Borehole Log February 27, 1996 •
BOREHOLE LOG
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Project: 1996 PORTUGUESE BEND LANDSLIDE STUDY Boring No.: P85-9 Sheet 1 of 2
GPS boringTocation: N4,018,534 E4,179,000 GPS boring el-F.51ion: 185.1'
Grillers: A. Parra with AP 1000 air rig Drilling company: Layne EnvironmentaT Services
Drilled on: 2/27/96 Geology logged by: R. Crook
Depth Lithic Description
(feet) log
0- Landslide affected material (0 to 87 feet)
¢:' 17—fi21 Silty sandy clay and gravelly sandy clayey silt; yellowish brown.
_.e
10- ':o
20- o
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21 to 51' Fine to very fine-grained sand; gravelly and slightly clayey.
-p
Some rounded pebbles.
30- o_
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40- 1 .
D.:.o
50- to.—
'= 51 to 55' Paleosol; silty, slightly sandy clay; very dark gray brown.
55 to 58' Sand; coarse to fine; slightly silty; dark yellowish brown.
58 to 68.5' Silty clay; slightly sandy and gravelly; brown.
60-
Carbonized wood fragments.
L.
68.5' Slide plane; some sheared bentonite fragments
70- _ 69-to 87' Siltstone; thinly laminated; minor fine-grained sandstone; few fish
scales; very dark gray to dark brown.
80-
Fine to coarse lithic fragments in siltstone.
F. 86 to 88' Mater.
87.7' Slide base (not recognized during drilling but casing sheared off at this
90- = depth.
91 to 91.5' Claystone with thin laminations of sheared bentonite.
91.5 to 104' Siltstone; thin bedded to thinly laminated; black.
100-
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104 to 106' Bentonite; massive; waxy; gray.
1—. 106 to 107' Siltstone thinly laminated; black.
=r -� 107 to 173' Portuguese Tuff (bentonite)
110- ( ' 107 to 108' 8entonitic tuttaceous sandstone; light gray.
108 to 160' Soft waxy bentonite; light gray.
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120- `�� `
BOREHOLE LOG P85-9. Sheet 2
4111 depth lithic Description
(feet) log
120- VN
J
-�� 127' Six inch layer or rip-up Y clast of siltstone
130- �^`„
140- r,�
150- e-
17.
72-1
160- 160 to 173' Bentonitic, tuffaceous fine-grained sandstone.
170-
173
JG to 175' Tuffaceous sandstone with lithic fragments.
175 to 176' Siltstone; dark gray-brown; hard.
Total depth 176 feet. Two-inch PVC installed to 90 feet.
PVC perforated 50 to 70 feet.
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