The researchers will spend almost two years in the laboratory before trying small-scale experiments in the field. Their first field experiments will focus on how well the calcite forms beneath the Idaho desert and in characterizing the mineral.

Laboratory experiments will focus on the chemistry of calcite formation in simulated subsurface conditions, looking for ways to increase the rate of that formation. While Smith will examine the geochemistry of the reaction, Colwell, Ferris, and Reysenbach will determine ways to characterize and stimulate the naturally occurring bacteria to help the precipitation along. Ingram will examine the resulting mineral composition using analytical chemistry techniques in the laboratory.

The laboratory research will use artificial surfaces called coupons, upon which bacteria and calcite will be deposited. Ultimately, coupons will be placed in deep holes, such as INEEL wells, for a period of time and then removed and analyzed for mineral deposition. The researchers may use a slab of basalt rock or other material as their coupon to transport their experiments to the subsurface.

Analyzing the potentially complicated mineral and coupon surfaces will be Ingram's responsibility. At the INEEL, she currently studies ways to examine surfaces whose heterogeneity makes their study difficult, such as the surfaces of basalt, a rock common to several DOE sites.

Smith brought together a large and diverse group of researchers because the natural world doesn't usually behave like isolated experiments in the lab. He said, "It is nontrivial to reproduce a 20-year process in a 6-month experiment. And that's why collaboration is so important to the success of this project."

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Contact: Mary Beckman
beckmt@inel.gov
208-526-0061
DOE/Idaho National Laboratory
20-Sep-1999