HYDRO31382

• Permit No: C1981022
• IBM Index Class Name: Hydrology
• Doc Name: SOMERSET MINING CO COAL LEASE APPLICATION C-53510 ENVIRONMENTAL ANAYSIS U-92-13
• Permit Index Doc Type: OTHER GROUND WATER
• Media Type: D
• Archive: No

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(1) The Rollins Sandstone Member
(2) The Lower Coal Member (Bowie Member)
• (3) The Upper Coal Member (Paonia Member)
(4) The Barren Hember
The Rollins Sandstone Member is a conspicuous cliff-forming white to
buff sandstone, 150 to 200 feet thick. It ie the moat persistent marker
horizon in the area and is overlain by the Bowie Member.
The Bowie or Lower Coal Member is about 270 feet thick and consists of
four correlated coals in the bottom 100 feet of this member, two of
which are minable. The A seam ie a thin coal ranging in thickness from
several inches to several feet. It generally marks the top of the
Rollins Sandstone Member. The Lower H seam has a characteristic
thickness of six to seven feet. The Upper B seam le generally separated
from the Lower B seam by six to ten feet of shale. The upper B seam ie
consistently the thickest coal of the Meeaverde sequence in this area.
In the vicinity of the proposed lease tract, it ranges in thickness from
13 to 22 feet. The C seam ie the uppermost coal of the Bowie Member
with a thickness of six to seven feet.
The clastic sediments associated with these coals are generally fine
grained and carbonaceous. They range from shales and siltetones to fine
grained eandetonee. The top part of the Bowie Member is a barren
clastic sequence of shale, eiltetone, and sand of approximately 175 feet
in thickness.
The Paonia, or upper Coal Member of the Meeaverde contains three and
occasionally four minable coals in a total sedimentary thickness of 400
to 600 feet. These coals are more variable in thickness and lateral
extent than the coals of the Bowie Member. The D seam thickens
southward with a range of about 6 feet to over 14 feet. This coal
directly overlies the Howie Member and was mined by the Oliver Mine.
• The lower E seam is highly erratic with generally discontinuous thin
coals and exhibits numerous splits and generally has poor roof and floor
sediments. The E seam was mined at the Hawk's Nest Mine and ranges in
thickneee from 5 feet to over 12 feet. The F seam ie generally erratic
and ranges in thickneee from several feet to eight feet. It ie split by
shales and has not been mined in the Somerset coal district.
The clastic sediments associated with the coals of the Paonia Member are
more continental than those of the underlying Bowie Hember. The top of
the Paonia Member was marked by Johnson as a thick continuous sandstone.
The Barren Member represents all of the upper portion of the Meeaverde
Formation above the Paonia Hember. It ie composed predominately of buff
lenticular eandetonee with subordinate interbedded grey shales.
The Tertiary Wasatch Formation overlies the Meeaverde Formation with a
regional low angle unconformity. It consists of red and buff shales,
red eandetonee, and red to grey conglomerates.
The Quaternary colluvial deposits are an unsorted mixture of soil and
rock formed by various mass-wasting processes ae landslides, earth
flows, soil creep and debris avalanches.
The structural geology appears to be simple. The coal bearing
sedimentary strata of the Hesaverde Formation ie relatively flat lying
with a regional dip of 3.5 degrees to the north-northeast. Local dips
of up to 6.0 degrees are also found.
Geologic hazards such ae faults, wants or slips only exist to the extent
of large cracks with no displacement found in the 2ERT working section
• of the E seam in the Hawke Neet Mine. There is little evidence of any
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