WSP12169

• File Number: 8146.100
• Description: Pueblo Dam - Project Description
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 1/20/1970
• Title: Drawings - Pueblo Dam - Logs of Exploration Section A - A, Sheet 4 of 6
• Water Supply Pro - Doc Type: Report/Study

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4550.

0-2.2' SILT: 907. no to low plasticity fines, 107. fine
sand' max size meditun sand, high reaction to HCl,
low dry strength, dry, hardness 3, tan, numerous small
toots. (ML)
2.2'-31.0' SANDSTONE: With shale 27.7'-28.4' (sent to
Chief Engineer's Lab prior to Logging), and 0.01 at
30.81; sandstone is predominantly fine to medium quartz
grains, sugary appearance, porous-water ~rop~ placed. on
core are quickly absorbed, crossbedded 5 -30 from l~ne
normalm core axis, a few paper thin carbonaceous strea~s
28.4'-31.1', noncalcareous, however the core has a partlal
coating left by drill water that has a high reaction to
HCl; numerous small vugs (pinhead) to 25', hardness ~-7,
fresh broken surface is slightly friable, grayish wh~te.
31.0'-38.1' SHALE. Waxed and sent to Chief Engineer's Lab
prior to logging. Adjacent holes indicate it to be a
clayey, fissile, dark gray shale which air-water-'slakes
38 I~~~g~l; SANDSTONE: With occasional shale seans and
.carbonaceous streaking and bedding; sandstone is composed
of fine-medium quartz grains, sugary texture, porous-
water placed on core is readily absorbed, noncalcareous.
Core is partially coated with drill water residue that
has high reaction to HCl, crossbe~de~ ?_250 measured,
from a line normal to core axis, ~nd1v~dual beds 0.2 -
2.0' thick, hardness 7, slightly friable on broken
surface, core breaks readily along bedding, sandstone
below 80.0' becomes finer, siltier, and harder (7-8);
thin carbonaceous streaks 73.5'-77.0', 3/4" carbonaceous
chunk at 43.7 I; shale occurs; paper thin at 38.21,
C ~4' at 38 2' 0.15' at 38.6', 65.5'-66.9' 0.08' at
67'8' 0 08i at 72.6',0.01' at 77.1',77.9' 78.71, and
78:85', ~everal 0.011 at 81.5'-83.2', shale 83.2'-83.91,
006' at 84 5' 86.2'-86.9' (to Chief En~ineer's Lab
p;ior to loggi~g), 0.02' at 87.5',89.5'-89.6'.
0.01' at 89.8', shale to 67.8' is dark gray, silty, brittle,
noncalcareous hardness 6-7, and does not air-. or water-
slake; shale below 67.8' is clayey - waxey luster when
po 1 ished, noncalcareous, air- and water- slakes, some cor7
damage during drilling, dark gray, Max. core length 7.0
aver age 1.5 I .
90.11-98.5' SHALE fissile, clayey, waxy luster when.
polished noncaicareous hardness 5-6, can be cut wlth
knife air-and water-sl~kes in 5-10 minutes, considerable
core damage from drilling, dark gral'; occasional 0.05'
thick brittle, sandy siltstones; 70 open joint at 91.2'.
98.5'-168.2' SIIALE: Hardness 5-6, scratches with knife,
gray to black, fissile (varies to nonfissile), air-slakes
in !40 milutes after exposure, noncalcareous. Occasional
scattered zones do not air-slake. Occasional laminae of
calcareous, sandy silt to 1/4". Core damaged by drilling
the softer shales.
125.4' - Thin coal seam 1/16" thick along joint plane.
135 _ 2 '-135.7 '- Light gray bentonite zone. Destroyed when
removed from core barrel.
135.7' -136.2', 138.6' -139'. 9', and 162.2' -164.3' - Sandy
siltstone, noncalcareous, hardness 7, calcite healing
on_breaks.
168.2'-177.7' SANDSTONE: Hardness 6, light gray, medium to
fine' grained, fairly well cemented, slightly friable,
scratches with a knife. Rounded to subrounded gravels to
1/2" imbedded in matrix.
NOTE Artesian seep -Water level above ground surface 4761,2+
Jar,uary, 1970

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9-25-6810_11_68

PART 2C OF SECTION A-A

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0-1.6' SILTY SAND: About 80'7. hard sand, predOOlinately
fine, about 20% nonplastic fines. Moderate reaction to
HC1. Maximum size: fine sand. Color: brown.
Moisture: dry. (SM)
1.6'-12.5' SANDSTONE: Hard, cemented, fine to medium-
grained, sugary, moderately porous. 1.6'-2.9' slightly
calcareous; 2.9 -12.5' noncalcareous; 8.6'-12.51 moder-
ately fractured (10-15 fractures in 3.9') (heavy limonite
staining on fractures). Fractures diV 500 and 900. Core
badly broken 2"-4" pieces. 1.6'-8.6 slightly fractured
(3-4 fractures in 7.0'), vuggy a~pearance (numerous small
(1/16") solution cavities). 4.2 -7.1' heavy carbonaceous
seams in bedding (approximately 3"_611 apart). Beds dip
25". Slightly crossbedded. Color: greyish white.
Maximum core length is 1.0' Average core length is
.3' - ,4'.
12.5'-29.1' SANDSTONE: Hard, cemented, fine to medit.ml-
g~ained, sugary, nonca lcareous, moderately porous.
18.8'-20.0' slightly fractured, 4 fractures dip 50" and
dne iron-stained fracture dipping 800. Broken core. 3'
Ipieces. 25.4'-28.2' Two fractures (iron stained), one
lopen fracture with slight pyrite mineralization running
length of core and dippinl; 80"-85". Beds dip 20".
23.6'-23.9' few thin carbonaceous streak.. 25.5'-25.6'
2-1/4" shale beds. Maximum core length is 2.51. Average
core length is .5' - .7' .
29.1'-36.5' SHALE: Hard, dark grey shale, nonealcareous,
very slightly sandy. Nonfractured. Two fractures, one
at 31.0' and one at 31.3' dip 50". Slightly fissile.
Core breaks to 1/16" to 1/4" beds with moderate hand
pres_ure. A few streaks of gypsum coatings 36.0'-38.0'.
Average core lengths are .2'-.3'. Beds dip 0.50.
38.5'-81.9' SANDSTONE: Hard, cemented, fine to medium-
grained) noncalcareous, sugary, moderately porous.
Slightly fractured. Beds dip at 15"-30". Slightly
crossbedded. Slight pyrite mineralization filling
solution cavities at 43.1' and 45.9'. A few zones
having soft carbonaceous streaks, and one seam .5' wide.
A few thin (up to .5") shale beds in zones. 70.5'.
71.5' interbedded sandstone and shale (shale beds up to
0.4'). 71.5'-72.6 shale inclusions in medium-grained
sandstone. There are l' zones of vuggy appearance
(1/16" solution cavities). Maximum core length is 2.9'
Average core len~th is 1.0'.
81.9'-89.5' SANDSTONE and SIIALE: Interbedded hard, gray,
noncalc~reous shales WTith hard, cemented, fine-grained
noncalcareous sandstonie. Sandstone beds vary from .5'
to 1.0'. Nonfracturedl. Beds dip 0_50. Haxim1.m core
length is 1.0'. Averalge core length is 0.2'-0.4'.

89.5'-110.0' SHALE: Hatrd, gray-black, noncalcareaus,
slightly fissile. COIre breaks into 1/16" to 1/4" beds
with moderate hand \?r",ssure. Slightly fractuted.
Fractures dip at 50. Some gypsum coatings, slight
pyrite mineralization in a few zones. Nonweethered.
Ma.ximum core length iss .6'. Average length is O. 2' .

NOTE Water level elev. 47419.5 Januory, 1970

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0-94.3' SANDSTONE with occasional shale beds and carbon-
aceous laminae; sandstone is primarily composed of fine
to medium quartz grains, sugary texture, porous - water
placed on core surface is readily absorbed, noncalcar-
eous; core has partial coating from drill water that has
high reaction to HCI, hardness 6-7, is slightly friable
on broken surface, occasional large ~1/4"-1/2") vugs
0-13.0' and 81.0'-83.0'. 65.5'-67.2 is very porous and
friable, appears to be solution zone, light gray-white
has light oil stains 28.0'-38.0'; numerous carbbnaceous
streaks and laminae 69.0'-77.0'; shale, fissile, clayey-
waxy luster when polished, nonca1careous, hardness 5,
can be cut with knife when fresh, a few shrinkage
cracks from drying, oore partially damaged by drill
water durin~ coring occurs at: 22.7'-22.8', 0.05' at
23.4'. 0.01 at 64.9', 67.2'-67.5', 0.05' at 89.7',
0.1' at 90.2',0.01' at 91.6', and 91.8'-92.5'. Open
bedding planes are vufgy 0-13.0'. Rusty and vugged open
bedding ~lane at 29.6 .
94.3'-113.3 SIIALE with thin (0.05') silty fine-grained
sandstone lens, shale is fissile, clayey, waxy luster
when polished, hardness 5, can be cut with knife when
fresh, scratched by knife when dry, breaks readily but
irregularly along bedding planes, shrinkage cracks after
drying, core eroded by drill water, badly eroded 105.7'
to 113.3', dark gray; open 30" joint at 106.5'.

0-34.5' SANDSTONE
34.5'-34.8' SHALE: HE~dness (5) hard to crush chips in
fingers, brittle, clayey, fresh, fissile to slightly
blocky with silty dolOlllitic laminae, dark, gray; Max.
core length 1/2" average 1/4", air-slaked, completely
deteriorates after 5 min. in water, eroded 1/10" deep
frOlll drill water.
34.8'-42.8' SANDSTONE: Hardness (7) only lUllps smaller
than 1/2" can be broken w/pliers, fine-med. grained,
sugary and moderately porous, few solution vugs (1/10-1/4")
to 37.51, crossbedded 30_150 to core axis, beds 0.2'-1.3'
thick, shale bed 0.4' thick (sane as shale @ 34.5') at
36.41 and 1/2" bed @39.0', carbonaceous laminae along
bedding planes in part and lightly banded w/s...e grayish
white; max. core length: 0.7',average 0.21., vert. jt.
tight-open (1/16"), 39.2'-40.0"

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9-19-66

0-4.5' CLAY, silty, 85'7. low plasticity fines, 15'7. fine
sand; max1mtnn size recovered medium sand, high reaction
to HCl, dry, hardness 3, 1" dry chunks can be crushed
with fingers, tan; numerous rootlets, several lime vein-
lets at 3.0'. (ML-CL)
4.5' -98.0' SANDSTONE, composed primarily of fine to medium
quartz sand, has sugary appearance and texture, porous,
drops of wa ter dropped on surface are absorbed quickly,
occasional carbonaceous bedding, paper thin to 1/16",
carbonaceous banding and streakin~ is numerous and con-
torted giving marbled effect 30.1 -37.0' and 79.6'-85.6',
core breaks readily along these planes, crossbedded
100_300 depositional dip normal to core axis, 0.1' to
2.0' beds, 1/8" vugs are cotIlDOn and in horizontal bands
to 25.0', below 25.0' are occasional and no pattern and
larger (1/8"-3/8") noncalcareous, hardness 7, but is
slightly friable on a freshly broken surface, dirty
white with gray to black streaking; several shale beds
c.f varying thickness, silty, hardness 6, can be scratched
with a knife, dark gray, paper thin bedding, does not air-
or water slake noticeably, shale occurs: 0.031 at 32.3'
and 32.6', 33.7'-33.8', 0.01' at 34.4' and 34.9',
78.9'-79.5', 83.3'-83.55', 0.02' at 83.75'4 84.45'-
84.55', several paper thin laminae 72.6'-7 ."7' and
93.9'-95.3'; a clayey shale, dark gray, waxy luster
when polished, hardness 5-6, air-slakes and water-slakes
rapidly, 93.8 -93.9', 95.3'-96.1' and 96.9'-97.3';
97.4'-98.0' is alternating 0.03'-0.1' layers of sand-
stone and shale; siltstone 93.9'-93.4', hardness 6-7,
paper thin laminae, noncalcareous, dark gray. Open
rusty bedding: 30.4', 31.5', 31.6', 32.5', numerous
fresh bedding breaks, but impossible to determine if
drill caused. Maximum core length: 5.0', average 1.5',
many breaks appear to be drill caused.
98.0'-103.4' SIIALE, clayey shale with an occasional silt-
stone (hardness 7 - light gray), lens 0.05' to 0.2'
thick, paper thin laminations, hardness 5-6, can be cut
with knife, core breaks readily along bedding planes,
dark gray to black, noncalcareous; shrinkage cracks
develop a few minutes after exposure to air, water
turns it to fat c lay in 5 minutes, pyrite along some
bedding planes. Max. core length: 1.0', average 0.5',
breaks are probably drill caused. Core badly eroded by
drill water.

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0-37.0' SANDSTONE: Hardness (6), 1/2" lumps can be broken
w/pliers, fine-medium grained, porous-mod. r.orous,
slightly weathered w/few solution vugs (1/8 '-1/4")
slightlr crossbedded dipping 50_20" to core axis, beds
are 0.3 -2.2' thick, top 3' is limy limonite stained
at 26.6', for the most part carbon ;'odules (1/4"t) and
stained bands along bedding planes, gray w/banded dark
brown stains; few open joints. dipping 750 to core axis
and broken into (I":!) pieces in part. Max. core length
2.2' average 0.3' and 0.6'.
37.0'-62.4' SANDSTONE: Hardness (6) 1/2" lumps can be
broken w/pliers, fine-medium grained. sugary and mod-
erately porous, more porous between 42' and 441 beds
dip 5-_100 to core axis and are 0.4'-2.41 thick' wavy
carbonaceous laminae 42' -44 I, be low 44 I to tota i depth
are few carbon streaks (l"t) wide grayish white' open
joint at 56.71 dipping 750 to cor~ axis, max. co~e
length 2.41. average 0 _ 7 I.

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0-7.0' SANDSTONE: Hardness 6. MediUll-to fine-grained WL t.)
sugary and po:ous, ~lig~tly weathered and vuggy (l/l()"f) I~I~~;~~.~'-\-l I
cro~sbed~ed d~p 10 -20 normal to core axis. Beds f.1
1.0 -2.0 thick, top 3.0' slightly limy, light gray; healed 11
joint diGfting 75" normal to core axis, healed with limy fJ
silt (1/ ') and limonite stained at 4.8', slightly oo"j
fractured and broken top 2.5'. Max. core length: 1.51 I>.:':
l.' average 0.5 I . 2B.7'~
V.0'-29.0' SANDSTONE: Hardness 7. Fine-grained, slight ,,-j..
to moderately porous, fresh crossbedded 100 _200 normal 347 r-.-1
to core axis, beds 1.0'-2.5' thick, carbonaceous seams II
and vuggy along bedding planes, slightly limonite stained, t I
slightlyvuggy 0/16"t) 8.3'-20.0'. Light gray to rusty t I
gray; few healed joints with silty limonite stained limy I J
at 15.5', dip 600_850 normal to core axis, max. co;e 1..:1
length 3.2', average 1.5' .....
29.0'-36.7' SHALE: Hardness 5. Clayey-silty with 8everal II
silty laminae, beds 0.4'-0.6' thick dipping 3" normal I I
to core axis, botton 2.0' has alternating beds of II
sandstone 0.J'-0.6' thiCk, fissile, dull black, silt '.'1
healed joint 0/10") at 3L.0' dipping 25" normal to I
core axis, air-slakes along planes of fissility, water F,J
slakes in 5-10 minutes. Max. core length 0.8', I.. )
average 0.5'. ..
36.7' -49.5' SANDSTONE: Hardness 7. Fine-grained, sugary [I
and slightly porous, crossbedded 100 _200 normal to core 88,6'H
axis, beds 0.6' -1. 5 thick, banded with carbonaceous ':'oj
laminae 3/4" to 1.0' apart, slightly vuggy (1/16") 41'-45', II
light gray with charcoal banding; open joint dipping 55" I I
normal to core axis at 49.0', few near vertical tight 1032'U
fractures. Max. core length 1.51, average O.SI. 9-25-68

0-20.5' SANDSTONE: Hardness (6-7), hard to crush 1/2"
lumps w/ pliers, fine-med. grained, su~ary and porous,
moderately weathered, cross bedded 5-20 dip to core axis
beds 0.3' -2.5' thick, bottcm 1. 8' has many wavy carbona~eou8
laminae, rusty gray; joints have strong limonite staining
along joint planes, vertical open joints (broken in
part) 0.5'-6.0', 11.5'-16.2', and tight 17.4'-19.0',
max. core length 1.5', average 0.6'.
20.5'-44.9' SANDSTONE: Hardness (7), very hard to crush
1/2" lu:nps w/pliers, medium-grained, very sugary and
porous, fresh. crossbedded dips 150 _250 to core axis
beds 0.3'-3.0 thick, manx carbonaceous laminae '
throughout and about 1/10' thick along bedding planes,
many wavy shale beds 1/2 -1 1/2" thick frOlll 30 3' -31 4'
gray with black laminae bands; max. core length; 2.0'. ,
average 0.2'.
44.9' -63.2' SANDSTONE: Hardness (8) has a dull ring w/
h3lIlller blow, fine-med. grained, slightly-mod. porous
crossbedded, 100_200 dip to core axis, beds 1.0'-6.0'
thick, massive, carbonaceous seams (1/1011) along bedding
plane@45.5' and 49.l',vugs (1/16-1/4") 49.1'-50.2',
grayish white; max. core length 3.7', average 0.9'.
Water level data not obtained.

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5-20~48

0-14.0' SANDSTONE.
No water level data available>.

0-0.7' CLAY, silty, 90io low plasticity fines, 10'7.. fine
sand; maximun size medilDTl sand, high reaction to HCl,
medilB dry strength J dry. hardness 3, tan; numerous
small roots. (CL-ML)
0.7 '-28.7' SAND3TONE with a few thin shale and carbonaceous
l-:-inae helow 20.0'; the sandstone is predominantly
f~ne-medium quartz grains J sugary appearance, porous -
drops of water placed on the core are quickly absorbed
crossbedded 50 _300 measured from a 1 ine normal to core'
axis, numerous small (1/16") vugs to 17' then only
occasionally; noncalcareo,:!s; a partial surface coating
on the core due to the dr1ll water has a high reaction
to Hel, hardness 6-7; broken surface slightly friable
grayish ~ite; 0.03' thick carbonaceous layer at 17.2';
shale (sllty and brittle) 0.041 at 20.8', 0.01' at 25.2'.
Several open bedding planes; ones above 18.0' contain
several vugs.
28.7'-34.7' SHALE with 2 sandstone beds (31.6'-32.3' and
34.3'-34.51), fissile, clayey, has waxy luster when
polished, noncalcareous, hardness 5, can be cut with knife
when fresh, scratched with knife when dry breaks readily
but irregularly alonl? bedding planes, shrinkage cracks
were noted after drying. core was water eroded during
drillin~, dark gray.
34.7'-88.6 SANDSTONE with several shale beds below 82.01
saru:tstone is primarily composed of fine-mediun quartz '
gra~ns, sugary texture, porous. water is quickly absorbed
when placed on core surface, cross bedded 5-200 normal
to core axis, a few areas of small vugs (1/16") ntlllerous
vugs (up to 1/4") 74'-76'; noncalcareous, parti~l surface
coating on core due to drill water has high reaction to
He1. Hardr:'ess 7, br~ken surface slightly friable,
grayish wtnte; occaSional carbonaceous laminae and
streaking; shale - clayey. hardness 5, can be cut with
knife when fresh, scratched with knife when dry non-
calcareous, a few shrinkage cracks after drying'
core eroded by drill water, dark gra.y occurs: 0.03' at
46.8', 83.2'-83.5', 84.3'-84.5', (silty and brittle)
84.7'-84.8',85.6'-85.7',0.05' at 86.6',87.1'-88.11
0.02 at 88.3'
88.6'-103.2' SHALE with occasional silty, fine-grained
sandstone lens, fissile. clayey, waxy luster when
polished, hardness 5, can be cut with knife when fresh
scratched with knife when dry. breaks readily along ,
bedding planes. Shrinkag~ cracks develop upon drying,
core badly, damaged by dr11l water during drilling,
very slight reaction to Hel, dark gray. Open )oints
550 at 94.0', 350 at 94.41, 400 at 94.51 has 'slicks"
raking parallel to dip of joint.

NOTE: Water level elev 4746,6 Januar-y, 1970.

PROJ
DH 422
E I, 4754,0
[I ~7~9,2 09
'a - 29-=-69-\-1 1
II
~ I
297'f=,!
n
~
~
362'r4
t I
I I
f I
t I
I j
t 1
II
I I
[I
II
II
r I
923'0
fj
1032'~
10-11-68

PROJ
o H 408
EL4762.1
a9:q
291 1
t I
WL r I
-~~~;~~~+i I
t 1
I I
1 I
I I
t I
t I
1 :
I I
II
1 I
I I
72H
IJ
~ 1
87'~
11
~ 1
98,5'W
4-18-68

772.0 I

III

0-0.7' SAN~: 80'7. poorly graded fine-medium sand 10'7.
nonplast~c fines, 10'7. sandstone gravel (-1 1/211~
limy, brown. (SP) ) very
0.7'-2.9' SANDSTONE: Hardness 6. Fine-medium grained
sugary, porous, vuggy (-1/8"), slightly limy moderat~ly
wea~here~, crossbedded 5~ 15 0 nonnal to core' axis, beds
0.3 -0.6 thick, few carbonaceous laminae light-dirty
gray; few near vertical tight fractures broken in
vart. ,Max. core length: 0.6'; average 0.31.
2.9 -72.0 SANDSTONE: Hardness 7. Fine-medium grained
sugary, moderately porous to porous from 10 2'-13 81 '
and 42.61-48.8', vuggy (-1/811) where found ~ore o~rou8
cr<:>ssbedded 50_150 normal to core axis, beds 0.5'-8.0"
th~ck, several carbonaceous laminae that are broken in
part, reworked and brecciated 67.7'-68.81, li~ht gray
and black ~anded, trace of open joints dip 70 normal
to core ax~s, trace tight near vertical fractures Max
core length: 4.0' average' 2 0' ' .
72.0'-87.0' SANDSTONE: Hard;'es~ 7: Fine-/;lrained, slightly
sugary, moderately vorous, crossbedded 5 _200 normal to
core axi~, beds 0.5 -1.51 thick, shale lense (2") in
lower 18. Many carbonaceo~ laminae limonite
stained 761-78.0', light gray with bl~ck banding'
3 j o+nts . dip 700 no~al to core axis, open at 85 rand
g~99.; tlght at 87.0. Max. core length 1.8'; average
87.0'-98.5' SHALE: Hardness 5. Silty fissile in part
beds 0.3'-0.8' thick dip 3~50 normal'to core axis '
interbedded siltstone (0.1'-0.31) in upper 3.0' dark
gray shal~, light gray siltstone; drill water e;odes
~ore -1/4 deep for most part, air-slakes, water-slakes
in 5-l0minutes. Max. core length; 0.9', average 0.5'.

0-29.7' SANDS'IONE: Predominantly fine-medium grained
quartz grains with carbonaceous streaking and bedding
planes, sugary texture and appearance, porous, water
drops placed on core surface are readily absorbed-
nonc:alcareous, hardness 6-7, fresh broken surface~ are
friable, core breaks readily along carbonaceous bedding
planes with varying thickness from paper thin to 0 02'.
crOtlsbedded 0-250 normal to core axis, 0.21 to 2.0i '
bedaj lJ#tt gray t~ white, heavily rust-stained 27.6'-
28.2 ; several 1/8 and smaller vugs to 23 5' then
occasional ones, two 1/2" vugs at 19 5' . ,
29.7'-36.2' SMLE: Top 1.0' is gray, brittle, 0.01' platy,
silty, hardness 6, can be scraped with knife' remainder
is clay with occasional hard brittle sand siitstones has
waxy luster when polished, 0.01' plates hardness 5' can
be cut readily with knife, air-slakes and water-s1ak~s
rapidly, core eroded during drilling, noncalcareous
dark gray. '
36.2' -92.3' SANDSTONE: Cdmposed primarily of fine to
medium quartz grains wiUh carbonaceous streaks and bedding
some thin shale lens. sugary texture and appearance, '
porous - water drops placed on core are readily absorbed-
noncalcareous J hardness 7. Fresh broken surfaces are '
friable, core breaks readily along carbonaceous and
sbale bedding flanes; ctossbedded 0-250 normal to core
axia, 0.1'-4.0 beds; ltght gray to white. Shale lens
8'2.9 -83.3', silty, brittle, hardness. 6, grav. Shale
lens,90.3'-9l;4', 92.0'-92.2' and 92.3'-92.7', 88.7'-
90.3 is 0.03 thick sandstone layers with paper thin
parting, the shale is clayey, air-and water-slakes
rapidly, dark gray, hardness 5, can be cut with knife.
Carbonaceous beddinf are paper thin to 0.01', verv
numerous 53.5'-54.2 , numerous and contorted 734'-
74.5', 81.0'-82.9', and 84.0'-84.5'; light gray. to
white; occasional 1/8" vugs with several 1/2" vugs
partially filled with shale and carbon at 80.0'-83.0'.
Several open bedding planes, but some are drill action
caused. Max. core length: 4.0'. average 2 01
92.3'-103.2' SIIAlE: Clayey, thinly bedded (0:01;)
occasional O.OS' thick hard, brittle siltstone l~ns
air-and water-slakes rapidly, noncalcareous hardne~s
5-6, can be cut by knife, breaks readily al~ng bedding
planes, has waxy luster when polished, dark gray'
75" joint at 97.3'. '

NOTE
For explanation and notes, see Dwg 382- 0 -802

0-6.0' SAND and CLAY.
6.5 ' -17' 10" SANDSTONE.
No water level data available.

~ ALWAYS flUnK SAfETY

UNITED STATES
DEPARTMENT OF THE INTERIOR
BUREAu OF RECLAMATION
FRYINGPAN -ARKANSAS PROJECT- COLORADO

PUEBLO DAM
LOGS OF EXPLORATION
SECTION A-A

DENVER,

DRAWN L.C - N. R.W.

SUBMITTED

TRACED

CHECKED 10.0.

RECOMMENDE