
The microbiology, mineralogy, and structure of these biofilms has been studied in great detail. Results show that the biofilms consist of a complex community of microoganisms and spherical, micron-scale aggregates of tiny nanoparticles that are only 2-5 nm in diameter. These ZnS crystals are forming due to the activity of sulfate reducing bacteria in the presence of < 1 ppm Zn. The paper describing a subset of our findings is the cover story for the December 1, 2000 issue of Science. This paper is by Matthias Labrenz et al.
Optical microscope image showing a typical cross section of the biofilm. Greenish, high contrast objects are the ZnS aggregates evident in the next SEM image.
Scanning electron microscope image of the biofilms and associated ZnS
To see more data, to read about the results, and a discussion of the work from these biofilms click here
What is the story with the red biofilms?
Scanning electron microscope image of the biofilms and associated ZnS