2008-04-30_REPORT - M1973021 ‎(3)‎

• Permit No: M1973021
• IBM Index Class Name: REPORT
• Doc Date: 4/30/2008
• Doc Name: Geotechnical Addendum/ 2007 Annual Report
• From: Tetra Tech
• To: DRMS
• Permit Index Doc Type: Annual Reclamation Report
• Media Type: D
• Archive: No

Stations 0+75 through 1+40 consisted of massive biotite gneiss. The foliation strike in
this area varies due to the anticlinal/synclinal nature of the gneiss and ranges from 190
to 210 degrees with dips of 25 to 35 degrees, parallel or slightly out of the face.
Foliation spacing averages approximately 12 inches and foliation apertures were
closed and rough. The primary joint set strike ranges from 225 to 245 degrees and
generally dips from 78 to 87 degrees. The secondary joint set strike ranges from 134 to
143 degrees and generally dips 74 to 81 degrees. Joint set spacing averages
approximately 15 to 21 inches and joint apertures were generally closed and slightly
rough to rough.
~ Stations 1+40 through 1+90 consisted of mixed granitic and biotite gneiss. Foliation
strike in this area ranges 188 to 197 degrees and dip values range from 40 to 50
degrees parallel or slightly out of the face. Foliation averages 12 inch spacing with
• moderately open, slightly rough faces. The primary joint set strike ranges from 43 to
52 and generally dips from 85 degrees to near vertical. The secondary joint set
• exhibits a strike of 310 to 320 degrees with dips of 75 to 85 degrees. The spacing of
both the joint sets averaged approximately 9 to 12 inches and joint apertures were
moderately open with slightly rough faces.
Stations 1+90 through 2+OS consisted of a shear zone containing highly weathered
biotite gneiss and biotite schist. Foliation and joint orientations were indistinct due to
the very close spacing of joints combined with the disintegrated nature of the zone.
The rock displays moderate iron staining and the area is inferred to be disintegrated
due to a combination of weathering and local shear. Blocks observed in this area were
generally less than 6 inches diameter due to the disintegrated nature of the rock and
the tight joint spacing. Raveling from this zone is anticipated to cause only minor
safety hazards or local. operational delays.
Stations 2+OS through 4+10 consisted of massive biotite gneiss with
anticlinaUsynclinal features with an average approximate wavelength of 25 to 40 feet.
The foliation strike ranges from 185 to 195 degrees and dips range from 12 to 22
degrees generally exiting the highwall, with average spacing of 24 inches and smooth,
wavy apertures that are generally closed. The primary joint set strike ranges from 230
to 240 degrees and generally dips from 75 to 85 degrees. The secondary joint set
exhibits a strike of 92 to 113 degrees with dips of 65 to 72 degrees. The spacing of
joint set 1 averaged 9 inches and the spacing of joint set 2 averaged 100 inches. Both
joint sets exhibited moderately open to closed, slightly rough faces.
Stations 4+10 to 5+60 consisted of a shear zone consisting of biotite gneiss and biotite
schist. Foliation and joint orientations were indistinct due to the very close spacing of
joints combined with the disintegrated nature of the zone. The rock displays very little
iron staining and the area is inferred to be disintegrated due to local shear. This shear
feature is observed to be persistent as a near vertical zone of grey rock present on the
northeast wall of the quarry for approximately 160 feet. Blocks observed in this area
were generally less than 6 inches diameter due to the disintegrated nature of the rock
and the tight joint spacing. Raveling from this zone is anticipated to cause only minor
safety hazards or local operational delays.
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