Date of Award
Master of Science (MS)
This study presents a biogeochemical analysis of microbial communities in flooded underground mines in Butte, Montana, USA. Samples were collected from nine mineshafts representing three distinct geochemical zones. These zones consist of the East, West, and Outer Camp mines. The East Camp mines, bordering the Berkeley Pit Superfund site, have the highest concentrations of dissolved metals and the most acidic pH values. Dissolved metal concentrations in the West Camp are one to three orders of magnitude lower than in the East Camp and have nearly neutral pH values. The Outer Camp mines have similar metal concentrations to the West Camp but are neutral to alkaline in pH. Sulfide levels also differ between the zones. In the East Camp, sulfide levels were below detection limits, whereas the West and Outer Camp mines had sulfide concentrations ranging from 10-6 to 10-4 mol/L. δD and δ18O, major cations and anions, dissolved inorganic carbon (DIC) with δ13CDIC, dissolved organic carbon (DOC) with δ13CDOC, and trace elements characterized the microbial habitat in each mine. DNA from planktonic biomass was assessed for phylogenetic diversity using 16S and 18S rRNA gene sequencing. Biological trends were predicted to parallel the geochemical zones; however, the microbial communities showed characteristics unique to each site. The East Camp and Orphan Boy from the Outer Camp had the greatest microbial diversity. The Emma and Travona from the West Camp had similar microbial communities, but the Ophir had the least diversity and bacterial phyla not found in the other sites. Both the geochemical and microbial findings from the Ophir suggest that mine water is mixing with a surficial source or from storm water input. This thesis provides a foundation for future biological work involving metabolic potential (metagenomic) and activity (proteomic) analysis in anoxic mine waters. Additionally, these results have relevance to industrial applications in bioleaching and bioremediation.
Schmidt, Renee, "BIOGEOCHEMICAL INTERACTIONS IN FLOODED UNDERGROUND MINES" (2017). Graduate Theses & Non-Theses. 129.