PRELIMINARY MINERALOGY AND GEOMICROBIOLOGY OF CHEROKEE CAVERNS, A UNIQUE DOLOMITE CAVE IN EAST TENNESSEE

Cherokee Caverns is decorated with a wide variety of speleothems, including rare anthodites and bulbous soda straws, placing it among the small number of caves in the world with these formations. The minerals and geomicrobiology of the cave system have not been investigated except on a macroscopic scale to identify Cherokee Caverns as forming in Copper Ridge Dolomite in the Knox Formation. Using x-ray diffraction and scanning electron microscopy/energy dispersive spectrometry (SEM/EDS), the minerals, huntite, hydromagnesite, kaolinite-group minerals, gypsum and quartz have been identified. Staining of bacteria incubated in the cave on TSA plates, indicate the presence of the biotas, bacillus, coccus and staphylococcus.

In some places in the cave, anthodites extend from crusty orange bacteria-rich clay attached to grey dolomite bedrock. SEM/EDS images and spectral analyses indicate the side of the crusty orange clay adjacent to the dolomite bedrock is populated with numerous ten-micron spheres of unknown origin, and with crystals that look degraded. Holes in one crystal are one micron in diameter, the size of some bacteria. The crusty clay side away from the dolomite bedrock, from which anthodites protrude, lacks these features.

Elsewhere, ephemeral ceiling fibers similar to snottites have gypsum attached to carbon-rich fibers while sprays of carbonates are attached to fibers associated with stalagmites. One remarkable SEM/EDS image shows microbes attached to a 15-micron iron-rich sphere, possibly oxidizing the iron to gain energy in the dark confines of the cave. In Cherokee Caverns, minerals and bacteria are intimately related.