Bruce Fouke Laboratory
Funded by NASA
The lacy patterns in this image are part of a paper-thin section of travertine limestone collected from Mammoth Hot Springs in Yellowstone National Park. The travertine is composed of filaments of bacteria around which tiny crystals of the mineral aragonite have formed. In order to examine these delicate samples, the minerals are embedded in epoxy and polished down to a thin section. The research that produced this image examines the ways in which water, minerals, and microbes interact with one another in a hot spring environment.