Guadalupe Mountains National Park 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2008/023 

National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 
THIS PAGE: 

Guadalupe Mountains National Park Geologist Gorden Bell shows a group of park visitors a limestone outcrop with hammer and chisel 

marks from illegal fossil collection. The outcrop is located near Stop 19 on the Permian Reef Trail in Guadalupe Mountains National Park. 

ON THE COVER: 

View of El Capitan (2,464 m [8,085 ft]) from the Permian Reef Trail in Guadalupe Mountains National Park. El Capitan is the eighth-highest 

peak in Texas, and is composed of Permian age limestone. 

Photos by: Ron Karpilo 
Guadalupe Mountains National Park 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2008/023 

Geologic Resources Division 

Natural Resource Program Center 

P.O. Box 25287 

Denver, Colorado 80225 

February 2008 

U.S. Department of the Interior 

Washington, D.C.
The Natural Resource Publication series addresses natural resource topics that are of interest 

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general, diverse audience, and may contain NPS policy considerations or address sensitive 

issues of management applicability. Examples of the diverse array of reports published in this 

series include vital signs monitoring plans; "how to" resource management papers; 

proceedings of resource management workshops or conferences; annual reports of resource 

programs or divisions of the Natural Resource Program Center; resource action plans; fact 

sheets; and regularly- published newsletters. 

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not constitute endorsement or recommendation for use by the National Park Service. 

Printed copies of reports in these series may be produced in a limited quantity and they are 

only available as long as the supply lasts. This report is also available from the Geologic 

Resource Evaluation Program website (http://www2.nature.nps.gov/geology/inventory/

gre_publications) on the internet, or by sending a request to the address on the back cover. 

Please cite this publication as: 

KellerLynn, K. 2008. Guadalupe Mountains National Park Geologic Resource Evaluation 

Report. Natural Resource Report NPS/NRPC/GRD/NRR—2008/023. National Park Service, 

Denver, Colorado. 

NPS D- 181, February 2008 
 GUMO Geologic Resource Evaluation Report iii

Table of Contents 

List of Figures .............................................................................................................. iv

List of Tables ................................................................................................................ iv

Executive Summary ...................................................................................................... 1

Introduction ................................................................................................................... 3

Purpose of the Geologic Resource Evaluation Program ............................................................................................3

Establishment of Guadalupe Mountains National Park...............................................................................................3

Geologic Setting of Guadalupe Mountains National Park...........................................................................................4

Geologic Issues............................................................................................................. 7

Abandoned Mine Land Mitigation ...............................................................................................................................7

Cave Resources and Protection.................................................................................................................................8

Flood Hazards ............................................................................................................................................................9

Geologic Hazards.......................................................................................................................................................9

Groundwater.............................................................................................................................................................11

Oil and Gas Development ........................................................................................................................................11

Paleontological Resources .......................................................................................................................................12

Geologic Features and Processes............................................................................. 14

Global Boundary Stratotype Sections and Points.....................................................................................................14

El Capitan.................................................................................................................................................................14

Sedimentary and Structural Features .......................................................................................................................14

Dunes .......................................................................................................................................................................15

Mineral Resources....................................................................................................................................................16

Map Unit Properties .................................................................................................... 20

Map Unit Properties Table........................................................................................................................................22

Geologic History.......................................................................................................... 25

References Cited......................................................................................................... 28

Glossary....................................................................................................................... 31

Appendix A: Geologic Map Graphic .......................................................................... 33

Appendix B: Scoping Summary................................................................................. 35

Attachment 1: Geologic Resource Evaluation Products CD 
 NPS Geologic Resources Division iv 

List of Figures 

Figure 1. Generalized Map of Guadalupe Mountains National Park ..............................................................................2

Figure 2. Geologic Time Scale.......................................................................................................................................5

Figure 3. Map of Exposures of the Capitan Reef. ..........................................................................................................6

Figure 4. Zones of Cave Dissolution in Guadalupe Rocks .............................................................................................8

Figure 5. Manzanita Spring ..........................................................................................................................................13

Figure 6. Guadalupe Escarpment Wilderness Study Area. ..........................................................................................18

Figure 7. El Capitan .....................................................................................................................................................19

Figure 8. Permian Geography of West Texas and Adjoining New Mexico ...................................................................26

Figure 9. Depositional Environments of the Capitan Reef Complex.............................................................................27

List of Tables 

Table 1. Abandoned Mine Land Openings at Texas and Calumet Mine ........................................................................7

Table 2. Permian Rock Formations in Stratigraphic Provinces ....................................................................................21
 GUMO Geologic Resource Evaluation Report 1

Executive Summary 

This report accompanies the digital geologic map for Guadalupe Mountains National Park 

in Texas, which the Geologic Resources Division produced in collaboration with its 

partners. It contains information relevant to resource management and scientific research. 

The geology of the Guadalupe Mountains is exceptional, 

so exceptional that the International Commission on 

Stratigraphy selected this section of rocks to serve as the 

standard against which all other rocks of Middle 

Permian age (270–260 million years ago) are compared. 

This distinction is a benefit to the National Park Service, 

supporting its mission, as well as a benefit to the 

international scientific community. It is also a bonus for 

backcountry visitors, providing an interesting hiking 

destination recognized for its geologic uniqueness. 

A striking cross section of Middle Permian rocks is 

exposed at Guadalupe Mountains National Park in 

McKittrick Canyon (fig. 1). This cross section reveals the 

world’s most extensive and significant Middle Permian 

limestone—the Permian Reef Complex. This complex of 

rocks includes not only the reef and forereef that 

paralleled the Permian shoreline but also backreef 

deposits between the reef and land and the sediments 

deposited in the deep waters of the Delaware Sea. 

In addition to their scientific significance, the rocks of 

Guadalupe Mountains National Park are also the 

foundation for stunning scenery, possibly the most 

striking feature being the thousand- foot cliff of El 

Capitan, which is part of the Capitan forereef. The park 

is also notable for its cave resources, red quartz and 

white gypsum sand dunes, and flaggy dolomite and 

limestone. Abundant travertine deposits have helped the 

caves of the Guadalupe Mountains earn the reputation of 

being among the most beautiful in the world. The rocks 

in the park also host eye- catching sedimentary and 

structural features such as ripple marks, submarine 

slides, tepee structures, and a plethora of fossils. 

Though preserved in time, geologic features are not 

stagnant. The following processes occur in the park: 

• Abandoned Mine Land Mitigation—17 mine openings 

associated with the abandoned Texas and Calumet 

Mine in the park have been identified and were 

mitigated appropriately in the early 1990s. Following 

closure, routine monitoring and inspection by park 

staff will ensure the continued integrity of the closures. 

• Flood Hazards—Simulations of the 100- year 

floodplain at Guadalupe Mountains National Park 

resulted in velocities up to 3.4 m/s (11.1 ft/s). Mass 

transport of debris in major channels and flash 

flooding in smaller ephemeral drainages are issues for 

park planning. 

• Mass Wasting—The most prevalent mass- wasting 

hazard in the park is rockfall, whereby relatively large 

fragments of rock become detached and fall rapidly 

downslope. The most hazardous areas are on talus 

slopes, below cliffs of massive limestone. Factors that 

could trigger rockfalls are shock waves from distant or 

nearby earthquakes, repeated freeze- thaw cycles, 

airplane and vehicular noise and vibrations, high 

winds, and blasting during construction or mining. 

• Seismicity—Study of microearthquakes in Guadalupe 

Mountains National Park show that this area is not 

seismically active. Nevertheless, the possibility that a 

large earthquake will occur at some point in the future 

cannot be ruled out. In 1995, the nearby Alpine 

earthquake recorded a magnitude 5.6 on the Richter 

scale. Significant shocks in the vicinity of the park can 

be expected to trigger a number of rockfalls. 

• Solution Collapse—No solution sinks (sinkholes) are 

known to exist in the park; however, the nature of the 

rocks makes the existence of some subsurface cavities 

probable. Dissolution occurs in areas underlain by 

highly soluble rock formations, especially gypsum and 

halite, and to a lesser degree limestone. Removal of 

consolidated or unconsolidated materials by water 

solution leads to surface collapse. Hydrologic factors 

that may cause the solution and removal of material 

may be natural or anthropogenic. 

Other issues of concern include the following: 

• Cave Protection—Caves are a significant resource 

throughout much of the Capitan Reef. There are 27 

known caves within Guadalupe Mountains National 

Park. The regional director approved a cave 

management plan for the park in 1972. More recently 

identified threats, such as those related to oil and gas 

drilling, may impair cave resources and point to the 

possible need to update the plan. 

• Oil and Gas Development—Though oil and gas 

production is prohibited within Guadalupe Mountains 

National Park, oil and gas operations outside the 

boundary may directly impact park resources such as 

wildlife, vegetation, caves, air and water quality, and 

aesthetic values, including panoramic views and 

pervading quiet. 

• Paleontological Resources Inventory—Fossil- rich 

geologic formations underlie approximately 31% of the 

park’s acreage. Investigators have identified more than 

500 Permian marine fossil species in the Guadalupe 

Mountains. Remains of Holocene (now extinct in the 

area) and Pleistocene amphibians, mammals, reptiles, 

and birds are also significant in the caves in the park. 

Neither the National Park Service nor its collaborators 

have conducted a thorough inventory of the park’s 

paleontological resources. 
 NPS Geologic Resources Division 2 

Figure 1. Generalized Map of Guadalupe Mountains National Park, Hudspeth and Culberson Counties, Texas. 
 GUMO Geologic Resource Evaluation Report 3

Introduction 

The following section briefly describes the NPS Geologic Resource Evaluation Program 

and the regional geologic setting of Guadalupe Mountains National Park. 

Purpose of the Geologic Resource Evaluation Program 

The Geologic Resource Evaluation (GRE) Program is 

one of 12 inventories funded under the NPS Natural 

Resource Challenge designed to enhance baseline 

information available to park managers. The program 

carries out the geologic component of the inventory 

effort from the development of digital geologic maps to 

providing park staff with a geologic report tailored to a 

park’s specific geologic resource issues. The Geologic 

Resources Division of the Natural Resource Program 

Center administers this program. The GRE team relies 

heavily on partnerships with the U.S. Geological Survey, 

Colorado State University, state surveys, and others in 

developing GRE products. 

The goal of the GRE Program is to increase 

understanding of the geologic processes at work in parks 

and provide sound geologic information for use in park 

decision making. Sound park stewardship relies on 

understanding natural resources and their role in the 

ecosystem. Geology is the foundation of park 

ecosystems. The compilation and use of natural resource 

information by park managers is called for in section 204 

of the National Parks Omnibus Management Act of 1998 

and in NPS- 75, Natural Resources Inventory and 

Monitoring Guideline. 

To realize this goal, the GRE team is systematically 

working towards providing each of the identified 270 

natural area parks with a geologic scoping meeting, a 

digital geologic map, and a geologic report. These 

products support the stewardship of park resources and 

are designed for non- geoscientists. During scoping 

meetings the GRE team brings together park staff and 

geologic experts to review available geologic maps and 

discuss specific geologic issues, features, and processes. 

Scoping meetings are usually held for individual parks 

and on occasion for an entire Vital Signs Monitoring 

Network. The GRE mapping team converts the geologic 

maps identified for park use at the scoping meeting into 

digital geologic data in accordance with their innovative 

Geographic Information Systems (GIS) Data Model. 

These digital data sets bring an exciting interactive 

dimension to traditional paper maps by providing 

geologic data for use in park GIS and facilitating the 

incorporation of geologic considerations into a wide 

range of resource management applications. The newest 

maps come complete with interactive help files. As a 

companion to the digital geologic maps, the GRE team 

prepares a park- specific geologic report that aids in use 

of the maps and provides park managers with an 

overview of park geology and geologic resource 

management issues. 

For additional information regarding the content of this 

report and up to date GRE contact information please 

refer to the Geologic Resource Evaluation Web site 

(http://www2.nature.nps.gov/geology/inventory/). 

Establishment of Guadalupe Mountains National Park 

The Guadalupe Mountains host the finest example of an 

ancient fossil reef. The fault- block range displays 

portions of the world’s most extensive and significant 

Middle Permian limestone, containing one of the most 

complete Permian marine fossil sequences in the world. 

So exceptional are the Guadalupe Mountains that the 

International Commission on Stratigraphy selected this 

section of rocks (Guadalupian Series) to be the Global 

Boundary Stratotype Section and Point (GSSP) for 

Middle Permian age (270–260 million years ago). 

Geologists from around the globe have studied this 

world- renowned reef, and it has been traversed by 

innumerable geology students and visitors. 

Largely because of the area’s geologic importance, the 

U.S. Congress authorized Guadalupe Mountains 

National Park on October 15, 1966, by Public Law 89-

667, “to preserve in public ownership an area in the State 

of Texas possessing outstanding geological values 

together with scenic and other natural values of great 

significance” (16 U.S.C. § 283 et seq.). The national park 

was established on September 30, 1972, and 18,960 ha 

(46,850 ac) of wilderness was designated on November 

10, 1978. 

Texas Judge J. C. Hunter was years ahead of his time 

when, in 1925, he first proposed a park in the area. 

Hunter purchased land in McKittrick Canyon which he 

managed as a wildlife preserve. This land was part of the 

29,140- ha (72,000- ac) Guadalupe Mountain Ranch, on 

which he raised sheep, goats, and cattle. Three years after 

establishment of the park, Hunter’s son, J. C. Jr., sold 

these holdings to the National Park Service at a bargain 

price of $22 an acre. 

The reef, rugged cliffs, wilderness setting, and the highest 

peak in Texas (Guadalupe Peak) led Wallace Pratt, an oil 

geologist, to purchase and later donate 2,279 ha (5,632 ac) 

of land in McKittrick Canyon to the National Park 

Service in 1959, prior to park authorization. Pratt’s 

donation later formed the nucleus of the new park, and 

the purchase of the Hunter’s land augmented it. The 

park, including wilderness area, now comprises 34,973 ha 

(86,416 ac) of mountains, canyons, and desert in western 

Texas. 
 NPS Geologic Resources Division 4 

Geologic Setting of Guadalupe Mountains National Park 

The rocks that make up the Guadalupe Mountains 

formed in the Delaware Basin during the Permian Period 

(fig. 2). Sediments were deposited in an inland sea, which 

covered more than 26,000 km2 (10,000 mi2

) of Texas and 

New Mexico at the time. Calcareous sponges, bryozoans, 

fusulinids, and algae, as well as calcium carbonate that 

precipitated from the water, built the Capitan Reef in the 

shallow water near the shore of this sea. In the park the 

reef forms a wedge pointing southward; El Capitan and 

Guadalupe Peak are two of its prominent points. The 

reef grew upward and seaward upon forereef talus 

broken loose by storms and persistent wave action, as 

well as upon the skeletal remains of algae and animals 

that fell or washed off the steep reef face. The south face 

of the Guadalupe Mountains marks the location of the 

seaward face of the Capitan Reef. The wide- open 

landscape was once covered by the deep waters of the 

Delaware Sea. The portion of the mountains that extends 

northward from the reef was once the backreef (lagoon 

and coastal plain). 

The reef, which once paralleled the Permian shoreline, 

today extends across 563 km (350 mi) of western Texas 

and southeastern New Mexico. The majority of the reef 

is not exposed above ground, though reef exposures are 

revealed in canyons and caves throughout the Guadalupe 

Mountains. The famous caves of Carlsbad Caverns 

National Park formed within the same reef that is now 

exposed at the surface in Guadalupe Mountains National 

Park. The most extensive exposed portion is the 64- km- 

(40- mi- ) long eastern Guadalupe escarpment that 

stretches northward through Guadalupe Mountains and 

Carlsbad Caverns National Parks. The reef is also 

exposed in the Apache Mountains (about 24 km [15 

mi]exposed) and Glass Mountains (about 6.4 km [4 mi] 

exposed) near Van Horn and Alpine, Texas, respectively 

(fig. 3). 

A striking cross section of the Capitan Reef is displayed 

in the north wall of McKittrick Canyon. The entire 609-

m (2,000- ft) height of the reef is visible. By contrast, 

most canyons north of McKittrick Canyon do not incise 

deeply enough to expose the lower beds. Regional dip 

causes the reef to slope down to the northeast until it is 

completely buried near the city of Carlsbad, New 

Mexico (fig. 3). 
 GUMO Geologic Resource Evaluation Report 5

Figure 2. Geologic time scale; adapted from the U.S. Geological Survey (http://pubs.usgs.gov/fs/2007/3015/). Red lines indicate major 

unconformities between eras. Included are major events in life history and tectonic events occurring on the North American continent. 

Absolute ages shown are in millions of years. 
 NPS Geologic Resources Division 6 

Figure 3. Map of Exposures of the Capitan Reef. The reef, which paralleled the Permian shoreline, extends across 563 km (350 mi) of 

western Texas and southeastern New Mexico. The majority of the reef is buried. The most extensive exposed portion is the escarpment 

in Guadalupe Mountains and Carlsbad Caverns National Parks. Other exposed segments occur in the Glass and Apache Mountains. 

Source: http://www.nps.gov/gumo/gumo/geology.htm. 
 GUMO Geologic Resource Evaluation Report 7

Geologic Issues 

On March 6–8, 2001, participants at the Geologic Resources Inventory (GRI) workshop 

for Guadalupe Mountains National Park addressed the status of geologic mapping and 

discussed resource management issues and needs. The Geologic Resources Inventory 

was a precursor to the Geologic Resource Evaluation (GRE) Program. The following 

section synthesizes the results of the workshop, as well as geologic literature and other 

NPS documents, highlighting issues that may require attention from resource managers. 

The issues that appear in this section are listed in 

alphabetical order because participants at the workshop 

in 2001 did not prioritize them. The two issues listed in 

the workshop summary are (1) geologic hazards and (2) 

identification of paleontological locations. Additional 

issues are abandoned mine lands, the protection of cave 

resources, flood hazards, groundwater exploitation, and 

oil and gas development adjacent to the park. 

Abandoned Mine Land Mitigation 

In February 1990, the NPS Land Resources Division, 

Mining and Minerals Branch (MMB)—predecessor of 

the Geologic Resources Division—received an inventory 

of abandoned mine openings and oil wells in the park 

from staff at Guadalupe Mountains National Park. The 

inventory included 17 mine openings comprising the 

Texas and Calumet Mine, and four oil wells (see “Oil and 

Gas Development” section). Several of these openings 

presented significant hazards to park visitors and staff. 

The then Southwest Regional Office, now Intermountian 

Region, requested that division staff assist the park in 

inspecting the mines and wells, and help in seeking 

assistance for mitigation from the Railroad Commission 

of Texas, which administers funding for abandoned mine 

land (AML) mitigation and reclamation throughout the 

state. 

The Texas and Calumet Mine operated intermittently 

from 1891 to 1938; its copper ore bodies were small, and 

operations ceased when they became uneconomic. The 

mine area is included on the Guadalupe Peak 7.5- minute 

USGS topographic quadrangle map on the northeastern 

flank of Lost Peak. The mine openings and associated 

waste rock piles are within 3 km (2 mi) of the Dog 

Canyon Ranger Station in the north- central portion of 

the park. The Tejas Trail passes within 30 m (100 ft) of 

seven of the openings. Park and division staff inspected 

the site in May 1991. The openings inventoried included 

one shaft (vertical mine working), seven adits (horizontal 

workings), and two prospects (small workings with 

minimal development) (table 1). The other seven features 

listed in the park’s inventory were small prospect pits 

that either were not found during the 1991 fieldwork or 

required no mitigation (John Burghardt, Geologic 

Resources Division, written communication, January 12, 

2007). 

In September 1993, the NPS Southwest Region entered 

into a cooperative agreement with the Railroad 

Commission of Texas for closure of abandoned mines on 

NPS lands in Texas. In early 1996, the Southwest System 

Support Office (now Southwest Regional Office) 

completed an environmental assessment (EA) for closure 

of abandoned mine openings at the Texas and Calumet 

Mine. Because of the site’s historical significance, the 

environmental assessment did not consider destructive 

closures such as blasting for the site’s major features. All 

closure work was done with minimal impact to the 

historic fabric and maximum sensitivity to the 

environment (table 1). Underground wildlife surveys in 

1993, particularly those of Dr. J. Scott Altenbach and Roy 

Powers (private wildlife/mine closure consultants), 

confirmed the presence of significant bat populations in 

four of the openings. For these four openings, the EA 

recommended 10- cm (4- in), angle- iron bat gates, as 

designed by the American Cave Conservation 

Association and approved by Bat Conservation 

International. 

TABLE 1. Abandoned Mine Land Openings at Texas and Calumet Mine 

Opening Description Closure 

1 Vertical shaft: 10' × 11' × 25' deep Backfill 

2 Coyote prospect: 3' wide × 2' high × 15' deep Backfill 

3 Adit: 4.5' wide × 6' high × 125' long Bat gate 

4 Adit: 5' wide × 7' high × 64' long Bat gate 

5 Adit: 4' wide × 6'–9' high × 21' long No action 

6 Trench / adit prospect: 5' wide × 15' high × 20' deep No action 

7 Prospect pit: 4' × 7' × 5' deep Backfill 

8 Adit: 4.5' wide × 5.5' high × 205' long Bat gate 

9 Adit: 4.5' wide × 5' high × 17' long Construct native stone/mortar bulkhead 

10 Adit: 6' wide × 7' high × 800' long Corrugated steel culvert with bat gate 
 NPS Geologic Resources Division 8 

Backfill closures were recommended for four other 

openings, and a no- action alternative was selected for 

the two shallow adit prospects that were neither 

hazardous nor suitable as bat habitat. 

The Railroad Commission of Texas contracted and 

funded the closure project at the Texas and Calumet 

Mine in 1996. Although GRD staff were not present 

during closure work, park staff ensured that contractors 

followed the EA recommendations for the abandoned 

mine openings as summarized in table 1. 

Following closure, routine monitoring and inspection by 

park staff will ensure the continued integrity of the 

closures and identify areas needing additional corrective 

action. Routine surveys of the mine openings for bat use 

and trends in bat population provide information that 

could guide the National Park Service in adopting new 

mitigation measures in the future (National Park Service 

1995). 

Cave Resources and Protection 

According to the Statement for Management, Guadalupe 

Mountains National Park, Texas (1988, p. 14), “caves are a 

significant resource throughout much of the exposed 

Capitan Reef.” Investigators have identified 27 caves 

within the park boundaries (Santucci et al. 2001), and 

many more are likely to exist (National Park Service 

1988). Most of these caves are administratively closed to 

the public. Glori Cave is currently the largest known cave 

in the park with approximately 183 m (600 ft) of surveyed 

passage (National Park Service 1988). 

The resource management plan and environmental 

assessment for Guadalupe Mountains National Park

describe the caves of the Guadalupe Mountains as being 

large in volume but small in surveyed linear distance. The 

caves in the park are generally dry, though many are 

decorated with delicate speleothems. Such cave 

resources are nonrenewable and are particularly 

susceptible to human disturbance. Cave resources also 

include deposits of guano (see “Economic and Mineral 

Resources” section). 

According to DuChene and Martinez (2000), most caves 

in the Guadalupe Mountains are located near the reefbackreef contact between the Capitan Formation and the 

Seven Rivers and Yates Formations (fig. 4). In areas such 

as Guadalupe Mountains National Park, canyons are 

deeply incised into cave- bearing strata, and a large 

amount of the limestone most likely to contain caves has 

been removed by erosion. Long cave systems probably 

once existed throughout the Guadalupe Mountains, but 

erosion has destroyed many of them, leaving only 

truncated remnants stranded high on canyon walls 

(DuChene and Martinez 2000). 

As a result of post- formation erosion, caves at 

Guadalupe Mountains National Park differ significantly 

from the cave systems to the north (e.g., Lechuguilla 

Cave and Carlsbad Caverns). The caves in Guadalupe 

Mountains National Park are fewer in number per area, 

have smaller footprints, and their passageways are low 

and small, though several consist of very deep vertical 

pits. This suggests that even if they did form in a similar 

way to other caves in the Guadalupe Mountains, 

percolating groundwater has subsequently modified 

them significantly. Large caves are not known, and if they 

once existed, probably collapsed as a result of deeper 

weathering and dissolution in the older and higher parts 

of the mountain range (Gorden Bell, Guadalupe 

Mountains National Park, written communication, 

March 13, 2007). 

Figure 2. Zones of Cave Dissolution in Guadalupe Rocks. The four zones of preferential dissolution in the Guadalupe Mountains are (1) below the 

Yates transition into the massive Capitan Limestone, (2) at the contact between the massive and forereef members of the Capitan Limestone, (3) at the 

transition between the backreef Artesia Group members and the Capitan Limestone, and (4) immediately beneath the Yates Formation in the Seven 

Rivers Formation. Arrows indicate the movement of groundwater along the impermeable siltstone in the Yates Formation. Source: Hill (2000).
 GUMO Geologic Resource Evaluation Report 9

In 1972 the regional director approved a cave 

management plan for Guadalupe Mountains and 

Carlsbad Caverns National Parks (National Park Service 

1972). The plan is based on the following management 

objectives: 

• Protect and perpetuate natural cave systems. 

• Provide educational and recreational opportunities for 

a broad spectrum of park visitors (from the casually 

curious to the avid caver) to discover, study, respect, 

and enjoy the parks’ caves at their individual levels of 

interest. 

• Provide opportunities for scientific study of cave 

resources and systems. 

• Classify caves in management categories based on their 

resources and hazard characteristics. 

• Establish regulations, guidelines, and permit 

stipulations that ensure maximum safety for the cave 

visitor and preservation of park resources. 

The cave management plan also (1) establishes 

procedures for inventorying and maintaining files for all 

known caves; (2) contains programs for monitoring, 

protecting, and restoring cave resources; (3) outlines 

provisions for cave entry for research purposes; (4) 

identifies training needed by staff involved in cave search 

and rescue, interpretation, and wild cave trips; and (5) 

delineates staff responsibilities. 

The caves of the Guadalupe Mountains are probably part 

of a large, pervasive cave complex that is spread 

throughout the rocks of the reef and backreef (DuChene 

et al. 1993). Because the rocks of the Guadalupe 

Mountains are broken by linear, vertical cracks (joints), 

pollutants introduced into the cave complex outside the 

park have the potential to contaminate caves within the 

park. Joints serve as conduits into cave passages through 

which hydrocarbons, hydrogen sulfide, formation waters 

from oil- and- gas drill holes, and drilling fluids can enter 

(DuChene et al. 1993). In addition to toxic and flammable 

materials such as hydrocarbon gases and hydrogen 

sulfide, saline water from lower rock formations could 

leak into the cave system through improperly sealed well 

bores. Drilling fluids and chemicals, lost circulation 

material, cement, and gravel can be introduced into cave 

passages during drilling. (See discussion about oil and gas 

development on page 10). 

On the surface, roads, pipelines, drill pads, separators, 

tank batteries, and mud pits are potential sources of 

contamination that surface water can transport into the 

cave system. Pollutants carried into the ground by 

surface waters could eventually reach the water table. In 

addition to the preservation of underground ecosystems, 

this is a concern because northeast of Carlsbad Caverns 

National Park, the Capitan Reef contains fresh water that 

is used as a local water supply (DuChene et al. 1993). 

Flood Hazards 

Running water is a mechanism for mass transport of 

debris. In a study conducted in 1978, simulations of 

critical velocities of water in the 100- year floodplain at 

Guadalupe Mountains varied from 2.4 to 3.4 m/s (7.9 to 

11.1 ft/s). This velocity range is highly erosive and can 

cause sudden bank failure and radical channel shifts (B. 

D. Lare, hydrologic report, in memorandum to assistant 

manager, Southeast/Southwest Team, Denver Service 

Center, from L. A. May, Environmental Investigations 

Unit, Denver Service Center, October 17, 1978). As 

emphasized in this memorandum, construction is not 

advisable in any of the major drainage systems in the 

park or in the smaller, more local, ephemeral stream 

valleys. 

There is approximately 23 m (75 ft) of alluvial fill in most 

valley floors in Guadalupe Mountains National Park, and 

there could be massive undercutting of this fill during 

flooding (B. D. Lare, hydrologic report, in memorandum 

to assistant manager, Southeast/Southwest Team, Denver 

Service Center, from L. A. May, Environmental 

Investigations Unit, Denver Service Center, October 17, 

1978). Therefore, investigators recommend that 

structures be built on bedrock, where possible, to reduce 

the danger of removal of underlying material by erosion. 

A considerable margin of safety is required in the 

placement of construction sites because many of these 

areas (particularly in the low country) may be subject to 

flash flooding (Railsback and Reeves 1976). 

Geologic Hazards 

Participants at the GRI workshop in 2001 identified the 

need for an assessment of geologic hazards at Guadalupe 

Mountains National Park. However, they suspected that 

the areas most susceptible to slope failure and rock falls 

do not include park infrastructure. Geologic hazards 

would nonetheless have the potential to affect any future 

development. Therefore, careful planning and 

engineering are necessary to minimize geologic hazards 

and future problems. Any unmitigated disturbance (e.g., 

the clearing of vegetation and soil removal) has the 

potential to greatly accelerate natural erosion and may 

result in irreparable damage to the landscape (Railsback 

and Reeves 1976). Recommendations for projects with 

geotechnical requirements are to be carefully integrated 

with ecological and environmental considerations 

(Railsback and Reeves 1976). 

Geologic hazards at Guadalupe Mountains National 

Park include mass wasting (landslides and rockfall), 

seismicity, and solution collapse, each is discussed below. 

Mass Wasting 

According to Murphy (1984), the landslide deposit north 

of the Pine Springs Campground is jumbled debris of a 

different density and texture than the rest of the slope. 

Water moves through this deposit in a way that causes 

water and soil to collect at the edges, resulting in a 

slightly different plant community and different overall 

color. The green border includes a few more trees that 

have managed to take root and survive. Mass wasting 

thus plays a role in the ecological development of park 

landscapes. 
 NPS Geologic Resources Division 10 

Mass wasting becomes hazardous when park 

infrastructure or human activities come in contact with 

the transfer of debris. The most prevalent hazard in the 

park is rockfall, whereby “relatively large fragments of 

rock become detached and by means of free- fall, rolling, 

and bounding move rapidly downslope under the force 

of gravity” (Rogers et al. 1974, p. 30). Rockfall events are 

common on cliffs of massive, broken, faulted, or jointed 

bedrock (e.g., Capitan Limestone). Solution by 

groundwater and surface water widens joints in the 

limestone, and natural erosion in turn removes 

underlying, thin- bedded layers of limestone and 

sandstone, thus undercutting the massive limestone and 

creating a number of unstable areas (Railsback and 

Reeves 1976). Generally, factors that trigger rockfalls are 

shock waves earthquakes, repeated freeze- thaw cycles of 

groundwater or surface water, airplane and car noise and 

vibration, high winds, and blasting for construction or 

mining (Railsback and Reeves 1976). 

Seismicity 

According to Rogers et al. (1974), seismicity results from 

naturally occurring earthquakes and from effects created 

directly by humans or triggered by human activities. The 

effects from naturally occurring earthquakes include (1) 

ground displacement due directly to surface faulting or 

other abrupt earthquake- related land level change; (2) 

damage from earthquake- generated ground shaking; 

and (3) ground failure such as landsliding, soil 

liquefaction, lurching, dam failure, and ground cracking. 

Potentially hazardous seismic effects due to human 

activities include those resulting from (1) nuclear testing; 

(2) injection of fluids under high pressure into the 

ground, which may trigger earthquakes; (3) large 

underground mine cave- ins; and, (4) impoundment of 

large bodies of water, which is known to increase the 

seismicity of an area. 

Three relatively recent earthquakes have been recorded 

in the Delaware Basin region. The first was the Valentine 

earthquake in 1931, which occurred in the vicinity of 

Valentine, Texas (just west of the Delaware Basin). It 

measured an equivalent 6.0 on the Richter scale. The 

second was a moderate earthquake (magnitude 5.0) on 

January 2, 1992. It was centered approximately 60 km (37 

mi) east- southeast of the Waste Isolation Pilot Plant 

(WIPP) site. The third was the Alpine earthquake, on 

April 13, 1995, having a magnitude of 5.6 and an epicenter 

located about 32 km (20 mi) east- southeast of Alpine, 

Texas, at a depth of 13 km (8 mi). 

In addition to these three earthquakes, more than 1,300 

earthquakes have been recorded from depths of 3–5 km 

(2–3 mi) in the War- Wink gas field in Ward and Winkler 

Counties on the east side of the Delaware Basin (Luo et 

al. 1991). These earthquakes are probably the result of a 

non- uniform stress field associated with hydrocarbon 

generation and mitigation (Hill 1996). 

In 1976 investigators conducted a study of 

microearthquake activity in Guadalupe Mountains 

National Park (Railsback and Reeves 1976). This report 

concluded that no more than 19 earthquakes of 

magnitude 2 or less on the Richter scale can be expected 

every year. Such earthquakes are probably not felt. Two 

or three shocks of magnitude 3 or greater per year are 

predicted; magnitude 3 vibrations could be felt indoors, 

with hanging objects swinging. No more than four 

earthquakes of magnitude 5 or greater can be expected in 

this area within a 100- year time span. Domestic impacts 

of a magnitude 5 earthquake are furniture moving or 

being overturned, and cracking of weak, non- reinforced 

masonry. 

Data from this study do not indicate that this area is very 

seismically active; however, the possibility that a large 

earthquake will occur at some point in the future cannot 

be ruled out (Railsback and Reeves 1976). Moreover, any 

significant shocks in the park area can be expected to 

trigger a number of rockfalls. Due to the highly fractured 

nature of the rocks in this area, distant earthquakes may 

also play a role in triggering rockfalls. 

Solution Collapse 

According to Rogers et al. (1974), dissolution of soluble 

rock or soil materials results in ground subsidence and 

surface collapse. This occurs in areas underlain by highly 

soluble rock formations, especially gypsum and halite, 

and to a lesser degree limestone. Hydrologic factors that 

may cause the solution and removal of material may be 

natural or anthropogenic. Natural solution is the result 

of the normal hydrologic processes of downward 

percolation of surface water or lateral movement of 

groundwater. Human activities, or results of them, can 

have much the same effect on soluble earth materials. 

Examples include stream channel changes, irrigation and 

irrigation ditches, leaking or broken pipes, impoundment 

of surface waters, or the mining of soluble material by 

means of forced circulation of water into the subsurface. 

The existence of closely spaced faults and joints offers 

planes along which dissolution can take place. The action 

of groundwater is evidenced by active springs in the 

park, such as Guadalupe, Manzanita, and Smith Springs; 

and springs in McKittrick Canyon (figs. 1 and 5). Though 

no solution sinks are known to exist in the mountains, 

the nature of the rocks makes the existence of some 

subsurface cavities probable (Railsback and Reeves 1976). 

According to Railsback and Reeves (1976), solution is 

most likely to affect the massive limestone in the area; 

however, other rock types, in particular Quaternary 

alluvium, may also be affected. Quaternary alluvium is 

often partially consolidated at the surface and 

unconsolidated at depth, reflecting the action of 

groundwater. Solution in Quaternary deposits generally 

occurs near bluffs along stream channels; construction in 

such areas should be avoided because of undercutting.
 GUMO Geologic Resource Evaluation Report 11

Groundwater 

Areas immediately south and west of Guadalupe 

Mountains National Park currently support large tracts 

of irrigated farmland. The source of irrigation water is 

groundwater, which may be part of the groundwater 

flow system underlying the park. The NPS Water 

Resources Division does not have enough information to 

determine whether groundwater pumping for irrigation 

or possible export of some of this irrigation water to 

distant municipalities (e.g., El Paso) poses a threat to the 

water and water- dependent resources of the park (Larry 

Martin, National Park Service, Water Resources 

Division, oral communication, April 5, 2007). 

Exploration for hydrocarbon energy sources is occurring 

in two areas adjacent to the park. One area in the Otero 

Mesa, a few miles north and west of the park, has been 

leased by the Bureau of Land Management (BLM) for 

test drilling and energy development (see “Oil and Gas 

Development” section). An area southeast of the park is 

being tested for deep gas production. Such development 

and production have the potential to contaminate 

groundwater supplies significant to Guadalupe 

Mountains NP (Larry Martin, NPS, Water Resources 

Division, written communication, April 6, 2007). 

As of January 12, 2007, park staff had submitted a 

proposal to the Project Management Information System 

(PMIS 107571) to characterize groundwater quality, 

potential water- quality risks, and the hydrogeologic 

framework for the park and surrounding area. 

Hydrogeologic characterization of local aquifers and 

geologic formations would help managers better 

understand the park’s water resources for the purpose of 

protecting caves, springs and associated ecosystems and 

maintaining water levels and water quality in aquifers 

that provide the park water supply of the park. To 

develop the hydrogeologic framework, investigators 

would use existing data and also inventory, characterize, 

and evaluate existing wells and springs in the park. The 

hydrogeologic framework would facilitate evaluation of 

geochemical and hydrologic processes within the areas 

that affect the park’s water quality and water resources. 

The framework would also provide a basis for addressing 

whether, and how, adjacent groundwater pumping might 

affect groundwater resources in the park. 

Oil and Gas Development 

Oil and gas production is a significant part of the regional 

economy of western Texas and southeastern New 

Mexico. Recent emphasis on U.S. energy development 

and self- sufficiency is reflected in increased oil and gas 

activity in the local area. Oil and gas operations outside 

the park’s boundary may directly affect park resources. 

Nearby exploration and extraction activities could 

potentially impact scenic views, air quality, wildlife, 

vegetation, water resources, and visitor activities. Federal 

oil and gas exploration is prohibited within Guadalupe 

Mountains National Park; however, the enabling 

legislation for the park (Public Law 89- 667, appended) 

stipulates that if an act of Congress provides that the 

national welfare in an emergency requires the 

development and production of subsurface minerals 

within the park, the Secretary of the Interior may lease 

the park lands for mineral exploration and development. 

In addition 226 acres of private land exist within the 

park. At this time, no interest has been expressed 

regarding the development of mineral rights, including 

oil and gas, associated with this acreage. 

In the three units of the National Park System where 

leasing is permissible (i.e., Glen Canyon, Lake Mead, and 

Whiskeytown National Recreation Areas), the Bureau of 

Land Management—the federal government’s onshore 

mineral leasing agent—must obtain the consent of the 

National Park Service prior to the issuance of a lease. 

The National Park Service can only grant its consent if it 

finds that the leasing and subsequent development will 

not have a significant, adverse impact on park resources 

and administration; the governing regulations are 

provided in 43 CFR 3100–3500. However, GRD staff 

cannot predict if the same process would apply to 

Guadalupe Mountains National Park under a declared 

national emergency (Pat O’Dell, Geologic Resources 

Division, written communication, July 19, 2006). 

Guadalupe Mountains National Park is located in 

Culberson and Hudspeth Counties. According to the 

Railroad Commission of Texas (http://www.rrc.state. 

tx.us/divisions/og/statistics/wells/wellcount/), Culberson 

County had 81 regularly producing oil wells and 19 

regularly producing gas wells as of February 2007 (the 

month in which new results are posted). Hudspeth 

County had no regularly producing oil or gas wells. 

The Bureau of Land Management (BLM) issues the 

majority of oil and gas leases in the vicinity of Guadalupe 

Mountains National Park on lands managed by the 

USDA Forest Service (USDA- FS) and BLM. The BLM 

approves exploration and drilling permits and prepares 

National Environmental Policy Act (NEPA) compliance 

documents for these operations. Oil and gas leasing was 

once proposed for USDA- FS and BLM lands adjoining 

the park’s northeastern boundary. If these lands were 

leased, drilling would be permitted on Camp Wilderness 

Ridge at the head of North McKittrick Canyon. Leasing 

has also been proposed for the Brokeoff Mountains 

Wilderness Study Area (National Park Service 1988) and 

Otero Mesa (Otero County, New Mexico), both 

northwest of the park. The plan for leasing in Otero 

County (and Sierra County, farther from the park, near 

White Sands National Monument) calls for “very limited 

development,” possibly 5% surface occupancy. 

However, according to the BLM, it will only allow for the 

surface disturbance of 1/10 of 1% of Sierra and Otero 

Counties combined (Kerry Moss, Geologic Resources 

Division, e- mail, April 4, 2007). The Environmental 

Working Group, a source of minerals- related leasing 

information, particularly in the West, reports the 5% 

surface occupancy in their publications (see 

http://www.ewg.org/oil_and_gas/part7.php, accessed 

April 6, 2007). 
 NPS Geologic Resources Division 12 

The public and the Governor of Texas voiced concerns 

about the approved BLM plan, which resulted in the 

Bureau of Land Management “deferring” a lease sold in 

2005 in the Bennett Ranch Unit of Otero County. This 

unit is located in the southern part of Otero County and 

could impact the surrounding area, potentially including 

Guadalupe Mountains National Park. As of April 2007, 

GRD staff concluded that the Bureau of Land 

Management is leasing on Otero Mesa, but drilling 

locations are not close to the park yet (see 

http://www.ewg.org/issues_content/publiclands/200509

29/images/Otero_Mesa_150.png, accessed April 6, 2007). 

Establishing effective communication with the USDA 

Forest Service and Bureau of Land Management and 

monitoring their activities are critical to assuring that oil 

and gas operations do not impair park values. This will 

require the National Park Service (i.e., park and Geologic 

Resources Division staffs) being assertive and keeping 

informed of all proposed oil and gas operations in the 

vicinity of Guadalupe Mountains National Park and 

maintaining cooperative relations with the Bureau of 

Land Management, USDA Forest Service, and U.S. 

Geological Survey. Operations involving access through 

the park would be reviewed and approved as provided in 

36 CFR 9B and 43 CFR 3100. If the National Park Service 

determines that external operations might affect park 

resources, appropriate recommendations would be made 

to the BLM and the Texas Railroad Comission (i.e., state 

permitting agency) for mitigating actions (National Park 

Service 1988). 

Paleontological Resources 

In 1855 G. G. Shumard—geologist and member of a party 

exploring for a feasible railroad route to California along 

the newly established United States–Mexico border—

recorded strata of the southern tip of the Guadalupe 

Mountains and collected fossils from the thousandfoot- thick “upper or white limestone” unit (i.e., Capitan 

Limestone) in the vicinity of Guadalupe Pass and El 

Capitan. In 1858 he reported the circumstances of his 

field work in the St. Louis Academy of Science 

Transactions. His brother, B. F. Shumard, used this 

collection to identify the Guadalupe Mountains as the 

first known marine Permian outcrops in North America 

(B. F. Shumard 1858). Little further work was done in the 

region in the ensuing half- century (Pray 1988). However, 

in early 1901 G. H. Girty, a USGS geologist, extensively 

collected invertebrate fauna from the strata of the 

southern Guadalupe Mountains, mostly of the Capitan 

Limestone on the southern slopes of Guadalupe Peak. In 

1908, the U.S. Geological Survey published Girty’s 651-

page monograph based on these collections as 

Professional Paper 58. 

Since the 1950s the majority of paleontological studies of 

Guadalupe Mountains National Park have focused on 

paleoecology, in particular, understanding of the 

sedimentological origin of the Permian (Guadalupian) 

Capitan Reef and equivalent backreef (i.e., the Yates and 

Tansill Formations) and basin (i.e., Bell Canyon, Cherry 

Canyon, and Brushy Canyon Formations) depositional 

systems. 

Investigators have found more than 500 Permian fossil 

species in the Guadalupe Mountains (Rennicke 1985). 

Principal frame- building organisms include calcareous 

sponges, encrusting calcareous algae, and bryozoans. A 

group of common fossils is the brachiopods—shelled 

creatures abundant in the Permian Basin. While some 

200 species of brachiopods survive today, investigators 

have identified 30,000 forms as fossils. Also abundant 

during reef building in the Delaware Basin were 

fusulinids, which date back 250 to 350 million years. 

These creatures became extinct in the latter part of the 

Permian Period. Fusulinids are members of a major 

group of fossils called foraminifera that possess limerich shells, which helped build the Capitan Reef. During 

the reef- building period, foraminifers covered 

thousands of miles of the ocean floor with lime 

(Rennicke 1985). A third abundant group of fossils in the 

Permian reef is echinoderms, such as crinoids (sea lilies) 

and echinoids (sea urchins). Echinoderms are solitary, 

bottom- dwelling, marine organisms. An endoskeleton 

with bilateral symmetry, which is formed of plates or 

ossicles composed of crystalline calcite, characterizes 

these organisms. Various mollusks are also part of the 

reef complex, for example, gastropods (snails), 

cephalopods with chambered shells (modern 

cephalopod species include octopi and squid), and 

pelecypods (clams) (DuChene 2000), as well as corals, 

trilobites, and conodonts (Santucci et al. 2001). 

Since the 1930s investigators have recognized the 

Guadalupe Mountains for their significant 

Pleistocene/Holocene cave fossils, including 

herptefauna; avian remains (i.e., bones and feathers); 

small mammals; and extinct sloth remains (i.e., dung and 

hide with hair). Four of the 10 known localities in the 

world for fossil sloth dung occur in Guadalupe 

Mountains National Park: Lower Sloth Cave, Upper 

Sloth Cave, Dust Cave, and Williams Cave (Spaulding 

and Martin 1979). 

Based on plant macrofossils and pollen collected from 

caves in Guadalupe Mountains National Park, 

investigators have established a 13,000- year- long 

chronological sequence of late Pleistocene and Holocene 

plant communities in the Guadalupe Mountains (Van 

Devender et al. 1977). The plant communities in the 

Guadalupe Mountains have gradually changed from 

relatively mesic (moist) woodland and forest associations 

during pluvio- glacial climates in the Late Wisconsin 

glacial epoch to the present xeric (dry) Chihuahuan 

desert scrub (Van Devender et al. 1977). 

In 2001 Greg McDonald (GRD paleontologist) suggested 

that an encompassing, systematic inventory of 

paleontological resources at Guadalupe Mountains 

National Park be conducted. Such an inventory would 

describe known paleontological resources and provide 

recommendations on how to best manage these 

resources. A related task is establishing the geographic 
 GUMO Geologic Resource Evaluation Report 13

position of cited localities. Older literature does not 

pinpoint localities on a map, and many localities have 

been reported outside but immediately adjacent to the 

park boundaries. 

As of January 2008, neither the National Park Service nor 

its collaborators had conducted a formal inventory of the 

paleontological resources at the park. However, Santucci 

et al. (2001) discusses the paleontological resources in the 

park’s caves, and Santucci et al. (2007) provides a general 

overview, brief descriptions of rock units and their 

depositional settings, and a preliminary literature review 

of the paleontological resources in the park. 

A more comprehensive inventory is unlikely to be 

completed in the near future for two reasons (Gorden 

Bell, Guadalupe Mountains National Park, written 

communication, March 30, 2005). First, the lack of 

human and fiscal resources precludes the ability to plan, 

organize, and implement an in- depth inventory. Second, 

compiling the voluminous amount of published material 

that is available and continues to grow would be very 

time consuming. Paleontological research at the national 

park constantly yields new information and even new 

fossil species (e.g., Bell et al. 2002, Rigby and Bell 2005, 

and Rigby et al. 2007). 

Figure 3. Manzanita Spring. Active springs in the park such as Guadalupe, Manzanita, and Smith Springs, and springs in McKittrick Canyon 

are evidence of the action of groundwater. Solution collapse—a geologic hazard and the result of groundwater dissolution—commonly 

occurs in limestone in semiarid regions. NPS photo by Ron Kerbo.
 NPS Geologic Resources Division 14 

Geologic Features and Processes 

This section describes the most prominent and distinctive geologic features and processes 

in Guadalupe Mountains National Park. 

Guadalupe Mountains National Park is both nationally 

and internationally significant because of a combination 

of outstanding geologic, scientific, and scenic resources. 

The park preserves an important section of the Capitan 

Reef—one of the most extensive non- coral, fossil reefs 

in the world—and serves as the Global Boundary 

Stratotype Section and Point (GSSP) for Middle Permian 

time. The reef complex also hosts stunning El Capitan 

and interesting sedimentary and structural features. 

The first recognition of the Capitan Limestone as a reef 

deposit was published in 1928 (Ruedemann letter cited in 

King and King, 1928, p. 139). Several authors apparently 

made these conclusions almost simultaneously (Lloyd 

1929; Crandall 1929; Blanchard and Davis 1929). 

According to Hill (1996), most of these early authors 

believed the formation to have resulted from a barrier 

reef type of deposition. 

Other distinctive geologic features in the park include 

dunes and various economic and mineral resources. 

Global Boundary Stratotype Sections and Points 

Guadalupe Mountains National Park contains an 

international geologic reference point. The International 

Union of Geological Sciences (IUGS), Subcommission 

on Permian Stratigraphy, selected the Guadalupian 

Series to be the world’s reference standard for the 

Middle Permian—a major unit of the geologic time scale. 

Predicated mostly on the outcrops within Guadalupe 

Mountains National Park, this section of rock is one of 

only a few chronostratigraphic references selected 

within the United States. The International Union of 

Geological Sciences also ratified three component 

chronostratigraphic stages within the Guadalupian 

Series. The lowest is the Roadian Stage, the base of which 

coincides with the base of the Guadalupian Series. This 

point is located in Stratotype Canyon, 1 km (0.6 mi) south 

of Bone Canyon (Williams Ranch House; fig. 1) in the 

Middle of the El Centro Member of the Cutoff 

Formation. The base of the middle stage, the Wordian, is 

located near the park boundary at the top of the east wall 

of Guadalupe Canyon within the Getaway Limestone 

Member of the Cherry Canyon Formation. The base of 

the highest stage (Capitanian) is located at the crest of 

Nipple Hill, 1.1 km (0.7 mi) east of Frijole Ranch (fig. 1) 

within the Pinery Limestone Member of the Bell Canyon 

Formation. 

One of the strengths of the Guadalupian Series’ 

candidacy is that the National Park Service agreed to set 

the area aside as a geologic preserve, with dedicated 

international scientific access. In a memorandum to the 

superintendent of Guadalupe Mountains National Park 

on March 27, 1992, the regional director, of the then 

Southwest Region, discussed the potential benefits to 

both the mission of the National Park Service and the 

scientific community of this “prestigious designation.” 

Moreover, a designation such as this one “will have no 

impact on our management polices or our conservation 

mandates” with respect to site designation, accessibility, 

and collecting. Another bonus for the National Park 

Service is that backcountry hikers gained an interesting 

destination, one that emphasizes the internationally 

recognized geologic uniqueness of Guadalupe 

Mountains National Park (Glenister and Wardlaw 2000). 

El Capitan 

One of the most striking features of Guadalupe 

Mountains National Park is the thousand- foot- high El 

Capitan cliff, composed entirely of forereef limestone 

(fig. 7). Early settlers used it as “a leader” (“capitan”) on 

the route through Guadalupe Pass, and it remains a 

landmark for visitors today. In 1854 J. R. Bartlett wrote 

about the landmark when he journeyed by wagon from 

San Antonio to El Paso: 

Our road led in a direction nearly west, towards the bold 

head of the great Guadalupe Mountain, which had been 

before us some eight or ten days. This is a most remarkable 

landmark, rising as it does far above the surrounding plain. 

The sierra which ends with it comes from the northeast. It is 

a dark, gloomy looking range, with bold and forbidding 

sides, consisting of huge piles of rocks, their debris heaped 

far above the surrounding hills. As it approaches its 

termination the color changes to a pure white, tinted with 

buff or light orange, presenting a beautiful contrast with the 

other portions of the range, or with the light blue of the sky 

beyond, for in this elevated region the heavens have a 

remarkable brilliancy and depth of color. 

Sedimentary and Structural Features 

The Guadalupe Mountains area and the northwestern 

part of the Delaware Basin are exceptional for the wealth 

of remarkable sedimentary features formed during and 

soon after the deposition of Permian sediments. Three of 

these distinctive features are highlighted here: (1) ripple 

marks, (2) submarine gravity features, and (3) tepee 

structures. 

Ripple Marks 

Various investigators observed ripple marks in the 

Cherry Canyon and Brushy Canyon Formations (King 

1948) and the Grayburg- Queen sequence (Boyd 1958). In 

other cases (e.g., in the rocks immediately behind the 

Capitan Reef) the lack of ripples is notable (Newell et al. 

1953). The older sandstone beds of the backreef facies 

exhibit these structures, which are indicative of 

deposition in agitated waters—that is, formed by 

currents. To explain the rarity of ripples in some of the 
 GUMO Geologic Resource Evaluation Report 15

backreef deposits, investigators have suggested that the 

growth of algae or other vegetation may serve as an 

inhibitor (Boyd 1958). N. D. Newell and D. W. Boyd 

surmised that perhaps the growth of algal or other 

vegetation in the Permian shelf seas during times of 

carbonate deposition prevented rippling of the surface 

by current action. Using the Bahamas as an analogy, 

Newell and Boyd suggested that ocean bottoms with 

even scattered vegetation are usually free of ripples 

because the plants break up the regular oscillations of 

bottom currents. 

Submarine Gravity Features 

The talus apron below and basinward of the reef forms 

one of the most important features of the Permian Reef 

Complex. The apron consists of steeply dipping beds of 

reef rubble with minor contributions from the outer shelf 

and upper slope of the reef. Brachiopods, bryozoans, and 

echinoderms living on the slope and siliceous sponges 

living at the base of the slope trapped fine sediments 

descending from the reef face and bound the loose 

material together (Scholle 2000). However, slope 

sedimentation was overwhelmingly dominated by 

fragmented material transported as a result of rockfall, 

grain flow, debris flow, and turbidity currents. Thereby, 

the forereef deposits consist of numerous small- scale, 

individual accumulations that have coalesced to form a 

relatively uniform debris apron (Bebout and Kerans 

1993). 

Occasionally, a large area of the reef front would collapse 

under its own weight, producing a massive submarine 

landslide. These Permian slides had little effect on the 

substratum: large boulders weighing many tons floated 

on highly mobile mud. The well- exposed Permian slides 

are clearly defined across the eastern escarpment and up 

to 10 km (6 mi) into the basin (Rigby 1950). According to 

Newell et al. (1953, p. 11), “they are perhaps as impressive 

as any submarine slides known from the stratigraphic 

record.” 

Tepee Structures 

The small, irregularly spaced, chevron or V- shaped, 

symmetrical folds (non- tectonic) in the Capitan backreef 

deposits are known as “tepees” because of their 

resemblance to this type of tent (Adams and Frenzel 

1950). Investigators have documented tepee structures in 

the Yates, Seven Rivers, and Tansill Formations (Hayes 

1964; Smith 1974) and similar structures in the GrayburgQueen sequence (Boyd 1958). Tepee structures range in 

amplitude from a few inches to 1.2 m (4 ft), and in width 

from 0.6 m (2 ft) to 4.6 m (15 ft). Tepees, once 

established, tend to be “stacked” (Smith 1974). With few 

exceptions, tepees are not truncated above by erosion 

but die out upward as though progressively buried 

beneath accumulating sediments. Upward propagation 

may continue for tens or hundreds of feet. 

The origin of tepees has been the subject of numerous 

studies and considerable controversy. Since the 1950s, 

investigators have provided various explanations for the 

formation of tepees: compression, desiccationcontraction, breakout and injection of confined 

formation fluids or liquefied sediments, and vadose soilforming processes. Advocates of any of these models can 

point to modern analogs, mainly from the Persian Gulf, 

Red Sea, and Australia, as “proof.” Nevertheless, no one 

has yet found an exact analog that comes close to 

modeling the breadth and abundance of the tepees (and 

associated pisoliths) seen in the Permian record (Scholle 

2000). 

In 1974 D. B. Smith concluded that “tepees are probably 

large- scale pressure polygons caused by the expansion 

of newly formed carbonate sediments because of the 

growth of interstitial cement—probably aragonite—

during contemporaneous lithification” (p. 63). 

Additionally Smith (1974) found that most tepees 

underwent considerable erosion after formation; in 

many crests were nearly planed off. These observations 

hold true today (Scholle 2000). 

Smith interpreted the close association of tepees with 

fenestral mat- bound sediments as indicating formation 

in an intertidal or supratidal setting, rather than a wholly 

subaqueous one as other investigators have suggested 

(e.g., Shinn 1969). The distribution of tepees suggests that 

at any one time they formed patchily in parts of a belt a 

few hundred yards wide on a flat or gently sloping 

platform within a few feet of mean sea level. From time 

to time as sea level fell relative to the platform, tepeebearing sediments were exposed subaerially for lengthy 

periods (Smith 1974). 

Dunes 

An expansion of the park boundary in 1987 added about 

4,050 ha (10,000 ac) to the park’s western boundary and 

resulted in a significant portion of the red quartz and 

white gypsum dunes becoming incorporated into 

Guadalupe Mountains National Park. The National Park 

Service, various organizations, and individuals had long 

been interested in preservation of these dunes because of 

their scenic beauty. As the only area of gypsum dunes in 

United States outside of White Sands National 

Monument in New Mexico, these dunes are also 

geologically significant. In addition, the dunes contain 

unusual plant associations and rare species, marking 

their biological significance (National Park Service 1988). 

In 1948 P. B. King described the dunes as “a conspicuous 

feature of the basin floor” (p. 138). Reaching a maximum 

height of 9 m (30 ft) in the northern area, the quartz 

dunes spread over the edge of the basin floor and appear 

to be moving up the slopes of the bajada to the east. The 

overall form and depressions within the dunes are 

irregular. Many of the dune surfaces are bare and ripple 

marked, though mesquite and yucca commonly grow 

between the dunes. 

One possible origin of dune sand is reworked Permian 

sandstone of the Delaware Mountain Group (King 1948; 

see “Map Unit Properties” section). This model is based 

on observations that the sands are spatially restricted 

with the distribution of sand correlating with the toes of 
 NPS Geologic Resources Division 16 

alluvial fans that drain the western slopes of the 

Guadalupe and Delaware Mountains on the eastern 

margin of Salt Basin (see fig. 1). An absence of eolian 

sands in areas where runoff from the mountains is 

blocked by foothills further supports this model (King 

1948). 

In 1999 Wilkins and Currey proposed a second source 

for the dune sands: thin sheets of reworked sands 

originally deposited on the basin floor at the mouths of 

ephemeral tributaries (i.e., in a delta). This model is 

based on observations of pockets of loose, drifting sand, 

similar to those found in the red dunes, the channel, and 

on the delta front of Eight- Mile Draw—a large, 

ephemeral tributary located across the playa floor to the 

south- southwest (i.e., upwind) of the quartz dunes area. 

In addition to these quartz sand deposits, gypsum 

deflated from the playa surface forms active dunes in the 

northeastern portion of the basin. These dunes are much 

less extensive than the dunes of quartz sand; only one 

large tract in the Salt Basin covers about 10 km2

 (4 mi2). 

The northeastern end of the tract is a crescent- shaped 

ridge a mile across, made up of white, shifting dunes, 

bare of vegetation, with an appearance similar to the 

well- known White Sands area of the Tularosa Basin in 

New Mexico (King 1948). The gypsum sand dunes 

include an active front approximately 15 m (50 ft) high. 

According to Wilkins and Currey (1999), these dunes are 

advancing to the northeast as evidenced by the alignment 

of the limbs of the parabolas. To the southwest, nearer 

the playa margins, the gypsum dunes are mostly stable 

and covered with vegetation. 

Mineral Resources 

In 1948 P. B. King considered the resource most worthy 

of investigation and conservation in the Guadalupe 

Mountains to be groundwater because “it makes life 

possible in a land that is otherwise barren” (p. 160; also 

see “Groundwater” section of this report). Though 

King’s comment may still hold true, since his time, 

“liquid gold” has made the Permian Basin famous. The 

backreef environments account for greater than 90% of 

all hydrocarbon production in the area, with basin 

sediments accounting for the rest. Reef deposits are 

nonproductive (Scholle 2000). 

The oil and gas development in the vicinity of the park is 

discussed in the “Geologic Issues” section of this report. 

Other significant mineral resources in the area around 

the park include building stone, calcareous tufa and 

travertine, copper, guano, road material, and evaporite 

minerals. 

Building Stone 

No high- quality building stone is present in the area, but 

flaggy dolomite from the Tansill Formation (see “Map 

Unit Properties” section) has found local use, notably for 

the construction of buildings at Carlsbad Caverns 

National Park. Some of the buildings at Frijole Ranch in 

the park are made of cobbles of Capitan Limestone 

obtained from the gravel deposits washed out from the 

mountains (King 1948). Local residents have used other 

rocks for houses and stone walls (Hayes 1964). In 

addition, the rocks of the Delaware Mountain Group 

(see “Map Unit Properties” section) include several 

varieties of stone that are used locally for building 

purposes. Of them the most distinctive and useful are the 

even- bedded, flaggy limestone and sandstone. These 

rocks are used in building houses and in making fences 

and other structures along the highway. The most 

extensively used bed is the McCombs Limestone 

Member of the Bell Canyon Formation. This bed is about 

3 m (10 ft) thick and crops out over an extensive area 

(e.g., southeast of the mouth of McKittrick Canyon). 

Local residents have excavated numerous small quarries 

into it (King 1948); none of which are in the park 

(Gorden Bell, Guadalupe Mountains National Park, email, January 16, 2008). However, one small quarry in the 

in the Rader Limestone Member, shown on the King 

(1948) map, is in close proximity to the McKittrick 

Canyon road and is within the park’s McKittrick Canyon 

access road right of way. The National Park Service owns 

this outright through purchase; it is not simply an 

easement (Gorden Bell, Guadalupe Mountains National 

Park, e- mail, January 16, 2008). 

Copper Mining and Mineralization 

The almost complete absence of igneous rocks in the 

area results in a lack of mineralization, except at a few 

localities such as the abandoned Texas and Calumet 

Mine in the park. The mine was excavated where veins in 

the Capitan Limestone contained copper minerals, for 

example, in the headwaters of Dog Canyon about a mile 

northeast of Lost Peak (fig. 1). Prospecting for various 

minerals has occurred since about 1900, but the workings 

are small and had been abandoned by 1938. The copper 

ore was hauled over a wagon road to a smelter in El Paso, 

Texas. Remnants of this road, an old miners’ cabin, and 

six mine shafts, including one with a short section of rail 

and an ore car, are evident near Lost Peak. 

Mining was never a major endeavor in the area due to the 

remote location and the distance from El Paso. 

Nevertheless, this unique aspect of the area’s history and 

development has not been addressed in any existing 

report (National Park Service 1988). Therefore the park’s 

resource management plan recommends a thorough 

study of the copper mining operation in Dog Canyon 

and any other mining activities in the present park area. 

The plan recommends an on- site investigation and 

photographic documentation of mine shafts, interviews 

with local people, and a search of legal documents and 

records of companies involved in this mining enterprise 

(National Park Service 1988). 

A letter from Wallace Pratt to P. B. King in January 1945 

identifies other locations of past mining activity: 

There are two other openings (shallow shafts) on 

mineralized limestone in the area; one is about a mile west 

of Bell Spring; the mountain flank, the prospector having 

camped at Bell Spring; the other opening is on the edge of 

the high plateau, a couple of hundred yards northeast of the 
 GUMO Geologic Resource Evaluation Report 17

trail from the Grisham- Hunter Lodge on South McKittrick 

Canyon to Grisham- Hunter Camp, at a point about a mile 

as the crow flies west of Grisham- Hunter Lodge. Both these 

openings uncover concentrated black iron oxides, with a 

trace of copper. Local tradition claims that silver also is 

present. The first described opening is in the upper part of 

the Bell Canyon formation and the second is in the 

Carlsbad limestone [now called Capitan Limestone], at 

the base of a sandstone phase. 

Evaporite Minerals 

Adjacent to the western border of Guadalupe Mountains 

National Park is a major basin or graben called Salt Flat 

(fig. 1). It is about 100 km (60 mi) long and 16 km (10 mi) 

wide at the easternmost edge of the Basin and Range 

Province. Salt Flat has been the site of continuous 

alluvial, fluvial, and lacustrine sedimentation since 

middle Tertiary time (see fig. 2). In a region of low 

rainfall (about 25 cm [10 in] per year) and high 

evaporation (about 200 cm [80 in] per year) (Dunham 

1972), modern saline playas occur in Salt Flat. Without a 

natural outlet, all drainage is internal. Groundwater, 

which stands at a level near the playa surface, is drawn 

upward and evaporated. This groundwater has 

percolated through evaporite- bearing Permian strata 

(e.g., Castile Formation) and is thereby already charged 

with considerable dissolved solids, which are further 

concentrated through evaporation at the surface, leading 

to very elevated salinities (exceeding 250–300 parts per 

thousand). These high salinities greatly restrict 

vegetation and allow eolian deflation of the fine- grained 

playa precipitates. 

Gypsum and halite are the dominant evaporite minerals, 

but calcite, aragonite, and dolomite also occur in the 

playa sediments (Friedman 1966; Dunham 1972). 

Carbon- 14 dating and geologic mapping of rock units in 

the basin indicate that much of the sediment found at the 

surface today may be relict from a larger Pleistocene 

pluvial lake (King 1948; Dunham 1972). Wind erosion and 

deposition has piled up some of the primary and 

secondary minerals from this sediment (mainly gypsum) 

as dunes along the margins of the playa area (see 

“Dunes” section). 

Though not preserved to any extent in buried sediments, 

halite has been mined from the surface of the playa. Used 

for food preservation and the final curing of hides, halite 

was a highly valued commodity in the 1880s. Mule- and 

ox- drawn vehicles hauled the substance for many 

hundreds of miles over the Southwest Trail to Fort 

Quitman, then to San Elizaro, Franklin (now El Paso), 

Paso del Norte (now Juarez), and on to Chihuahua City. 

Disputes between Mexican and American mining 

interests in the area led to the El Paso Salt War of 1877. 

The conflict culminated in the Battle of San Elizaro (then 

the county seat of El Paso County). Modern foodpreservation techniques and more economical sources of 

salt have eliminated the relatively small- scale mining in 

this area since the 1950s. 

Guano 

According to Hayes et al. (1983), guano is found in small 

amounts in Cottonwood Cave along the Guadalupe 

Ridge in the Guadalupe Escarpment Wilderness Study 

Area (fig. 6) and possibly in other small solution caves in 

the study area. Guano was formerly mined as nitraterich fertilizer from caves now in Carlsbad Caverns 

National Park. Today most nitrate fertilizer is obtained 

from the destructive distillation of coal and coke, sewage 

treatment plants, and by fixation from the atmosphere. 

Present or future demand for guano seems minimal; 

therefore, the incentive to mine guano in the area is low, 

except at large, easily mined deposits. Investigators from 

the U.S. Geological Survey and Bureau of Land 

Management consider the guano that exists in the study 

area to be of negligible importance (Hayes et al. 1983). 

Nevertheless, guano finds its way into novelty shops 

where for a price interested buyers can purchase a bag to 

use on cherished flowers and potted plants (Moore and 

Sullivan 1997). 

Aside from its economic value, guano is an important 

source of food for cave- dwelling animals. Cave 

explorers may find crawling into a guano deposit 

unpleasant because of the guano’s mushy consistency 

and fetid ammoniac odor, and also because of the 

innumerable beetles, ticks, lice, and mites that swarm 

over it. To these creatures, however, guano is welcomed 

food, and the heaviest concentrations of cave life occur 

where guano abounds (Moore and Sullivan 1997). 

Road Material 

Historically, the Texas Department of Transportation 

has quarried limestone gravel at several places along U.S. 

Highway 62 for use as road base (Hayes 1964). These 

quarries are part of the Texas Department of 

Transportation’s right of way (Gorden Bell, Guadalupe 

Mountains National Park, e- mail, January 16, 2008). In 

many places the highway extends across patches of 

gravel, some of which are too coarse to use as road base 

and require screening to remove the larger stones. In 

places, the gravels and other alluvial deposits are strongly 

cemented by caliche, which has been used for surfacing 

the highway (King 1948). Park staff used the gravel from 

one pit near the mouth of McKittrick for surfacing the 

McKittrick Canyon access road. This borrow pit is just 

outside park land. In coordination with the Geologic 

Resources Division, park managers have prepared a sand 

and gravel management plan that outlines best 

management practices for minimizing the amount of 

sand and gravel needed for roads and trails and reducing 

potential impacts so that natural, cultural, and scenic 

values of the area are preserved (Greco et al. 2007). 

Travertine and Tufa 

The waters of McKittrick Canyon are laden with calcium 

carbonate (CaCO3

). As the water splashes over the creek 

bed, dissolved calcium carbonate is released and 

deposited. Calcium carbonate is also precipitated from 

very limy spring water, which loses carbon dioxide as it is 

warmed by the atmosphere, thus decreasing the 

solubility of calcium carbonate. The hard, dense deposit 
 NPS Geologic Resources Division 18 

that results is travertine; a spongy or less compact variety 

is tufa. Algae, which use the carbon dioxide in the water, 

are often abundant on CaCO3

 deposits in the spring- fed 

pools. These organisms likely play a role in the 

precipitation of the calcium carbonate (Hayes 1964). 

Calcium- carbonate deposits have an important effect on 

the streambed and the course of the creek in McKittrick 

Canyon. Travertine cements the gravel of the streambed, 

sealing it so the water cannot run underground. Dams 

also form across the stream and convex to the flow, 

creating pools. Floods occur every few years, changing 

the flow of the stream and altering the deposition of 

travertine. After each flood, travertine deposits gradually 

re- cement the streambed (Rennicke 1985). Travertine is 

also an important cave deposit, forming stalactites, 

stalagmites, and other cave features. 

Figure 4. Guadalupe Escarpment Wilderness Study Area. In 1983 investigators from the U.S. Geological Survey and Bureau of Land 

Management classified the potential for oil and gas beneath the study area as moderate. Source: Hayes et al. (1983). 
 GUMO Geologic Resource Evaluation Report 19

Figure 5. El Capitan. The thousand-foot-high El Capitan cliff, possibly the most striking feature in Guadalupe Mountains National Park, is 

composed entirely of Permian forereef limestone. NPS photo by Ron Kerbo. 
 NPS Geologic Resources Division 20 

Map Unit Properties 

This section identifies characteristics of map units that appear on the Geologic Resource 

Evaluation digital geologic map of Guadalupe Mountains National Park. The 

accompanying table is highly generalized and is provided for background purposes only. 

Ground- disturbing activities should not be permitted or denied on the basis of 

information in this table. More detailed map unit descriptions can be found in the help 

files that accompany the digital geologic map or by contacting the National Park Service 

Geologic Resources Division. 

The geologic map that accompanies this report is a digital 

version of King (1948, pl. 3). This map includes both 

bedrock and surficial units. Since publication of King 

(1948), investigators have refined many of the map units, 

and some units have been granted formation status. 

Nevertheless, “there has been nothing to match [King’s] 

treatment since” (Pray 1988, p. 5). The map unit 

descriptions in the accompanying table are primarily 

from King (1948); however, if these have been 

superseded, the new descriptions appear in the table. 

In 1948 King noted abrupt changes from one rock type 

into another within short distances and drastic changes 

in character from southeast to northwest across the 

region. The sequences of rocks in the northwestern and 

southeastern parts of the area are so different that 

constructing a single stratigraphic column for the park 

would have been awkward; hence, King divided the 

rocks into two separate columns on his map. Later 

investigators discovered that a rare sequence of exposed 

evaporites, carbonates, and sandstones in the Guadalupe 

Mountains shows all of the lateral transitions resulting 

from deposition of a massive reef at the edge of a deep 

marine basin. The abrupt changes that King noted are 

represented in this sequence of rocks called the Permian 

Reef Complex. This complex includes rocks formed in 

lagoons and shoals of the shallow shelf (backreef), the 

organic buildup of the reef and the debris shed down the 

steep reef front (forereef), and sediments deposited in 

the deep waters of the Delaware Sea (basin). This 

complex of rocks contains one of the largest fossil reefs 

in the world, the Capitan Reef, which overlies the slightly 

older Goat Seep Reef. 

The consolidated rocks of Guadalupe Mountains 

National Park are marine and coastal sediments of 

Permian age. The four series of the Permian System 

previously used in Texas and New Mexico are, from 

oldest to youngest, the Wolfcampian, Leonardian, 

Guadalupian, and Ochoan (Adams et al. 1939). Three of 

these series are represented in Guadalupe Mountains 

National Park (i.e., Ochoan, Guadalupian, and 

Leonardian); Wolfcampian rocks are not exposed at the 

surface. Designation of the Middle Permian global 

stratotype as the Guadalupian Series necessitated a 

reorganization of the international terminology for the 

Permian System. The Wolfcampian and Leonardian of 

regional usage are now included in the Lower Permian 

Cisuralian Series, and the Ochoan is considered the 

Lopingian Series of Late Permian age (Glenister et al. 

1999). Cisuralian and Guadalupian rocks in the Delaware 

Basin reach a maximum thickness of about 2,130 m (7,000 

ft). The rocks consist chiefly of sandstone and limestone 

with various textures and structures. 

Table 2 shows the stratigraphic relationship among rock 

formations of the three provinces, which are 

stratigraphically contemporaneous but very dissimilar. 

Table 2 also relates the three sections of the map unit 

properties table. For instance, the Seven Rivers, Yates, 

and Tansill Formations were being deposited in the 

backreef at the same time that the Capitan Limestone 

was being deposited as reef and forereef and the Bell 

Canyon Formation was being deposited in the Delaware 

Basin. The map unit properties table highlights features 

such as age, name and map symbol, description, 

suitability for development and recreation, hazards, and 

the occurrence of various resources (e.g., 

paleontological, cave and karst, and mineral). 
 GUMO Geologic Resource Evaluation Report 21

TABLE 2. Permian Rock Formations in Stratigraphic Provinces 

AGE BACKREEF REEF and FOREREEF BASIN 

RUSTLER (dolomite with 

gypsum, also sandstone and 

siltstone) 

SALADO (salt , anhydrite, and 

potash) 

Lopingian 

(formerly 

Ochoan) CASTILE (anhydrite and 

gypsum) with SALADO solution 

breccia 

Reef Trail 

TANSILL (dolomite and 

siltstone) Lamar 

C McCombs 

B YATES (dolomite and 

sandstone) A Rader 

Pinery SEVEN RIVERS (separate 

layers of dolomite and gypsum) 

CAPITAN (limestone) 

Hegler 

BELL 

CANYON 

(sandstone 

with 

limestone 

members) 

Manzanita 

South Wells QUEEN (dolomite and 

sandstone) Quartzite 

GRAYBURG (dolomite) 

GOAT SEEP 

(limestone) 

Getaway 

SAN ANDRES, upper 

(limestone and dolomite) CHERRY CANYON sandstone tongue 

CHERRY 

CANYON 

(sandstone 

with 

limestone 

members) 

BRUSHY CANYON (sandstone) 

Basal shale (Pipeline Member) 

Guadalupian 

SAN ANDRES, lower 

(limestone and dolomite) 

Cisuralian CUTOFF (shale) CUTOFF (limestone and shale) 

(formerly 

Leonardian) YESO (gypsiferous dolomite) VICTORIO PEAK 

(limestone) 

BONE SPRING (limestone) 

Sources: Newell et al. (1953), Hayes (1964), Bebout and Kerans (1993), Hill (1996). 

 GUMO Geologic Resource Evaluation Report 25

Geologic History 

This section describes the rocks and unconsolidated deposits that appear on the digital 

geologic map of Guadalupe Mountains National Park, the environment in which those 

units were deposited, and the timing of geologic events that created the present 

landscape. 

A portion of the rock record, spanning more than 1 

billion years, is preserved in the Delaware Basin. These 

deposits range in age from the 1.3- billion- year- old 

Precambrian basement to the 10,000- year- old Holocene 

sediments of the Pecos River Valley (Hill 1996). This 

geologic summary focuses on about 50 million years of 

this record, that is, the rocks of the Permian Period (299–

251 million years ago). Because an estimated 95% of all 

the outcrops in the Delaware Basin date from this period, 

more is known about the Permian- age rocks than all of 

the pre- Permian rocks combined (Hill 1996). 

Globally speaking, the supercontinent Pangaea had not 

yet broken apart during the Permian Period, and Texas 

and New Mexico occupied the western edge of this 

landmass near the equator. A vast Permian ocean, called 

the Tethys Ocean, surrounded Pangaea; a narrow inlet 

connected this ocean to the “Permian Basin,” which 

consisted of four subbasins: Val Verde, Midland, 

Delaware, and Marfa (fig. 8). The Delaware Basin 

contained the 240- km- (150- mi- ) long, 120- km- (75-

mi- ) wide Delaware Sea. This sea was the depositional 

setting for the rocks now exposed in Guadalupe 

Mountains National Park. 

Before and during the Cisuralian (formerly Leonardian) 

Epoch (see table 2), the Delaware Basin subsided rapidly, 

accumulating sediments that would form limestone (e.g., 

Bone Spring and Victorio Peak Formations), dolomite 

(e.g., Yeso Formation), and shale (e.g., Cutoff 

Formation). Starting in the Cisuralian and continuing 

into the Guadalupian, these sediments record marine 

transgressions (e.g., San Andres Formation) and 

regressions (e.g., Grayburg Formation). Some of this 

material was deposited in incised submarine canyons, 

such as the Brushy Basin and Cutoff Formations; the 

Cutoff Formation is also notable for its debris flows. 

Ultimately, 3–5 km (2–3 mi) of sediments accumulated in 

the Permian Delaware Basin. Also during Cisuralian time, 

a reef bordering the Delaware Sea began to develop at 

the margins of the basin, and the general backreef- reefbasin sequence was established. Initially the reef was not 

a reef in the strictest sense of the word. Multiple reefs, 

really banks of carbonate sand, accumulated locally 

along the margins of the basin. These banks became the 

foundation upon which the later, more massive, 

Guadalupian reefs grew (Hill 1996). The earlier “reef” 

banks were composed of mainly fusulinid foraminifers, 

oolitic grainstone, or other high- energy carbonate 

material (Hill 1996). 

As the ocean floor continued to slowly sink, reef deposits 

grew upward, remaining relatively near the water’s 

surface. By middle to late Guadalupian time, the sea had 

shrunk to the confines of the Delaware Basin, and 

conditions became favorable for massive reef growth. 

Over millions of years, calcareous sponges, algae, and 

other lime- secreting marine organisms, along with 

calcium carbonate that precipitated from the water (a 

source of lime recently discovered to be primary in this 

process) built up to form the 640- km- (400- mi- ) long, 

horseshoe- shaped Capitan Reef. This “stratigraphic 

reef” contains a small organic component and larger 

inorganic component bound together into a waveresistant structure (Hill 1996). According to Hill (1996), 

the Capitan Reef was a barrier reef in the Guadalupe, 

Apache, and Glass Mountains, but was broken into 

discontinuous mound- like structures by submarine 

canyons on the north and east sides of the basin. Part of 

the reef environment is the “forereef,” where the massive 

reef grew over (prograded) its own debris. The forereef 

was composed of material from the front (seaward) side 

of the reef that had broken away from the steep slope, 

slipped to the bottom, and collected as sediments. The 

Goat Seep and Capitan Formations are the rock units 

composing the Guadalupian reef (see table 2). 

Behind the reef, a broad, shallow shelf or “backreef” 

composed of eolian, tidal flat, and lagoon deposits 

formed. The Guadalupian backreef consists of the 

Grayburg, Queen, Seven Rivers, Yates, and Tansill 

Formations. Based on variations in the types of 

sediments composing these rock units, geologists have 

divided the backreef into four environments: outer shelf, 

shelf crest, inner shelf, and evaporite shelf (fig. 9). The 

evaporite shelf was the area nearest the shore and 

consisted of coastal sabkha and playa settings; as 

characterizes such settings, eolian processes were 

probably active. The deposits are red siltstone and 

evaporites (e.g., gypsum and some halite). The red color 

of the clastic deposits of the evaporite shelf is due to the 

oxidation of iron in the very shallow, nearshore zone. An 

abrupt transition of rock type—from evaporites (sabkha) 

to dolomite (lagoon)—occurs between the evaporite 

shelf and inner shelf. The inner shelf consisted of tidal 

flats and lagoons. Heading basinward, the shelf crest, 

sometimes called the pisolite shoal, existed a few miles 

behind the reef front. The shelf crest represents an 

alternately emerged and submerged, peritidal 

environment characterized by pisolite and tepee 

structures (see “Sedimentary and Structural Features” 

section). Finally, the immediate backreef or outer shelf 

was located seaward from the shelf crest where the water 
 NPS Geologic Resources Division 26 

became deeper. The outer shelf is noted for a thickening 

of sediment (i.e., interbedded siliciclastics) adjacent to 

the reef and its increasing, basinward dipping of strata 

towards the reef. 

The Cherry Canyon and Bell Canyon Formations 

represent the strata of the Guadalupian- age Delaware 

Basin. Earlier (Cisuralian) basin deposits are the Bone 

Spring and Cutoff Formations (see table 2). Because of 

differences in lithology, geologists have separated the 

basin setting into the “basin” and “basin margin” (fig. 9). 

Reef sediments (i.e., limestone and dolomite) interfinger 

with basin sediments (i.e., siltstone and sandstone) in the 

basin margin. The basin sediments are primarily 

siliciclastics (rather than carbonates or fine- grained 

sedimentary rocks as in the basin margin), which is 

indicative of the long, an anastomosing channels that 

covered much of the basin floor. 

During the 10- million- year span of Guadalupian time, 

the Delaware Basin decreased in size. Sedimentation 

blocked the connection to the Permian Ocean and left 

the Delaware Basin as the last site of deep- water 

sedimentation and massive reef growth. Eventually the 

sea began to shrink and by evaporation the water became 

saltier, killing the reef- building organisms. Normal 

marine carbonate deposition in the Delaware Basin 

ceased at the end of Guadalupian time (Hill 1996). 

With an abrupt end to its growth, the reef was buried in 

thousands of feet of sediments during Lopingian 

(formerly Ochoan) time. Rivers deposited debris and 

playa lakes evaporated, infilling the basin and forming 

the Castile and Salado Formations. Dolomites and 

evaporites of the Rustler Formation were deposited later 

in mudflats. The Castile Formation occurs in the 

Patterson Hills area (see fig. 1); the Salado and Rustler 

Formations are not present in the park. Ultimately 

sedimentation entombed the reef for millions of years. 

The Delaware Basin remained buried as part of a stable 

platform during the Mesozoic Era, but faulting on the 

west side of the basin resulted in the uplift of the 

Guadalupe Mountains about 26 million years ago. Uplift 

exhumed the Capitan Reef and created the Western 

Escarpment, which runs from Bartlett Peak to El Capitan 

and includes 2,666- m (8,749- ft) Guadalupe Peak, the 

highest mountain in Texas. During uplift sediments were 

shed onto the High Plains and the ancestral Pecos River 

Valley. Stream erosion has removed softer sediment and 

lowered the region to its present level (Budd and Giles 

2003). In addition, caves in the area formed in the 

limestone units; the largest are those in Carlsbad Caverns 

National Park (Budd and Giles 2003). Wind and rain also 

helped to erode softer overlying sediments, leaving the 

more resistant limestone of the reef exposed. Because of 

the steep relief and sparse vegetation, landslides have 

eroded some hillsides, a process of mass wasting that 

continues in the present (see “Geologic Hazards” 

section). 

Figure 6. Permian Geography of West Texas and Adjoining New Mexico. Guadalupe Mountains National Park straddles the northwestern 

shelf and the Delaware Basin, which was one of four basins of the sea during Permian time. In the figure, G MTNS = Guadalupe Moutains, 

A MTNS = Apache Mountains, and GL MTNS = Glass Mountains. Source: Hill (1996). 
 GUMO Geologic Resource Evaluation Report 27

Figure 7. Depositional Environments of the Capitan Reef Complex. Geologists have divided the Capitan Reef Complex into backreef, reef, 

and basin settings. Pisolite, tepees, and fenestral carbonates of the shelf crest developed at times of peritidal shoals. Inset map (lower left) 

shows the regional relationship among the northwestern shelf (evaporite and sandstone), carbonate marginal mound (dolomite and 

limestone), and the basin (sandstone). Source: Hill (1996). 
 NPS Geologic Resources Division 28 

References Cited 

This section provides a listing of references cited in this report. A more complete geologic 

bibliography is available and can be obtained through the NPS Geologic Resources 

Division. 

Adams, J. E., M. G. Cheney, R. K. DeFord, R.I., Dickey, 

C. O. Dunbar, J. M. Hills, R. E. King, E. R. Lloyd, A. K. 

Miller, and C. E. Needham. 1939. Standard Permian 

section of North America. American Association of 

Petroleum Geologists Bulletin 23 (11): 1673–1681. 

Adams, J. E., and H. N. Frenzel. 1950. Capitan barrier 

reef, Texas and New Mexico. Journal of Geology 58: 

289–312. 

Bartlett, J. R. 1854. Personal narrative of explorations and 

incidents in Texas, New Mexico, California, Sonora, 

and Chihuahua, connected with the United States and 

Mexican Boundary Commission, during the years 1850, 

1851, 1852, and 1853, 117–121. Volume 1 of 2. New York: D. 

Appleton and Company. 

Bebout, D. G., and C. Kerans. 1993. Guide to the Permian 

reef geology trail, McKittrick Canyon, Guadalupe 

Mountains National Park, West Texas. Guidebook 26. 

University of Texas at Austin, Bureau of Economic 

Geology. 

Bell, G. L. C. J. Crow, and J. K. Rigby. 2002. Newly 

recognized reef fabric from the middle Capitan Reefs 

(Middle Permian), Guadalupe Mountains, Texas. 

Geological Society of America Abstracts with Programs

34 (6): 356. 

Bell, G. L. Jr., M. K. Nestell, G. P. Nestell, and L. L. 

Lambert. 2006, Day 1—road log. In Basinal facies of the 

uppermost Guadalupian—Applicability to exploration 

and development projects, ed. G. Hinterlong, 6–23. 

Publication 2006- 46 (field trip guidebook). Tulsa, OK: 

Society of Economic Paleontologists and 

Mineralogists. 

Blanchard, W. G. Jr., and M. J. Davis. 1929. Permian 

stratigraphy and structure of parts of southeastern 

New Mexico and southwestern Texas. American 

Association of Petroleum Geologists Bulletin 13: 957–995. 

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Budd, A. F., and K. A. Giles. 2003. Guadalupe Mountains 

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Crandall, K. H. 1929. Permian stratigraphy of 

southeastern New Mexico and adjacent parts of 

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DuChene, H. R., 2000, Bedrock features of Lechuguilla 

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Cave and Karst Studies 62 (2): 109–119. 

DuChene, H. R., D. H. Jagnow, L. Pray, and J. M. Queen. 

1993. Geologic considerations for the protection of the 

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reference to Lechuguilla Cave and Carlsbad Cavern. 

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Journal of Cave and Karst Studies 62 (2): 75–79. 

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Texas—Facts and questions to aid interpretation and 

group discussion. Publication 72- 141. Midland, TX: 

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Basin Section. 

Friedman, G. M. 1966. Occurrence and origin of 

Quaternary dolomite of Salt Flat, West Texas. Journal 

of Sedimentary Petrology 36: 263–267. 

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Paper 58. Washington, D.C.: U.S. Geological Survey. 

Glenister, B. F., and B. R. Wardlaw. 2000. Guadalupe 

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international Middle Permian reference (GSSP). 

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32 (7): p. 264. 

Glenister, B. F., B. R. Wardlaw, L. L. Lambert, C. Spinosa, 

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Wilde. 1999. Proposal of Guadalupian and component 

Roadian, Wordian and Capitanian Stages as 

international standards for the Middle Permian Series. 

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sand and gravel management plan. Lakewood, CO: 

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Center, Geologic Resources Division. 
 GUMO Geologic Resource Evaluation Report 29

Harris, M. T. 2000. Members for the Cutoff Formation, 

western escarpment of the Guadalupe Mountains, 

West Texas. In The Guadalupian Symposium, ed. B. R. 

Wardlaw, R. E. Grant, and D. M. Rohr, 101–120. 

Smithsonian Contributions to the Earth Sciences 32. 

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New Mexico. Professional Paper 446. Washington, 

D.C.: U.S. Geological Survey. 

Hayes, P. T., D. L. Thomas, and J. R. Thompson. 1983. 

Mineral resource potential and geology of the Guadalupe 

Escarpment Wilderness Study Area, Eddy County, New 

Mexico. Scale 1:24,000. Miscellaneous Field Studies 

Map MF- 1560- A. Washington, D.C.: U.S. Geological 

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Hill, C. A. 1996. Geology of the Delaware Basin, 

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and West Texas. Publication 96- 39. Midland, TX: 

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Basin Section. 

Hill, C. A. 2000. Overview of the geologic history of cave 

development in the Guadalupe Mountains, New 

Mexico. Journal of Cave and Karst Studies 62 (2): 60–71. 

King, P. B. 1948. Geology of the southern Guadalupe 

Mountains, Texas. Professional Paper 215. Washington, 

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King, P. B., and R. E. King. 1928. The Pennsylvanian and 

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Bulletin 2801. Austin, TX: University of Texas. 

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Mountains National Park, Texas. NPS report for 

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28: 298–315. 

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Mountains National Park, Texas. Journal of 

Paleontology 79 (1): 200–204. 

Rigby, J. K., G. L. Bell Jr., and K. Thompson. 2007. 

Hexactinellid and associated sponges from the upper 

Reef Trail Member of the Bell Canyon Formation, 

southern Guadalupe Mountains National Park, Texas. 

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 NPS Geologic Resources Division 30 

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inventory of paleontological resources associated with 

National Park Service caves. Technical Report 

NPS/NRGRD/GRDTR- 01/02. Lakewood, CO: 

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Chihuahuan Desert Network. TIC D- 500. Lakewood, 

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Center, Geologic Resources Division. 

Scholle, P. 2000. An introduction and virtual geologic 

field trip to the Permian Reef Complex, Guadalupe 

and Delaware Mountains, New Mexico–West Texas. 

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Mineral Resources. 

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Dr. George G. Shumard, geologist for the United 

States government expedition for obtaining water by 

means of artesian wells along the 32nd parallel, under 

the direction of Capt. John Pope, U.S. top. Eng. St. 

Louis Academy of Science Transactions 1: 290–297. 

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parallel. St. Louis Academy of Science Transactions 1: 

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shelf carbonate rocks of Guadalupe Mountains, New 

Mexico. American Association of Petroleum Geologists 

Bulletin 58 (1): 63–70. 

Spalding, W. G., and P. S. Martin. 1979. Ground sloth 

dung of the Guadalupe Mountains in biological 

investigations. In Biological investigations in the 

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and Mexico, ed. R. H. Wauer and D. H. Riskind, D.H., 

107–113. National Park Service Proceedings and 

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Warren, W. C. 1955. Introduction to the field trip. In 

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Harris, B. L. Kirkland, and S. J. Mazzullo, 63–83. 

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chronology and δ

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.
 GUMO Geologic Resource Evaluation Report 31

Glossary 

This glossary contains brief definitions of technical geologic terms used in this report. Not all 

geologic terms used are referenced. More detailed definitions and additional terms are 

available at http://wrgis.wr.usgs.gov/docs/parks/misc/glossarya.html. 

anastomosing stream. The channel pattern of a braided 

stream is anastomosing, meaning branching and 

recombining. 

alluvium. Stream- deposited sediment that is generally 

rounded, sorted, and stratified. 

aquifer. Rock or sediment that is sufficiently porous, 

permeable, and saturated to be useful as a source and 

reservoir of water. 

bajada. A convergence of neighboring alluvial fans into a 

single apron of deposits against a slope, also called a 

compound alluvial fan.

basement. The undifferentiated rocks, commonly 

igneous and metamorphic, that underlie the deposits at 

the surface. In many regions the basement is of 

Precambrian age, but it may be much younger. 

basin (structural). A doubly plunging syncline in which 

rocks dip inward from all sides. 

basin (sedimentary). Any depression, from continental 

to local scales, into which sediments are deposited. 

bed. The smallest sedimentary strata unit, commonly 

ranging in thickness from one centimeter to a meter or 

two and distinguishable from other beds above and 

below. 

bedding. Depositional layering or stratification of 

sediments. 

block (fault). A crustal unit bounded by faults, either 

completely or in part. 

breccia. A coarse- grained, generally unsorted, 

sedimentary rock consisting of cemented angular 

clasts. 

clastic. Rock or sediment made of fragments of 

preexisting rocks. 

cross section. A graphical interpretation of geology, 

structure, or stratigraphy in the third (vertical) 

dimension based on mapped and measured geologic 

extents and attitudes depicted in an oriented vertical 

plane. 

crystalline. Describes the structure of a regular, orderly, 

repeating geometric arrangement of atoms 

debris flow. A rapid and often sudden flow or slide of 

rock and other earth material involving a wide range of 

types and sizes. 

deformation. A general term for the process of faulting, 

folding, shearing, extension, or compression of rocks 

as a result of various Earth forces. 

dolomite. The name of both a carbonate rock and a 

mineral consisting of calcium magnesium carbonate 

(CaMg(CO3

)2). Limestone which is partially replaced 

by dolomite is referred to as dolomitic limestone. 

dune. A low mound or ridge of sediment, usually sand, 

deposited by wind. 

eolian. Formed, eroded, or deposited by or related to the 

action of the wind. 

escarpment. A long, more or less continuous cliff or 

relatively steep slope facing in one general direction, 

breaking the continuity of the land by separating two 

levels or gently sloping surfaces, and produced by 

erosion or faulting. The term is often used 

synonymously with scarp, although escarpment is more 

often applied to a cliff formed by differential erosion, 

and scarp is identified more with faulting. 

evaporite. Chemically precipitated mineral(s) formed by 

the evaporation of solute- rich water under restricted 

conditions. 

facies (sedimentary). The depositional or environmental 

conditions reflected in the sedimentary structures, 

textures, mineralogy, and fossils of a sedimentary rock. 

fanglomerate. A sedimentary rock consisting of 

waterworn fragments of various sizes, deposited in an 

alluvial fan and later cemented into a firm rock. 

fault. A subplanar break in rock along which relative 

movement occurs between the two sides. 

fault-block mountain. A linear mountain range that is 

formed by normal block faulting where surfaces of 

adjacent blocks typically end up with different 

elevations or tilts, also called “block mountain.” 

fenestrate. Having openings or transparent areas. The 

term has been applied especially to bryozoans, corals, 

and pollen. 

formation. Fundamental rock- stratigraphic unit that is 

mappable and lithologically distinct from adjoining 

strata and has definable upper and lower contacts. 

graben. A down- dropped structural block bounded by 

steeply dipping normal faults. 

igneous. Refers to a rock or mineral that originated from 

molten material; one of the three main classes of rocks: 

igneous, metamorphic, and sedimentary. 

intertidal. The same as “littoral,” meaning the benthic 

ocean environment (and organisms) between high 

water and low water. 

joint. A semiplanar break in rock without relative 

movement of rocks on either side of the fracture 

surface. 

karst topography. Topography characterized by 

abundant sinkholes and caverns formed by the 

dissolution of calcareous rocks. 

landslide. Any process or landform resulting from rapid 

mass movement under relatively dry conditions. 

lithology. The description of a rock or rock unit, 

especially the texture, composition, and structure of 

sedimentary rocks. 

member. A lithostratigraphic unit with definable contacts 

that subdivides a formation. 

mesa. A broad, flat- topped erosional hill or mountain 

that is bounded by steeply sloping sides or cliffs. 

mesic. Refers to a habitat or plant that requires a 

moderate amount of moisture. 
 NPS Geologic Resources Division 32 

mineral. A naturally occurring, inorganic crystalline solid 

with a definite chemical composition or compositional 

range. 

normal fault. A fault in which the hanging wall moves 

down relative to the footwall. 

outcrop. Any part of a rock mass or formation that is 

exposed or “crops out” at Earth’s surface. 

paleontology. The study of the life and chronology of 

Earth’s geologic past based on the stratigraphic 

distribution, morphology, and phylogeny of fossil 

organisms. 

parabolic dunes. Crescent- shaped dunes with horns or 

arms that point upwind. 

pisolite. A sedimentary rock, commonly limestone, made 

up chiefly of coated, pea- sized grains (oölites). 

plateau. A broad, flat- topped topographic high of great 

extent and elevation above the surrounding plains, 

canyons, or valleys (both land and marine landforms). 

playa. A dry lakebed, generally the shore or remnant of a 

lake in a closed basin.

pluvial lakes. Lakes formed during earlier times of more 

abundant precipitation. 

potash. An impure form of potassium carbonate (K2CO3) 

mixed with other potassium salts. Potash has been 

used since antiquity in the manufacture of glass and 

soap, and as a fertilizer. 

ripple marks. The undulating, subparallel, usually smallscale ridge pattern formed on sediment by the flow of 

wind or water. 

rock. A solid, cohesive aggregate of one or more 

minerals. 

sabkha. A supratidal environment of sedimentation, 

formed under arid to semiarid conditions on restricted 

coastal plains just above normal high- tide level (a 

saline marine marsh). 

sandstone. Clastic sedimentary rock of predominantly 

sand- sized grains. 

sediment. An eroded and deposited, unconsolidated 

accumulation of lithic and mineral fragments. 

sedimentary rock. A consolidated and lithified rock 

consisting of detrital or chemical sediment(s). 

sequence. A major informal rock- stratigraphic unit that 

is traceable over large areas and defined by a major sea 

level transgression- regression sediment package. 

shale. A clastic sedimentary rock made of clay- sized 

particles that exhibits parallel splitting properties. 

shoal. A relatively shallow place in a body of water.

sierra. An often used Spanish term for a rugged 

mountain range. 

silt. Clastic sedimentary material intermediate in size 

between fine- grained sand and coarse clay (1/256–1/16 

mm). 

siltstone. A variable- lithified sedimentary rock with siltsized grains. 

slope. The same as “gradient,” meaning the inclined 

surface (or its measurement) of any geomorphic 

feature. 

soil. Surface accumulation of weathered rock and 

organic matter capable of supporting plant growth and 

often overlying the parent rock from which it formed. 

speleothem. A formal term for a cave formation, from 

the Greek for “cave deposit.” Speleothems are the 

result of the interactions among water, rock, and air 

within caves. Examples of speleothems are stalactites, 

stalagmites, columns, cave popcorn, aragonite crystals, 

and cave bacon. 

spring. A site where water flows out at the surface due to 

the water table intersecting the ground surface. 

strata. Tabular or sheet- like masses or distinct layers of 

rock. 

stratigraphy. The geologic study of the origin, 

occurrence, distribution, classification, correlation, 

and age of rock layers, especially sedimentary rocks. 

stream. Any body of water moving under gravity flow 

and confined within a channel. 

subaerial. Formed, existing, or taking place on the land 

surface. 

subsidence. The gradual sinking or depression of part of 

Earth’s surface. 

supratidal. The same as “supralittoral,” referring to the 

shore area just above high- tide level. 

system (stratigraphy). The group of rocks formed during 

a period of geologic time. 

tectonic. Relating to large- scale movement and 

deformation of Earth’s crust. 

tectonics. The geologic study of the broad structural 

architecture and deformational processes of the 

lithosphere and asthenosphere. 

tongue (stratigraphy). A member of a formation that 

extends and wedges out away from the main body of a 

formation. 

travertine. A limestone deposit or crust, often banded, 

formed from precipitation of calcium carbonate from 

saturated waters, especially near hot springs and in 

caves. A spongy variety is tufa. 

trend. The direction or azimuth of elongation of a linear 

geologic feature. 

turbidity current. Rapidly moving, sediment- laden 

current moving down a slope and spreading 

horizontally. The term is most commonly used to 

describe underwater currents in lakes and oceans. 

They are believed to have produced the submarine 

canyons, notching the continental slope.

type locality. The geographic location where a 

stratigraphic unit is well displayed, is formally defined 

as a typical section, and derives its name. 

uplift. A structurally high area in Earth’s crust, produced 

by movement that raises the rocks. 

vadose. Refers to being unsaturated or occurring in the 

zone above the water table. 

water table. The upper surface of the saturated (phreatic) 

zone. 

xeric. Refers to a habitat or plant that requires only a 

small amount of moisture. 
 GUMO Geologic Resource Evaluation Report 33

Appendix A: Geologic Map Graphic 

The following page is a preview or snapshot of the geologic map for Guadalupe 

Mountains National Park. For a poster- size PDF of this map or for digital geologic map 

data, please see the included CD or visit the Geologic Resource Evaluation publications 

Web page (http://www2.nature.nps.gov/geology/inventory/gre_publications). 

 GUMO Geologic Resource Evaluation Report 35

Appendix B: Scoping Summary 

This appendix contains excerpts from the summary of a Geologic Resources Inventory 

(GRI) workshop for Guadalupe Mountains National Park on March 6–8, 2001. The 

Geologic Resources Inventory was the precursor to the Geologic Resource Evaluation 

(GRE) Program. The contact information and Web addresses referred to herein may be 

outdated. Please contact the Geologic Resources Division for current information. 

The purpose of the GRI workshop was to view and 

discuss the geologic resources at Carlsbad Caverns and 

Guadalupe Mountains National Parks, address the status 

of geologic mapping for compiling both paper and digital 

maps, and assess resource management issues and needs. 

Cooperators from the NPS Geologic Resources Division 

(GRD), Natural Resources Information Division 

(NRID), Carlsbad Caverns (CAVE), Guadalupe 

Mountains (GUMO), Colorado School of Mines, the 

New Mexico Bureau of Geology and Mineral Resources, 

and the Texas Bureau of Economic Geology were 

present at the workshop (table 3). 

The workshop included single- day field trips to view the 

geology of both Guadalupe Mountains (led by Gorden 

Bell, Mike Gardner, and Charles Kerans) and Carlsbad 

Caverns (led by Paul Burger), as well as a full- day 

scoping session to present overviews of the NPS 

Inventory and Monitoring (I&M) Program, the Geologic 

Resources Division, and the ongoing geologic resource 

inventory. Round table discussions about geologic issues 

for both parks included the status of geologic mapping 

efforts, interpretation, paleontological resources, sources 

of available data, and action items generated from this 

meeting. 

Existing Geologic Maps 

The U.S. Geological Survey has published professional 

papers about both the Texas and New Mexico portions 

of the Guadalupe Mountains. Professional Paper 215 

(King 1948) covers the Texas portion of the Guadalupe 

Mountains and contains a 1:48,000- scale geologic map 

that ends at the Texas State line. Professional Paper 446 

(Hayes 1964) covers the New Mexico portion of the 

Guadalupe Mountains (i.e., Carlsbad Caverns) and 

contains a 1:62,500- scale geologic map. Both were 

excellent, very comprehensive publications for their day 

and are still quite useful even though interpretations 

have been refined since their publications. 

The U.S. Geological Survey has also published a few 

other maps that cover the CAVE area. Mineral Resource 

Potential and Geologic Map of the Guadalupe Escarpment 

Wilderness Study Area, Eddy County, New Mexico (MF1560- A) is mapped at 1:24,000 scale. The U.S. Geological 

Survey published two separate geologic maps (i.e., GQ112 and GQ- 98), which predate Professional Paper 446 

and are both at 1:62,500 scale. Of note, however, is that 

MF- 1560- A only covers the most southwestern portion 

of Carlsbad Caverns National Park. 

Scoping participants considered all of these maps worthy 

of digitizing as they represent some of the best sources of 

existing “baseline” data. GRI staff will incorporate the 

digitization of these maps into their future work plan. 

Also the Colorado School of Mines (under the direction 

of Mike Gardner), has been concentrating efforts on 

large- scale mapping of the Permian reef at Guadalupe 

Mountains National Park, specifically the Brushy 

Canyon unit. They have digital versions of this mapping 

in ArcView format and are willing to share them with the 

National Park Service. 

Desired Enhancements to the Existing Maps 

Refinements to King’s 1948 map would involve splitting 

out the Carlsbad Group into three formations (Yates, 

Tansill, and Seven Rivers) to seamlessly edge- match with 

Hayes’ 1964 map and thereby eliminate the New 

Mexico–Texas “boundary fault.” Gorden Bell thought 

that aerial and satellite photos could be used to do this 

with minimal field checking. 

Other actions include the following items: 

• Integrate Mike Gardner’s large- scale mapping of the 

western escarpment with the King map for better 

detail of the Brushy Canyon unit members, which also 

include some minor faults that are not shown on 

King’s maps. 

• Work out the subdivision of the Bone Spring versus 

the Cutoff Formations where the units are shown but 

the interpretations have changed over time. 

• Work out the Victorio Peak–San Andres problem 

which relates to Goat Seep (which is really now known 

as the Grayburg and Queen). 

• Resurvey road cuts in and around both parks. 

• Conduct hazard and rockfall assessments, although 

most susceptible areas do not seem to affect facilities. 

• Essentially remap approximately one quadrangle 

worth of Carlsbad Group in Guadalupe Mountains 

National Park (not quad specific); New Mexico 

Bureau estimates ~$100,000 to do that work. 

Use of Lidar Technology for Higher Resolution 

Charles Kerans and Mike Gardner see the use of lidar 

technology as a great asset to refining any mapping and 

future research and would like to have these data 

available for the Guadalupe Mountains and Delaware 

Basin in the very near future. 
 NPS Geologic Resources Division 36 

They “rough” estimated the data acquisition at between 

$60,000 for a “poor- man’s DEM” and $100,000 for full 

lidar coverage. 

Various ideas were proposed on how to go about 

accomplishing this task; cooperators need to follow up 

with these items. Joe Gregson told the group of the 

Department of the Interior (DOI) high- priority program 

to obtain funding through regions for lidar information. 

He mentioned that leveraging with adjacent landmanagement agencies (e.g., USDA Forest Service and 

BLM) often is the most successful way to acquire funding 

for obtaining this technology. 

Digital Geologic Map Coverage 

As stated earlier, it was agreed upon by the consensus of 

the group that the King and Hayes maps were worthy of 

digitization with the caveat of the “desired 

enhancements” already listed. Once the maps exist in a 

digital format, they are easier to refine both in the field 

and electronically. 

GRI staff in Denver will attempt to accomplish this 

digitization in their work plan in FY- 2002. Of note is the 

existence of digital line work for Hayes’ map in 

Professional Paper 446, but there is no accompanying 

metadata. GRI staff would also like to get it attributed as 

per their NPS digital geologic map model. Dave Roemer 

(Carlsbad Caverns National Park, GIS) will need to be 

consulted for more specifics on metadata for this 

coverage. 

Charles Kerans thought that another additional piece of 

information that should be tied to any digital geologic 

database would be measured stratigraphic sections that 

could be geo- referenced and brought up in a GIS. This 

should be easy to add in to the NPS digital geologic 

database model. 

Other Desired GIS Data 

Soils 

Pete Biggam (NPS soil scientist) supplied the following 

information in reference to soils for both parks: 

We currently have in place an interagency agreement with 

the NRCS to map all National Park System units in Texas, 

based upon an estimated completion by 2005 (as funding 

allows). 

We are estimating that we might initiate soils mapping at 

Guadalupe Mountains National Park in 2003, and would 

be utilizing the NRCS soil survey crew that is currently 

located in El Paso, Texas. This, of course, is dependent on 

funding being provided by NPS I&M for this effort. 

We operate similar to the GRI: we would schedule a soil 

scoping session, look at soils research that was already 

performed at Guadalupe Mountains National Park, map it 

to National Cooperative Soil Survey standards with local 

input from Guadalupe Mountains National Park in 

regards to their soil resource management concerns. 

Products would be a digital soils map, digital soil attributes, 

metadata, soil report, as well as potentially some soil 

information/education products that could be incorporated 

into interpretive programs. There would be data that 

would be utilized within the NPS GIS theme manager as 

well, similar to what is being done with GRI. 

We would also have a "last acre mapped session," where we 

would have a soils field tour of the park. 

**Please note: The Soil Resources Inventory for 

Guadalupe Mountains National Park is currently in 

progress and completion is anticipated in 2010 (Judy 

Daniels, Soil Resources Inventory Program, e- mail, 

January 17, 2008).** 

Geologic Hazards 

Guadalupe Mountains National Park has a published 

hazards map from R. R. Railsback (University of Texas at 

Dallas) that was done in 1976. It has been digitized by 

Parsons Engineering. It is titled, Geologic Hazards in the 

Pine Springs Canyon Area, Guadalupe Mountains 

National Park. 

Paleontology 

Greg McDonald (GRD paleontologist) would like to see 

an encompassing, systematic paleontological inventory 

for both Guadalupe Mountains and Carlsbad Caverns 

National Parks, describing the known resources in both 

parks with suggestions on how to best manage these 

resources. 

Other Sources of Data 

• Charles Kerans did a presentation, “Hierarchical 

Stratigraphic Analysis of a Carbonate Platform, 

Permian of the Guadalupe Mountains.” He mentioned 

that much of this information will be available on CDROM in the near future. It will likely be available from 

the Texas Bureau of Economic Geology Web site 

(http://www.beg.utexas.edu). GRI staff is interested in 

obtaining a copy of this once it is available to the 

public. 

• The Colorado School of Mines has a Web site for 

research on the slope and basin consortium at 

http://www.mines.edu/Academic/geology/sbc/ 
 GUMO Geologic Resource Evaluation Report 37 

Interpretation 

Participants discussed interpretation of geologic 

resources; topics included the following: 

• The Permian Reef Complex should be better utilized 

in both parks as the major interpretive focus, and the 

tie of the Guadalupe escarpment between both parks 

should be made to illustrate the importance of the 

Capitan Reef as a world- class feature. This should also 

serve to illustrate the regional GUMO- CAVE story for 

Permian time. 

• Make better use of park trails to showcase and 

interpret the geology for visitors. 

• A reef diorama showing modern analogs and the 

process of reef building could be added to the displays 

in each visitor center. 

• Mike Gardner has offered to assemble a Bone Springs–

Shumard trail guide for Guadalupe Mountains 

National Park (for free). 

• Make better use of the story of P. B. King’s 

“interpretations” of the reef as a major contribution to 

the science of geology in general. 

Geologic Interpretation (*action items) 

• Geology trails: surface and *cave 

• 3D geologic and geomorphic representation of cave 

and trails 

• *Geologic story / core knowledge (need to get the 

word out to resource managers, interpreters, and 

visitors) 

• GUMO—Roadside geology waysides targeting lay 

people 

• Include both ancient and modern processes 

• GUMO—Global Boundary Stratotype Section and 

Point of the Middle Permian 

• How do we relate geology to a visitor’s own 

experiences? 

GIS 

• East and West Carlsbad 15- minute geology maps (ca 

1957) digitized 

• Staff at Guadalupe Mountains National Park has 

applied for SEPAS funding for 7.5- minute geologic 

mapping (field assistant); GRD would digitize. 

Other digital data needs: 

• Linear features (lineaments) 

• Springs/seeps 

• Soils maps 

• GUMO—Springs/seeps 

• GUMO—Caves 

• Paleontological locations 

• Geologic hazards 

Data synthesis could be done by GRD or Albuquerque 

GIS shop. 

Research 

• David Hunt—Syndepositional faulting in the back reef 

• Cave microbiology—Spider and Lechuguilla Caves 

• Cave development in the Guadalupes—Synthesis 

publication due out this fall 

• Infiltration study—Used for environmental 

assessment; proposed dye trace of Bat Cave Draw 

(CAVE staff) 

• GUMO—Fossil sponges, geopetals, Sr- isotope dating 

• GUMO—Deep channels (Mike Gardner’s group) 

• Add hydrologic studies, Quaternary studies, gypsum 

dunes 

• David Wilkins did Quaternary mapping of the Salt Flat 

basin 

Gorden Bell says investigators’ annual reports (IAR) get 

done, but investigators do not catalog paleontological 

specimens. 

Potential Partnerships 

(e.g., money, technical guidance and reviews, library 

materials) 

• Course materials 

• Updating park libraries 

• Technical assistance 

• Presentations and programs 

• WIPP and other national labs 

• Universities—students and faculty 

• NSF monies 

• NCKRI (caves and karst institute) 

• GRD 

• USGS 

• Oil industry 

Oil companies that close down may be very willing to 

give their publications holdings to NPS libraries; 

therefore, contact AAPG for donations of collections 

from retirees ready to donate their collections. 
 NPS Geologic Resources Division 38 

GRI Workshop Participants 

Name Affiliation Phone E-Mail 

Fred Armstrong Guadalupe Mountains National 

Park, Natural Resources 

915-828-3251, ext. 251 fred_armstrong@nps.gov 

Gorden Bell Guadalupe Mountains National 

Park, Geologist 

915-828-3251, ext. 249 gorden_bell@nps.gov 

Paul Burger Carlsbad Caverns National Park 505-785-2232, ext. 394 paul_burger@nps.gov 

Doug Buehler Guadalupe Mountains National 

Park, Interpretation 

915-828-3251, ext. 105 doug_buehler@nps.gov 

Tim Connors Geologic Resources Division 303-969-2093 tim_connors@nps.gov 

Steve Fryer Natural Resources Information 

Division 

970-225-3584 steve_fryer@nps.gov 

Mike Gardner Colorado School of Mines 303-384-2042 mgardner@mines.edu 

John Graham Natural Resources Information 

Division 

970-225-6333 john_p_graham@nps.gov 

Joe Gregson Natural Resources Information 

Division 

970-225-3559 joe_gregson@nps.gov 

Bruce Heise Geologic Resources Division 303-969-2017 bruce_heise@nps.gov 

Charles Kerans Bureau of Economic Geology 

Univ. of Texas at Austin 

512-471-1368 charles.kerans@beg.utexas.edu 

Vicki Magnis NPS Intermountain Region, GIS 303-969-2962 viktoria_magnis@nps.gov 

Greg McDonald Geologic Resources Division 303-969-2821 greg_mcdonald@nps.gov 

Dale Pate Carlsbad Caverns National Park, 

Cave Specialist 

505-785-2232 dale_pate@nps.gov 

Greer Price New Mexico Bureau of Geology 

and Mineral Resources 

505-835-5752 gprice@gis.nmt.edu 

Dave Roemer Carlsbad Caverns National Park, 

GIS 

 dave_roemer@nps.gov 

Peter Scholle New Mexico Bureau of Geology 

and Mineral Resources 

505-835-5302 pscholle@gis.nmt.edu 

Jan Wobbenhorst Guadalupe Mountains National 

Park, Chief of Natural 

Resources 

915-828-3251, ext. 109 jan_wobbenhorst@nps.gov 
The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides scientific and other 

information about those resources; and honors its special responsibilities to American Indians, Alaska Natives, and affiliated Island 

Communities. 

Guadalupe Mountains National Park 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2008/023 

NPS D-181, February 2008 

National Park Service 

Director • Mary A. Bomar 

Natural Resource Stewardship and Science 

Acting Associate Director • Mary Foley, Chief Scientist of the Northeast Region 

Natural Resource Program Center 

The Natural Resource Program Center (NRPC) is the core of the NPS Natural Resource Stewardship and 

Science Directorate. The Center Director is located in Fort Collins, with staff located principally in 

Lakewood and Fort Collins, Colorado and in Washington, D.C. The NRPC has five divisions: Air 

Resources Division, Biological Resource Management Division, Environmental Quality Division, Geologic 

Resources Division, and Water Resources Division. NRPC also includes three offices: The Office of 

Education and Outreach, the Office of Inventory, Monitoring and Evaluation, and the Office of Natural 

Resource Information Systems. In addition, Natural Resource Web Management and Partnership 

Coordination are cross- cutting disciplines under the Center Director. The multidisciplinary staff of NRPC 

is dedicated to resolving park resource management challenges originating in and outside units of the 

national park system. 

Geologic Resources Division 

Acting Chief• John Vimont 

Planning Evaluation and Permits Branch Chief • Carol McCoy 

Credits 

Author • Katie KellerLynn

Review• Gordon Bell 

Editing • Lorna Carter (USGS), Sid Covington, and Melanie Ransmeier 

Digital Map Production • Anne Poole 

Map Layout Design • Andrea Croskrey
Geologic Resources Division 

Natural Resource Program Center 

P.O. Box 25287 

Denver, CO 80225 

http://www.nature.nps.gov/geology/inventory/ 

(303) 969-2090 

EXPERIENCE YOUR AMERICATM 

National Park Service 

U.S. Department of the Interior