road log for kodachrome basin state park with side trips to grosvenor

Geologic Road, Trail, and Lake Guides of Utah’s Parks and Monuments
2000 Utah Geological Association Publication 29
P.B. Anderson and D.A. Sprinkel, editors
ROAD LOG FOR KODACHROME BASIN STATE
PARK WITH SIDE TRIPS TO GROSVENOR
ARCH AND BULL VALLEY GORGE, UTAH
James L. Baer, Brigham Young University, Provo, Utah
Robert H. Steed, Bryce Canyon Nature Association, Tropic, Utah
INTRODUCTION
The geology in and surrounding the Kodachrome State Park is typical of Colorado Plateau geology.
This style of geology is characterized by flat to low dipping sedimentary rock formations that are
broken by widely spaced faults and deformed by broadly spaced monoclines and gentle amplitude
anticlines and synclines (figure 1).
Sedimentary rocks of the Park are upper Jurassic to Cretaceous in age (figure 2) with a capping Tertiary- Quaternary (Plio-Pleistocene) conglomerate found on many of the spires and mesas. A significant unconformity separates this unnamed Tertiary conglomerate from the underlying rocks.
Within the Park the main attractions are the colorful carved rock formations and the curious sedimentary pipes that are concentrated in this area. It is the latter that sets Kodachrome Basin State
Park apart from the other parks of Utah.
The trails and roads within the Park are in good condition and are passable except in times of heavy
rains. These rains can make portions of the trail slippery and some of the roads dangerously slippery if not impassable. This is of concern mainly on the dirt roads to Grosvenor Arch and Bull Valley Gorge (figure 3). There are accommodations within the Park for visitors in the trailer park and a
limited number of individual cabins.
In order to accommodate visitors to the Kodachrome State Park coming from either the west or east
on State Scenic Byway 12 we have extended the road log in both directions from the road leading to
the Park at Cannonville. Those coming from the west on Scenic Byway 12 can start the road log at
Tropic, Utah. Those journeying from the east will start the road log at the Escalante Staircase
Monument boundary just east of Henrieville, Utah.
1
J.L. Baer and R.H. Steed
Road Log for Kodachrome Basin State Park with Side Trips to Grosvenor Arch and Bull Valley Gorge, Utah
Jeg
Jcw
Jcww
D
Jeg
Jh
Jec
Jee
Jee
Jec
D
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Jh
Ktd
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TQco
Jec
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6
4
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5
D
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9
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3
4
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Jh
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KBSP
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Jee
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38
S
Jec
Jcww
KBSP
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Jcww
5
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8
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10
9
8
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Jcw
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10
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6
Jcw
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0
1
One Mile
Jcp
KBSP
Jcp
R2W
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A
Jee
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Jec
Jeg
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A'
6000 feet
5500
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AGE
Figure 1. Simplified geologic map of the Kodachrome Basin State Park and surrounding area.
QT
Unnamed
Conglomerates
Tropic- Dakota
1.3
2.4
TROPIC TOWN LIMIT SIGN is
on alluvial fill.
Tropic Shale with thin coal bed units
along the road.
JURASSIC
1.1
Escalante
Member
2.9
100
Kdt
65
Jh
110
Jee
FLUVIAL
NEARSHORE MARINE
FLUVIAL
Grosvenor Arch
Unconformity
SHALLOW MARINE
SHALLOW MARINE
Cannonville
Member
138
Gunsight Butte
Member
280
Jec
Majority of pipes are found
in the Jeg, Jec, and Jee
Jeg
Wiggler Wash
member
45
Jcww
Winsor
Member
262
Jcw
Paria River
Member
200
Jcp
SHALLOW MARINE
TIDAL FLAT
Some pipes occur in
Jcww and Jcw
SHALLOW MARINE
TIDAL FLAT
Probable source
of slurry
SABHKA
Unconformity
Page Sandstone
65
Jcpt
EOLIAN-SABHKA
Unconformity
Judd Hollow Tge
Navajo Sandstone
0.5
QTco
ENVIRONMENT - COMMENTS
SHALLOW MARINE
CARMEL FORMATION
1.1
Center of Tropic, Utah going EAST
on Scenic Byway 12.
ENTRADA SANDSTONE
MILEAGE DESCRIPTION
INTERVAL/CUMULATIVE
0.0
40
LITHOLOGY
Unconformity
Henrieville Sandstone
0.0
MAP
THICKNESS
SYMBOL
(Feet)
Unconformity
CRET
ROAD LOG SEGMENT FROM TROPIC
UTAH
FORMATION
75
Jcj
TIDAL FLAT
15501700
Jn
EOLIAN
Bull Valley Gorge
cut into this formation
Dakota Sandstone cropping out near
Figure 2. Stratigraphic column of rocks in and near
the road.
Kodachrome Basin State Park.
2
P.B. Anderson and D.A. Sprinkel
2000 Utah Geological Association Publication 29
Sce
nic
Road South to Kodachrome
Basin State Park - Cannonville and Escalante Members of the Entrada Formation make up both mesas
bordering the alluvial fill
valley. GO TO ROAD
LOG INTO KODACHROME BASIN
STATE PARK.
Byw
a
y 1
2
PA
R
K
N
0
N
AL
6 Miles
AT
I
O
TROPIC
N
2
y 1
nic
a
Byw
CA
N
YO
N
Sce
E
4.4
BR
YC
1.5
HENRIEVILLE
CANNONVILLE
KODACHROME BASIN
STATE PARK
SHEPARD
POINT
BULL VALLEY
GORGE
x
GROSVENOR
ARCH
x
Figure 3. Index map for road logs.
ROAD LOG SEGMENT FROM HENRIEVILLE, UTAH
MILEAGE
INTERVAL/CUMULATIVE
DESCRIPTION
0.0
0.0
Start at Grand Staircase Escalante National monument sign that marks the west
boundary of the monument as you travel east on Scenic Byway 12. Sign is on the
south side of the road and can only be read going east. The base of the cliffs on both
sides of the road are the Cannonville and Escalante Members of the Entrada Formation (Jurassic). The rock that makes up the gray to buff cliff is the Henrieville Sandstone (Jurassic). This sandstone unit is bounded by unconformities and thins to the
west (figure 4). The Dakota Formation overlies the Henrieville Sandstone and consists of thin coals. The thin coals are indicators of a tropic to sub- tropic environment in which these sediments were deposited. It is suggested that the Cretaceous
rocks were deposited in shallow, warm seas with abundant sand being transported
into these basins mainly from the west. The vegetation that made up the coal beds
grew along protected parts of the shoreline such as the landward side of barrier islands and smaller sand bodies. Road is on a colluvial and alluvial valley fill.
0.8
0.8
HENRIEVILLE TOWN LIMIT Sign is on valley fill sediments.
0.7
1.5
Cross Bridge
0.5
2.0
HENRIEVILLE TOWN, Sandstones of Dakota Formation capping butte at 12
o’clock.
0.4
2.4
Red sandstones and siltstones of the Gunsight Butte Member of Entrada Formation
crops out near the valley floor and the ridge beyond.
3
J.L. Baer and R.H. Steed
Road Log for Kodachrome Basin State Park with Side Trips to Grosvenor Arch and Bull Valley Gorge, Utah
Figure 4. View looking northwest just east of Henrieville, Utah of typical Henrieville Formation. The formation is mostly
sandstone that has conspicuous limonite streaks throughout. The unit is bounded by unconformities in this area. This unit
displays both fluvial and shallow, still water sedimentation. It is in this formation that the Grosvenor Arch is so spectacularly carved.
0.4
2.8
The Pink Cliffs (Claron Formation) can be seen on the horizon at 11:00 o’clock.
0.9
3.7
Road cut is in the Cannonville Member of the Entrada Formation and is underlain by
the top most beds of the Gunsight Butte Member. The town of Cannonville is in the
valley directly ahead. The mesa beyond the town shows the Dakota Formation on
top, a full section of the Cannonville Member below that and the Gunsight Butte
Member crops out at the
base of the mesa (figure 5).
0.7
4.4
PARIA RIVER BRIDGE
0.2
4.6
TURN LEFT (SOUTH)
AT SIGN READING
“KODACHROME BASIN
9.0 MILES,” proceed
SOUTH on Main street of
Cannonville.
Figure 5. View looking west over Cannonville Town. The upper
mesas are capped in Cretaceous Dakota Formation. In the
prominent foreground hills the upper light colored beds of resistant sandstones are the entire Escalante Member of the Entrada
Formation. This unit is underlain by Cannonville Member light
gray to gray brown fine sandstones and siltstones The base of
these hills are red to red-brown thin sandstones and siltstones of
the Gunsight Butte Member.
4
P.B. Anderson and D.A. Sprinkel
2000 Utah Geological Association Publication 29
BEGIN ROAD LOG INTO KODACHROME BASIN STATE PARK
MILEAGE
INTERVAL/CUMULATIVE
DESCRIPTION
0.0
0.0
Start at intersection of Scenic Byway 12 and Main Street of Cannonville - GOING
SOUTH.
1.4
1.4
Remnant of Gunsight Butte Member of the Entrada Formation crops out on the left
side (east) of road.
0.6
2.0
Flood plain and river course of the Paria River on the left. The Paria River experiences many flash floods therefore caution should be exercised with any activity in or
near this river.
0.9
2.9
Intersection with unimproved road on the right. This road goes to BULL VALLEY
GORGE and beyond. Road log for this side trip is printed at the end of the Kodachrome Basin road log.
0.4
3.3
PARIA RIVER BRIDGE
0.6
3.9
Cattle Guard
0.8
4.7
Top of Paria River Member of the Carmel Formation.
0.2
4.9
Shepard Point is made of the Winsor Member capped by a Plio-Pleistocene conglomerate.
0.3
5.2
STOP -Road cut in the Winsor Member. It is suggested that a stop be made here but pull ahead and get completely off the road in the unimproved turnout. In the
road cut are spectacular sand-filled mud cracks as well as two smaller sand pipes.
Additional sand pipes can be seen on the southwest cliff face of SHEPARD POINT.
The road cut and the cliff face of SHEPARD POINT affords the best, readily accessible, view of the sedimentary pipes and some other geologic features. Figures 6 - 13
have detail descriptions of these features. By using these photos the reader will be
able to locate and closely observe these intriguing features. Continue trip- SOUTH.
1.7
5.9
Gunsight Butte Member is well exposed at 11:00 o’clock. Note the light-colored
sand pipe in the central part of the butte.
0.3
6.2
Entrance to KODACHROME BASIN STATE PARK - TURN LEFT ON UTAH
STATE ROAD 308. The Park has many sand pipes. Walking trails are available to
see many of these up close. The side-trip road log to Grosvenor Arch begins at this
intersection.
5
J.L. Baer and R.H. Steed
Road Log for Kodachrome Basin State Park with Side Trips to Grosvenor Arch and Bull Valley Gorge, Utah
Figure 6. Stop 1- Shepard Point. This site has many examples of the sedimentary pipes found in and around the KBSP. The
road cut is in the Winsor Member of the Carmel Formation. The view of the southwest cliff face displays least seven pipes to
the observer. The three-dimensional aspects of these pipes can also be observed. Note that the pipes here not only follow
some of the sedimentary weak zones but also cause some local deformation of the strata.
Figure 7. Stop 1- At least two sedimentary
pipes pierce the Winsor strata here and form a
small graben structure. A closer view of these
pipes shows how breccciated the contents are
of some of the pipes.
0.4
6.6
CATTLE GUARD - Winsor Member in knoll on left - notice pipe at 3 o’clock.
0.3
6.9
Directly ahead the stratigraphic column from the Winsor Member to the Dakota Formation is exposed.
0.6
7.5
CATTLE GUARD - Gunsight Butte Member on both sides of the road with several
pipes of widely different shapes are found along this outcrop.
0.4
7.9
TRAIL HEAD STATION - just beyond here two prominent sand pipes can be seen
on the right. See figures 14,15,16,17,18, 19, and 20.
6
P.B. Anderson and D.A. Sprinkel
2000 Utah Geological Association Publication 29
Figure 8. Stop 1- A
small, but persistent.
pipe traverses the whole
section and appears to
spread at the contact
with the capping conglomerate Small fault
seems to have little effect
on the pipe. Another
pipe, right side of figure
apparently follows a
fracture, A portion of
another pipe seems to
follow a fracture that is
parallel with the other
fracture. In this view neither of these pipes makes
it to the conglomerate
contact. Perhaps only a
portion of the pipes is
exposed as the pipes appear to wind their way
through the strata.
0.2
8.1
Note sand pipe protruding from the red sandstone.
0.2
8.3
Camp Ground - This is the END of the road log. You are encouraged to stop here
and examine the several sand pipes visible from the campground.
BULL VALLEY GORGE SIDE TRIP ROAD LOG
This road log starts at mile 2.9 on the Kodachrome Basin State Park road log. The graded dirt road is
passable for high clearance vehicles but it not recommended for most passenger cars. Because of the
nature of substratum and grade of this road it is recommended that only vehicles with four-wheel drive
and high clearance attempt the trip. Extreme caution must be exercised if there is running water in the
gullies.
MILEAGE
DESCRIPTION
INTERVAL/CUMULATIVE
0.0
0.0
Begin at intersection of Kodachrome Basin road and BLM. ROAD SIGN.
0.1
0.1
Cross tributary of Paria River.
7
J.L. Baer and R.H. Steed
Road Log for Kodachrome Basin State Park with Side Trips to Grosvenor Arch and Bull Valley Gorge, Utah
Figure 9. Stop 1 - Three
pipes are exposed on the
Shepard Point cliff. These
pipes appear to stop at
the thin-bedded dark
brown shale units.
Figure 10. Stop 1 - Some
of the pipes can be seen
in the roadcut proper.
This closer view shows
the three- dimensional
character of the pipes.
Internal texture can
change in a given pipe.
Note o that the pipe has
reduced the iron along
the contact with the intruded beds. There may
be a sill-like orientation
for a portion of the pipe.
0.1
0.2
Enter GRAND STAIRCASE-ESCALANTE NATIONAL MONUMENT. Road
cut on left is in the Cannonville Member.
0.8
1.0
Winsor Member of Carmel Formation crops out on the right.
0.1
1.1
Crest of hill - good view of Pink Cliffs at 1 o’clock.
0.4
1.5
CATTLE GUARD.
0.8
2.3
Traveling on the Paria River Member of the Carmel Formation.
8
P.B. Anderson and D.A. Sprinkel
2000 Utah Geological Association Publication 29
Figure 11. Stop 1- Spectacular sand- filled mudcracks in mudstones and another two pipes. This pipe lacks the prominent reduction contacts but has several small breccia pieces within it. See figure 13 for close-up.
Figure 12. Stop 1- Breccia pieces within the sedimentary pipe here appears to have an injection conduit
within a conduit. This suggests that the intrusion could
be multi-phase.
Figure 13. Stop 1 - Close up of mudcracks in mudstones
of the Winsor Member found in the roadcut.
9
J.L. Baer and R.H. Steed
Road Log for Kodachrome Basin State Park with Side Trips to Grosvenor Arch and Bull Valley Gorge, Utah
Figure 14. One of the spectacular columnar sedimentary pipes
(Mile.6.6). This column stands
alone and is over 10 feet in diameter. These sentinel-like
structures can be seen in many
places in the KBSP and are indeed the unique features of the
park. The craggy appearance of
this pipe is partly due to the
strongly brecciated nature of the
pipe. This pipe also shows what
appears to be a general slump
structure in its center.
0.6
2.9
Cross OLD RESERVOIR DAM sandstone outcrop, in lower valley walls is the
Page Sandstone Member.
0.1
3.0
Spillway
0.3
3..3
Plio - Pleistocene conglomerate
0.5
3.8
Crest of hill - Paria River Member on both sides of road. Excellent view of Pink
Cliffs.
0.6
4.4
Massive gypsum beds of the Paria River Member on both sides of the road.
0.1
4.5
Page Sandstone Member make up canyon rims, a minor fold can be seen directly
ahead.
0.2
4.7
Gully crossing.
0.1
4.8
Soft sediment deformation in outcrop.
0.2
5.0
Top of mesa.
1.2
6.2
Top of Navajo Formation in drainage on the left.
0.1
6.3
Paria River Member outcrop.
10
P.B. Anderson and D.A. Sprinkel
2000 Utah Geological Association Publication 29
Figure 15. This pipe is located
just north and east of the commercial store. It is more resistant to
erosion than the rocks that previously encased it. Its diameter is
approximately seven feet and it
has much smoother walls that the
column seen in figure 14.
0.7
7.0
Pink Cliffs at 2 o’clock. Directly
ahead the Yavimpa Point of Bryce
Canyon can be seen on the left and
Rainbow Point is on the right.
0.1
7.8
Navajo Sandstone rims and makes up
the body of the rock in which the
BULL VALLEY GORGE is cut.
0.2
8.0
TURN AROUND - BULL VALLEY
GORGE. This gorge is over 100 feet
deep in some places and less than 8
feet wide in many places. This deep,
narrow chasm is like many of the
gorges incised in the Navajo Sandstone. Late Tertiary uplift and the
relatively young downcutting leaves
these remarkable geomorphic features. Because of their steepness they
are popular, but always dangerous,
Figure 16. View of the figure 12 column from the
climbing spots for rock climbing en- east. Note how the texture changes from the
smooth wall to the pock marked , brecciated intethusiasts.
rior. This column also displays the reduction contacts. See figures 17 and 18.
11
J.L. Baer and R.H. Steed
Road Log for Kodachrome Basin State Park with Side Trips to Grosvenor Arch and Bull Valley Gorge, Utah
Figure 18. Reduction contact of Wiggler Wash Member siltstones and
flow structures seen on column shown in figure 12. These types of flow
structures indicate that the intruding material was of mushy when injected.
Figure 17. Reduction contact of sedimentary pipe wall and country rock. Reduced
region is nearly six inches thick.
0.2
8.0
(continued) If one walks down to the right along the Navajo Sandstone about
100-120 feet from the road and looks back at the under part of the somewhat
makeshift bridge you can see the remains of a pickup track that is lodged in the
gorge. Unfortunately three men lost their lives when the pickup fell into the
gorge and was wedged in its narrow opening.
SIDE TRIP TO GROSVENOR ARCH ROAD LOG
MILEAGE
INTERVAL/CUMULATIVE
DESCRIPTION
0.0
0.0
Start at intersection of UTAH STATE ROAD 308 and unimproved road that continues south and connects with U.S. Highway 89.
1.5
1.5
Butte directly ahead is the Winsor Member capped by the Gunsight Butte Member.
0.1
1.6
Cross drainage - be cautious.
1.6
3.2
At 9 o’clock is the butte with the Winsor Member capped by the Gunsight Butte
Member.
12
P.B. Anderson and D.A. Sprinkel
2000 Utah Geological Association Publication 29
Figure 19. Smooth
rind on column is a
layer of fine sand that
surrounds this structure.
2.1
5.3
At 9 o’clock is a prominent hogback held up by the Henrieville Sandstone with
the Cannonville Member making up the back slope.
0.2
5.5
High level terrace gravels.
0.3
5.8
STOP - Pull off road and view the panorama of the valley to the north - the rocks
making up the eastern scarp are the Winsor Member of the Carmel FormationCATTLE GUARD (figure 21).
0.6
6.4
Henrieville Sandstone makes up the cliffs ahead which are capped by the Dakota
Formation . Gunsight Butte Member exposed at 9 o’clock.
0.3
6.7
ROUND VALLEY DRAW
0.9
7.6
High level gravels near divide.
0.1
7.7
CATTLE GUARD
1.9
9.6
TURN OFF TO GROSVENOR ARCH TURN LEFT (EAST).
0.8
10.4
Cattle guard at 1:00 o’clock Cannonville Member at the base of slope, the Henrieville Sandstone overlies it with the Dakota Formation capping the bluff. The
rocks here are fractured. These fractures play an important role in the weathering
and eroding processes that make the arches.
13
J.L. Baer and R.H. Steed
Road Log for Kodachrome Basin State Park with Side Trips to Grosvenor Arch and Bull Valley Gorge, Utah
Figure 20. Panorama view from mile 5.8 on roadlog to Grosvenor Arch. View is north-northeast with the prominent
cliff line made up of members of the Entrada Formation.
0.2
10.6
GROSVENOR ARCH PARKING. The arch is formed in the Henrieville Sandstone. The short hike to the arch is well worth the effort. Seeing the arch from
many angles affords a greater appreciation of the beauty of this spectacular geomorphic feature.
END OF ROAD LOG
Figure 21. Grosvenor Arch is the result of a unique set of fractures, sedimentary structures, and weathering. This arch is named in honor of Gilbert. H. Grosvenor, longtime editor of the National Geographic
magazine. The arch is carved in the Henrieville Formation.
14