2006-08-02_PERMIT FILE - C1980007 ‎(3)‎

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 8/2/2006
• Doc Name: UMS, Inc. - Seismic Refraction Survey
• Section_Exhibit Name: Exhibit 75 SGARE Appendix D
• Media Type: D
• Archive: No

Mountain Coat Company -West EIk Mine
SyMester Gulch Road Geotechnical Irnestigation
Seismic Refraction Survey
Summary of Operations
17+00
Seismic refraction results reveal a second layer of higher velocity material which occurs nearly parallel to
the surface at an average depth of 18 feet (Figure 2). 'ihe velocity of the first layer is typical of
unconsolidated sediments. '111e velocity of the second layer is characteristic of highly weathered bedrock.
S ester Gulch Seismic Line 17+00
7120
7110 ~ --.. ........ _. .. .._.__.. ..____..... ..... .-. _ _. ........ ~~ ..
Gt7
7100 .. ...--- ....... ..... .. ... .---.. _.. _ ___. _.Qa _..__-
27090 ~. ~ ~. a- m ~ .. - --- --_ .... _~... .. .
e
9 7080 m os
..__ . ... ..... .. . ..~.~_ ._ - -- ... ... .. ~ ere. .. __..-.... __._ ..
v 7070
_. p6 .. _.. _'__ -
_ .. _ p0 oa _...
0>2 00 ~ ~
7060 `Ornud Surface .. - ... ... .. _ .....
..
-
W = 112$ R/a
~lioundaryl
7050 _. .... _ - -... _ _-. .._ .- - _. Y2-5&SOttls ..
7040

o +o zo 3o w so so 70 90 90 f00 110 120 +3D t40 150 [phone] Z00 210 220 230 240 250 Z60 270 280 290
oKwK. tn)
Frgure Z. Seismic refraction profile at 17+00.
•
Correlating borehole data to the seismic refraction survey, higher velocities of the second layer can be
imerpreted as probably highly weathered sandstone lransitioning with elevation i~o a shale or claystone
bedrock (Figure 3). T71is is supported by the scatter observed in the emergent seismic rays, which likely
indicates some refracted energy was caused at lateral interfaces between the shaleJclaystoneernd
sandstone bedrock horizons. Simply stated, the combined data indicates the right and left sloping flanks
are probably sandstone bedrock, while the center of the pro51e is probably a claystone or shale bedrock.
Figure 3. Correta6on between seismic refraction profile and borehole logging at Station ]7+00. Green line
indicates surface. Red line indicates the acoustic impedance boundary.
17+00
O
_` ~-
CLAY (CL)
8rown, same sOrttlslone medium sized ara.:el,
plastic. stiff, moist. -
c!'_iY CLAY (CL)
Brown, some sandstone fragments, very stiff, plastic,
refusal of 11 feet due to sanEstone cobbles.
- SANDSTONE COBELES Possibly t~ATHERED SANDSTONE
Light brown, fine grained, weathered, cobble sized.
moist, Hoot. ,
•
grown,
UMS, inc.
_a
iERED CLAYSTONE
re fragments and subanqular
stlc, most.
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