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 Coal Company-West EIk Mine
Sylvester Gulch Road Geotechnical Investigation
• 25-F50
Slyvester Gulch Seismic Line 25+50
7200
9~za

7780 -.-.._._._._ .... .. .. _. ... _.... .._ _ .._.._ _.__._. ___... _._~0. ._ _.
7770 ....... _.... .__. _. __
9,0
NV
B18
7160 .. y7_ .. - ... .... .. _
. .
- ._ _ .917
~ O? p3
8 n60 _ __. ~ ~ . _ e+ -
~ 98 g7 ps
914
Y
98
99
> 71a0 _ .. _.. _.... . __... _.
.
-
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- t0 ,,
e e d,z o73
m
7730 .. ..... .. - - -- ~---~-- --- __-- ---- --. __ _. .
7,2b . . - - -~ - Vt-=1500 ft/s - .. ..... .._
77,0 _ .. - - _ _ .
---Ground Surface
7,00 -Bounds t - - V2 = 5300 ft/s-
7090
0 7o m 30 ao s0 w 7o e0 7b ,m ,m ,m ,30 Tao ,s0 ,so ,7c ,80 ,90 zro zm zz0 z30 zao zfio z6o z7o z6 o
ns,9~. M
Sersmrc refraction results reveal a second layer of higher velocity material that unduhttes considerably
across the line (Figure 8). The velocity of the first layer is typical of unconsolidated sediments.
Velocities for the second layer indicate a weathered bedrock, possibly shale or claystone. Based on the
strucfirre of the second layer it is possible to interpreR this scenario as an older charnel on the southwest
side that has been subsequerttly 5lled in.

Figure 8. Seismic refraction profile at 25+50.
28+00
Seismic refraction results reveal a second layer of higher velocity material which occurs approximately at
a depth of 40 ft on the smrthwest side and gradually decreases to a depth of 5 ft on the northeast side
(Figure 9). The velocity of the fnst layer is typical of unconsolidated sedimerns. Velocities of the second
layer indicate probably a competed unit of weathereA bedrock, possibly sandstone.
Syylvester Gulch Selsaie Late 26+00
lz+o
lzm - .. - - ... - ... _ ~ ~. _

nm o? ... ~
rmo 9? .-' - .. .__. .. .. ... _~
a ~
~ 1,90 ~ - m 99 ..

1789 m 9a
.. ~ .. - _ .. ... .. . _ -' 09.
Q717a ~... ...-__ ~Op.- - .. ___.-. ... .... ....-_. __. Ob _..

1 92 9K ~
8~
c
9
+
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.._.
- -.
6
a• m w. m m m w rn as 09
n6o

l,ao .....- - --_...... - __ - .. - -- - .... .. _ _
~ Qound Surface Vt =1425 ftla
- -... V2 = 7575 Ws

1738 - Boundary 1

o ,o zo 3o ao w so to m 90 ,oo „o ,zo ,w ,a 750 ,s0 ,ro i80 ,9D ata z,o an z3o za0 zso aso zm zao z9o Sao a,o 3zo 330
ahe.ne. (a)
Seismic Refraction Survey
Summary of Operations
Figure 9. Seismic refraction profile at 28+Op.
UMS, Inc.
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05/17/03