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

Moulttain Coal Company -West Elk Mine
Sylvester Gulch Road Geotechnical Investigation
Seismic Refraction Survey
Summary of Operations
• 46+50
Seismic refraction results reveal a second layer of higher velocity material which varies considerably is
depth across the line (Figure 27). The velocity of the first layer is typical of unconsolidated sediments.
Velocities for the second layer indicate highly consolidated sediments or weathered bedrock. Based on
the structure of the second layer it is possible to interpret an older channel on the northeast side that has
been cut and subsequently 5lled-in.
•
Syylvester Guladl Seismic Line 48+50
739D
NE
1380 .. __._. .. _.. _._ ..._ .... _ _ ....._ .. _.. ._..... _.. _. _. ... _....._ . .__ @! ....... .._

7370 _ _ •.. _. _ _ _... _____ ____ ___ ____ __ _

7380 ... ..... .... . _ ~ ... .. . .
b1N
~
~
~ ~ O>S
_ ... ...._. _.. _ __.. ...
.. __ _ _ . ...
_.
e ~
~ ~
734D - Sp ... .. ... .. ... _ .. ..~. ey ... _
~ ~ NE2e4
N
733D ... __.. _..~ _. ~.. S
_. _ _ ..__ ._ .. .. _
~ /iAC! ~
73Zt a7 -
. .
V7 = 1400 ft/s
V2 =6650 tt/s
7310 _ . _._ _
-~Glolad SUAaee ... _ _.. _.- _ _ __ _ .. ... ..
73m ~

o to zo ~ 40 5o m 7o eo m too tto tm 13o too 15o tso t7o 1so tw zm zto zzo z3o zoo aso
Ofst~ce (Iq
Figure 27. Seismic refraction profile at 46+50.
48+00
Seismic refiaction results reveal a second layer of higher velocity material which occurs nearly parallel to
the surface at as average depth of 18 feet (Figure 28). The velocity of the first layer is typical of
unconsolidated sediments. Velocities for the second layer indicate consolidated sediments or highly
weathered bedrock.
Slyve~er Qdch Belsmle Line 4HtOD
rasp
ar
~ °'
ram _..
a
~ ~{ NE
~
1310 ._.. _ .. ... _. __ .. ~

~]38f1

c
... ..
- - - - _ --Y41 ._
sF ~
°
°
L~ _
.. oa_ _... . . ..
_. p. ._ ... _ ~ ~ ae .
v W Sp ~ ~ N
7310 ... ....... .... .. _.. _ ......_.... .. .. _.._ ..
V1 = 1450 11/5
7~D ~-Civn0 9lfse ... ....... ... _ _ _ V2 °5500 p/8 ...
Sm5En7t
7320
-so -m a5 -zp -t5 o t5 m pp m w so m m m lap tto tm ,3o tm uo tw rro tm tw mo
1161mp tftt
Figure 28. Seismic refraction profile at 48+00.
•
By correlating borehole dab to the results of the seismic refraction survey, higher velocities of the second
layer can be attnbuted to a weathered claystone bedrock (Figure 29).
UMS, Inc. Page 18 05/17/03