![](media/image1.png){width="6.492361111111111in"
height="0.7597222222222222in"}

**Geologic Map of Pipe Spring National Monument and the Western
Kaibab-Paiute Indian Reservation, Mohave County, Arizona**

By George H. Billingsley, Susan S. Priest, and Tracey J. Felger

Prepared in cooperation with the

National Park Service and the Kaibab-Paiute Tribe

Pamphlet to accompany

Scientific Investigations Map 2863

2004

U.S. Department of the Interior

U.S. Geological Survey

###### INTRODUCTION {#introduction .Style-Heading-6-+-Before:--12-pt-Line-spacing:--single}

This geologic map is a product of a cooperative project between the U.S.
Geological Survey, the National Park Service, and the Kaibab-Paiute
Indian Tribe to provide a uniform quality geologic database for this
part of the Uinkaret Plateau of the Arizona Strip north of Grand Canyon
National Park and west of Fredonia, Arizona. The geologic data will be
useful for future geologic, biologic, and hydrologic resource studies of
this area conducted by the National Park Service, the Kaibab-Paiute
Tribe, the citizens of Moccasin, Arizona, the Bureau of Land Management
(BLM), the State of Arizona, local private ranching organizations, and
individuals.

Sandy Canyon Wash, Bitter Seeps Wash, and Bulrush Wash are the principal
drainages in the map area that flow south into Kanab Creek, the
principal drainage of this region that flows south toward the Colorado
River in Grand Canyon. Moccasin Mountain and Moquith Mountain (Moki
Mountain on old maps) form highland plateaus west and north of Moccasin
and Kaibab, Arizona. The Vermilion Cliffs are a prominent topographic
expression of the landscape that marks the southern and eastern edges of
Moccasin and Moquith Mountains. The north edge of the map area abuts the
Utah/Arizona State line. Access to the map area is by Arizona State
Highway 389 and a short paved road to Pipe Spring National Monument and
the towns of Kaibab and Moccasin, Arizona (fig. 1). Several unimproved
dirt roads lead from these paved roads to various locations within the
map area, but travel on some of these roads requires 4-wheel-drive
vehicles. Extra food and water are highly recommended for travelers to
this remote area.

The Kaibab-Paiute Tribe manages the reservation lands that encompass
most of the map area. Visitors to the Kaibab-Paiute Indian Reservation
are required to obtain a permit and permission from the Tribal Offices
at the junction of Highway 389 and the road to Pipe Spring National
Monument. The Bureau of Land Management (BLM), Arizona Strip Field
Office in St. George, Utah, manages BLM lands west and south of the
Kaibab-Paiute Indian Reservation area. Part of the BLM Cottonwood Point
Wilderness area is included in the northwest corner of the map (fig. 1).
There are 22 sections of land belonging to the State of Arizona and 26
sections of private ranch land, which includes the town of Moccasin,
Arizona (U.S. Department of the Interior, 1999). Elevations range from
about 4,265 ft at Bulrush Wash in the southeast corner of the map area
to about 7,042 ft on Moquith Mountain, northeast edge of map area.
Elevations below 5,000 ft generally support a sparse growth of
sagebrush, cactus, grass, and various high-desert shrubs. Elevations
above 5,000 ft commonly support moderate to thick growths of sagebrush
and grass in alluvial valleys, while pinion pine, juniper, and oak trees
thrive on Moccasin and Moquith Mountains. Salt cedar (tamarisk) and
Russian olive trees grow along the banks of local tributary washes east
of Kaibab and Moccasin, Arizona.

###### PREVIOUS WORK {#previous-work .Style-Heading-6-+-Before:--12-pt-Line-spacing:--single}

Marshall (1956a, b), Pillmore (1956), and Hemphill (1956) made the
earliest photogeologic maps of the area for the U.S. Atomic Energy
Commission. Those maps were later compiled onto the state geologic map
of Arizona by Wilson and others (1969) and later modified by Reynolds
(1988). Geologic maps of adjacent areas (fig. 1) include photogeologic
maps of the Short Creek NW quadrangle (now Colorado City quadrangle) by
Marshall and Pillmore (1956); the Short Creek SW quadrangle (now Maroney
Well quadrangle) by Marshall (1956c); the Heaton Knolls NW quadrangle
(now Wild Band Pockets quadrangle) by Marshall (1956d); and the Fredonia
NE quadrangle (now Fredonia quadrangle) by Morris (1957). Other nearby
geologic maps include Clayhole Wash and vicinity, scale 1:31,680, about
9 mi west of the map area (Billingsley and others, 2002); Upper Clayhole
Valley and vicinity about 6 mi southwest of the map area (Billingsley
and Priest, 2003); and Jumpup Canyon and Big Springs quadrangles near
the southeast edge of the map area (Billingsley, 1992).

![](media/image2.wmf)

**Figure 1.** Map showing the Moccasin (A), Kaibab (B), Pipe Valley (C),
and Pipe Spring (D) U.S. Geological Survey 7.5-minute quadrangles and
adjacent mapped areas, northern Mohave County, northern Arizona.

###### MAPPING METHODS

The geology was mapped using Bureau of Land Management 1:24,000-scale
1976 aerial infrared photographs and 1:24,000-scale 2002 aerial color
photographs followed by extensive field checking. Many of the Quaternary
alluvial deposits have similar lithologies but different geomorphic
characteristics and were mapped almost entirely by aerial photography.
Relative ages of surficial fluvial and eolian deposits were determined
using stratigraphic position and the amount of erosional degradation.
The map units and geologic structures were field checked to insure
accuracy and consistency of map unit descriptions.

###### GEOLOGIC SETTING

The map area lies within the north part of the Uinkaret Plateau, a
subplateau of the southwestern part of the Colorado Plateau
physiographic province (Billingsley and others, 1997). The area is
characterized by nearly flat Paleozoic and Mesozoic sedimentary strata
that have an average regional dip of about 1° to 2° north-northeast and
are gently warped by minor north-south-trending folds and offset by
normal faults. About 650 ft of Permian strata and about 3,400 ft of
Triassic and Jurassic strata make up the sedimentary section within the
map area. The Sevier Fault that offsets all Paleozoic and Mesozoic
strata and the Moccasin Monocline are the principal structures in the
map area and have a general north-south and northeast strike.

Quaternary deposits are widely distributed in the map area and consist
of fluvial alluvium deposits, eolian sand sheets and sand dune deposits,
mixed fluvial and eolian deposits, talus, rock fall, and landslide
debris. Manmade quarries, drainage diversion dams, and stock tanks are
also mapped. Agricultural fields and minor road cut excavations are not
mapped. Map contacts between several Quaternary surficial deposits are
arbitrarily placed because of intertonguing and gradational facies
changes in both the lateral and vertical sense. The information about
surficial units strongly influences many resource management decisions
for managing rangeland conditions, flood control problems, biological
studies, soil erosion and development, and the development of local
construction projects. The surficial deposits are Pleistocene or
Holocene age (less than 2 m.y.) based on datable volcanic rocks
associated with similar surficial deposits mapped in adjacent areas
(Billingsley and Workman, 2000; Billingsley and others 2002; Billingsley
and Priest, 2003).

###### STRATIGRAPHY {#stratigraphy .Style-Heading-6-+-Before:--12-pt-Line-spacing:--single}

The Paleozoic and Mesozoic stratigraphic units exposed within the map
area include, in order of decreasing age, the Kaibab Formation (Lower
Permian), the Moenkopi Formation (Lower and Middle? Triassic), the
Chinle Formation (Upper Triassic), the Moenave Formation (Lower
Jurassic), the Kayenta Formation (Lower Jurassic), and the Navajo
Sandstone (Lower Jurassic). Ages of the Mesozoic strata have been
revised to reflect new data described and published by Biek and others,
2000.

Gray cherty limestone and gray, red, and white siltstone and gypsum beds
of the Kaibab Formation crop out in the southeast corner of the map
area. A complete section of the Kaibab Formation is exposed just
southeast of the map area in Kanab Canyon (Billingsley, 1992). About
three-fourths of the surface bedrock in the south and east part of the
map area is composed of red siltstone and sandstone, gray gypsum, and
gray dolomite of the Moenkopi Formation, and white sandstone and
multi-colored siltstone and claystone of the Chinle Formation. Red-brown
claystone, siltstone, and sandstone of the Moenave and Kayenta
Formations form the lower slopes of the Vermilion Cliffs, whereas
light-red and white, cross-bedded Navajo Sandstone forms the cliffs of
the upper part of the Vermilion Cliffs as well as the highlands of
Moccasin and Moquith Mountains in the northwest quarter of the map area.
A regional unconformity separates the Permian Kaibab Formation from the
Triassic Moenkopi Formation. Another regional unconformity separates the
Moenkopi Formation from the Triassic Chinle Formation, and a third
regional unconformity separates the Chinle Formation from the Jurassic
Moenave Formation.

Light-red, gray, and brown alluvial and eolian surficial deposits that
are locally derived from bedrock outcrops cover more than half of the
map area. All surficial deposits are generally 3 to 60 ft thick. Most of
the fluvial deposits, such as alluvial fans and alluvial terrace
deposits, are locally derived from Triassic and Jurassic strata of the
Vermilion Cliffs. The eolian deposits are commonly derived from local
fluvial deposits below the Vermilion Cliffs and outcrops of the Navajo
Sandstone on Moccasin and Moquith Mountains. The thickest and most
widespread eolian deposits are on Moccasin and Moquith Mountains. Most
of the eolian deposits are stabilized by grassy vegetation during wet
climatic conditions but do become active during prolonged dry conditions
coupled with extensive overgrazing.

###### STRUCTURAL GEOLOGY {#structural-geology .Style-Heading-6-+-Before:--12-pt-Line-spacing:--single}

The Sevier Fault is the principle structural feature in the map area and
forms the boundary between the Uinkaret Plateau west of the fault and
the Kanab Plateau east of the fault (Billingsley and others, 1997). The
Sevier Fault north of Pipe Spring National Monument generally has a
north-south strike that extends into Utah. South of the Monument the
fault has a slightly southwest-northeast strike and connects to the
Toroweap Fault about 13 mi south of the map area. Just north of Pipe
Spring National Monument, a short west segment of the Sevier Fault
extends northwest toward Moccasin, Arizona, and dies out about 2 mi
north of Moccasin. Paleozoic and Mesozoic strata have a north-northeast
regional dip about 1° to 2° throughout the map area. There are minor
faults and folds and a few local collapse structures scattered
throughout the map area.

The main segment of the Sevier Fault continues northeast of Pipe Spring
National Monument to the Vermilion Cliffs where the fault parallels the
east-facing Vermilion Cliffs for about 3 mi to Sand Wash, then continues
north into Utah east of the Coral Pink Sand Dunes State Park. A gentle
east-dipping monocline is present along the Sevier Fault at the north
edge of the map west of the Moquith Mountains. Monoclines on the
Colorado Plateau have developed in response to the Laramide orogeny of
Late Cretaceous through Eocene time along pre-existing Precambrian fault
zones (Huntoon, 2003). Mesozoic strata along the Moccasin Monocline dip
east as much as 10º elevating the landscape about 200 to 300 ft west of
the Sevier Fault. Extensional stresses from Late Miocene to the present
time have resulted in down-to-the-west normal faulting along the
Precambrian basement faults effectively reversing part of the Laramide
offset of strata by displacing strata down-to-the-west as much as 1,300
ft near Pipe Spring. Most of the fault displacement probably occurred
during Pliocene and Pleistocene time and likely continues today, as
observed on the Toroweap and Hurricane Faults west and southwest of the
map area (Billingsley and Workman, 2000; Billingsley and Wellmeyer,
2003).

###### West segment of the Sevier Fault

The west segment of the Sevier Fault branches from the main segment just
north of Pipe Spring National Monument. Associated with the west segment
is an east-dipping monocline herein referred to as the Moccasin
Monocline. At the base of the Moccasin Monocline is a small syncline
that parallels the strike of the monocline. The west segment of the
Sevier Fault, Moccasin Monocline, and syncline all gradually die out
northward into Moccasin Mountain about 2 mi north of Moccasin, Arizona.
The monocline and syncline extend southwest of Pipe Spring National
Monument and gradually die. The syncline is subtly visible in the
monoclinal flex in the Vermilion Cliffs just west of Pipe Spring. The
monocline, syncline, and Sevier Fault all parallel the west side of the
paved road between Pipe Spring National Monument and Moccasin, Arizona.
The northwest structural trend of the west segment of the Sevier Fault
may be continuous as a small fault at depth in the Precambrian basement
rocks under Moccasin Mountain and reconnect to the main segment of the
Sevier Fault near Sandy Canyon Wash just south of the Arizona/Utah State
line.

###### Main segment of the Sevier Fault

Fluvial and eolian sand deposits largely cover the main segment of the
Sevier Fault north of its junction with the west segment of the Sevier
Fault. About 2 mi northeast of the junction, the Sevier Fault displaces
the Shinarump Member of the Chinle Formation about 240 ft near South
Moccasin Wash. The offset results in a fault scarp that forms a
northeast-trending slope of the red Moenkopi Formation capped by a white
sandstone of the Shinarump Member of the Chinle Formation. Three miles
north of South Moccasin Wash, the Sevier Fault is partly visible in
Mesozoic strata between landslide deposits near the base of the
Vermilion Cliffs. The fault is mostly covered by landslide debris or
surficial deposits for 3 mi along the Vermilion Cliffs to Sandy Canyon
Wash. Just southwest of Blue Knolls, the Sevier Fault is poorly exposed
in small drainages at the base of the Vermilion Cliffs and the fault
plane appears to dip west about 70º to 75º. Surficial deposits largely
cover the Sevier Fault from Sandy Canyon Wash north into Utah, but its
position is marked by topographic expression where the Sevier Fault
separates the higher Moquith Mountains east of the fault from the lower
Moccasin Mountains west of the fault.

A monocline is not apparent along the main segment of the Sevier Fault
until it reaches the vicinity of the Arizona/Utah State line, but a
syncline is present just east of the Vermilion Cliffs for about 3 mi to
Sandy Canyon Wash where the syncline dies out. Triassic strata east of
and along most the main segment of the Sevier Fault dip about 2º
northeast.

South of the Pipe Spring National Monument, fluvial and eolian deposits
cover the Sevier Fault and Moccasin Monocline. The existence of the
Moccasin Monocline south of Pipe Spring is somewhat conjectural and the
Sevier Fault trace is approximate marked for about 3 mi south to Pipe
Valley Wash. Fault drag on the upthrown side (east) of the fault in a
drainage 1 mi south of Pipe Spring shows strata dipping west as much as
45º. South of the map area, the Sevier Fault and a monocline continue
for several miles forming a near perpendicular intersection with the
Toroweap Fault.

One structural peculiarity within the map area is a local graben in the
Vermilion Cliffs 2 mi north of Kaibab, Arizona. The graben, oriented
generally north-south, cuts through the southeast tip of Moccasin
Mountain then turns sharply east toward the Sevier Fault at its northern
extension. The displacement of the Navajo Sandstone into the graben is
about 160 ft near the Sevier Fault and about 200 ft at its southern
extension. The graben has a U-shaped profile in cross section instead of
a typical V-shaped profile. The U-shaped graben is well exposed in the
Vermilion Cliffs just west of the Sevier Fault. The Navajo Sandstone is
faulted down into the graben and slid southward within the graben as a
landslide mass. The sandstone beds within the graben have rotated
backward and dip north against the parent wall from which they
originated. The landslide mass protrudes out beyond and below the
Vermilion Cliffs as a lower broken cliff of the Navajo Sandstone. The
base of the graben terminates within the lower part of the Kayenta
Formation where the mudstone and siltstone beds provide a surface for
the Navajo Sandstone to slide. A minor synclinal fold is present beneath
the graben in the lower strata of the Kayenta and Moenave Formations
that may reflect a graben structure at depth.

The minor synclines in the south-central part of the map have a general
north-south trend and these folds, like others found elsewhere on the
Colorado Plateau, are probably related to early Laramide compressional
stresses (Huntoon, 2003).

###### JOINTS 

Joints are prominent features visible in the sandstone bedrock units
throughout the map area. There are four different orientations of joints
in the Moccasin Canyon and Moccasin Mountain area northwest of Pipe
Spring National Monument: north-south, northeast, northwest, and
east-west. At least two and sometimes three joint sets are present in
different parts of the map area, but typically only two sets are
commonly present, the northeast and northwest oriented.

Joints are vertically continuous through all hard and soft Paleozoic and
Mesozoic rock strata exposed in the Grand Canyon south of the map area.
The joints reflect older regional stress patterns from compressional
tectonic events of different geologic ages from Proterozoic through
Cenozoic time for the Colorado Plateau. The joints are prominently
displayed on surface exposures of hard sandstone and sandy limestone
bedrock units of the Kaibab Formation, the Shinarump Member of the
Chinle Formation, the Springdale Sandstone Member of the Moenave
Formation, and the Navajo Sandstone. These rocks units are
well-cemented, competent cliff-forming strata that tend to break and
fracture rather than bend and flow as the softer interbedded mudstone
and siltstone strata that form steep slopes between the cliff-forming
sandstones. The northwest- and northeast-orientated joint systems appear
to be the most active in the map area because many of the joints are
visible as semi-open cracks in the Navajo Sandstone. The cracks are also
visible in the surficial eolian sand deposits on Moccasin Mountain as
linear vegetation growths, especially in the upper reaches of Moccasin
Canyon where the joints are filled with eolian sand deposits and the
local vegetation has established a deep roothold. On aerial photographs,
the linear vegetation growth patterns are visible in sand sheet or sand
dune deposits.

A north-northwest joint zone at Zion National Park, 10 mi northwest of
the map area, is documented by Rodgers (2002) as the youngest in the
region. Rodgers concluded that the north-northwest trending joint zones
and subsequent isolated joints indicate a pervasive extension
characteristic of west-southwest extension of the central Basin and
Range Province that has affected the western Colorado Plateau since
mid-Miocene time. However, the northwest joint system may be as old as
Laramide age and may have been reactivated from Miocene time to the
present because of the following observation. The abundant northwest-
and north-orientated joints form open cracks in the canyon walls of
Navajo Sandstone in Moccasin Canyon. The joint planes are parallel to
the Moccasin Monocline and dip as much as 8º to 10º west in the middle
of the monocline. The Navajo Sandstone and Kayenta Formation strata dip
east as much as 8º to 10º. By unfolding the monocline back to its nearly
flat-lying position of pre-Laramide time, the joints would be nearly
vertical as they are in the nearly flat-lying strata in upper Moccasin
Canyon. Thus, the joint systems along the Moccasin Monocline are either
pre-Laramide and were tilted by Laramide folding, or if the joints at
Zion National Park are Miocene age as suggested by Rodgers (2002), then
the Moccasin Monocline would have to be Late Miocene or younger in age
because of the tilted joint planes.

###### COLLAPSE STRUCTURES

Circular bowl-shaped areas with inward-dipping strata are collapse
structures that may have developed because of collapse-formed breccia
pipes caused primarily by dissolution of the deeply buried Mississippian
Redwall Limestone (Wenrich and Huntoon, 1989; Wenrich and Sutphin,
1989). A dot and the letter C on the map mark such features. These
collapse features, however, cannot be distinguished with certainty from
shallow collapse structures caused by the dissolution of gypsum in the
Kaibab or Toroweap Formations. Drilling is required to confirm that
breccia pipes do originate in the Redwall Limestone. The deep-seated
breccia pipes contain potential economic high-grade ore deposits of
copper and uranium minerals (Wenrich, 1985). The primary metal is
uranium along with Ag, Pb, Zn, Cu, Co, and Ni (Wenrich and Huntoon,
1989).

A large collapse structure is present in the upper reaches of Cove
Canyon about 3 miles east of Kaibab, Arizona. This collapse structure is
about 1/8 mi in diameter and is likely a breccia pipe at depth. The
smaller breccia pipes marked near Pipe Valley Wash are also probably
collapse breccia pipes.

###### SPRINGS OF THE MAP AREA

Water is a critical natural resource that is responsible for the early
pioneer development of this part of the high desert of the Arizona
Strip. The historical use of Pipe Spring is the reason for the existence
of Pipe Spring National Monument that helps to preserve the historical
and natural resources of this unique area. Moccasin Spring, northwest of
Pipe Spring, is also a critical natural water resource for the town of
Moccasin, Arizona, and it is critical for human and animal habitats of
this remote part of northern Arizona (fig. 2).

There are similar structural and bedrock characteristics that control
the spring discharges at Pipe Spring and Moccasin Spring. Both springs
(1) are on the down-thrown side of either the west segment or main
segment of the Sevier Fault, (2) discharge at the bottom of a local
syncline at the base of the east-dipping Moccasin Monocline, (3) are at
or near the contact of the Navajo Sandstone and the Kayenta Formation,
and (4) are associated with north-south and northwest-southeast oriented
bedrock joints.

Moccasin Spring is about 3.5 mi northwest of Pipe Spring at elevation
5,170 ft and Pipe Spring is at elevation 4,970 ft, a vertical difference
of 200 ft. Thus, the ground-water gradient is about 57 ft/mi from
Moccasin Spring to Pipe Spring assuming that both springs have the same
ground-water source. The ground-water flow is largely confined to the
base of the Navajo Sandstone and upper part of the Kayenta Formation,
mostly within the syncline at the base of Moccasin Monocline. The
high-angle, west-dipping fault plane of the west and main segments of
the Sevier Fault acts as a partial barrier to the eastward flow of
ground water, but most importantly, the impermeable strata of the Chinle
and Moenkopi Formations east of the faults forms the impermeable barrier
to ground-water leakage through the faults because of the abundant
claystone and gypsum content of those formations. Thus, ground water
accumulates on the west side of the west segment of the Sevier Fault
forming a saturated water zone within the syncline and against the fault
plane until the static water level reaches an erosional gap in the
bedrock for ground water to overflow the fault. Moccasin Wash has eroded
deep enough into the west segment of the Sevier Fault to provide a point
of overflow for ground water to flow east into the alluvial deposits of
South Moccasin Wash. The discharge for Pipe Spring is similar in that a
small drainage has eroded headward into the syncline just northwest of
Pipe Spring, allowing water to flow east and southeast over the eroded
main segment of the Sevier Fault.

At South Moccasin Wash, ground water flows over the fault barrier into
thick sandy alluvial and eolian deposits that overlie impermeable
bedrock strata of the Petrified Forest Member of the Chinle Formation,
or upper red member of the Moenkopi Formation. The Shinarump Member of
the Chinle Formation is porous conglomeratic sandstone that becomes
saturated with water as much as the alluvium of South Moccasin Wash and
that forms a perched water table in the South Moccasin Wash valley area
under the towns of Moccasin and Kaibab, Arizona. The alluvial deposits
along South Moccasin Wash are as much as 120 ft thick or more along the
drainage.

The distance between the west and main segments of the Sevier Fault
along South Moccasin Wash is about 1.5 mi. The perched shallow ground
water within the alluvium between the faults is eventually forced over
the main Sevier Fault at the lowest eroded part of South Moccasin Wash
causing the static water table to become shallow and visible in South
Moccasin Wash just west of the fault. East of the main Sevier Fault,
bedrock under the alluvium is mostly impermeable gypsum and gypsiferous
siltstone and claystone of the Shnabkaib Member and lower red member of
the Moenkopi Formation. The ground water is again restricted to the
shallow alluvial and eolian deposits of South Moccasin Wash drainage
valley forming a perched water zone as far downstream as the alluvial
deposits extend. When there is no more alluvium, such as at State
Highway 389, water is visibly flowing on bedrock of the Moenkopi
Formation in South Moccasin Wash. South Moccasin Wash becomes Twomile
Wash just downstream of Highway 389. Some of the water, after
evaporation and domestic use, shows up at Twomile Seep in Twomile Wash
south of Highway 389 (fig. 2). Tamarisk trees commonly grow where
shallow ground water exists due to the close proximity of bedrock in
Twomile Wash.

Other springs and seeps within the map area have relatively small
discharges, generally less than one gallon per minute, and many become
dry during sequential drought year conditions. The next largest springs
within the map area is a small cluster of springs collectively known as
Upper Moccasin Springs in the upper reaches of Moccasin Canyon (fig. 2).
These springs discharge an estimated one or two gallons per minute each,
as of spring 2003, a dry year, but discharge will likely increase in
wetter climatic conditions.

Joints in the bedrock control the flow of ground water toward most
spring outlets in the map area to a certain extent, but it is the
bedrock composition and dip of strata of nearly flat-lying or gently
folded strata aided by gravity that control the basic ground-water flow.
The Navajo Sandstone is commonly a permeable rock unit in which ground
water moves and collects within the lower sandstone stratum. Bedding
planes and numerous joints within the Navajo Sandstone allow ground
water to migrate or flow at a faster rate through the rock unit than
within the sandstone itself. The joints and fractures act as direct
conduits for ground water flow while the sandstone acts as the reservoir
that accumulates and stores ground water and that slowly discharges
water into joints and bedding planes to flow toward springs. The most
important

![](media/image3.wmf)

Figure 2. Schematic index map of springs shown on the Moccasin, Kaibab,
Pipe Valley, and Pipe Spring U.S. Geological Survey 7.5-minute
quadrangles, Mohave County, northern Arizona.

factor is that the Navajo Sandstone overlies the impermeable claystone
and siltstone strata of the upper part of the Kayenta Formation, which
acts as a barrier to the downward percolation of ground water. The
contact between the Navajo Sandstone and Kayenta Formation is
gradational and variable throughout the map area as a gradational
intertonguing transition zone about 40 to 60 ft thick. This transition
zone consists of a sequence of interbedded red sandstone and siltstone
beds that form alternating slopes and ledges. The map contacts are
approximate and arbitrarily placed at about the lowest red sandstone
cliff of the Navajo Sandstone, or near the topmost red siltstone bed
within the upper part of the Kayenta Formation that is generally within
the Navajo/Kayenta transition zone. In either case, ground water is
largely restricted to the base of the Navajo Sandstone and to some
extent to permeable sandstone beds within the upper part of the Kayenta
Formation. Ground water at or near this contact zone moves down slope
through joints or along bedding planes largely controlled by the local
or regional dip of strata in the lowest sandstone exposures along the
Vermilion Cliffs and in canyon drainages. Springs and seeps commonly
located in the Navajo Sandstone/Kayenta Formation transition zone are
Pipe Spring, Moccasin Spring, Upper Moccasin Springs, Red Cliffs Spring
(Moquith Mountains), Bull Pasture Spring (Bull Pasture, northwest part
of map area), Meeks Spring (in upper Potter Canyon), and an unnamed
spring in Rosy Canyon, northwest corner of the map area (fig. 2).

A few springs owe their existence, in part, to the permeable Springdale
Sandstone Member of the Moenave Formation that is sandwiched between the
impermeable strata of the Kayenta Formation above and the Whitmore Point
Member of the Moenave Formation below. Two miles north of Kaibab,
Arizona, there are three unnamed springs in the Cedar Ridge area (Fig.
2) and Point Spring, two miles north of Kaibab, Arizona, that are
usually dry except during wet weather conditions (fig. 2). The recharge
for ground water in the Springdale Sandstone is likely limited to
surface rainfall collection areas where the Springdale Sandstone is
exposed. A likely recharge zone for water at Point Spring is the thick
landslide debris masses that overlie the impermeable beds of the Kayenta
Formation.

Aulson Spring in Aulson Canyon and Moonshine Spring at Yellowstone Mesa
(fig. 2) discharge water at the contact between the Shinarump Member of
the Chinle Formation and the upper red member of the Moenkopi Formation.
Surface recharge areas of these seep springs are due to extensive
exposures of permeable coarse-grained sandstone outcrops of the
Shinarump Member of the Chinle Formation that overly impermeable
claystone and mudstone beds of the Moenkopi Formation. Large surface
exposures of the Shinarump Member above Aulson and Moonshine Springs
provide a good surface recharge area for these springs. Often there are
other local wet weather seeps at the base of the Shinarump Member
outcrops in both areas of the map during wetter climatic conditions.

Pine Spring and Wolf Spring discharge small amounts of water at the
contact between alluvium and the Petrified Forest Member of the Chinle
Formation. These seep springs are the result of ground water collected
from rainfall on alluvial fan deposits uphill of the spring outlets. The
impermeable claystone and siltstone beds of the Chinle Formation
effectively prevents the downward percolation of ground water at the
base of the alluvial fans and forces most of the local perched
accumulated ground water to flow down to exposures of the Chinle
bedrock.

Wooley Spring west of Pipe Spring discharges below a large landslide
debris mass that overlies impermeable siltstone and claystone strata of
the Kayenta Formation. The large landslide mass is an excellent recharge
zone for Wooley Spring during wet weather years because of the fractured
nature of the landslide. Willow Spring and Burnt Corral Spring on
Moccasin Mountain are wet weather springs within the Navajo Sandstone.
These springs discharge from minor impermeable cherty limestone beds
that have limited lateral extent within the Navajo Sandstone. As a
result, these springs are short lived because they are largely
restricted to the extent of the cherty limestone beds within the Navajo
Sandstone.

The swamp in Parashont Canyon is a perched water zone in the surficial
valley alluvium that fills a canyon drainage eroded into the impermeable
Kayenta Formation. This shallow perched ground water is dependent on
local runoff into the canyon drainage. The alluvial filled valleys of
Rosy Canyon, Parashont Canyon, Bull Pasture, and Woodberry Canyon, in
the northwest quarter of the map area, all have potential shallow well
water producing capabilities that may be limited in volume and
restricted to the alluviated valleys.

###### ACKNOWLEDGMENTS

We thank Steve Condon and Charles Powell, II of the U.S. Geological
Survey, and Greer Price of the New Mexico Bureau of Mines and Mineral
Resources for their scientific assistance in the preparation of this
report. Becky Hammond, a geologist with the Bureau of Land Management,
Arizona Strip Field Office, St. George, Utah assisted in providing the
1976 infrared aerial photos and the 2002 color aerial photographs for
this study. Joann Isbrecht and Edwin Pfiefer of the Southwest Geographic
Science Information Team at the U.S. Geological Survey, Flagstaff,
Arizona, graciously provided Landsat 1999 satellite image coverage for
this map area. Discussions with Tom Sabol and Paul Umhoefer, Northern
Arizona University, were helpful in the structural interpretations. The
advice, suggestions, and final map and report edits by Theresa Iki of
the U.S. Geological Survey, Menlo Park, California are greatly
appreciated.

### Description of map units

### SURFICIAL DEPOSITS

Surficial deposits are differentiated from one another chiefly on the
basis of difference in morphologic character and physiographic position
observed on 1976 aerial photographs and field observations. Older
alluvial and eolian deposits generally exhibit extensive erosion,
whereas younger deposits are actively accumulating material or are
lightly eroded. Salt is a common constituent in all alluvial deposits
derived from the Chinle and Moenkopi Formations in the south and east
part of the map area.

Qaf **Artificial fill and quarries (Holocene)**---Alluvium and bedrock
material removed from quarries and trench excavations to build stock
tanks, drainage diversion dams, roads, or other manmade construction
projects other than modern highways. No map distinctions between cut or
fill excavations. Agricultural fields are not shown

Qs **Stream-channel alluvium (Holocene)**---White to light-red
interbedded silt, sand, gravel, and pebbles; unconsolidated and poorly
sorted. Pebbles and some cobbles are mostly sandstone above the
topographic position of the Shinarump Member of the Chinle Formation;
below the Chinle, clasts are dominated by black, well-rounded pebbles of
quartzite or chert of volcanic origin. Locally overlaps or is deposited
adjacent to young and intermediate alluvial terrace-gravel deposits
(Qg1, Qg2) and commonly overlaps young and intermediate alluvial fan
(Qa1, Qa2) deposits. Gradational and arbitrary contacts with other
surficial alluvial or eolian deposits are approximate and subject to
change. Stream channels are subject to intermittent high-energy flash
floods that can produce local sediment accumulation on floodplain (Qfp)
and young terrace alluvial (Qg1) deposits and widespread sediment
accumulations on young alluvial fan (Qa1) deposits. Stream-channel
alluvium is a common source for local sand dune or sand sheet
accumulations in Pipe Valley and Sandy Canyon Wash areas. Little or no
vegetation in stream channels except for occasional tamarisk trees or
willow trees and grass. Thickness, 3 to 12 ft

Qfp **Floodplain deposits (Holocene)**---Light-red or tan silt, fine- to
coarse-grained sand, and lenses of pebble gravel; partly consolidated by
gypsum or calcite cement. Gravel locally contains yellow, red, black,
and white subrounded to subangular chert fragments, well-rounded white
quartzite, and gray-blue, rounded limestone pebbles ¼ to ¾ inch in
diameter. Seasonal floods may produce fresh deposits that generally
accumulate temporary deposits on point bars of drainages, on young
alluvial terrace-gravel (Qg1) deposits, and on flatland areas adjacent
to young alluvial fan (Qa1) deposits when drainages area clogged by
debris flows or man-made obstructions. Gradational and arbitrary contact
both laterally and vertically between stream-channel (Qs), floodplain
(Qfp), and young alluvial fan (Qa1) deposits. Support thick growth of
tamarisk trees and other water-dependent plants where stream bedrock is
very shallow, usually less than 10 ft to bedrock. Dense growths of
tamarisk often help trap and accumulate sediment to form floodplain
deposits within and along drainages. Deposits are generally 3 to 6 ft
above stream-channel (Qs) deposits and often grade laterally into
stream-channel deposits. Thickness, 3 to 20 ft

Qps **Ponded sediments (Holocene)**---Light-red to white clay, mud,
silt, and fine-grained sand. Locally include small angular to subrounded
fragments of bedrock from nearby rock outcrops. Sediment accumulates in
temporarily ponded areas on young and intermediate alluvial
terrace-gravel (Qg1, Qg2) deposits due to temporary sand dune
accumulations or overbank sand levee deposits that prevent sediments
from eroding back into local drainages for an extended amount of time.
Includes ponded deposits consisting mostly of sand and silt on Moccasin
Mountain where widespread sand sheet and sand dunes form temporary dams
across local drainages or as internal dunal depressions formed within
dunes. South of Pipe Spring National Monument, ponded deposits
accumulate in lowland areas where artificial diversion dams, stock
tanks, or small sand dunes block drainage. Desiccation cracks often form
on dry hardpan surfaces. Clay and fine silt largely restrict plant
growth. Thickness, 1 to 6 ft

Qes **Eolian sand sheet deposits (Holocene)**---On Moccasin and Moquith
Mountains above Vermilion Cliffs, light-red to white silt and fine- to
coarse-grained eolian sand derived from the Navajo Sandstone (Jn). Forms
thick deposits over gently sloping terrain of Navajo Sandstone where
sand fills large cracks and joints on the surface of Navajo allowing
deep-rooted vegetation to develop linear growths on sand sheet or sand
dune (Qd) deposits. Only most extensive and thickest deposits on
Moccasin Mountain are shown; map contacts are arbitrary and gradational
between sand sheet (Qes), sand dune (Qd), and mixed eolian and fluvial
(Qae) deposits and are based on morphologic interpretation on aerial
photos. Below Vermilion Cliffs, deposits accumulate along local stream
drainages and on gentle slopes of young and intermediate alluvial fan
(Qa1, Qa2) deposits. Unit forms coarse-grained sand ramps on gentle
slopes of the Shinarump Member of the Chinle Formation where the
Shinarump is the sand source. Deposit often leads to fine-grained
climbing or falling sand dune (Qd) accumulations on steep bedrock or
landslide (Ql) deposits along Vermilion Cliffs and other small isolated
mesas and buttes where wind speed is reduced to allow sand accumulation.
In Pipe Valley south of State Highway 389, sand sheet deposits are thin,
widespread, and partly stabilized by grass and small high-desert shrubs
during wet conditions on young alluvial fan (Qa1) deposits; also
stabilized by lag gravel consisting mostly of black pebbles derived from
the Shinarump Member of the Chinle Formation of Yellowstone Mesa. Sand
sheet veneer deposits are widespread and common through the map area but
most are too thin to show. Support moderate growths of grass, black
brush, and other small high-desert shrubs above Vermilion Cliffs, mostly
grass below Vermilion Cliffs. Thickness, 0.5 to 3 ft in south half of
map; as much as 9 to 15 ft in large valleys on Moccasin Mountain and
within tributary canyons eroded into Moccasin Mountain

Qd **Eolian sand dune deposits (Holocene)---**Light-red to white, fine-
to coarse-grained sand. Form complex lumpy dune shapes and random dune
accumulations on variable sloping topography. Include climbing or
falling dunes on steep sloping topography along Vermilion Cliffs.
Arbitrary and gradational contact with sand sheet (Qes) and mixed eolian
and fluvial (Qae) deposits are based on aerial photography
interpretation. Dune surfaces are commonly active in large open valley
areas that support sparse growth of grass or small shrubs and on steep
topography. Unit is partly stabilized by grassy vegetation or by
crypto-organic soil growths in local canyon drainage areas below
Vermilion Cliffs. Thickness, 12 to 35 ft

Qae **Mixed eolian and fluvial deposits (Holocene)**---Composed of gray,
light-red, and white silt and fine- to coarse-grained eolian and fluvial
sand lenses interbedded with red-brown and gray silt and clay. Include
some coarse-grained gravel composed of angular chert fragments and red
to white sub-rounded sandstone pebbles on Moccasin Mountain. Below
Vermilion Cliffs, southeast half of map area, include multicolored,
well-rounded quartzite pebbles derived from the Shinarump Member of the
Chinle Formation. Commonly occupy upper slopes of young and intermediate
alluvial fan (Qa1, Qa2) deposits. Below Vermilion Cliffs, northwest
quarter of map area, mostly composed of white and light-red sandstone
and red siltstone that forms young alluvial fan deposits but deposits
are dominated by interbedded mixed fluvial and eolian deposits in
Parashont and Woodberry Canyons. Often overlapped by surficial sand
sheet (Qes) or sand dune (Qd) deposits with arbitrary or approximate map
contacts based on aerial photo interpretations. Support thick to
moderate growths of grass, cactus, and some sagebrush below Vermilion
Cliffs; sagebrush, oak brush, cliffrose bush, pinion pine, oak, and
juniper trees above Vermilion Cliffs. Thickness, 5 to 60 ft

Qv **Valley fill alluvial deposits (Holocene)**---Gray to light-red,
slope-forming, unsorted mixture of mud, silt, sand, gravel, small
pebbles, and cobbles. Partly consolidated by calcite and gypsum cement.
Sandstone, limestone, and chert in sandy matrix is locally derived from
nearby Paleozoic and Mesozoic sedimentary rock outcrops in southeast
quarter of map area. Similar to stream-channel (Qs) deposits but occupy
low-gradient drainages that deposit mostly fine-grained sand or silt
over nearly flat drainage floor. Similar to or interbedded with
floodplain (Qfp) deposits in Pipe Valley area. Subject to extensive
sheet wash erosion, deposition, flash flood debris flows, and arroyo
erosion. Commonly interbedded with local stream-channel alluvium (Qs)
and sand sheet (Qes) or sand dune (Qd) deposits. Contacts with other
alluvial deposits are arbitrary and approximate. Thickness, 3 to 20 ft

Qtr **Talus and rock fall deposits (Holocene)**---Include silt, sand,
and large to small broken rocks and boulders that form talus debris
slopes in steep-walled canyons and lower part of Vermilion Cliffs. Some
boulders of Navajo Sandstone or sandstone of the Shinarump Member of the
Chinle Formation are as large as vehicles and up to house size near
landslide debris (Ql) deposits below Vermilion Cliffs. Arbitrary and
gradational contact between landslide debris (Ql) deposits, talus and
rock fall debris (Qtr), young, intermediate, and old alluvial fan (Qa1,
Qa2, Qa3) deposits as determined by aerial photo interpretation. Unit
grades downslope into young, intermediate, or old alluvial fan (Qa1,
Qa2, Qa3) deposits. Thickness, 5 to 45 ft

Qg1 **Young alluvial terrace-gravel deposits (Holocene)**---Red, white,
and gray interbedded fine- to coarse-grained sand and thinly laminated
silt; partly consolidated by gypsum and calcite cement. Include
interbedded thin beds of gray or red mud and clay and some interbedded
lenses of gravel composed of gray subangular chert fragments above
outcrops of the Chinle Formation. Include gray-blue subrounded limestone
pebbles, and red, yellow, black, or white, well-rounded quartzite
pebbles below outcrops of the Shinarump Member of the Chinle Formation.
Deposits are inset against intermediate alluvial terrace-gravel (Qg2)
deposits and young and intermediate alluvial fan (Qa1, Qa2) deposits.
Subject to erosion by flash floods or overbank floodplain (Qfp) sediment
accumulation in lower reaches of drainages. Moderately vegetated by
sagebrush, grass, cactus, tamarisk trees, willow trees, juniper trees,
and some pinion pine trees in canyons eroded into Vermilion Cliffs.
Terraces are generally 4 to 10 ft above stream-channel (Qs) deposits and
as much as 40 ft above stream channels in lower reaches of Bulrush Wash
and Bitter Seeps Wash. Unit cut by modern arroyos as much as 30 ft deep
in Moccasin Canyon and in other unnamed canyons eroded into Vermilion
Cliffs. Thickness, 4 to 50 ft or more

Qa1 **Young alluvial fan deposits (Holocene)**---Light-red, gray, and
brown silt, fine- to coarse-grained interbedded sand and gravel; partly
consolidated by gypsum, calcite, and clay. Contain light-red to brown
silt, red and white chert fragments and small red and white sandstone
pebbles locally derived from outcrops of the Kayenta Formation and
Navajo Sandstone below the Vermilion Cliffs. Locally include boulders of
the Shinarump Member of the Chinle Formation as much as 6 ft in diameter
near outcrops of the Shinarump below Yellowstone Mesa and Bitter Seeps
Wash areas. Clay content greatest near outcrops of Petrified Forest
Member of the Chinle Formation in Sandy Canyon Wash, and Pipe Valley
areas. Include numerous black, brown, yellow, red, and gray, very well
rounded quartzite and chert pebbles 0.5 to 2 inches in diameter and
rare, rounded, gray-white petrified wood fragments derived from
Shinarump Member of the Chinle Formation. Locally covered by thin sand
sheet (Qes) and mixed eolian and fluvial (Qae) or sand dune (Qd)
deposits at distal ends of alluvial fan deposits. Commonly overlapped by
or intertongue with stream (Qs) deposits. Subject to extensive sheet
wash erosion or sediment accumulation during heavy storms. Support
moderate growths of grass, sagebrush, and various small high-desert
shrubs. All deposits below Vermilion Cliffs are composed of sediment
derived locally from Triassic and Jurassic sedimentary strata.
Thickness, 5 to 40 ft

Qg2 **Intermediate alluvial terrace-gravel deposits (Holocene and
Pleistocene(?))---**Gray, light-red to brown, thin- to massive-bedded,
interbedded clay, silt, and fine-to coarse-grained sand similar to young
alluvial terrace-gravel (Qg1) deposits; partly consolidated by clay and
gypsum. Unit intertongues with young and intermediate alluvial fan (Qa1,
Qa2) deposits along Bulrush Wash. Map contact is arbitrary between
alluvial units. Deposit forms terraces generally 8 to 20 ft above local
streambeds in upper reaches of drainages near Vermilion Cliffs and as
much as 60 ft above stream channels in lower Bulrush Wash and Bitter
Seeps Wash. Intertongue with young and intermediate alluvial fan (Qa1,
Qa2) deposits in upper Pipe Valley Wash, Twomile Wash, and Sandy Canyon
Wash. Arbitrary and gradational contact with young and intermediate
alluvial fan deposits. Support moderate growth of grass, cactus, black
brush, and sparse sagebrush. Thickness, 8 to 30 ft

Qa2 **Intermediate alluvial fan deposits (Holocene and
Pleistocene(?))**---Similar to young alluvial fan (Qa1) deposits; partly
consolidated by calcite, clay, and gypsum cement below stratigraphic
level of the Chinle Formation; mostly unconsolidated above Chinle
Formation. Commonly overlapped by young alluvial fan (Qa1) and
stream-channel (Qs) deposits. Intertongue with intermediate alluvial
terrace-gravel (Qg2) deposits near distil ends of fans. Intertongue with
landslide (Ql) deposits and talus and rock fall (Qtr) deposits at upper
reaches of alluvial fans below Vermilion Cliffs where unit is heavily
dissected by erosion. Support moderate growths of sagebrush, cactus, and
grass. Thickness, 6 to 45 ft

Ql **Landslide debris deposits (Holocene and
Pleistocene)**---Unconsolidated masses of unsorted rock debris typically
along lower slopes of Vermilion Cliffs. Include detached blocks of
strata that have rotated backward and slid downslope as loose incoherent
masses of broken rock and deformed strata, often surrounded by talus and
rock fall (Qtr) debris. Often covered in part by sand sheet (Qes) and
sand dune (Qd) deposits. Individual landslides may become unstable
during wet conditions and creep downslope where unit overlies claystone
or siltstone bedrock of Petrified Forest Member of the Chinle Formation
or lower part of the Kayenta Formation. Support sparse growth of
sagebrush, cactus, grass, juniper trees, and pinion trees. Thickness, 25
to 200 ft

Qg3 **Old alluvial terrace-gravel deposits (Pleistocene)---**Gray and
light-brown to light-red clay, silt, and sand similar to young and
intermediate alluvial terrace-gravel (Qg1, Qg2) deposits. Locally
contain lenses of small pebble gravel and conglomerate composed of white
and red, rounded sandstone, blue-gray rounded limestone, sub-rounded
white chert, and scattered well rounded multicolored quartzite pebbles
in fine- to coarse-grained gravel matrix. Unit preserved as scattered
deposits along lower reaches of Bulrush Wash and Bitter Seeps Wash,
southeast corner of map area. Form terraces about 30 to 120 ft above
stream (Qs) deposits. Unit often covered by thin sand sheet deposits too
thin to show at map scale. Support sparse growth of sagebrush, black
brush, cactus, and grass. Thickness, 10 to 20 ft

Qa3 **Old alluvial fan deposits (Pleistocene)**---Similar to young and
intermediate alluvial fan (Qa1, Qa2) deposits; stony surface where not
covered by sand dune (Qd) deposits along base of Vermilion Cliffs in
northeast quarter of map area. Contribute material to young and
intermediate alluvial fan deposits. Composed mainly of silt, sand,
gravel, cobbles, and boulders of sandstone locally derived from the
Kayenta Formation or Navajo Sandstone. Intertongue with talus and rock
fall (Qtr) and landslide debris (Ql) deposits. Adjacent to or overlapped
by young and intermediate alluvial fan (Qa1, Qa2), sand sheet (Qes), and
sand dune (Qd) deposits. Thickness, 10 to 50 ft

QTg4 **Oldest alluvial terrace-gravel deposits (Pleistocene and
Pliocene(?))**---Lithologically similar to young, intermediate, and old
alluvial terrace-gravel (Qg1, Qg2, Qg3) deposits as isolated deposits in
Bulrush Wash about 120 to 180 ft above modern drainage. Deposits are
partially preserved in abandoned cutoff meander loops or isolated
abandoned point bars in southeast quarter of map area. Thickness, 6 to
20 ft

####### SEDIMENTARY ROCKS

Jn **Navajo Sandstone (Lower Jurassic)**---White to light-red and
yellow-gray, cliff-forming, medium-crossbedded to thickly-crossbedded,
well-sorted, fine- to coarse-grained eolian quartz sandstone interbedded
with dark-red, coarse-grained sandstone and siltstone in lower part. Age
determination by Peterson and Pipiringos (1979) and Biek and others
(2000). Lower part is commonly red, upper part commonly white. Includes
lenses of interbedded dark purple-gray, thin-bedded, calcareous
sandstone beds that formed freshwater deposits within and between
coastal sand dunes. High-angle, crossbedded sandstone sets interbedded
with low-angle, crossbedded sandstone and thin flat-bedded sandstone
sets. Unit commonly covered by thin to thick sand sheet (Qes), sand dune
(Qd), or mixed eolian and fluvial (Qae) deposits. Unit is highly
fractured by near vertical northeast-, northwest-, and
north-south-oriented bedrock joints. Joints that parallel the Moccasin
Monocline dip west or southwest as much as 82º and strata of the Navajo
Sandstone and Kayenta Formation dip east 8º at Moccasin Canyon and just
northwest of Pipe Spring National Monument. Joints are near vertical in
upper Moccasin Canyon where strata are nearly horizontal verifying that
the joints likely developed prior to development of the Moccasin
Monocline. Gradational but sharp contact with underlying Tenney Canyon
Tongue of the Kayenta Formation placed at base of Navajo Sandstone cliff
at Moquith Mountains and the Kayenta Formation elsewhere. Supports
moderate growth of pinion and juniper trees, cliff-rose bush; thick
growths of sagebrush, various high-mountain shrubs and grasses on
Moccasin and Moquith Mountains. Incomplete section due to removal of top
part by modern erosion. Unit thickens north of map area to as much as
2,000 ft. Thickness, about 1,500 ft

Jkt **Tenney Canyon Tongue of the** **Kayenta Formation (Lower
Jurassic)**---Age as described by Biek and others (2000). Dark-red to
light red-brown, slope-forming, very fine-grained, thin-bedded to
laminated, fluvial siltstone and sandstone. Includes dark-red sandstone
lenses that form ledges in upper part. Gradational southwesterly facies
change from fine-grained, ledge- and slope- forming sequence to
alternating slope-forming, fine- to coarse-grained, mudstone, siltstone,
and sandstone sequence. Unit intertongues laterally with underlying Lamb
Point Tongue (Jnl) of the Navajo Sandstone. Forms sharp local horizontal
contact at top of Lamb Point Tongue cliff marked by color contrast of
dark-red siltstone and sandstone of Tenney Canyon Tongue to white and
light-red sandstone of Lamb Point Tongue at Moquith (Moki) Mountain
area. Unit thickens from 120 ft at Kanab, Utah, to 220 ft at Ed Lamb
Point, Moquith Mountains 8 miles northeast of Kaibab and Moccasin,
Arizona. Tenney Canyon Tongue becomes upper part of Kayenta Formation
where Lamb Point Tongue of Navajo Sandstone pinches out west and south
of Moquith Mountains. Thickness at Moquith Mountain area, 220 ft

Jnl **Lamb Point Tongue of the Navajo Sandstone (Lower Jurassic)**---Age
as described by Biek and others (2000). Type locality is Ed Lamb Point
on USGS 7.5' Kaibab quadrangle, Vermilion Cliffs of Moquith Mountains, 8
miles northeast of Moccasin and Kaibab, Arizona (Wilson, 1967).
Gray-white to orange-brown, cliff-forming, very fine-grained to
fine-grained, crossbedded quartz sandstone of eolian origin. Top 10 to
15 ft east of Ed Lamb Point locally shows penecontemporaneous deformed
beds that are beveled by overlying Tenney Canyon Tongue (Jkt) of the
Kayenta Formation. Forms gradational and sharp contact with underlying
Kayenta Formation (Jk) marked at base of white and red sandstone cliff
of the Lamb Point Tongue. Forms cliff of white and red cross-bedded
Navajo Sandstone within upper part of Kayenta Formation along Vermilion
Cliffs from Moquith Mountains east to Kanab, Utah. Unit is 400 ft thick
near Kanab, Utah, thins south and west to 140 ft thick at Moquith
Mountains; is mostly a red sandstone cliff about 100 ft thick near Point
Spring of Vermilion Cliffs 2 mi north of Moccasin and Kaibab, Arizona.
Unit forms an elongated 1-mi-wide tongue of sand that extends southwest
from Ed Lamb Point to Moccasin Mountains 2 mi north of Kaibab, Arizona
and pinches out as a red sandstone ledge in Vermilion Cliffs 1 mi west
of Pipe Spring National Monument. Thickness, 0 to 140 ft

Jk **Kayenta Formation (Lower Jurassic)**---Dark-red and light
red-brown, slope-forming calcareous mudstone, siltstone, and sandstone.
Unit deposited in river floodplains, river channels, playas, and shallow
lake environments (Blakey, 1994; Peterson, 1994). Age of unit determined
by Peterson and Pipiringoes (1979) and Biek and others (2000). Unit
often covered by landslide debris (Ql) and talus and rockfall (Qtr)
deposits along lower part of Vermilion Cliffs. Erosion of soft sediments
of the Kayenta Formation undercuts the resistant overlying Navajo
Sandstone causing large sections of Navajo and upper Kayenta units to
fail as landslide blocks along Vermilion Cliffs, especially where local
joints parallel Vermilion Cliffs. Thickness increases from 270 ft at Ed
Lamb Point to nearly 400 ft at Potter Canyon at the expense and loss of
the Lambs Point Tongue of the Navajo Sandstone southwest of Moccasin
Mountain. Thickness, 270 to 400 ft

**Moenave Formation (Lower Jurassic)**---Includes, in descending order,
the Springdale Sandstone Member, Whitmore Point Member, and Dinosaur
Canyon Member as defined by Averitt and others (1955); Stewart and
others (1972); and Sargent and Philpott (1987). Age determination after
Peterson and Pipiringos (1979) and Biek and others (2000)

Jms **Springdale Sandstone Member (Lower Jurassic)**---Light-red to
red-brown, cliff-forming, thin- to thick-bedded sandstone and lenses of
conglomerate. Includes low-angle trough crossbedded sets of fluvial
sandstone that contain dark red mudstone and siltstone rip-up clasts and
poorly preserved petrified and carbonized fossil plant remains within
crossbedded sets (Peterson and Pipiringos, 1979; Biek and others, 2000).
Crossbeds are separated by thin-bedded to laminated dark red siltstone
and mudstone beds that locally contain mudstone pellets (Wilson, 1967).
Gradational contact with underlying Whitmore Point Member. Unit
deposited by northeast to southwest flowing streams based on
crossbedding studies by Wilson (1967). Thickens north and east of map
area to about 200 ft at Kanab, Utah, thins southward and intertongues
with lower part of the Kayenta Formation. Thickness, 120 to 170 ft

Jmw **Whitmore Point Member (Lower Jurassic)**---Type section is near
Potter Canyon at southwest point of Moccasin Mountains (elev. 6,603 ft
at Radio Towers, left end of cross section B-B'). Named for Whitmore
Point by Wilson (1967) 3.5 mi west of Pipe Spring National Monument, but
the name Whitmore Point is not on the current USGS 7.5' Moccasin
quadrangle. Composed of red-brown sandstone and siltstone interbedded
with red-purple to green-gray and blue mudstone and claystone and thin
gray dolomitic limestone. Limestone contains small red-brown chert
nodules and poorly preserved fossil algal structures and fish scales and
bones near Zion National Park north of map area (Biek and others, 2000).
Gradational contact with underlying Dinosaur Canyon Member (Jmd) marked
by distinct color contrast of blue-green, green, and yellow mudstone and
siltstone of Whitmore Point Member to red-brown siltstone and sandstone
of underlying Dinosaur Canyon Member. Thickness, 60 to 80 ft

Jmd **Dinosaur Canyon Member (Lower Jurassic)**---Red-brown, slope and
ledge-forming, thin-bedded, very fine-grained sandstone and silty
sandstone. Unconformable contact with underlying undivided Owl Rock and
Petrified Forest Members of the Chinle Formation. Unit gradually
thickens west to east and is about 200 ft thick at Kanab, Utah (Wilson,
1967). Thickness, 120 to 200 ft

**Chinle Formation (Upper Triassic)**---Includes, in descending order,
the Owl Rock Member, Petrified Forest Member, and Shinarump Member as
used by Stewart and others (1972); Sargent and Philpott (1987); Biek and
others (2000)

\^cp **Owl Rock and** **Petrified Forest Members, undivided (Upper
Triassic)**---The Owl Rock Member of the Chinle Formation, (not mapped
separately) is present at the south end of the Moquith Mountains,
northeast corner of the map area and gradually thins to the west and
southwest and overlies the Petrified Forest Member. The Owl Rock is
composed of light-red and white, coarse-grained sandstone, gray,
fine-grained sandstone and siltstone interbedded with thin-bedded (5 in
to 2 ft) gray-white siliceous limestone beds. Limestone contains red and
white chert nodules. The Owl Rock is 40 ft thick at Kanab, Utah, and
thins to less than 30 ft at Ed Lamb Point and grades into the upper part
of the Petrified Forest Member throughout the map area. The Petrified
Forest Member is composed of gray, light-purple, blue, light- to
dark-red, slope-forming claystone, siltstone, and white, coarse-grained
sandstone. Weathers to frothy popcorn surface. Includes petrified wood
and calcite nodules at the Blue Knolls area. Unit is mostly covered by
sand sheet (Qes) and sand dune (Qd) and mixed fluvial and eolian (Qae)
deposits, and young, intermediate, and old alluvial fan (Qa1, Qa2, Qa3)
deposits. Contact with underlying Shinarump Member is gradational in the
vertical and lateral extent because multicolored mudstone and siltstone
intertongue with white gritty sandstone and conglomerate of the
Shinarump Member. Thickness, 600 to 700 ft

\^cs **Shinarump Member (Upper Triassic)**---White to yellow-brown,
cliff-forming, thin- to thick-bedded, coarse-grained, low-angle
crossbedded sandstone, gravel, and conglomeratic sandstone. Includes
numerous small channel lenses and pockets of small pebble conglomerate
composed of well rounded to subrounded, multicolored quartz, quartzite,
and black chert pebbles in gravely sandstone matrix. Black chert pebbles
are the dominant pebble. Pebbles average 1 to 2 inches in diameter and
include some well-rounded quartzite cobbles as much as 10 inches in
diameter and numerous petrified wood fragments and segments of petrified
logs. Black pebbles eroded from the Yellowstone Mesa area form a desert
pavement of lag gravel on all alluvial fan surfaces around Yellowstone
Mesa, southwest quarter of map area. Unit is the common source for
multicolored quartz, quartzite, and chert pebbles in all surficial units
below outcrops of the Shinarump Member of the Chinle Formation.
Weathered sand from the Shinarump Member is a source for local sand
sheet (Qes) and sand dune (Qd) deposits that overlie the Petrified
Forest Member east of the Vermilion Cliffs. Unit overlies and fills
broad erosion channels that are as deep as 30 ft and ½ to 1 mi wide
eroded into underlying upper red member of the Moenkopi Formation.
Thickness, 20 to 125 ft

**Moenkopi Formation (Middle(?) and Lower Triassic)**---Includes, in
descending order, upper red member, Shnabkaib Member, middle red member,
Virgin Limestone Member, lower red member and Timpoweap Member,
undivided, as used by Stewart and others (1972). (Timpoweap Member is
redefined for this map area due to facies changes of the Timpoweap
Member from that defined by Stewart and others \[1972\])

\^mu **Upper red member (Middle(?) and Lower Triassic)**---Light-red and
dark-red, slope- and ledge-forming sequence of siltstone and sandstone.
Forms small cliffs in upper part. Gradational contact with underlying
Shnabkaib Member placed arbitrarily at top of highest thick white
siltstone and dolomite bed of Shnabkaib Member. Thickness, 160 ft

\^ms **Shnabkaib Member (Lower Triassic)**---White to light-gray,
laminated to thinly bedded, slope-forming, aphanitic dolomite
interbedded with light-gray, calcareous silty gypsum. Includes some thin
light red mudstone, siltstone, and sandstone beds in lower and upper
part. Gradational contact with underlying middle red member placed at
lowest thick white or light-gray calcareous siltstone and dolomite bed
of the Shnabkaib Member. Unit thickens northwest of map area, thins
southeast. Thickness, 90 to 110 ft

\^mm **Middle red member (Lower Triassic)**---Red-brown, thin-bedded to
laminated, slope-forming gypsiferous siltstone and sandstone. Includes
thin veinlets and stringers of gypsum deposited in fractures and cracks
throughout unit. Includes minor beds of white laminated dolomite, green
siltstone, and gray-green to red gypsiferous mudstone. Mudcracks and
ripple marks common throughout. Gradational lower contact with Virgin
Limestone Member placed at top of highest gray limestone bed of Virgin
Limestone Member. Thickness, 280 to 300 ft

\^mv **Virgin Limestone Member (Lower Triassic)**---Includes two
light-gray, thin-bedded to laminated, ledge-forming limestone beds (1 to
3 ft thick), separated by pale-yellow, light-red, and bluish-gray,
thin-bedded to massive, slope-forming gypsiferous siltstone that makes
up the bulk of the unit. Lowest limestone bed contains star-shaped
crinoid plates and poorly preserved [Composita]{.underline} brachiopods
in upper part 18 mi east of map area; locally, upper limestone bed
contains fossil algae. Erosional unconformity separates lower gray
limestone from underlying dark red siltstone and sandstone of lower red
member of the Moenkopi Formation with erosional relief as much as 4 ft.
Lower limestone bed thickens and thins as shallow channel-fill deposit.
Forms small mesas near Bitter Seeps Wash and Pipe Valley Wash.
Thickness, 120 ft

\^ml **Lower red member and Timpoweap Member, undivided (Lower
Triassic)**---Dark-red, slope-forming, thin-bedded, fine-grained,
gypsiferous, sandy siltstone, sandstone, and pale-yellow to gray
laminated silty gypsum. Gypsum, siltstone, and sandstone in lower part
are derived from erosion of Harrisburg Member of the Kaibab Formation.
Includes a prominent ledge-forming red-gray to light purple-red,
coarse-grained, low-angle crossbedded calcareous sandstone marker bed in
lower part 3 to 7 ft thick that often forms resistant sandstone surface
of Kanab Plateau near Bulrush Wash and Bitter Seeps Wash. Marker bed
includes raindrop impressions and rare carbonaceous plant fossils 18 mi
east of map area (Billingsley and others, 2002). Has unconformable
contact with underlying gray limestone and red sandstone and siltstone
of Harrisburg Member of the Kaibab Formation at southeast edge of map
area. Thickness, 120 to 180 ft

**Kaibab Formation (Lower Permian)**---Includes, in descending order,
Harrisburg and Fossil Mountain Members as defined by Sorauf and
Billingsley (1991)

Pkh **Harrisburg Member**---Red and gray, slope-forming, interbedded
gypsiferous siltstone, sandstone, gypsum, and gray, cliff-forming,
thin-bedded limestone. Yellow-gray to light-red alternating slope and
ledge-forming calcareous sandstone and sandy limestone in upper part;
contains calcite and gypsum cement. Upper part includes thin beds of
low-angle crossbedded, calcareous sandstone, conglomerate, and minor
siltstone that form small ledges in Burnt Canyon Point area, southeast
corner of map area. Limestone beds are as much as 14 ft thick consisting
of a gray, thin-bedded, cherty limestone that weathers dark brown or
black and a light-gray, thin-bedded, sandy limestone. Limestone beds
thicken and thin laterally and form small cliffs in the Bulrush and
Sandy Canyon Wash areas. Dissolution of gypsum in lower part has locally
distorted some limestone beds causing them to slump or bend into local
drainages. Contact with underlying Fossil Mountain Member is gradational
and marked at top of cherty limestone bed of the Fossil Mountain Member
of the Kaibab Formation. Thickness, 160 ft

Pkf **Fossil Mountain Member**---Light-gray, fine- to medium-grained,
thin-bedded, fossiliferous, cliff-forming, sandy, cherty limestone. Unit
characterized by thin bedded, white chert beds and nodules in sandy
cliff-forming limestone. Contact with underlying Woods Ranch Member of
the Toroweap Formation is not exposed in map area but is exposed 3 mi
southeast of map area in Kanab Canyon where contact is an unconformity
caused by a combination of dissolution of gypsum and channel erosion
with relief as much as 6 to 15 ft. Thickness, 250 ft

####### Units shown only in crosssection

**Toroweap Formation (Lower Permian)**---Includes, in descending order,
Woods Ranch, Brady Canyon, and Seligman Members, as defined by Sorauf
and Billingsley (1991) and described by Billingsley and Priest (2003)
adjacent to southwest corner of map area. Units are exposed in Kanab
Canyon just south of the map area

Ptw **Woods Ranch Member**---Gray, slope-forming gypsiferous siltstone
and pale-red silty sandstone interbedded with white laminated gypsum.
Beds are locally distorted because of the dissolution of gypsum. Lower
contact gradational. Thickness varies from 180 to 265 ft because of the
dissolution of gypsum

Ptb **Brady Canyon Member**---Gray, cliff-forming, medium-bedded, fine-
to coarse-grained, fetid, fossiliferous limestone; weathers dark gray.
Includes thin-bedded dolomite in upper and lower parts. Limestone beds
average about 1 to 2 ft thick and include chert lenses and nodules.
Lower gradational contact with underlying Seligman Member of the
Toroweap Formation. Contact commonly covered by minor slump or talus
debris. Thickness, 230 ft

Pts **Seligman Member**---Gray, thin-bedded, slope-forming dolomite and
gypsiferous sandstone. Middle part includes gray to red, thinly
interbedded siltstone, sandstone, and gypsum; includes interbedded,
crossbedded sandstone of the Coconino Sandstone in the middle part.
Lower part includes brown, purple, and yellow, fine- to medium-grained,
thin-bedded, low- to high-angle crossbedded and planar-bedded sandstone
that is mostly covered by talus debris. Contact with underlying Hermit
Formation is unconformable with erosional relief as much as 3 ft;
contact mostly covered by talus and alluvial deposits. Thickness, 170 ft

####### REFERENCES CITED

Averitt, Paul, Wilson, R.F., Determan, J.S., Harshbarger, J.W., and
Repenning, C.A.H., 1955, Revisions in correlation and nomenclature of
Triassic and Jurassic formations in southwestern Utah and northern
Arizona: Bulletin of the American Association of Petroleum Geologists,
v. 39, no. 12, p. 2515-2524.

Biek, R.F., Willis, G.C., Hylland, M.D., and Doelling, H.H., 2000,
Geology of Zion National Park, Utah, *in* Sprinkel, D.A., Chidsey Jr.,
T.C., and Anderson, P.B., eds., Geology of Utah\'s parks and monuments:
Utah Geological Association millennium guidebook, publication 28, p.
107-138.

Billingsley, G.H., 1992, Geologic map of the Jumpup Canyon and Big
Springs quadrangles, Mohave and Coconino Counties, Arizona: U.S.
Geological Survey Miscellaneous Investigations Series Map I-2290, scale
1:62,500.

Billingsley, G.H., Priest, S.S., 2003, Geologic map of Upper Clayhole
Valley and vicinity, Mohave County, northwestern Arizona: U.S.
Geological Survey Miscellaneous Field Studies Map MF-2418, scale
1:31,680, 27 p. \[available on the World Wide Web at
http://geopubs.wr.usgs.gov/map-mf/mf2418/\].

Billingsley, G.H., Priest, S.S., Wellmeyer, J.L., and Dudash, Stephanie,
2002, Geologic map of Clayhole Wash and vicinity, Mohave County,
northwestern Arizona: U.S. Geological Survey Miscellaneous Field Studies
Map MF-2394, scale 1:31,680, 20 p. \[available on the World Wide Web at
http://geopubs.wr.usgs.gov/map-mf/mf2394/\].

Billingsley, G.H., Spamer, E.E., and Menkes, Dove, 1997, Quest for the
pillar of gold, the mines and miners of the Grand Canyon: Grand Canyon,
Arizona, Grand Canyon Association Monograph no. 10, 112 p.

Billingsley, G.H., and Wellmeyer, J.L., 2003, Geologic map of the Mount
Trumbull 30\' x 60\' quadrangle, Mohave and Coconino Counties,
northwestern Arizona: U.S. Geological Survey Geologic Investigations
Series I-2766, scale 1:100,000. \[available on the World Wide Web at
http://geopubs.wr.usgs.gov/i-map/i2766/\].

Billingsley, G.H., and Workman, J.B., 2000, Geologic map of the
Littlefield 30\' x 60\' quadrangle, Mohave County, northwestern Arizona:
U.S. Geological Survey Geologic Investigations Series I-2628, scale
1:100,000, 25 p. \[available on the World Wide Web at
http://geopubs.wr.usgs.gov/i-map/i2628/\].

Blakey, R.C., 1994, Paleogeographic and tectonic controls on some Lower
and Middle Jurassic erg deposits, Colorado Plateau, *in* Caputo, M.V.,
Peterson, J.A., and Franczyk, K.J., eds., Mesozoic Systems of the Rocky
Mountain region, USA: Denver, Colorado, Rocky Mountain Section of the
Society of Sedimentary Geology, p. 273-298.

Hemphill, W.R., 1956, Photogeologic map of the Fredonia NW quadrangle,
Mohave County, Arizona: U.S. Geological Survey Miscellaneous
Investigations Series Map I-133, scale 1:24,000.

Huntoon, P.W., 1989, Phanerozoic Tectonism, Grand Canyon, Arizona, *in*
Elston, D.P., Billingsley, G.H., and Young, R.A., eds., Geology of Grand
Canyon, northern Arizona (with Colorado River guides): Washington, D.C.,
28th International Geological Congress Field Trip Guidebook T115\\T315,
American Geophysical Union, p. 76-89.

Huntoon, P.W., 2003, Post-Precambrian tectonism in the Grand Canyon
region (Chapter 14): *in* Beus, S.S., and Morales, Michael, eds., Grand
Canyon Geology (2 ed.); New York, Oxford University Press, p. 222-259.

Marshall, C.H., 1956a, Photogeologic map of the Short Creek SE
quadrangle, Mohave County, Arizona: U.S. Geological Survey Miscellaneous
Investigations Series Map I-153, scale 1:24,000.

Marshall, C.H., 1956b, Photogeologic map of the Fredonia SW quadrangle,
Mohave County, Arizona: U.S. Geological Survey Miscellaneous
Investigations Series Map I-160, scale 1:24,000.

Marshall, C.H., 1956c, Photogeologic map of the Short Creek SW
quadrangle, Mohave County, Arizona: U.S Geological Survey Miscellaneous
Investigations Series Map I-140, scale 1:24,000.

Marshall, C.H., 1956d, Photogeologic map of the Heaton Knolls NW
quadrangle, Mohave County, Arizona: U.S. Geological Survey Miscellaneous
Investigations Series Map I-143, scale 1:24,000.

Marshall, C.H., and Pillmore, C.L., 1956, Photogeologic map of the Short
Creek NW quadrangle, Mohave County, Arizona: U.S. Geological Survey
Miscellaneous Investigations Series Map I-141, scale 1:24,000.

Morris, R.H., 1957, Photogeologic map of the Fredonia NE quadrangle,
Coconino and Mohave Counties, Arizona: U.S. Geological Survey
Miscellaneous Investigations Series Map I-247, scale 1:24,000.

Peterson, Fred, 1994, Sand dunes, sabkhas, streams, and shallow seas --
Jurassic paleogegraphy in the southern part of the Western Interior
Basin, *in* Caputo, M.V., Peterson, J.A., and Franczyk, K.J., eds.,
Mesozoic systems of the Rocky Mountain region, USA: Denver, Colorado,
Rocky Mountain Section of the Society for Sedimentary Geology, p.
233-272.

Peterson, Fred, and Pipiringos, G.N., 1979, Stratigraphic relations of
the Navajo Sandstone to Middle Jurassic Formations, southern Utah and
northern Arizona: U.S. Geological Survey Professional Paper 1035-B, p.
B1-B43.

Pillmore, C.L., 1956, Photogeologic map of the Short Creek NE
quadrangle, Mohave County, Arizona: U.S. Geological Survey Miscellaneous
Investigations Series Map I-142, scale 1:24,000.

Reynolds, S.J., 1988, Geologic map of Arizona: Arizona Geological
Survey, Tucson, Arizona, Map 26, scale 1:1,000,000.

Rodgers, C.M., 2002, Kinematic implications and dynamic analysis of
regularly spaced joint zones of the Navajo Sandstone, Zion National
Park, Utah: University Park, Pennsylvania, Unpublished MS Thesis,
Pennsylvania State University, 123 p.

Sargent, K.A., and Philpott, B.C., 1987, Geologic map of the Kanab
Quadrangle, Kane County, Utah, and Mohave and Coconino Counties,
Arizona: U.S. Geological Survey Geologic Quadrangle Map GQ-1603, scale
1:62,500.

Sorauf, J.E., and Billingsley, G.H., 1991, Members of the Toroweap and
Kaibab Formations, Lower Permian, northern Arizona and southwestern
Utah: The Mountain Geologists, v. 28, no. 1, p. 9-24.

Stewart, J.H., Poole, F.G., and Wilson, R.F., 1972, Stratigraphy and
origin of the Triassic Moenkopi Formation and related strata in the
Colorado Plateau region: U.S. Geological Survey Professional Paper 691,
195 p.

U.S. Department of the Interior, Bureau of Land Management, 1999,
Arizona Strip visitor map, Arizona: Bureau of Land Management, scale
1:168,960.

Wenrich, K.J., 1985, Mineralization of breccia pipes in northern
Arizona: Economic Geology, v. 80, no. 6, p. 1722-1735.

Wenrich, K.J., and Huntoon, P.W., 1989, Breccia pipes and associated
mineralization in the Grand Canyon region, northern Arizona, *in*
Elston, D.P., Billingsley, G.H., and Young, R.A., eds., Geology of Grand
Canyon, Northern Arizona (with Colorado River Guides): Washington, D.C.,
28th International Geological Congress Field Trip Guidebook T115/315,
American Geophysical Union, p. 212-218.

Wenrich, K.J., and Sutphin, H.B., 1989, Lithotectonic setting necessary
for formation of a uranium-rich, solution-collapse breccia-pipe
province, Grand Canyon region, Arizona: U.S. Geological Survey Open-File
Report 89-0173, 33 p.

Wilson, E.D., Moore, R.T., and Cooper, J.R., 1969, Geologic map of the
State of Arizona: Arizona Bureau of Mines, University of Arizona, scale
1:500,000.

Wilson, R.F., 1967, Whitmore Point, a new Member of the Moenave
Formation in Utah and Arizona: Museum of Northern Arizona, Plateau, v.
40, no. 1, p. 29-40.