Abstract Hard rocks or crystalline (i.e., plutonic and metamorphic rocks) constitute the basement of all continents, are particularly exposed at surface in large shields Africa, India, North South America, Australia Europe. They were, still some cases, to deep weathering processes. The storativity hydraulic conductivity hard rocks, thus their groundwater resources, controlled by these processes...

The bioreduction of soluble uranium [U(VI)] to sparingly soluble U(IV) species is an attractive remedial technology for contaminated soil and groundwater due to the potential for immobilizing uranium and impeding its migration in subsurface environments. This manuscript describes a column study designed to simulate a three-step strategy proposed for the remediation of a heavily contaminated sit...

Brazil plays an important role in global food production, but faces challenges due to its dependence on imported fertilizers. To reduce this vulnerability of the agricultural sector, use natural sources such as agrominerals, also known rock dust, is gaining ground. The objective study was characterize and evaluate a new source potassium, extracted from deposit located Brazilian Midwest, through...

Exometabolomics enables analysis of metabolite utilization of low molecular weight organic substances by soil bacteria. Environmentally-based defined media are needed to examine ecologically relevant patterns of substrate utilization. Here, we describe an approach for the construction of defined media using untargeted characterization of water soluble soil microbial metabolites from a saprolite...

The influence of sediment bioreduction and reoxidation on U(VI) sorption was studied using Fe(II) oxide-containing saprolite from the U.S. Department of Energy (DOE) Oak Ridge site. Bioreduced sediments were generated by anoxic incubation with a metal-reducing bacterium, Shewanella putrefaciens strain CN32, supplied with lactate as an electron donor. The reduced sediments were subsequently reox...

s and presentations Jardine, P.M., T.L. Mehlhorn, I.L. Larsen. 2001. Quantifying time-dependent physical and chemical processes that influence the migration of chelated radionuclides in fractured shale. Fractured Rock 2001. March 26-28, 2001, Toronto, Ontario, Canada. Jardine, P.M., M.A. Mayes, T.L. Mehlhorn, and S.C. Brooks. 2001. Reactive transport of chelated radionuclides through weathered ...

Chemical weathering indices are commonly used for characterizing weathering profiles by incorporating bulk major element oxide chemishy inlo a single metric for each sample. Generally, on homogeneous parent rocks, weathering indices change systematically with depth. However, the weathering of heterogeneous metamorphic rocks confounds the relationship between weathering index and depth. In this ...

Aeolian dust deposition is an important phosphorus (P) input to terrestrial ecosystems, but it lacks evidence of how inputs supply available P and affect geochemistry dynamics in soils sub-humid ecosystems. We determined soil speciation using K-edge X-ray absorption near edge spectroscopy availability modified Hedley sequential chemical extractions a weakly acidic profile (2.5 m thick) temperat...