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Geological Survey Water-Supply Paper 1475-M
Ground-Water Resources of the Bryce Canyon National Park, Utah
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GEOLOGY
STRATIGRAPHY
The oldest rock formation known to underlie the Bryce
Canyon area is the Redwall limestone of Mississippian age. This
formation was penetrated at a depth of 10,189 feet below the surface in
an oil test in Johns Valley (table 4) about 12 miles northeast of the
lodge and headquarters area (off pl. 24). This same test hole passed
through 779 feet of Pennsylvanian strata comparable to the Molas and
Hermosa formations. Rocks of Permian age were penetrated in the Lion Oil
Co. test hole, 4 miles northwest of the lodge and headquarters area (pl.
24; table 4). These rocks were the Coconino sandstone, the Toroweap
formation, and the Kaibab limestone.
TABLE 4.Logs of wells and auger holes in the Bryce Canyon National Park area, Utah
[See pls. 24, 25A for location. All water levels in this table are in feet below land surface]
| Thickness (feet) | Depth (feet) |
Headquarters well, National Park Service |
Yield, 160 gpd; diameter, 48 in. to 30 ft, 12 in. to 50 ft, 8 in. to 80 ft. Static water level, 49 ft. |
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Alluvium: Old dug well | 30 | 30 |
Wasatch formation: |
Rock | 10 | 40 |
Fractured rock | 10 | 50 |
Rock | 30 | 80 |
Well 1, Utah Parks Co. |
Yield, 180 gpm; diameter, 12 in. |
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Alluvium: |
Clay | 12 | 12 |
Gravel | 3 | 15 |
Porous formation | 9 | 24 |
Tight formation | 6 | 30 |
Wasatch formation: Dry chalky formation | 50 | 80 |
Well 2, Utah Parks Co. |
Yield, 90 gpm; diameter, 12 in. Static water level, 4 ft. |
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Alluvium: |
Clay | 6 | 6 |
Sand and gravel | 4 | 10 |
Clay | 2 | 12 |
Gravel | 2 | 14 |
Clay | 4 | 18 |
Gravel and sand | 8 | 26 |
Clay | 4 | 30 |
Wasatch formation: Rock | -- | 30+ |
Daves Hollow Ranger Station, Forest Service |
Yield, 90 gallons per hour; diameter, 6 in. Static water level, 15 ft. |
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Alluvium: Clay, sandy, and gravel | 20 | 20 |
Kaiparowits formation: |
Clay, sandy, gray | 15 | 35 |
Clay, sandy, gray (water) | 15 | 50 |
Clay, sandy, gray | 60 | 110 |
Clay, sandy, gray (very hard) | 12 | 122 |
Shale, sandy, brown (caving) | 3 | 125 |
Clay, sandy, gray | 82 | 207 |
Bryce Canyon Airport, Civil Aeronautics Administration |
Yield, 10 gpm; diameter, 6 in. Static water level, 33 ft. |
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Alluvium: |
Conglomerate and hardpan | 12 | 12 |
Clay, yellow | 4 | 16 |
Clay, light brown | 7 | 23 |
Clay, blue-gray | 11 | 34 |
Clay, gray-brown | 9 | 43 |
Clay, sandy, light-brown | 5 | 48 |
Clay, sandy, light | 3 | 51 |
Kaiparowits formation: |
Sandstone, gray | 40 | 91 |
Shale, gray | 8 | 99 |
Shale, sandy, blue | 26 | 125 |
Shale, sandy, hard, blue | 2 | 127 |
Shale, sandy, blue | 9 | 136 |
Shale, sandy, hard, blue | 2 | 138 |
Shale, sandy, soft | 12 | 150 |
Sawmill Well, E. A. Crofts |
Yield, 40 gpm; diameter, 6 in. Static water level, 18 ft. |
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Alluvium: |
Clay | 20 | 20 |
Sand (little water) | 15 | 35 |
Clay | 25 | 60 |
Gravel (water) | 6 | 66 |
Kaiparowits formation: Shale, light-gray (no water) | 244 | 310 |
Lion Oil Co. water well |
Yield, 10 gpm; diameter, 6 in. |
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Alluvium: |
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Sand rock | 70 | 70 |
Rock formation, porous | 6 | 76 |
Sand rock | 40 | 116 |
Rock formation, porous | 6 | 122 |
Sand rock | 8 | 130 |
Rock, porous | 6 | 136 |
Lion Oil Co. oil test |
Kaiparowits formation and Wahweap and Straight Cliffs sandstones | 940 | 940 |
Tropic shale | 1,305 | 2,245 |
Dakota sandstone | 415 | 2,660 |
Morrison formation | 1,965 | 4,625 |
Carmel formation | 1,430 | 6,005 |
Navajo sandstone | 2,075 | 8,130 |
Chinle formation, upper part | 598 | 8,728 |
Shinarump member of Chinle formation | 129 | 8,857 |
Moenkopi formation | 1,125 | 9,982 |
Timpoweap member of Moenkopi formation | 104 | 10,086 |
Kaibab limestone | 479 | 10,565 |
Toroweap formation | 451 | 11,016 |
Coconino sandstone | 205 | 11,221 |
The Pines Motel, Mayo Rich |
Diameter, 6 in. Static water level, 15 ft. |
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Alluvium: Clay, sandy | 10 | 10 |
Wasatch formation: Sand rock, red | 160 | 170 |
Forest Oil Corp. oil test
[about 3 miles west of Lion Oil Co. oil test, off pl. 24] |
Wasatch formation | 496 | 496 |
Kaiparowits formation | 155 | 651 |
Wahweap sandstone | 231 | 882 |
Straight Cliffs sandstone | 2,398 | 3,280 |
Tropic shale | 1,130 | 4,410 |
Dakota sandstone | 218 | 4,628 |
Winsor formation | 507 | 5,135 |
Entrada sandstone | 470 | 5,605 |
Carmel formation | 586 | 6,191 |
Navajo sandstone | 51 | 6,242 |
California Co. oil test, Johns valley No. 1 in sec. 22, T. 35 S. R. 2 W. |
Wahweap and Straight Cliffs sandstones | 910 | 910 |
Tropic shale | 898 | 1,808 |
Dakota sandstone | 202 | 2,010 |
Morrison formation | 685 | 2,695 |
San Rafael group | 955 | 3,650 |
Glen Canyon group | 2,085 | 5,735 |
Chinle formation, upper part | 560 | 6,295 |
Shinarump member of Chinle formation | 75 | 6,370 |
Moenkopi formation | 995 | 7,365 |
Kaibab limestone | 923 | 8,288 |
Coconino sandstone | 1,022 | 9,410 |
Formations comparable to Hermosa and Molas formations (combined) | 779 | 10,189 |
Redwall limestone | 146 | 10,335 |
Logs of auger holes in alluvium of East Creek valley |
AUGER HOLE 1 |
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Sand, clayey tan | 14 | 14 |
Gravel and sand, tan (water) |
| 14-1/2 |
AUGER HOLE 2 |
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Sand, clayey tan | 2-1/2 | 2-1/2 |
Gravel and sand, tan (dry) |
| 2-1/2 |
AUGER HOLE 3 |
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Soil, dark clayey | 2 | 2 |
Gravel and clay, light-brown | 2 | 4 |
Gravel, angular, white (water) | 1 | 5 |
AUGER HOLE 4 |
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Clay, sticky, gray-brown | 2 | 2 |
Sand, clayey, brown | 2 | 4 |
Gravel, fine; sand and clay, tan | 2 | 6 |
Gravel, coarse, reddish-white (water) | 1 | 7 |
AUGER HOLE 5 |
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Soil, sandy, dark-gray | 2 | 2 |
Clay, sticky, gray | 2 | 4 |
Clay, sticky, yellow | 4 | 8 |
Gravel, sand and clay, yellow (water) |
| 8 |
AUGER HOLE 6 |
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Soil, clayey, black | 2 | 2 |
Clay, sticky, black | 2 | 4 |
Clay, sandy, (water) | 1 | 5 |
AUGER HOLE 7 |
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In gully about 15 ft below general land surface. |
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Bank of gully, red sand | 15 | 15 |
Red sand | 6-1/2 | 21-1/2 |
Gravel (dry) |
| 21-1/2 |
AUGER HOLE 8 |
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Clay, sandy, dark-gray | 8-/12 | 8-1/2 |
Gravel and clay, white | 1/2 | 9 |
Sand, reddish-white | 1-1/2 | 10-1/2 |
Gravel (dry) |
| 10-1/2 |
AUGER ROLE 9, DAVES HOLLOW |
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Pit | 4 | 4 |
Clay, sticky, red | 8 | 12 |
Sand, fine, red | 1 | 13 |
Gravel, reddish-white (dry) | 1 | 14 |
The thickness and the geologic and hydrologic
character of the Mesozoic and Cenozoic rocks underlying Bryce Canyon
National Park are given in table 5. Of these formations the oldest shown
on the geologic map (fig. 55) is the Winsor formation of Late Jurassic
age.
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FIGURE 55Geologic map of the northern part of Bryce Canyon National
Park area, Utah. Modified from Gregory (1951). (click on image for an enlargement in a new window)
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The Mesozoic rocks in table 5 are predominantly
sandstone and shale with only minor limestone or conglomerate beds.
Except for the Navajo sandstone, most formations have gypsum as a common
cementing agent. This mineral is easily soluble, and thus may be present
in much of the ground water contained in these beds. Gypsum is not so
common in rocks of Cenozoic age, which are mostly limestone or sand and
gravel.
TABLE 5.Generalized section of the geologic formations in the Bryce Canyon National Park area, Utah
[Based on information obtained from several sources, including Gregory (1951), Gregory and Moore (1931), and Harshbarger and Repenning (1934)]
System | Series | Geologic unit |
Thickness (feet) | Depth to bottom of formation1 (feet) |
Physical character | Water supply |
Quaternary | Recent and Pleistocene | Alluvium |
0-136 | 0 |
Gravel, sand, silt, and clay filling the valley bottoms of East Creek, Daves Hollow, and
other small streams, and the valley of the East Fork of the Sevier River. Attains
maximum thickness in Emery valley. Fills valley bottoms of water, Campbell, and
Bryce Canyons, Yellow and Sheep Creeks, Swamp Canyon, and other canyons below the rim. |
Gravel and sand lenses in the alluvial valleys on the Paunsaugunt Plateau
yield as much as 180 gpm to a well. Gravel fill in the canyons below the rim
is very porous and in the washes this gravel is very permeable; yields large quantities
of water where saturated, but in general the gravel contains water only in the vicinity
of bedrock springs, with resultant limited yields. |
Unconformity |
Tertiary | Eocene | Wasatch formation | 150-700 at the rim.
1,000 at Boat Mesa. 0-700 between the East Fork of the Sevier River and the rim. |
500 |
Upper white beds present on Boat Mesa and Whiteman Bench are white, gray, or
light-brown sandstone, conglomerate, and limestone containing siliceous cement and volcanic tuff and ash.
Middle pink beds, chiefly pink, gray, and white massive limestone and interbedded
sandstone and conglomerate.
Basal conglomerate consists of pebbles poorly cemented by calcium carbonate; absent in Swamp Canyon and Yellow Creek; 10 to 30 ft thick at Bryce Point,
composed of sandstone and conglomerate; 30 ft thick at Campbell Canyon, composed
of lenses of conglomerate in limestone. |
The white beds support springs of unstable yield on Whiteman Bench.
A few small springs issue from sandy lenses and fractures, but the beds are not likely to yield water to wells.
Basal conglomerate beds support several springs just below the rim and in the
valley of the East Fork of the Sevier. If lenses of conglomerate are penetrated,
the basal conglomerate might yield moderate quantities of water to wells. |
Unconformity |
Cretaceous | Upper Cretaceous | Kaiparowits formation |
Absent in Bryce and Campbell Canyons.
400 in Yellow Creek and Sheep Creek areas. | 900 |
Dark-gray, gray-green, yellow, and tan coarse- and
medium-grained arkosic sandstone poorly cemented by calcium carbonate
and in part by gypsum and iron oxide. Brown, white, and greenish
limestone and blue and purple shale. Contains vertebrate bones, fossil
wood, invertebrates, and ironstone nodules and concretions. |
Yields water to several springs below the rim. Wells that penetrate this
formation have very low yields (10 gpm or less). |
Unconformity |
Wahweap sandstone | 880+ | 1,750 |
Yellow and buff fine to medium sandstone, 40 to 60 ft thick in upper
part. Interbedded sandstone and shaly sandstone in extensive lenses in
lower part. Cemented mainly by calcite, but hard layers are cemented by
iron oxide. Contains some gypsum and wood. |
These two formations support most of the prolific springs below the rim.
Although no water wells penetrate these formations in the Bryce Canyon
area, they might yield water to wells in sufficient quantity for a
public supply. The extensive sandstone layers make up most of the two
formations which are saturated throughout the area; thus, most wells are
apt to penetrate water-bearing material. (Lithologic equivalent in the
Navajo Indian Reservation yields 20 to 40 gpm.) |
Straight Cliffs sandstone |
Tan sandstones make up 95 percent of this formation, and sandstone
layers greater than 10 ft thick make up 60 percent. Some of the sand is
fine, but most is medium to coarse, and some conglomerates contain
pebbles 1 to 3 in. across. Cemented mainly by calcite but in part by
some iron oxide. Disseminated gypsum and carbonaceous beds occur. |
Tropic shale | 800 | 2,550 |
Bluish-drab clayey to sandy shale; irregularly bedded sandstones;
abundantly fossiliferous; gypsum and selenite crystals are common.
Contains sand lenses 2 to 15 ft thick and carbonaceous beds. |
Very poor water-bearing formation. Forms impermeable barrier along Paunsaugunt
fault, causing faultline springs. Sandstone lenses might produce
small quantities of water, but such water would
be high in calcium and sulfate and probably of unsatisfactory quality. |
Dakota sandstone | 30 | 2,580 |
Buff-gray medium- to coarse-grained sandstone and conglomerate
containing some shale and carbonaceous beds. Sandstones
are weakly cemented. Contains some silicified wood. |
Springs issue from the base of this formation in the
Paria Valley. If sufficient thickness is penetrated, this formation
would yield some water to wells. It is saturated everywhere west of the
Paunsaugunt fault. The water might be of unsatisfactory quality owing
to seepage from the overlying Tropic shale. (Yields 5 to 10 gpm in
Navajo Indian Reservation, but water is highly mineralized.) |
Unconformity |
Jurassic | Upper Jurassic | Winsor formation |
600-700 | 3,280 |
Thin-bedded red- and white-banded arkosic sandstone. Sand is medium- to
coarse-grained; cemented by iron oxide, calcite, and gypsum. |
Many of the creeks become perennial on or just below the outcrop of this
formation. Several springs undoubtedly issue from this formation but
only one at the base has been observed. Yields to wells should be
moderate to small, but the water may be of poor quality. |
Unconformity |
San Rafael Group | Curtis formation |
110-180 | 3,460 |
Massive gypsum, dense thin-bedded limestone, calcareous sandstone and
shale, and gypsiferous very sandy shale. |
Very poor water-bearing formation, would yield very small amounts of
highly mineralized water to wells. |
Unconformity |
Entrada sandstone | 170-240 | 3,630 |
Thinly stratified friable fine-grained and very fine grained red, brown
and gray sandstone; some limestone, shale, and gypsum beds; contains abundant
gypsum, which constitutes the chief cement, and fills cracks. Thickest
individual sand bed about 30 ft. |
Springs issue at various horizons from the Entrada, but owing to the
fine texture of the sand, yields to wells would be small unless
abundant fractures improved the permeability. Under the Paunsaugunt
Plateau water would probably be highly mineralized. |
Carmel formation | 0-165 | 3,795 |
Regularly interstratified beds of tan and blue-gray shale, limestone, and sandstone,
containing smaller amounts of gypsum and conglomerate in both thin and thick lenticular beds. |
Very poor water-bearing formation. Water probably highly mineralized. |
Unconformity |
Jurassic and Jurassic(?) | Middle Jurassic |
Glen Canyon Group | Navajo sandstone |
1,200-1,800 | 5,595 |
Light creamy-yellow, white, and buff highly crossbedded sandstone. Forms the White Cliffs. |
Probably would yield largest amounts of good-quality water of any formation below the Wahweap and Straight Cliffs
sandstones. (Yields as much as 70 gpm in the Navajo Indian Reservation.) |
Unconformity |
Triassic | Upper Triassic | Chinle formation |
Upper part of Chinle formation | 600-800 | 6,395 |
Red and brown shale, sandstone, and limestone. |
Probably not water bearing. |
Shinarump member | 0-115 | 6,510 |
Red and gray conglomerate. |
May yield a small quantity of water to wells, hub water would probably be somewhat mineralized. |
Unconformity |
Middle(?) and Lower Triassic |
| Moenkopi formation |
500 | 7,010 |
Chocolate-brown shale and some sandstone. |
Probably not water bearing. |
1Representative of depths and thicknesses underlying the vicinity
of Paria View observation point in park.
STRUCTURE
The principal structural features of the Bryce Canyon
National Park area are gently northeastward-dipping beds and several
major normal faults. The regional dip of the beds ranges from 1/2° to
3° north, northeast, and east. Departures from the regional dip are
found only in the immediate vicinity of faults and in gentle folds. A
gently north-plunging anticline in the vicinity of Willis and Heward
Creeks was described by Hager (1957). The axis of this anticline is west
of the Pink Cliffs escarpment in the Heward Creek area, but it crosses
the escarpment in the vicinity of Sheep Creek.
Faulting is restricted to a few large-scale normal
faults; two of these faultsthe Paunsaugunt and Sevierare
regional in extent. The Sevier fault is about 7 miles west of the area
covered by this report. These two faults trend northward, and the east
block of each fault is upthrown in relation to the west block. The
Paunsaugunt fault does not coincide with the Pink Cliffs escarpment and,
in fact, is not noticeable as a topographic feature of any kind. Two
cross faults that trend generally eastward, connecting the Sevier and
Paunsaugunt faults, are evident as topographic featuresfaultline
scarps that form the borders of Emery Valley.
Each of these structural features exercises some
control on the occurrence and movement of ground water in the bedrock
aquifers of the area. Ground water moves through the rocks in the
general direction of the regional dip, which accounts for the many
springs along the eastern scarp of the Paunsaugunt Plateau. Along the
Paunsaugunt fault, springs occur where the eastward movement of ground
water is blocked by upfaulted relatively impervious beds, which force
the water to rise to the surface. Tension fractures along the axis of
the Bryce Canyon anticline (fig. 55) might create secondary permeability
and afford an opportunity to obtain successful water supplies from wells
penetrating the bedrock.
wsp/1475-M/sec2\.htm
Last Updated: 28-Jul-2007
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