TITLE: Opportunities for Geomicrobiological Characterization and Experimentation During DUSEL Site Selection and Development.

Auth1: Thomas L. Kieft, New Mexico Tech * tkieft@nmt.edu
Auth2: Tommy J. Phelps, Oak Ridge National Laboratory
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In addition to the geomicrobiological experiments that are proposed in the EarthLab document (www.earthlab.org) for implementation in a completed DUSEL facility, there are multiple opportunities for geomicrobiologists to contribute to and to benefit from the site selection and development of DUSEL. Several candidate DUSEL sites have been identified. While clearly not all of these will be fully developed into underground laboratories, each offers unique opportunities for geomicrobiological characterization and experimentation. Each is an invaluable target of opportunity for geomicrobiologists. Deep subsurface science is limited by the paucity of sites; none is current available in the U.S. Interdisciplinary characterization can provide geomicrobiological, geotechnical, geochemical, and geophysical data that will help to inform decision making regarding the siting and development of DUSEL. It will also begin to generate fundamental geomicrobiological knowledge of previously uncharacterized subsurface environments at modest cost and in the near term. Sites with existing mines can serve as deep platforms for sampling groundwater and rock. Deep mine adits can serve as platforms for drilling exploratory boreholes that probe the lower limits of the biosphere. Well developed tunnel systems can be exploited for preliminary reactive transport experiments. Sites without preexisting underground infrastructure offer “green fields” with largely unknown and uncharacterized microbial communities and biogeochemical processes that can be accessed via exploratory boreholes from the surface. Cores from these boreholes will provide detailed geological information, and the boreholes will also be available for geophysical characterization of proposed and developing DUSEL sites. Samples obtained at these sites will enable detailed geochemical, molecular, and physiological studies of indigenous subsurface microbial communities and the geochemical processes that they mediate.