Preliminary Investigation of Structural Controls of

Ground-Water Movement in

Pipe Spring National Monument, Arizona

Scientific Investigations Report 2004—5082

Prepared in cooperation with the NATIONAL PARK SERVICE

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Preliminary Investigation of Structural 

Controls of Ground-Water Movement in 

Pipe Spring National Monument, Arizona 

By Margot Truini, J.B. Fleming, and H.A. Pierce 

Prepared in cooperation with the 

NATIONAL PARK SERVICE 

Scientific Investigations Report 2004–5082 

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior 

Gale A. Norton, Secretary 

U.S. Geological Survey

Charles G. Groat, Director 

U.S. Geological Survey, Reston, Virginia: 2004 

For sale by U.S. Geological Survey, Information Services


Box 25286, Denver Federal Center


Denver, CO 80225–0286


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Suggested citation:


Truini, Margot, Fleming, J.B., and Pierce, H.A., 2004, Preliminary investigation of structural controls of ground-water


movement in Pipe Spring National Monument, Arizona: U.S. Geological Survey Scientific Investigations Report 2004–


5082, 16 p.

 iii 

Contents


Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


History of the study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Previousenvestigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Hydrogeologic setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


Geophysical methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11


Structural controls of ground-water movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13


Summary and conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17


Selected references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

iv 

Figures 

Figure 1. Map showing location of study area and wells and springs, Pipe Spring 

National Monument area, northern Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Figure 2. Graph showing spring discharge, 1976–2003, Pipe Spring National 

Monument, northern Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Figure 3. Map showing surface geology, location of selected EM31 and EM34 lines, 

and approximate location of spikes in apparent conductivity near Winsor 

Point, Pipe Spring National Monument area, northern Arizona . . . . . . . . . . . . . . . . . 6 

Figure 4. Diagram showing generalized lithologic units in the Pipe Spring National 

Monument area and a photograph showing the sandstone facies of 

the Kayenta Formation and the Navajo Sandstone at Pipe Spring 

National Monument, northern Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Figure 5. Photographs showing fractured bedrock of the Kayenta Formation in the 

open adit during reconstruction of Tunnel Spring in 2001, Pipe Spring 

National Monument, northern Arizona 

A. Fractures in the Kayenta Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

B. Ground-water seepage from fractures in the Kayenta Formation . . . . . . . . . . . . 9 

Figure 6. Map showing direction of ground-water movement and locations of 

seismic and electromagnetic lines in Pipe Spring National 

Monument, northern Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Figure 7. Photograph showing equipment for the seismic profile (line 1) in front 

of Winsor Castle, Pipe Spring National Monument, northern Arizona . . . . . . . . . . . 11 

Figure 8. Photograph showing electromagnetic-induction (EM) tools, Pipe Spring 

National Monument, northern Arizona 

A. EM31 tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

B. EM34 tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Figure 9. Graph showing eismic-refraction record from line 2 indicating low 

signal-to-noise ratio, making useful interpretation impossible, 

Pipe Spring National Monument, northern Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

Figure 10. Map showing areas of high and low apparent conductivity, Pipe Spring 

National Monument, northern Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Figure 11. Graphs showing apparent conductivity from EM34 data north of Pipe Spring 

National Monument, northern Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

Tables 

Table 1. Nominal depths of exploration for Genoics EM instruments . . . . . . . . . . . . . . . . . . . 13 
 v 

Conversion Factors and Datum 

Multiply By To obtain 

meter (m) 3.281 feet 

kilometer (km) 0.6214 mile 

square kilometer (km2) 247.1 acre 

square kilometer (km2) 0.3861 square mile 

liter (L) 0.2642 gallon 

cubic meter (m3) 264.2 gallon 

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NVGD29)—a geodetic datum derived from a general adjustment of the first-order level nets of both 

the United States and Canada, formerly called Sea Level Datum of 1929; horizontal coordinate 

information is referenced to the North American Datum of 1927 (NAD 27). Elevation, as used in this 

report, refers to distance above or below NGVD 29. 

WELL-NUMBERING AND NAMING SYSTEM 

WELL (B-40-04)08bab1 

A 

C D

B 

R. 4 W. 

T.

40

N. c 

6 5 4 

7 11 12 

18 16 13 

19 

30 

31 32 33 34

9 

21 

17 

23 

14 

d 

a 

a 

c d

b 

08 

20 22

8 10 

1 

26 

35 36 

29 28 27 

24 

b 

25 

D 

15 

3 2 

a 

c d 

b 

a 

Quadrant B, Township 40 North, Range 4 West, section 8, quarter section b, 

quarter section a, quarter section b, well 1 

The well numbers used by the U.S. Geological Survey in Arizona are in accordance with the Bureau of Land 

Management's system of land subdivision. The land survey in Arizona is based on the Gila and Salt River Meridian 

and Base Line, which divide the State into four quadrants that are designated by capital letters A, B, C, and D in a 

counterclockwise direction, beginning in the northeast quarter. The first digit of a well number indicates the township, 

the second the range, and the third the section in which the well is situated. The lowercase letters a, b, c, and d after 

the section number indicate the well location within the section. The first letter denotes a particular 160-acre tract, 

the second the 40-acre tract, and the third the 10-acre tract. These letters also are assigned in a counterclockwise 

direction, beginning in the northeast quarter. If the location is known within the 10-acre tract, three lowercase letters 

are shown in the well number. Where more than one well is within a 10-acre tract, consecutive numbers beginning 

with 1 are added as suffixes. In the example shown, well number (B-40-04)08bab1 designates the well as being in 

the NW1/4, NE1/4, NW1/4, section 8, Township 40 North, and Range 4 West. 

Preliminary Investigation of Structural 

Controls of Ground-Water Movement in 

Pipe Spring National Monument, Arizona 

By Margot Truini, J.B. Fleming, and H.A. Pierce 

Abstract 

Pipe Spring National Monument, near the border of Arizona and Utah, includes several low-discharge springs that are the 

primary natural features of the monument. The National Park Service is concerned about the declines in spring discharge. Seismicrefraction and frequency-domain electromagnetic-induction methods were employed in an attempt to better understand the relation 

between spring discharge and geologic structure. The particular method used for the seismic-refraction surveys was unable to 

resolve structural features in the monument. Electromagnetic surveys delineated differences in apparent conductivity of the shallow 

subsurface deposits. The differences are attributable to differences in saturation, lithology, and structure of these deposits. 

INTRODUCTION 

Pipe Spring National Monument, near the border of 

Arizona and Utah, is an area of natural and historical interest. 

Several low-discharge springs are the primary natural features 

of the monument. The National Park Service (NPS) is 

concerned about the declines in spring discharge. The 

discharge at these springs is influenced by geologic structures 

in the area (George Billingsley, geologist, U.S. Geological 

Survey, written commun., 2004). The monument is about 

24 km west of Fredonia, Arizona, and 32 km southwest of 

Kanab, Utah (fig. 1). The study area is approximately 0.7 km2 

and includes the monument, which occupies 0.16 km2 

(40 acres) within the boundaries of the Kaibab-Paiute Indian 

Reservation at the base of the southern tip of Winsor Point on 

a section of the Vermilion Cliffs, and adjacent areas (fig. 1). 

Four springs—West Cabin Spring, Main Spring, Spring 

Room Spring, and Tunnel Spring—are within the monument 

boundaries. West Cabin Spring is an undeveloped spring that 

discharges on the west side of Moccasin Point. Main Spring 

and Spring Room Spring are two man-made emanation points 

constructed by the Mormon pioneer occupants of the Pipe 

Spring ranch from 1870 to 1900 and ostensibly represent the 

flow of the original natural spring known as Pipe Spring. 

Tunnel Spring is a horizontal well, hand dug between 1902 and 

1907. Since July 1976, the NPS staff have measured discharge 

monthly at all four springs owing to a concern about declining 

discharges (Rick Inglis, hydrologist, National Park Service, 

written commun., 1998). From 1976 to 1986, the combined 

spring discharges declined about 7.6 L per minute per year 

(Barrett and Williams, 1986). From 1986 to 2001, combined 

spring discharge has declined by about 1.9 L per minute per 

year (Terry Strong, Facility Manager, National Park Service, 

written commun., 2001). During this recent period, discharge 

from West Cabin Spring has remained steady, discharges from 

Spring Room Spring and Main Spring have dropped to 

immeasurable levels, and the discharge from Tunnel Spring has 

increased (fig. 2). 

The U.S. Geological Survey (USGS), in cooperation with 

the NPS, conducted preliminary geophysical surveys during 

September 1999 to gain a better understanding of how geologic 

structure controls the relation between ground-water 

movement and spring discharge in the monument. Seismic 

refraction and frequency-domain electromagnetic-induction 

(EM) methods were employed. Four seismic-refraction surveys 

were conducted around Winsor Castle near Main Spring and 

Spring Room Spring. Multiple EM31 and EM34 surveys were 

conducted along transects near the four springs within the 

monument boundary and along transects north of the 

monument boundary. 

Purpose and Scope

 The purpose of this report is to describe the results of the 

geophysical surveys that were conducted to help define the 

subsurface geologic structure that controls ground-water 

movement within the monument and in areas north of the 

monument. The report provides information regarding the 

effectiveness of the methods employed. General structural 

controls within and north of the monument are described in 

relation to spring discharges. 
2 Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

112 48' ° 47' 46' 45' 112 44' °

36 55' °

54' 

53' 

36 52' °

a W 

o cas c M o in

wer 

U 

M 

W ash 

o 

as in

cc 

pper 

T. 

41 

N. 

T. 

40 

N. 

Moccasin 

Kaibab 

Moccasin 

Spring 

Sand 

Spring 

Spring 

s h

MOCCASIN MOUNTAINS 

VERMILION CLIFFS 

WINSOR 

M OCCASI N CANYON 

Unnamed 

Spring 

(See 

Pipe Spring Road 

STUDY 

AREA 

KAIBAB – INDIAN 

L 

R. 5 W. R. 4 W. 

(B-40-04)08bab1 

(B-40-04)17aac 

West Cabin Spring, 

Main Spring, 

Wooley 

POINT 

fig. 3) 

Pipe Spring 

(B-40-04)05cdd 

PAIUTE R E S E R VATI O N 

Base from U.S. Geological Survey National Spring Room Spring, 

digital data, 1:100,000, 1980 Monument Tunnel Spring Universal Transverse Mercator projection 

Zone 12 

STUDY 

AREA 

ARI

UTAH 

ZONA 

113 00'' ° 45' 30' 112 15' ° 37 07'30" °

VERMILION CLIFFS 

Fredonia 

Kanab 

WEST 

BRANCH 

SEVIER 

INDIAN 

ARIZONA 

STUDY 

AREA 

389 

89 

89 

OF SEVIER 

FAULT 

FAULT 

KAIBAB -PAIUTE 

RESER VATION 

UTAH 

ALT 

0 1 KILOMETER 

0 1 MILE 37 00' °

EXPLANATION 

(B-40-04)17aac WELL — 

(B-40-04)17aac 

is well 

identification 

number 

36 50' °

Figure 1. Location of study area and wells and springs, Pipe Spring National Monument area, northern Arizona. 
Introduction 3 

1 

2 

3 

4 

5 

6 

7 

8 

0 

SPRING DISCHARGE, IN LITERS PER MINUTE 

Period of tunnel restabalizationfor Tunnel Spring 

Spring Room Spring 

Spring Room Spring 

moving trend line 

Main Spring 

Main Spring moving 

trend line 

West Cabin Spring 

West Cabin Spring moving 

trend line 

Tunnel Spring 

Tunnel Spring moving 

trend line 

1976 1980 1985 1990 1995 2000 2003

Figure 2. Spring discharge, 1976–2003, Pipe Spring National Monument, northern Arizona. 
4 Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

History of the Study Area 

Archeological evidence indicates that the riparian 

resources supported by the springs in the monument have 

attracted people to the site for the past 8,000 years. Spring flow 

was the major source of drinking water in the 1870s during the 

establishment of Winsor Castle and the associated Mormon 

cattle-ranching operations. Winsor Castle was built directly 

over Pipe Spring to establish a secure drinking-water supply in 

an otherwise arid land. As Mormon cattle ranching developed, 

the springs supplied water for orchards, vegetable gardens, and 

livestock. In 1923, the monument was established around 

Winsor Castle to preserve the site of the historic Mormon 

cattle-ranching operations (Inglis, 1997). 

Early modifications to the water-supply systems of the 

monument included adding cisterns and pipelines from the 

springs to supply water for ranch operations (Inglis, 1997). 

Parts of the historic water-distribution system in the monument, such as rock-work channels and ponds, are maintained. 

Drains and pipelines have been installed to stabilize the 

buildings against damage from moisture. The pipeline from 

Tunnel Spring that conveys water outside the monument was 

replaced in 1988 to maintain water-use agreements with the 

local cattlemen’s association. The adit that forms Tunnel 

Spring was reconstructed in 2001 to prevent imminent collapse 

and ensure continued water availability to the cattlemen and 

monument. In 1971, NPS Culinary well (B-40-04)05cdd was 

drilled outside the monument to meet the increasing needs of 

the monument and the Kaibab-Paiute Tribe (E.H. McGavock, 

hydrologist, U.S. Geological Survey, written commun., 1974). 

Previous Investigations 

During 1972–74, the USGS evaluated the quantity and 

quality of available ground water from the Shinarump Member 

of the Chinle Formation and the potential for ground-water 

development in the Navajo Sandstone near the village of 

Kaibab (Gary Levings, hydrologist, U.S. Geological Survey, 

written commun., 1974). Levings found that ground water 

from the Shinarump Member contained concentrations of 

sulfate in excess of recommended levels for public supply 

(U.S. Public Health Service, 1962) and that ground water from 

the Navajo Sandstone was suitable for domestic use (Gary 

Levings, hydrologist, U.S. Geological Survey, written 

commun., 1974). Levings also stated that large-scale pumping 

of ground water from the Navajo Sandstone near Moccasin or 

the monument might decrease flow to the springs in these 

areas. 

Barrett and Williams (1986) evaluated the declining 

spring flows in the monument and analyzed spring-flow data 

from 1976 to 1986 with respect to water quality, precipitation, 

and geology. They concluded that the decline in spring flow 

probably was the result of ground-water pumping in the area 

rather than of natural variations in precipitation. 

Inglis (1997) examined precipitation data and data 

collected from the springs at the monument, from Moccasin 

Spring, and from wells (B-40-04)17aac and (B-40-04)05cdd 

(fig. 1), and was not able to establish a correlation between 

precipitation and the declining spring discharges. From August 

1990 to June 1992, Inglis (1997) measured water levels at 

wells (B-40-04)08bab1 and (B-40-04)17aac (fig. 1) and spring 

discharges at the monument. He concluded that the cause of 

annual fluctuations in ground-water levels and spring 

discharges, whether it be variations in seasonal recharge, 

seasonal pumping from wells, or a combination of these 

factors, could not be determined at that time. 

Truini (1998) characterized the ground-water system in 

the western part of the Kaibab-Paiute Indian Reservation from 

north of Moccasin, Arizona, to the monument. She determined 

ground-water flow direction and used geochemical methods to 

determine ages of ground water and recharge characteristics. 

She concluded that ground-water movement is from north to 

south, that the ground water is between 200 and 9,000 years 

old, and that components of recharge to ground water within 

the study area are from the same source. Within the study area, 

estimated ground-water withdrawals were greater than the 

estimated recharge. 

Acknowledgments 

John Hiscock (NPS, Superintendent of Pipe Spring 

National Monument), Dave Sharrow (NPS, Hydrologist, 

National Park Service), Terry Strong (NPS, Facility Manager, 

Pipe Spring National Monument), and other staff of the NPS 

helped in the organization and collection of geophysical data. 

Members of the Kaibab Band of the Paiute Tribe gave 

permission to access study areas and helped with the collection 

of geophysical data. 
Hydrogeologic Setting 5 

HYDROGEOLOGIC SETTING 

The study area encompasses Winsor Point at the southern 

end of a section of the Vermilion Cliffs (fig. 3). This section of 

the Vermilion Cliffs is a monocline resulting from Laramide 

(late Cretaceous to Paleocene) folding and subsequent faulting 

(George Billingsley, geologist, U.S. Geological Survey, 

written commun., 2003). 

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 [fig. 3]. 

The west segment of the Sevier Fault, the Moccasin 

Monocline, and the syncline all gradually die out 

northward into Moccasin Mountain about 3.2 km 

north of Moccasin, Arizona. The monocline and 

syncline extend southwest of Pipe Spring National 

Monument. The syncline is subtly visible in the 

monoclinal flex in the Vermilion Cliffs just west of 

the monument. The fault, monocline, and syncline 

parallel the paved road between the monument and 

Moccasin, Arizona. The northwest 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 Sand 

Canyon Wash just south of the Arizona/Utah State 

line. (George Billingsley, geologist, U.S. Geological 

Survey, written commun, 2003.)

 The Navajo Sandstone and the upper facies of the 

Kayenta Formation form the unconfined fractured rock aquifer 

from which ground water discharges at springs in the 

monument (fig. 4; Truini, 1998). On the basis of water-level 

measurements in area wells, ground-water movement is from 

north to south along the Vermilion Cliffs (Truini, 1998). Finegrained sediments below the upper sandstone facies of the 

Kayenta Formation behave as a confining unit that restricts 

vertical ground-water movement, forcing the water to move 

along the bedding planes and fractures in the Navajo 

Sandstone and upper facies of the Kayenta Formation (fig. 4). 

Displacement along the Sevier Fault in the southern part of the 

ground-water flow path has placed the older Triassic 

Schnabkaib Member of the Moenkopi Formation on the east 

side of the Sevier Fault against the younger Kayenta Formation 

and Navajo Sandstone on the west side of the Sevier fault 

(George Billingsley, geologist, U.S. Geological Survey, 

written commun., 2003.). The Schnabkaib Member forms a 

semi-impermeable boundary, preventing water from moving 

west to east across the Sevier Fault. 

Spring discharge within the monument issues from the 

sandstone facies of the Kayenta Formation (fig. 4). During 

reconstruction of the adit for Tunnel Spring in 2001, ground 

water was observed seeping from the direction of West Cabin 

Spring (the northwest side of the open trench) through small 

fractures in the Kayenta Formation at an elevation of 1,502 m 

(± 0.6 m; fig. 5). The elevation of the uppermost discharge 

point for West Cabin Spring is 1,515 m, and the measured 

elevation at Main Spring is 1,511 m. The NPS has confirmed 

that Main Spring and Spring Room Spring are hydraulically 

connected and are considered to discharge from the same 

ground-water source (fig. 6; David Sharrow, hydrologist, 

National Park Service, oral commun., 2002). On the basis of 

the visual observation in the Tunnel Spring adit and the 

differences in elevation between West Cabin Spring and Main 

Spring, it is likely that ground water within the monument 

moves from the area of West Cabin Spring to the southeast 

(fig. 6). 
6 Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

112° 45' 

36° 52' 

Jn 

Jn 

Jn 

Jn 

Jn 

Jn 

Qae 

Qae Qes 

Qes 

Qes 

Jk 

Jk 

Jk 

Jk 

Jk 

Jk 

Qa1 

Qa1 

Qa1 Qa1 

Ql 

Qaf 

EM31 line 104 and EM34 line 402 

EM31 line 103 and EM34 line 401 

PIPE SPRING NATIONAL MONUMENT 

Moccasin monocline 

Syncline 

Sevier Fault 

650 meters 

420–460 meters 

700 meters 

0 meters 

Qes 

Qd 

Qd 

Qd 

Qd Qd 

Qd 

Qes 

Ql 

Sevier Fault 

ms 

mm 

T R

T Rms

T Rms

T Rms

T R

T Rmm

5,600 

5,700 

5,500 

5,400 

5,300 

5,200 

5,100 

4,900 

5,000 

EM34 line 400 

330 meters 

0 meters 

Vermilion Cliffs 

Winsor Point 

Base from U.S. Geological Survey, 1:24,000, Moccasin, Geology from George Billingsley and others, U.S. Geological Survey, written commun., 2003 

Kaibab, Pipe Valley, and Pipe Spring; 1988 

Universal Transverse Mercator Projection 1927 North 0 0.25 KILOMETER 

American Datum Clark 1866 Ellipsoid, Zone 12 0 1/4 MILE 

CONTOUR INTERVAL 20 FEET (6.10 METERS) 

Figure 3. Surface geology, location of selected EM31 and EM34 lines, and approximate location of spikes in apparent conductivity near Winsor 

Point, Pipe Spring National Monument area, northern Arizona. 
Hydrogeologic Setting 7 

Qaf 

Qes 

Qd 

Qae 

Qa1 

Ql 

Jn 

Jk 

T Rms

T Rmm

330 meters 

Figure 3. Continued. 

EXPLANATION 

SURFICIAL DEPOSITS 

Artificial fill and quarries (Holocene) 

Eolian sand sheet deposits (Holocene)

Eolian sand dune deposits (Holocene)

Mixed eolian and fluvial deposits (Holocene)

Young alluvial fan deposits (Holocene)

Landslide debris deposits (Holocene and Pleistocene)

SEDIMENTARY ROCKS 

Navajo Sandstone (Lower Jurassic) 

Kayenta Formation (Lower Jurassic) 

Schnabkaib Member of Moenkopi Formation (Lower Triassic) 

Middle Red Member of Moenkopi Formation (Lower Triassic) 

CONTACT — Approximate contact for alluvial units only 

FAULT— Dotted where concealed. Faults shown as bounding 

alluvium do not offset alluvium 

FOLDS — Showing trace of axial surface and direction of plunge. 

Dotted where concealed 

Syncline 

Monocline 

Approximate location of the spikes in apparent conductivity 
8 Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

PETRIFIED FOREST MEMBER 

SHINARUMP MEMBER 

SCHNABKAIB MEMBER 

MIDDLE RED MEMBER 

UPPER RED MEMBER 

Water bearing in places 

Water bearing in places 

Water bearing in places 

Water bearing 

Water bearing 

ALLUVIUM QUATERNARY

NAVAJO SANDSTONE 

JURASSIC 

KAYENTA FORMATION 

MOENAVE FORMATION 

CHINLE FORMATION 

TRIASSIC 

MOENKOPI FORMATION 

Modified from Harshbarger and others, 1957 

Geologic contact between the Kayenta Formation and the Navajo 

Sandstone, and fractures and bedding plane in the upper sandstone 

facies of the Kayenta Formation and the Navajo Sandstone. 

j

Fractures 

Kayenta Formation 

Nava o Sandstone 

Bedding plane 

Geologic contact 

between Kayenta 

Formation and 

Navajo Sandstone 

Figure 4. Generalized lithologic units in the Pipe Spring National Monument area and a photograph showing the sandstone facies of the Kayenta 

Formation and the Navajo Sandstone at Pipe Spring National Monument, northern Arizona. 
Hydrogeologic Setting 9 

A. 

Fractures 

B. 

Fracture 

Figure 5. Fractured bedrock of the Kayenta Formation in the open adit during reconstruction of Tunnel Spring in 2001, Pipe 

Spring National Monument, northern Arizona. A, Fractures in the Kayenta Formation. B, Ground-water seepage from fractures in 

the Kayenta Formation. 
Paved trails

ond

(Original Spring under

the Parlor Room)

Courtyard

Cistern Courtyard

Spring Room Spring

measuring point

Spring Room pipe

Spring Room

"Main Spring"

Pool

Spring Room Spring

To the ponds Conduit

Conduit

Parlor Room

Winsor Castle

N

10 Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

Enlargement of Winsor Castle 

and the relation of Spring Room Spring to Main Spring 

Tunnel Spring Adit/culvert 

0 25 METERS 

N 0 50 100 FEET 

EXPLANATION 

2 SEISMIC LINE AND NUMBER DIRECTION OF SPRING 

FLOW 

ELECTROMAGNETIC-INDUCTION (EM) 113 DIRECTION OF GROUNDWATER MOVEMENT 

LINE AND NUMBER (EM31) 

HISTORIC STRUCTURE 

Figure 6. Direction of ground-water movement and locations of seismic and electromagnetic lines in Pipe Spring 

National Monument, northern Arizona. 
GEOPHYSICAL METHODS 

Seismic and electromagnetic techniques were used in the 

study. The shallow seismic-refraction method was used in the 

seismic surveys, and EM31 and EM34 tools (Geonics, Inc.) 

were used in the electromagnetic surveys. 

Application of the seismic-refraction method is based on 

the assumptions of two subsurface layers that have different 

seismic velocity; the travel time is determined from refracted 

seismic waves at the interface between the two layers. Seismic 

energy is generated using a source known as a ‘shot,’ and for 

shallow application this usually is a hammer and (or) a small 

explosive. Seismic-refraction data were collected within the 

monument boundaries using a 48-channel seismograph 

(Geometrics, Inc.). Compressional waves were generated 

using a small explosive source (8-gauge black powder charge). 

Shots were set off 5 and 10 m from each end of the four seismic 

survey lines.

 Seismic-refraction data were collected along transect 

lines near Winsor Castle (figs. 6 and 7). Seismic lines 1 and 4 

Geophysical Methods 11 

were parallel to one another and oriented northeast-southwest. 

Seismic lines 2 and 3 had a common starting point and were 

oriented northwest-southeast. Each survey line consisted of 

48 geophones spaced at either 1- or 2-m intervals (fig. 7). 

Data were recorded on a seismograph and then transferred to a 

computer where the refraction records could be used to 

construct travel-time curves. Because the refraction records 

were not sufficient to construct travel-time curves, a depth 

profile of subsurface layers delineated by seismic velocity 

could not be constructed. 

The electromagnetic-induction instruments (EM31 

and EM34; fig. 8A, B) were used to measure the apparent 

electrical conductivity, in millisiemens per meter, of the 

subsurface within the monument and in the area north of the 

monument. The depth of exploration depended on the 

separation between the transmitter coil and receiver as well 

as on the coil orientations. Eight configurations of coil 

separation and orientation are summarized in table 1. 

Seismic 

Cable 

Geophones 

Geophones 

Seismic Cable 

Figure 7. Equipment for the seismic profile (line 1) in front of Winsor Castle, Pipe Spring National Monument, northern Arizona. 
12 Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

A.

B.

Figure 8. Electromagnetic-induction (EM) tools, Pipe Spring National Monument, northern 

Arizona. A, EM31 tool. B, EM34 tool. 
Table 1. Nominal depths of exploration for Geonics EM instruments 

[From Northwest Geophysical Associates, Inc. (2000). Depth of exploration 

is depth above which 67 percent of the signal originates in a uniform earth. 

HD, horizontal dipole; VD, vertical dipole] 

Coil Nominal depth 

Instrument separation, Orientation of exploration, 

in meters in meters 

EM31 3.7 HD 2.5 

EM31 3.7 VD 5.2 

EM34 10 HD 6.8 

EM34 10 VD 14.3 

EM34 20 HD 13.5 

EM34 20 VD 28.6 

EM34 40 HD 27 

EM34 40 VD 57 

Measurements of apparent conductivity included thirteen 

100-series EM31 transects and three 400-series EM34 

transects within the monument and north of the monument 

boundary (figs. 3 and 6). EM31 measurements use vertical 

dipole (VD) and horizontal dipole (HD) orientations. These 

orientations provide two data points per station on the EM31 

lines. The EM34 uses VD and HD orientations with three 

separations (10 m, 20 m, and 40 m) at each station. These 

configurations provide six data points per station. The different 

orientations and separations provide information about the 

apparent conductivity of the earth at different depths in 

millisiemens per meter. The deeper VD orientations for both 

the EM31 and the EM34 were used to characterize the apparent 

conductivity for the purposes of this report. 

EM31VD data were used to create contour maps of the 

measured apparent conductivity within the monument as a 

means of characterizing relative differences in conductivity. 

Analysis of data from the two EM31 lines (103 and 104) north 

of the monument are not presented in this report because the 

depth of exploration for these lines (table 1) was shallower 

than that for the corresponding EM34 lines and analysis of the 

EM31 data was concurrent with that of the EM34 data. 

EM34 VD data for the three separations (10 m, 20 m, 

and 40 m) were plotted for lines 401 and 402 north of the 

monument (fig. 3). The plots were used to examine the 

apparent conductivity at the depths associated with the three 

coil spacings (table 1). Measurements from EM34 line 400 are 

not described in this report because the line was short and the 

results were inconclusive. 

Structural Controls of Ground-Water Movement 13 

STRUCTURAL CONTROLS OF 

GROUND-WATER MOVEMENT 

Geophysical surveys using seismic-refraction and EM 

techniques were partially successful in delineating structural 

controls of ground-water movement. Lithologic and structural 

features could not be distinguished from the seismic-refraction 

data; however, data from the EM31 and EM34 surveys 

revealed patterns in apparent conductivity. 

The lithology and structure of the rocks near Winsor Point 

attenuated the acoustic energy from the seismic-refraction 

surveys which resulted in low signal-to-noise ratios. At the 

time of the seismic-refraction surveys, the subsurface lithology 

was poorly understood, and the method employed was unable 

to produce a clear signal to delineate distinct layers on the basis 

of seismic velocity (fig. 9). 

Contours of apparent conductivity revealed areas of high 

and low apparent conductivity within the monument. An area 

of low apparent conductivity (10–30 millisiemens per meter), 

between Winsor Castle and West Cabin, exists between two 

areas of high apparent conductivity (greater than 

40 millisiemens per meter; fig. 10). The zone of high apparent 

conductivity to the west is likely associated with saturated 

fine-grained sediments of the Kayenta Formation near West 

Cabin Spring where ground water discharges on a slope and 

creates a marshy area (fig. 10). The area of high apparent 

conductivity to the east may also reflect saturated conditions 

near the land surface. The steep gradient in apparent 

conductivity between the areas of high and low conductivity, 

represented by the blue and light blue areas, respectively, on 

figure 10 indicate the likelihood of north-south trending 

fractures that could provide secondary permeability for 

ground-water movement and control the location of spring 

discharge. 

EM34 VD data from lines 401 and 402 appear to 

correlate to the structural positions of units attributable to the 

Moccasin Monocline, the associated syncline, and the Sevier 

Fault, and to lithologic differences among the geologic units 

in the subsurface (George Billingsley, geologist, U.S. 

Geological Survey, written commun., 2004; fig. 3). Apparent 

conductivity data correspond to the change in lithology from 

the shale and clay sediments of the Schnabkaib Member of 

the Moenkopi Formation to the sandstone sediments of the 

Navajo Sandstone and the shaly sediments of the Kayenta 

Formation across the Sevier Fault between 120 and 220 m 

from the east end of EM34 line 402 (figs. 3 and 11A). The 

difference in the apparent conductivity measured using the 

10- and 20-m spacings compared to that measured using the 

40-m spacing is much greater from 220 to 650 m along the line 

than from 0 to 220 m (fig. 11A). 
14 Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

50 

75 

meters 

0 

25 

50 

75 

0 

25 

50 

75 

20253035404550 1015 5 

25 

50 

75 

0 

W E 

0 

100 

125 

150 

Source at 

– 5 

100 

Source at 

–10 meters 

TIME, IN MILLISECONDS 

Source at 

52 meters 

100 

Source at 

57 meters 

100 

DISTANCE RELATIVE TO GEOPHONE NUMBER 1, IN METERS 

Figure 9. Seismic-refraction record from line 2 indicating low signal-to-noise ratio, making useful 

interpretation impossible, Pipe Spring National Monument, northern Arizona. 
Spring

Room

Spring

0

60

05

50

20

10

50

6

Structural Controls of Ground-Water Movement 15 

Cabin 

Spring 

0 

0 50

Tu 

Paved trails 

Dirt trails 

Cabin 

Adit/culvert 

50

40 

3 

40 

4

40 

0 

0 

30 

30 

30

30 

Castle 

Main 

Spring 

N 

Pond 

Pond 

Marsh 

West 

Tunnel Spring 

25 METERS 

100 FEET 

West 

Probable north-south fractures 

Winsor 

EXPLANATION 

30 

AREA OF LOW APPARENT CONDUCTIVITY 

AREA OF HIGH APPARENT CONDUCTIVITY 

Figure 10. i i i l i

DIRECTION OF GROUND-WATER MOVEMENT 

Areas of h gh and low apparent conduct vity, Pipe Spr ng Nationa Monument, northern Ar zona. 

HISTORIC STRUCTURE 

LINE OF EQUAL AVERAGE MEASURED 

CONDUCTIVITY— Interval 10, in millisiemens 

per meter. Data from EM31 measurements. 

Dashed where uncertain 

ELECTROMAGNETIC-INDUCTION (EM) 

LINE (EM31) 
APPARENT CONDUCTIVITY FROM VERTICAL APPARENT CONDUCTIVITY FROM VERTICAL

DIPOLE ORIENTATION, IN MILLISIEMENS PER METER DIPOLE ORIENTATION, IN MILLISIEMENS PER METER 

DISTANCE, IN METERS FROM EAST END 

Figure 11. Apparent conductivity from EM34 data north of Pipe Spring National Monument, northern Arizona. 

80

70

60

50

40

30

20

10

0

B. 

90 

Saturated 

Apparent conductivity 

could correspond to shales in 

the Kayenta Formation 

DISTANCE, IN METERS FROM EAST END 

LINE 401 (see figure 3 for location) 

Sevier Fault ? 

Kayenta Formation outcrop 

Conductivity data 

possibly representative of 

Schnabkaib Member of 

Moenkopi Formation 

fracture ? 

Saturated fracture ? 

10 METER SPACING 

20 METER SPACING See table 1 for nominal depths 

of exploration 40 METER SPACING 

35

30

25

20

15

10

5

0

740

720

700680

660

640

620600580560

540

520

500

480460

440420400

380

360

340

320

300

280260

240

220

200

180

160

140

120

100

80

60 

680

660

640

620

600580560

540

520

500

480460

440

420

400

380360

340

320300

280260

240

220

200

180

160

140120

100

80

60 

16 

40 

A. 

Preliminary Investigation of Structural Controls of Ground-Water Movement in Pipe Spring National Monument, Arizona 

High apparent conductivity 

could correspond to shales in 

the Kayenta Formation 

Low apparent conductivity could correspond 

to sandstone in the Navajo Sandstone 

10 METER SPACING 

20 METER SPACING See table 1 for nominal depths 

of exploration 40 METER SPACING 

LINE 402 (see figure 3 for location) 

Sevier Fault ? 

Saturated fracture ? 

Conductivity data 

possibly representative of 

Schnabkaib Member of 

Moenkopi Formation 

Saturated fracture ? 

40 40 

20 20

0 0 
This greater difference can probably be attributed to the thick 

sequence of the Schnabkaib Member underlying the eastern 

part of the line and distinct lithologic differences between the 

Navajo Sandstone and the Kayenta Formation that underlie the 

western part of the line. 

From east to west along EM34 line 401 (fig. 11B), the 

change from the Schnabkaib Member of the Moenkopi 

Formation to the shaly sediments of the Kayenta Formation 

along the trace of the Sevier Fault is intimated at about 120 to 

140 m (fig. 11B). The more consistent values of apparent 

conductivity from the three spacings on line 401 compared to 

those from line 402 are likely due to the position of subsurface 

units associated with the syncline (fig. 3). The Navajo 

Sandstone may be present for only a few meters west of the 

Sevier Fault, and the fine-grained sediments of the Kayenta 

Formation that would have an apparent conductivity similar to 

that of the fine-grained sediments of the Schnabkaib Member 

of the Moenkopi Formation are likely the predominate 

subsurface strata in this area. Increases in apparent 

conductivity beginning at about 640 m probably correlate to an 

outcrop of the fine-grained facies of the Kayenta Formation 

that extends more than 100 m below the land surface (George 

Billingsley, geologist, U.S. Geological Survey, oral commun., 

2004). 

Spikes in apparent conductivity along lines 401 and 402 

may be indicative of small saturated fractures that control 

ground-water movement immediately north of the monument 

boundary (figs. 3 and 11). For example, the spike at about 

420 to 460 m along line 402 could be indicative of a saturated 

fracture in the bedrock. The approximate location of the spike 

coincides with a small surface drainage (fig. 3) where water 

could be infiltrating. Along line 401, the spike in apparent 

conductivity at about 320 m for spacings of 20 and 40 m could 

be indicative of a saturated fracture in this location (fig. 11B). 

The spikes emphasized could represent two of many possible 

small fractures that are conduits for ground-water movement 

north of the monument. 

SUMMARY AND CONCLUSIONS 

Exploratory geophysical methods were employed to 

better understand the relation between spring discharge and 

geologic structure in the area of Pipe Spring National 

Monument. Seismic and electromagnetic-induction techniques 

were used in the study. The seismic-refraction technique did 

not yield viable results owing to the approach used. EM31 and 

EM34 measurements of apparent conductivity indicated that 

ground-water movement is partially controlled by fractures. 

Summary and Conclusions 17 

EM31 data indicated that saturated conditions exist near 

West Cabin Spring and in an area east of Winsor Castle on 

Winsor Point. EM34 results indicated that saturated conditions 

could exist within small fractures associated with monoclines 

and synclines and the Sevier Fault. 

Data from the preliminary geophysical surveys conducted 

in this investigation indicate that ground-water discharge to the 

springs in Pipe Spring National Monument is controlled by 

geologic structure. Additional, more detailed study could be 

used to verify and expand on these limited conclusions. Future 

studies that include direct resistivity methods to map the twodimensional distribution of electrical properties within the 

monument could better delineate faults and fractures, and the 

relations of these structures to ground-water movement and 

spring discharge. 

SELECTED REFERENCES 

Barrett, D.C., and Williams, O.R., 1986, An evaluation of the 

decline in spring flow at Pipe Spring National Monument: 

Fort Collins, Colorado, National Park Service report, 13 p. 

Bassler, Harvey, and Reeside, J.B., Jr., 1921, Oil prospects in 

Washington County, Utah: U.S. Geological Survey 

Bulletin, 0726-C, p. 87–107. 

Fetter, C.W., 1994, Applied Hydrology, 3d ed.: Englewood 

Cliffs, New Jersey, Prentice-Hall, p. 557 

Harshbarger, J.W., Repenning, C.A., and Irwin, J.H., 1957, 

Stratigraphy of the uppermost Triassic and the Jurassic 

rocks of the Navajo country: U.S. Geological Survey 

Professional Paper 291, 74 p. 

Inglis, Rick, 1997, Monitoring and analysis of spring flows at 

Pipe Spring National Monument, Mojave County, Arizona: 

Fort Collins, Colorado, National Park Service Water 

Resources Division Technical Report 

NPS/NRWRD/NRTR-97125, 35 p. 

Marshall, C.H., 1956, Photogeologic map of the Fredonia, SW 

Quadrangle, Mohave County, Arizona: U.S. Geological 

Survey Miscellaneous Investigations Series, Map I–160, 

scale 1:24,000. 

Northwest Geophysical Associates, Inc., 2000, 

Electromagnetic Induction, accessed January 29, 2004, at 

URL http://www.nga.com/pdf_folder/EM_flyer.pdf. 

U.S. Public Health Service, 1962, Drinking water standards: 

U.S. Public Health Service Publication 956, 61 p. 

Truini, Margot, 1998, Geohydrology of Pipe Spring National 

Monument area, Northern Arizona: U.S. Geological Survey 

Water-Resources Investigations Report 98–4263, 25 p. 


Truini and others—PRELIMINARY INVESTIGATION OF STRUCTURAL CONTROLS OF GROUND-WATER MOVEMENT IN


PIPE SPRING NATIONAL MONUMENT ARIZONA—


U.S. Geological Survey Scientific Investigations Report 04—5082