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During this phase of the research, we propose to drill four
boreholes (hereafter referred to as preliminary boreholes or
wells). The location of each borehole will be determined based on
the predominant contaminants present in the bedrock (1 control (uncontaminated)
area outside the plume, 1 TCE predominant, 1 DCE predominant, 1
VC predominant). The locations will be selected based on the Phase
I evaluations of the USAF's natural attenuation data for Site 32.
There will be 100% recovery of the core material from each of the
preliminary boreholes. All of the cores recovered will be characterized
to determine more about the bedrock geology of the site. Specifically,
the lithology, fracture attitude and spacing, and mineral reactions
on the fracture surfaces (hereafter referred to as secondary mineralization
of the rock) will be assessed along with several other characteristics.
[Note: Secondary mineralization is a geologic process and is not
the same as microbial mineralization.]
In addition, bedrock outcrops at Pease will be studied to provide
local control on lithology and fracture patterns. All of these analyses
will be used to generate a subsurface map of the bedrock at Site
32 and help us begin to understand secondary mineralization of the
rock. Mineral coatings on fracture surfaces will be examined using
standard petrographic techniques. In Year II, XPS and SIMS will
be used to identify mineral types, composition and composition variation.
The petrographic data will help determine the history of mineral
growth relative to the onset of contamination (e.g., the history
(timing) of contamination at a given location).
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