7
of sand, and if necessary, to prepare a new evaluation of the
potential availability of the proppant at the site.
There were two main issues with the existing report:
1) The method to determine the “percent recovery” was
derived from a study of proppant-sand-sized material
underlying only the Montgomery/Lissie Formation portion
of the site, and was then applied to the entire site including
the Deweyville Formation. 2) The method made no dis-
tinction of whether or not the sand was mineable. Much
of the sand was widely disseminated through layers of clay.
A review of MSHA data showed that no sand of any type
was being mined from the Montgomery/Lissie Formation
all the sand being mined in the area was from operations in
the Deweyville Formation.
To better understand the geology at the site, a desktop
study of the regional and local geologic system was devel-
oped based on small scale geologic maps. The desktop study
was followed by a drilling and sampling program, core log-
ging, laboratory analyses, and data evaluation. Based on
the information from the literature, a conceptual geologic
model was created (fig 3b).
The property is underlain with a stack of two major
geologic formations the Williana/Willis and the
Montgomery/Lissie.
The Williana/Willis is buried everywhere on the
property. The upper part of the Williana/Willis is
consistently described in the literature as silty clay,
which has no prospect for use as proppant. Therefore,
for this study, the buried contact of the Williana/
Willis with the Montgomery/Lissie Formation is
considered to be the level below which no mining of
sand would take place.
The Montgomery/Lissie consists of a fining upward
sequence of sediments granular, fine to coarse sand
with few pebbles in the lower portion and very fine
sand, silt, and clay in the upper portion.
In the lowland valley traversing the property,
the Deweyville Formation lies on top of the
Montgomery/Lissie and Williana/Willis Formations.
The Deweyville Formation is primarily sand and was
identified as a likely source of proppant.
Thirty sonic drill holes were used to collect continu-
ous samples on the property 8 in the Montgomery/
Lissie Formation and 12 in the Deweyville Formation.
Drill holes commonly penetrated completely through the
Montgomery/Lissie Formation and (or) the Deweyville
Formation and extended at least ten feet into the Williana/
Willis Formation. The samples supported all the assump-
tions in the conceptual geologic model.
Figure 3b. Generalized cross section showing potential proppant at site in 10-foot intervals relative to elevation when
considering geology
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