Vertical Gradients in Biogeochemisty of Flooded Mine Shafts in
the Butte, Montana Flooded Mine Complex
Principal Investigator: Dr. Chris Gammons
cgammons@mtech.edu
This project, which began in March 2006, will investigate mine shaft
waters in Butte, Montana in the context of changes in geochemistry
and stable isotope composition as a function of depth. This latest
work is a continuation/outgrowth of previous projects (MWTP Activity
IV, Project 27 and MWTP Activity IV, Project 32). The previous projects
examined the geochemistry and isotopic composition of the Berkeley
Pit and the East Camp mine waters (Project 27) and those same aspects
of the West Camp mine waters (Project 32). Although data collected
from the previous two projects and monitoring associated with the
site’s Superfund status have amassed a wealth of information,
data from depths greater than 100 feet below the static water level
are nearly absent. In this research, an attempt will be made to
collect field parameters and ground water samples from 100 to 1000
feet below the static water level from several East Camp mine shafts.
The data will be used to assess differences in geochemistry in shallow
versus deep ground water; to compare and contrast the dominant solubility
controls on the concentrations of dissolved metals; to document
vertical and lateral gradients in redox state that reflect regional-scale
transitions in the dominant redox couples (e.g., O2/H2O, Mn3+/Mn2+,
Fe3+/Fe2+, As5+/As3+, SO4/H2S); to determine changes (if any) in
the water source, dissolved sulfate, H2S, or dissolved inorganic
carbon within the flooded mine system by way of stable isotope analysis;
to examine lateral and vertical changes in ground water temperature,
which could be an indication of areas of pyrite oxidation and may
aid in determining ground water flow paths, and to determine if
sulfate reducing bacteria are present at depth in the East Camp
mine workings.
MWTP Activity IV, Project 40
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