Carmichael is an Assistant Professor in the Department of Geology at Appalachian State University. She studies the mineralogy of manganese ore deposits and the characteristics of manganese biominerals in caves, in addition to her work on Si-deficient volcanic rocks and the geochemistry of mass extinctions. Her research heavily involves scanning and transmission electron microscopy, X-ray diffraction, and spectroscopic techniques.
She is studying the biomineralization process that occurs in caves when microbes utilize reduced metals, such as iron, as a source of energy, much like plants harvest light energy via photosynthesis. “These are minerals that do not have organic carbon as part of their makeup and the microbes are not using traditional pathways to obtain food. They are using metals instead of carbon as an energy source,” Carmichael said.
The iron and manganese oxide mineral deposits the professors collect from caves in eastern Tennessee and southwest Virginia are a result of this unusual process. The research is being conducted to better understand the microbial processes that form minerals in caves in eastern Tennessee in hopes that it may help NASA scientists determine if similar microbial processes are occurring on Mars. The work is supported by N.C. Space Grant, which is funded by NASA.
Carmichael is also comparing the mineral structures found in caves with the structures found in manganese oxide ore deposits in the southern Appalachians. Mars is thought to have hydrothermal fluids circulating in the subsurface, and hydrothermal ore deposits on earth will provide another useful analogue for determining if a mineral’s structure is biological or abiotic. This work will support NASA’s understanding of the diversity of microorganisms that can produce methane and oxidize manganese as well as the manganese oxide mineral structures produced by microorganisms which might exist in different environments on Mars.
SOURCE
http://www.news.appstate.edu/2011/12/12/appalachian-professors-are-part-of-the-search-for-early-life/
http://geomicrobiology.appstate.edu/personnel
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