Mineral Resources of the

Little Black Peak and Carrizozo Lava Flow

Wilderness Study Areas,

Lincoln County, New Mexico

U.S. GEOLOGICAL SURVEY BULLETIN 1734-E

Chapter E

Mineral Resources of the

Little Black Peak and Carrizozo Lava Flow

Wilderness Study Areas,

Lincoln County, New Mexico

By DOUGLAS B. STOESER and 

MICHAEL K. SENTERFIT 

U.S. Geological Survey

JEANNE E. ZELTEN 

U.S. Bureau of Mines

U.S. GEOLOGICAL SURVEY BULLETIN 1734

MINERAL RESOURCES OF WILDERNESS STUDY AREASWEST-CENTRAL NEW MEXICO
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U. S. GEOLOGICAL SURVEY 

Dallas L Peck, Director

Any use of trade, product, industry, or firm names in this publication is for 

descriptive purposes only and does not imply endorsement by the 

U.S. Government.

UNITED STATES GOVERNMENT PRINTING OFFICE: 1989

For sale by the

Books and Open-File Reports Section

U.S. Geological Survey

Federal Center

Box 25425

Denver, CO 80225

Library of Congress Cataloging-in-Publication Data

Stoeser, D.B.

Mineral resources of the Little Black Peak and Carrizozo Lava Flow 

Wilderness study areas, Lincoln County, New Mexico.

(U.S. Geological Survey bulletin ; 1734-E) (Mineral resources of wilderness 

study areas west-central New Mexico ; ch. E 

Bibliography: p. 

Supt. of Docs, no.: I 19.3:1734-E

1. Mines and mineral resources New Mexico Little Black Peak Wilderness.

2. Mines and mineral resources New Mexico Carrizozo Lava Flow 

Wilderness. 3. Little Black Peak Wilderness (N.M.) 4. Carrizozo Lava Flow 

Wilderness (N.M.) I. Senterfit, Michael K. II. Zelten, Jeanne E. III. Title. 

IV. Series. V. Series: Mineral resources of wilderness study areas westcentral New Mexico ; ch. E.

QE75.B9 no. 1734-E 557.3 s [553'.09789'64] 88-600464 

[TN24.N6]
STUDIES RELATED TO WILDERNESS 

Bureau of Land Management Wilderness Study Areas

The Federal Land Policy and Management Act (Public Law 94-579, October 21, 

1976) requires the U.S. Geological Survey and the U.S. Bureau of Mines to conduct mineral 

surveys on certain areas to determine the mineral values, if any, that may be present. Results 

must be made available to the public and be submitted to the President and the Congress. 

This report presents the results of a mineral survey of parts of the Little Black Peak 

(NM-060-109) and Carrizozo Lava Flow (NM-060-110) Wilderness Study Areas, 

Lincoln County, New Mexico.

CONTENTS

Summary £1

Abstract El 

Character and setting £1 

Resources E3 

Introduction E4

Investigations by the U.S. Bureau of Mines E5 

Investigations by the U.S. Geological Survey E5 

Appraisal of identified resources E5

Mining and mineral-exploration history E5 

Appraisal of sites examined E6

Assessment of potential for undiscovered resources E9 

Geology E9 

Geochemistry £12 

Geophysics £12 

Mineral and energy resource potential £13

Uranium associated with alkaline rocks £13 

Resources associated with magnetic highs £13 

Sediment-hosted uranium and copper £13 

Gypsum £15 

Salt £15 

Oil and gas £15 

Coal £15

Geothermal energy £15 

Recommendations for further work £16 

References cited £16 

Appendix £19

PLATE

[Plate is in pocket]

1. Geologic and mineral resource potential map of the Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas, Lincoln County, New Mexico

FIGURES

1. Summary map showing mineral resource potential and generalized geology of 

the Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas, Lincoln County, New Mexico £2

2. Index map showing the location of the Little Black Peak and Carrizozo Lava 

Flow Wilderness Study Areas, Lincoln County, New Mexico £4

3. Map showing oil and gas leases and lease applications in and near the Little 

Black Peak and Carrizozo Lava Flow study areas, Lincoln County, New 

Mexico £7

4. Generalized geologic and complete Bouguer gravity anomaly map of the Little 

Black Peak and Carrizozo Lava Flow Wilderness Study Areas and vicinity, Lincoln County, New Mexico £8

Contents
5. Diagrammatic east-west structure section through the Little Black Peak 

region £10

6. Aeromagnetic contour map of the Little Black Peak and Carrizozo Lava Flow 

Wilderness Study Areas, New Mexico, and vicinity E14

TABLE

1. Concentrations of selected trace elements in trachyte samples from in and near 

the Little Black Peak Wilderness Study Area, Lincoln County, New 

Mexico E12

VI Contents
MINERAL RESOURCES OF WILDERNESS STUDY AREAS-WEST-CENTRAL NEW MEXICO

Mineral Resources of the

Little Black Peak and Carrizozo Lava Flow

Wilderness Study Areas, Lincoln County, New Mexico

By Douglas B. Stoeser and Michael K. Senterfit 

U.S. Geological Survey

Jeanne E. Zelten 

U.S. Bureau of Mines

SUMMARY

Abstract

From 1985 to 1987 the U.S. Bureau of Mines and the 

U.S. Geological Survey conducted studies to appraise the 

identified mineral resources (known) and mineral resource 

potential (undiscovered) of the Little Black Peak 

(NM-060-109) and Carrizozo Lava Flow (NM-060-110) 

Wilderness Study Areas, Lincoln County, south-central New 

Mexico. A combined 24,249 acres were assessed. Both 

study areas have mainly Quaternary (see geologic time chart 

in the "Appendix") basalt flows (Carrizozo lava flows) 

exposed at the surface. The flows overlie an eastward to 

northward dipping section of Pennsylvanian to Cretaceous 

age sedimentary rocks. The only identified resource is the 

lava of the basalt flows which can be used for road metal, 

construction material, and decorative stone. The basalt is 

classed as an inferred subeconomic resource, but it is not 

likely to be developed due to its remote location distant from 

markets. A low resource potential was assessed for part of 

the Little Black Peak study area for undiscovered uranium 

associated with an alkaline Tertiary(?) intrusion. Both study 

areas were assessed a low resource potential for 

undiscovered sediment-hosted uranium and copper, oil, gas, 

coal, and geothermal energy, and moderate mineral 

resource potential for undiscovered gypsum and salt in 

Permian evaporites. Two contiguous aeromagnetic 

anomalies occur beneath the basalt of the study areas. 

Although the cause of the anomalies is not known, they may

Manuscript approved for publication, October 7, 1988.

be due to one or more concealed Tertiary(?) intrusions; the 

mineral resource potential associated with the anomalies is 

unknown.

Character and Setting

At the request of the U.S. Bureau of Land Management, 

the U.S. Bureau of Mines and the U.S. Geological Survey 

conducted investigations to appraise the identified mineral 

resources and to assess the mineral resource potential of the 

Little Black Peak and Carrizozo Lava Flow Wilderness Study 

Areas. The study areas cover 24,249 acres in south-central 

New Mexico in the western part of Lincoln County (figs. 1,2). 

In this report, the study areas are called the "wilderness study 

areas" or the "study areas." The study areas lie 

approximately 60 mi (miles) southeast of Socorro, 80 mi 

northwest of Roswell, and 4 mi northwest of the town of 

Carrizozo. Relief is low in both areas, with a maximum 

change in elevation of 425 and 565 ft (feet), respectively, in 

the Little Black Peak and Carrizozo Lava Flow study areas. 

Both areas are accessible from U.S. Highway 380, which 

divides the two areas, and from dirt roads which parallel most 

of the boundaries. The New Mexico Valley of Fires State Park 

is located along the eastern flanks of the study areas along 

Highway 380 (fig. 1; pi. 1).

The study areas are underlain by sedimentary rocks of 

the Pennsylvanian lower part of the Magdalena Group, the 

Permian Bursum Formation of Magdalena Group, Abo, Yeso, 

San Andres, and Bernal Formations, the Triassic Santa Rosa 

and Chinle Formations of Dockum Group, the Cretaceous 

Dakota Sandstone and Mancos Shale, an intrusive trachyte 

of probable Tertiary age, and the Quaternary basalt of the 

Carrizozo lava flow (see geologic time chart in the 

"Appendix" of this report). The most prominent geological

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas El
33°45'

106C00' 

T

105°55'

APPROXIMATE BOUNDARY OF 

" THE LITTLE BLACK PEAK 

WILDERNESS STUDY AREA 

(NM-060-109)

APPROXIMATE BOUNDARY OF

THE CARRIZOZO LAVA FLOW

WILDERNESS STUDY AREA

(NM-060-110)

Figure 1 (above and facing page). Summary map showing mineral resource potential and generalized geology of the 

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas, Lincoln County, New Mexico (geology modified 

from Smith, 1964; Weber, 1964).

E2 Mineral Resources of Wilderness Study Areas West-Central New Mexico
A 

B 

C

EXPLANATION OF IDENTIFIED RESOURCES 

AND MINERAL RESOURCE POTENTIAL

The Carrizozo lava flows (Qc) are an inferred subeconomic resource of lava in 

both study areas

Geologic terrane having moderate mineral resource potential for the nonmetallic commodities, gypsum and salt at certainty level C Applies to 

all of both study areas

Geologic terrane having low mineral resource potential for oil and gas, at 

certainty level C, and for coal and geothermal sources, at certainty 

level B Applies to all of both study areas

Geologic terrane having low mineral resource potential for uranium 

associated with Tertiary(?) trachyte, at certainty level C Applies to 

southeastern part of Little Black Peak Wilderness Study Area

Geologic terrane having low mineral resource potential for sedimenthosted copper and uranium, at certainty level B Applies to all of both 

study areas

Geologic terrane having unknown mineral resource potential associated 

with aeromagnetic anomalies, at certainty level A Applies to southern 

part of the Little Black Peak Wilderness Study Area and northern part of the 

Carrizozo Lava Flow Wilderness Study Area

Levels of certainty

Available information is not adequate for determination of the level of 

mineral resource potential

Available information suggests the level of mineral resource potential

Available information gives a good indication of the level of mineral 

resource potential

DESCRIPTION OF MAP UNITS

Qa Alluvium (Quaternary)

Qb Carrizozo lava flows (Quaternary)

Qbb Broken Back lava flow (Quaternary)

Tt Trachyte (Tertiary?)

Kmv Mesaverde Group (Cretaceous)

Km Mancos Shale (Cretaceous)

Kd Dakota Sandstone (Cretaceous)

"Re Chinle Formation (Triassic)

Its Santa Rosa Formation (Triassic)

Pb Bernal Formation (Permian)

Psa San Andres Formation (Permian)

Py Yeso Formation (Permian)

 Contact

 t ^ Anticline, Showing direction of plunge

X Prospect

 <J>- Drill hole

and physiographic feature of both study areas is the Carrizozo lava flows. The Little Black Peak study area has mostly 

basalt exposed at the surface with only local outcroppings of 

the San Andres and Santa Rosa Formations, Dakota 

Sandstone, and the trachyte. The Carrizozo Lava Flow study 

area also has chiefly basalt at the surface but also contains 

significant outcroppings of the Yeso and San Andres 

Formations in the southwestern part.

Resources

The only identified resource in either study area is 

inferred subeconomic resources of the Carrizozo lava flow, 

the rock of which can be used for road metal, construction 

material, or decorative stone. No mines are known to be 

present in either study area and prospects are present at only 

one locality in the Little Black Peak study area. The prospects 

consist of uranium exploration trenches dug along the 

contact zone between the Dakota Sandstone and trachyte 

where these units are exposed in a kipuka (outcrop island) 

within the basalt of the Carrizozo flows. The mineral resource 

potential for undiscovered uranium associated with the trachyte is assessed as low with a certainty level of C.

Two aeromagnetic anomalies beneath the northern 

part of the Carrizozo Lava Flow area and the southern part of 

the Little Black Peak area may indicate the existence of either 

Quaternary basaltic intrusions beneath and of the same age 

as the Carrizozo flows, or one or more intrusions of Tertiary (?) 

age. Elsewhere in the Carrizozo region, Tertiary intrusive 

rocks are associated with iron, gold, silver, zinc, copper, 

fluorspar, molybdenum, and rare-earth elements. There are 

no other data upon which to evaluate the rocks causing the

magnetic anomalies, and the associated mineral resource 

potential can only be assessed as unknown with certainty 

level A.

The Pennsylvanian to Cretaceous sedimentary 

formations that underlie both study areas are known to host 

redbed copper and sandstone uranium deposits elsewhere 

in New Mexico. Although these rocks represent a permissive 

environment such deposits are not known in the Carrizozo 

region, and the mineral resource potential for undiscovered 

sediment-hosted copper and uranium is low with a certainty 

level of B. The Permian Yeso and San Andres Formations 

underlying both study areas contain evaporites, and both 

areas are assessed as having a moderate mineral resource 

potential for undiscovered gypsum and salt with a certainty 

level of C.

On the basis of the results of previous test drilling in the 

region, the energy resource potential for oil and gas in both 

study areas is low with a certainty level of C. The most 

favorable stratigraphic units for hosting oil and gas are the 

Yeso and San Andres Formations and the Dakota 

Sandstone. Although the Sierra Blanca coal field lies 

immediately east of the study area, the Mesaverde Formation 

which hosts the coal is not present beneath the study areas 

and the resource potential for coal in the sedimentary rocks 

known to occur beneath the study areas is assessed as low 

with a certainty level of B. On the basis of the lack of hot 

springs and a low heat flow for the Carrizozo area, the 

resource potential for geothermal energy resources is low in 

both study areas with a certainty level of B.

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas E3
10700

34° 

OO1

33° 

00'

,, Socorro

___________106°00'

'. TORRANCE CO_____ 

SOCORRO CO. T

I

San Antonio BROKEN 

BACK 

FLOW..

APPROXIMATE BOUNDARY OF

THE CARRIZOZO LAVA FLOW

WILDERNESS STUDY rAREA _

I

SIERRA CO.

.APPROXIMATE BOUNDARY OF

THE LITTLE BLACK PEAK 

WILDERNESS STUDY AREA

NEW MEXICO

10

I

20

I

o ' '

Q/.t jfOscura 

<£V :

ffr k

I X-~" 

30 MILES

1 ;- '' ...-'"' Three Rivers |_ 

OTERO CO.

Figure 2. Index map showing the location of the Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas, Lincoln 

County, New Mexico.

INTRODUCTION

The Little Black Peak (NM-060-109) and Carrizozo Lava Flow (NM-060-110) Wilderness Study 

Areas are located in south-central New Mexico in Lincoln County about 60 mi (miles) southeast of Socorro 

and 80 mi northwest of Roswell (fig. 2). The town of 

Carrizozo lies 4 mi to the southeast along U.S. Highway 

380. The two study areas are contiguous and are 

separated only by U.S. Highway 380 (fig. 1). A resource 

assessment study of a combined area of 24,249 acres was 

requested by the U.S. Bureau of Land Management 

(BLM). In this report each studied area is called the 

"wilderness study area" or simply the "study area." Both 

areas are accessible from Highway 380 and from dirt 

roads which parallel most of the boundaries. The New 

Mexico Valley of Fires State Park (Weber, 1979) borders 

parts of both study areas along their eastern margins and 

is accessible from Highway 380 (fig. 1; pi. 1). 

Environmental, geomorphological, and cultural aspects 

of study areas are presented by the U.S. Bureau of Land 

Management (1985).

The dominant feature of both areas is a large lava 

flow, called the Carrizozo lava flow or Carrizozo Malpais 

(Alien, 1951). The surface of the Little Black Peak study 

area is completely covered by the flow except for kipukas;

whereas, the Carrizozo Lava Flow study area also has 

some surface area consisting of older sedimentary rock in 

the western part (fig. 1). Both study areas have low relief. 

Elevations range from about 5,250 ft on the eastern side 

of the Little Black Peak study area to a maximum 

elevation of 5,676 ft at the summit of Little Black Peak. 

Elevations in the Carrizozo Lava Flow study area range 

from approximately 5,000 ft to a maximum of 5,565 ft in 

the southwestern hills. Both study areas lack established 

drainage, except for a few eastward-draining intermittent 

streams in the southwestern part of the Carrizozo Lava 

Flow study area. These intermittent streams, as well as 

most intermittent streams near the border of the Carrizozo lava flow, drain towards and end at the margin of 

the flow. This has resulted in a zone of flat meadow lands 

and a number of small playas (dry lake beds formed by 

episodic ponding) along the margin of the flow.

This report presents an evaluation of the mineral 

endowment (identified resources and mineral resource 

potential) of the study area and is the product of several 

separate studies by the U.S. Bureau of Mines (USBM) 

and the U.S. Geological Survey (USGS). Identified 

resources are classified according to the system of the 

USBM and USGS (1980), which is shown in the 

"Appendix" of this report. Identified resources are 

studied by the USBM. Mineral resource potential is the

E4 Mineral Resources of Wilderness Study Areas-West-Central New Mexico
likelihood of occurrence of undiscovered metals and 

nonmetals, industrial rocks and minerals, and of 

undiscovered energy sources (coal, oil, gas, oil shale, and 

geothermal sources). It is classified according to the 

system of Goudarzi (1984) shown in the "Appendix." 

Undiscovered resources are studied by the USGS.

Investigations by the 

U.S. Bureau of Mines

Investigation of the Little Black Peak and Carrizozo Lava Flow study areas by the USBM consisted of a 

literature search and field work. Prior to the field 

investigation, various sources of minerals information, 

including published and unpublished literature and 

Bureau files, were reviewed regarding the geology and 

mineral resources of the region. Records at the BLM 

State Office in Santa Fe, N. Mex., and at the BLM district 

office in Roswell, N. Mex., were searched for mining 

claim, and oil, gas, and geothermal lease information 

pertinent to the study areas. Local residents, BLM 

personnel, and personnel from the New Mexico Bureau 

of Mines and Mineral Resources in Socorro, N. Mex., 

were interviewed regarding minerals information in the 

region.

Field investigation, consisting of a search for mines, 

prospects, and mineralized areas, and examining and 

sampling lava, uranium prospects, and outcrops, was 

conducted in April 1985. Seventeen chip samples were 

taken, including 7 lava samples, 8 samples of uraniumbearing sandstone exposed in prospect trenches, 1 

sample from a gypsum outcrop, and 1 sample from a 

dolomitic limestone outcrop.

All 17 samples were analyzed for gold and silver by 

fire assay. Ten of the samples were analyzed by fluorimetry for uranium. Whole rock analyses were performed 

on a sample of gypsum and a sample of dolomitic 

limestone. Sixteen samples were analyzed by semiquantitative optical emission spectrography for 40 elements. 

Analyses of all samples were performed by the U.S. 

Bureau of Mines, Reno Research Center, Reno, Nev. 

(Zelten, 1986). Additional sample information is 

available from the U.S. Bureau of Mines, Intermountain 

Field Operations Center, Building 20, Denver Federal 

Center, Denver, Colorado.

Investigations by the 

U.S. Geological Survey

In 1986 and 1987, D.B. Stoeser of the USGS 

conducted field investigations to assess the potential for 

undiscovered mineral resources of the Little Black Peak 

and Carrizozo Lava Flow Wilderness Study Areas. These

investigations included a field check of previous 

geological mapping, the collection of 14 rock and 10 

stream-sediment samples, and an examination of 

mineralized areas. All samples were analyzed by spectrographic and X-ray fluorescence methods in the USGS 

laboratories, Denver, Colo. Interpretation of available 

aeromagnetic and gravity data was by M.K. Senterfit.

The study areas lie within the Little Black Peak and 

Carrizozo 15-minute quadrangles which have been 

mapped by Smith (1964), Smith and Budding (1964), and 

Weber (1964). Their work, along with the regional 

geologic map of Dane and Bachman (1958), was used 

extensively in preparing the geologic map (pi. 1) for the 

present report. In addition, high-resolution, high-altitude 

infrared photography (scale 1:58,000) was used to 

compile plate 1. In addition to the present report, 

mineral and energy assessments that include the study 

areas are contained in unpublished reports by Krason 

and others (1982) and the U.S. Bureau of Land 

Management (1985).

APPRAISAL OF IDENTIFIED RESOURCES

By Jeanne E. Zelten 

U.S. Bureau of Mines

Mining and Mineral-Exploration History

The study areas are not included in any mining 

district and, as of November 1985, there were no mining 

claims in or within 1 mi of the boundaries. Precious and 

base metals, fluorite, uranium, gypsum-rich evaporites, 

coal, and vermiculite deposits occur in mining districts 

within 10 mi northeast to southeast of the study areas. 

The deposits occur in formations which are projected to 

underlie the lava, but there is no surface evidence of 

similar deposits beneath the lava. Most of the production 

from mining districts in this part of New Mexico was 

during World War II, and virtually no production has 

occurred since.

Claims were staked for uranium during the mid1950's across a large kipuka (Hawaiian term for an island 

of older rocks and surficial material surrounded by lava) 

in the southeastern part of the Little Black Peak study 

area in sees. 9 and 16, T. 7 S., R. 10 E. (pi. 1). Prospect 

trenches were bulldozed in limonite-stained Cretaceous 

Dakota Sandstone and Tertiary(?) trachyte along the 

summit of the kipuka, but no uranium was mined. The 

claims were abandoned in February 1985.

Small amounts of lava, extracted from near the 

edges of the flow, have been used locally for road metal

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas E5
(Smith, 1964), decorative stone, landscaping, and 

building material. From 1964 through 1972, lava was 

removed from outside the Carrizozo Lava Flow study 

area (SWVi sec. 31, T. 7 S., R. 10 E.) and sold to the Stone 

Center in St. Louis, Mo. Limited sales also were made 

over the years to local individuals (Custer, 1975).

As of April 1985, oil and gas leases and lease 

applications covered about 15 percent of the study areas 

(fig. 3). As of April 1982, seven exploration holes (fig. 4) 

had been drilled to depths ranging from 1,250 to 8,050 ft, 

within 3 mi of the boundaries (Krason and others, 1982); 

three of these wells, Bryce Dugger No. 1 Federal, Gallagher, and Helen (fig. 4), had a show of oil in the 

Permian San Andres Formation (Havener, 1964). 

Additional exploration is necessary to determine if oil 

and gas are present under the areas.

Appraisal of Sites Examined

Vesicular, basaltic lava underlies most of both 

study areas. Uranium occurs at the Dakota Sandstonetrachyte contact in the Little Black Peak study area. 

Gypsum and limestone crop out west of the lava and dip 

easterly beneath it.

The abundant lava from the study areas has local 

use for road metal, landscaping, and building material 

and represents an inferred subeconomic resource. 

Scoria, present in small cinder cones in the northern part 

of the Little Black Peak study area, could be used for 

construction purposes, specifically road metal and 

aggregate, and also as decorative stone. Much of the 

surface in the interior of the study areas is covered by 

pahoehoe (ropy) lava, with ropes averaging from 1 to 3 

in. (inches) in diameter, but sometimes as much as 6 in. 

This lava has value for decorative use.

Because of the extremely rugged lava surface, 

mining in the interior of the flows would be difficult and 

costly (Clippinger, 1946). No major population centers 

are nearby, so the cost of transporting a high-bulk, 

low-unit-value commodity, such as construction material, 

would be prohibitive (Osburn, 1979). Large, easily 

accessible quantities of scoria, suitable for construction, 

are available elsewhere in New Mexico and are adequate 

to supply current needs. Decorative stone has a higher 

unit value than construction material, and although 

extraction of lava for decorative stone is labor intensive 

and suitable rock is widely scattered, a low-volume 

operation might be profitable, as it was from 1964 to 

1972 when shipments were made to St. Louis. Seven lava 

samples were taken and analyzed; no unusual 

concentrations of elements were present (Zelten, 1986).

A contact between the Dakota Sandstone and 

trachyte crops out in a kipuka near the southeastern edge 

of the Little Black Peak study area. A uranium 

occurrence along the contact was explored by bulldozer 

trenches (fig. 1), but there is no evidence of any 

production. Total-count scintillometer readings taken 

along the length of the kipuka ranged from 20 to 1,500 

cps (counts per second); background for the area 

averaged 40 cps. Chip samples from the sandstone and 

trachyte exposed in the trenches contained from 0.98 to 

106 ppm (parts per million) uranium and averaged 44 

ppm. No uranium minerals were identified in or near the 

workings. Uranium deposits mined in New Mexico in 

1986 averaged at least 0.3 percent (3,000 ppm) U3O8 

(George Grandbouche, Department of Energy, Grand 

Junction, CO, oral commun., 1986), or about 2,550 ppm 

uranium. Analyses of samples from the workings did not 

exceed 106 ppm uranium. The uranium occurrence in 

the kipuka is small and low-grade; no uranium resource 

can be identified at this location. (See Zelten, 1986).

Gypsum in the Yeso and San Andres Formations 

crops out west of the Carrizozo lava flows. Alternating 

gypsum and limestone beds, each no more than about 

20-30 ft thick, occur in the San Andres near Crockett's 

Cave (Jagnow, 1973), about ¥2 mi west of the Carrizozo 

Lava Flow study area (pi. 1). Gypsum in the San Andres, 

exposed in a sinkhole near the southwestern boundary of 

the Little Black Peak study area, is at least 10 ft thick and 

dips about 20° southeast beneath the lava. Examination 

and analysis of the gypsum showed it to contain many 

impurities, which would limit its commercial value.

Minable gypsum beds are usually flat lying to 

moderately dipping, massive, with little to no overburden, 

and low in impurities. Gypsum occurs at or near the 

surface in beds up to 100 ft thick in New Mexico and is 

easily mined at localities closer to major population 

centers (Elston, 1967). Because of limited markets and 

the high cost of shipping a high-bulk, low-unit-value 

commodity, gypsum mines and plants are near markets 

(Logsdon, 1982). Large amounts of overburden would 

have to be removed to surface mine the gypsum in the 

study areas. If gypsum is present beneath the lava, it 

would not be economical to mine in the foreseeable 

future because of impurities, distance from markets, and 

expensive mining methods.

A sample of dolomitic limestone was taken from a 

sinkhole that exposes Yeso Formation just outside the 

western boundary of the Carrizozo Lava Flow study area. 

The limestone exposed at this location is intermixed with 

thin layers of dolomite and gypsum, and contains other 

impurities. Whole-rock analysis of the limestone showed 

it to be of poor quality and not commercially valuable for 

chemical use (Zelten, 1986).

E6 Mineral Resources of Wilderness Study Areas West-Central New Mexico
106°00' 105°45'

APPROXIMATE BOUNDARY OF

THE LITTLE BLACK PEAK 

WILDERNESS STUDY AREA

APPROXIMATE BOUNDARY OF

THE CARRIZOZO LAVA FLOW

WILDERNESS STUDY AREA

R.8E. R.9E. R.10E.

5 MILES 

J

R. 11 E.

EXPLANATION

OH and gas leases

Oil and gas lease applications

(Oil and gas lease information from the 

Bureau of Land Management, 1985)

U.S. highway

Figure 3. Map showing oil and gas leases and lease applications in and near the Little Black Peak and Carrizozo 

Lava Flow study areas, Lincoln County, New Mexico.

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas E7
33°45'

3 3° 30' *

106°00' 105°45'

&

M

^""\ M \/ v

APPROXIMATE BOUNDARY OF 

~ THE LITTLE BLACK PEAK 

/WILDERNESS STUDY AREA

% White Oaks '*~

-*^ mining district

DH

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-M

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/

M

M

It

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f APPROXIMATE 

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J CARRIZOZO LAVA 

I FLOW WILDERNESS 

? STUDY AREA

S$*

Cf.

\ r~ ~~ 

/ J/ Nogal

' f / «* « *»«<

Ti 

/

/

'/

mining 

'istrict

M

j

lv /

/

10 MILES 

I

Figure 4 (above and facing page). Generalized geologic and complete Bouguer gravity anomaly map of the Little Black 

Peak and Carrizozo Lava Flow Wilderness Study Areas and vicinity, Lincoln County, New Mexico (from Healy and others, 

1978). Contour interval, 5 milligals. Abbreviations: oil and gas test wells: DF Dugger No. 1 Federal, DG Dugger No. 1 

Gallagher, DH Dugger No. 1 Helen, and SH Standard of Texas No. 1 Heart.

E8 Mineral Resources of Wilderness Study Areas-West-Central New Mexico
Qb 

Ti 

TV 

M 

P

EXPLANATION 

Alluvium (Quaternary)

Carrizozo lava flows (Quaternary) 

Broken Back lava flow (Quaternary) 

Felsic intrusive rocks (Tertiary) 

Volcanic rocks (Tertiary) 

Sedimentary rocks (Mesozoic) 

Sedimentary rocks (Permian) 

Contact

Fault U on upthrown side and D on 

downthrown side

 ~^ + Anticline Showing direction of plunge

 165 Gravity contour line, in milligals 

9 Gravity station 

-<J>- Drill hole

 Mining and coal district boundary

ASSESSMENT OF POTENTIAL FOR 

UNDISCOVERED RESOURCES

By Douglas B. Stoeser and 

Michael K. Senterfit 

U.S. Geological Survey

Geology

The Little Black Peak and Carrizozo Lava Flow 

Wilderness Study Areas and adjoining region are 

underlain by sedimentary rocks of Pennsylvania^ Permian, Triassic, and Cretaceous age; by trachyte of 

probable Tertiary age; and by Quaternary age basaltic 

volcanic rock, stream alluvium, alluvial fan terrace 

deposits, and playa deposits (pi. 1). The Quaternary units 

were deposited in the northernmost part of the Tularosa 

Basin, the easternmost basin of the Highland section of 

the Basin and Range physiographic province in New 

Mexico (Weber, 1964; New Mexico Geological Society, 

1982).

The pre-Tertiary sedimentary rocks beneath the 

Carrizozo Lava Flow study area lie on the eastern flank 

of the north-northeast trending Carrizozo anticline (figs. 

1, 4, 5) (Kelly and Thompson, 1964); these sedimentary 

rocks have a simple monoclinal dip of generally less than

20° southeast. The nose of the Carrizozo anticline 

plunges north-northeast beneath the northern part of the 

Little Black Peak study area (fig. 1), and thus the strike of 

layered rocks immediately west of and beneath the Little 

Black Peak study area changes from north-northeast to 

northwest as these beds wrap around the nose of the fold 

(pi. 1). The Standard of Texas No. 1 Heard Well (fig. 4) 

was drilled on the axis of the anticline adjacent to 

Highway 85, approximately 3 mi west of the study areas 

and penetrated 7,740 ft of Permian and Pennsylvanian 

sedimentary rocks before bottoming in crystalline 

basement rocks (R.W. Foster in Griswold, 1959; figure 

20 of King and Harder, 1985). It is also thought that the 

stratigraphic section of these rocks beneath the anticline 

have been tectonically thickened due to mobilization of 

evaporites within the Permian section and that these 

units thin away from the core of the anticline (Kelley and 

Thompson, 1964; Weber, 1964).

Rock units exposed within the Little Black Peak 

study area are the Permian San Andres Formation, the 

Triassic Santa Rosa Formation, the Cretaceous Dakota 

Sandstone, a Tertiary(?) trachyte intrusive mass, and the 

Quaternary Carrizozo lava flows (also referred to as the 

Little Black Peak lava flow by Smith, 1964). In addition, 

the following sedimentary rock units occur adjacent to 

and beneath the study area (pi. 1): the Permian Bernal 

Formation, Triassic Chinle Formation, and Cretaceous 

Mancos Shale (Smith, 1964). The distribution of the 

Bernal Formation and Triassic units beneath the Carrizozo lava flows is not known, but it appears that they 

wedge out against the Dakota Sandstone going 

southwards and may or may not extend as far south as the 

Carrizozo study area.

Rock units exposed within the Carrizozo Lava 

Flow study area include the Permian Yeso and San 

Andres Formations and the Quaternary Carrizozo lava 

flows (Weber, 1964). The Cretaceous Dakota Sandstone, 

Mancos Shale, and Mesaverde Group crop out near the 

eastern margin of the study area (pi. 1), but only the 

Dakota Sandstone and Mancos Shale appear to underlie 

the southeasternmost part of the study area.

Although not exposed within the study areas, the 

Pennsylvanian Magdalena Group, and the Permian Bursum (of the Magdalena Group) and Abo Formations are 

interpreted to underlie both study areas (fig. 5) (Kelley 

and Thompson, 1964). In the study region, the lower 

Magdalena Group is approximately 1,300-1,700 ft thick 

and consists of limestone, shale, and minor 

conglomerate, the Bursum Formation is less than 250 ft 

thick and consists of shale interbedded with sandstone 

and conglomerate, and the Abo Formation is 

approximately 1,250-1,500 ft thick and consists of 

reddish-brown mudstone, claystone, and arkosic 

conglomerate (R.W. Foster in Griswold, 1959; Foster, 

1978; King and Harder, 1985).

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas E9
LITTLE BLACK PEAK 

STUDY AREA

WEST

BERNAL AND SAN ANDRES 

FORMATIONS

EAST

DOCKUM GROUP 

MANGOS SHALE AND 

DAKOTA SANDSTONE

10 MILES

I

Scale Approximate

Figure 5. Diagrammatic east-west structure section through the Little Black Peak region (modified from Kelley and 

Thompson, 1964).

The Permian Yeso Formation underlies both study 

areas and consists of interbedded limestone, dolomite, 

salt, gypsum, sandstone, and mudstone, including redbed 

sandstone and shale, and minor anhydrite (R.W. Foster 

in Griswold, 1959; King and Harder, 1985). In the study 

region, the Yeso is approximately 3,500-4,300 ft thick 

(Foster, 1978; King and Harder, 1985). The upper part of 

the Yeso Formation is exposed in the west-central part of 

the Carrizozo Lava Flow study area and consists of tan to 

brown interbedded limestone, sandstone, siltstone, and 

gypsum (Weber, 1964). In addition to these lithologies, 

evaporitic salt beds in the lower part of the Yeso 

Formation are reported for the Standard of Texas No. 1 

Heard well, including one 900-ft section consisting 

mainly of salt (R.W. Foster, reported in Griswold, 1959; 

Milner, 1978; King and Harder, 1985). Because of the 

presence of soluble rock types within the section, 

sinkholes (collapsed solution caves) have developed 

within the Yeso, and several of these are shown on 

plate 1.

The Permian San Andres Formation, which 

overlies the Yeso Formation, also underlies both study 

areas and consists of interbedded dolomite, dolomitic 

limestone and gypsum with minor cherty zones and 

sandstone beds (Weber, 1964; Foster, 1978). In the study 

region the San Andres Formation is approximately 

600-850 ft thick (Smith, 1964; Weber, 1964; Foster, 

1978). Extensive collapse due to solution of the gypsum 

and carbonate beds has caused structural complexity 

within the unit (Weber, 1964) as indicated by highly 

variable dips to more than 60° and local minor folds (pi. 

1). In addition, solution of these rocks has led to the

formation of sinkholes, several of which are shown on 

plate 1. One sinkhole occurs within the central part of the 

Carrizozo lava flows in the northern part of the Carrizozo 

Lava Flow Wilderness Study Area (sec. 24, T. 7 S., R. 9 

E.). Here, collapse within the San Andres occurred after 

the Carrizozo flow was erupted and, as a result, the upper 

part of the 160 ft deep sinkhole includes the basalt (pi. 1).

Although not exposed within the Little Black Peak 

study area, the Permian Bernal Formation underlies the 

northwestern part of the study area. It consists of red to 

brown thin-bedded siltstone, claystone, shale, and finegrained sandstone, and in the study area ranges in 

thickness from approximately 20 to 200 ft (Smith, 1964). 

As noted previously, it may extend beneath the Carrizozo Lava Flow study area, but this is not known.

Triassic sedimentary rocks of the Dockum Group 

underlie the Carrizozo region (Smith, 1964). The Dockum Group is subdivided into the Santa Rosa Formation 

at the base and the overlying Chinle Formation. The 

Santa Rosa Formation underlies much of the Little Black 

Peak study area and may extend as far south as the 

northeastern part of the Carrizozo Lava Flow study area. 

It consists of red, reddish-brown, and buff-colored, 

coarse- to medium-grained, crossbedded sandstone and 

pebble conglomerate, with minor interbeds of siltstone 

and claystone. In the Little Black Peak area, it is 

approximately 150-200 ft thick. The Chinle Formation 

underlies the northeastern and eastern part of the Little 

Black Peak study area. It consists of purplish-red to 

brown thin-bedded siltstone, mudstone, claystone, 

sandstone, and lenses of limestone-pebble conglomerate 

and is approximately 200-400 ft thick.

E10 Mineral Resources of Wilderness Study Areas-West-Central New Mexico
The Cretaceous Dakota Sandstone underlies the 

eastern part of both study areas and is approximately 

150-200 ft thick (Smith, 1964; Weber, 1964). The 

formation is composed of sandstone and shale. The lower 

part of the formation is composed of massive buff to 

brown sandstone characterized by crossbedding and 

ripple-mark features. Shaly partings and thin siltstone 

interbedded with sandstone occur in the middle part of 

the unit, and the upper part consists of interbedded 

sandstone and shale. The Dakota Sandstone exposed in 

the kipukas of the Little Black Peak study area and in the 

Valley of Fires State Park (pi. 1) consists of crossbedded 

cream to mottled brown or red carbonate-cemented 

sandstone, which suggests that the exposed sandstone 

belongs to the lower part of the formation.

The Mancos Shale is not exposed in either study 

area, but underlies the southeastern part of the Little 

Black Peak study area and the southeasternmost part of 

the Carrizozo study area. The Mancos Shale consists of 

gray to black calcareous pyritic shales, shaly to sandy 

limestone, and thin-bedded sandstones (Smith, 1964; 

Weber, 1964). The Mancos Shale is approximately 

600-700 ft thick, but only the lower part of the formation 

underlies the study areas.

Tan-colored trachyte (flow-banded, feldspar-rich 

intrusive igneous rock) occurs in the large kipuka within 

the Little Black Peak study area and along Highway 380 

at the eastern margin of the Carrizozo flow (fig. 1; pi. 1). 

At the kipuka locality the trachyte intrudes Dakota 

Sandstone; whereas, along Highway 380 it intrudes the 

Mancos Shale (Weber, 1964). It is not known whether 

the trachytes exposed at the two locations are part of the 

same intrusive body, but samples of the trachyte from 

both localities are virtually identical. The trachyte is 

weakly altered, porous, fine-grained, and contains greater 

than 95 percent feldspar. Minor minerals include 

aegerine-augite pyroxene, opaque minerals, late pale 

brown mica, and calcite. This unit was interpreted by 

Weber (1964) to be a sill in the Dakota Sandstone, but 

this is not apparent in outcrop since the trachyte cannot 

be shown to be overlain by Dakota Sandstone, nor can 

the dip of the contact with the sandstone be determined. 

The sill interpretation is supported by the fact that flow 

banding and a well-developed parting within the trachyte 

are parallel to the 13-16° east dip of the sandstone. The 

trachyte is undated but is interpreted to belong to a 

widespread series of middle Tertiary alkaline intrusive 

rocks that crop out to the east and southeast of the study 

areas (fig. 4) (Smith, 1964; Weber, 1964, Thompson, 

1972; Moore and others, 1986).

As noted previously, a number of uranium 

exploration trenches were bulldozed within the large 

kipuka in the Little Black Peak study area (collectively 

referred to as the "Harkey prospect" in McLemore, 

1983). Most of these trenches are across the Dakota

Sandstone-trachyte contact, but one is within the trachyte 

(pi. 1). Anomalous amounts of uranium are also 

reported at the trachyte-Mancos Shale contact along 

Highway 380 (sees. 21, 28, 29, T. 7 S., R. 10 E.) (Berry 

and others, 1982). Traverses made with a scintillometer 

across the kipuka showed that radioactivity is elevated 

above background levels up to 150 ft from and on both 

sides of the contact. Radioactivity is only strongly 

concentrated within a few feet of the contact, where 

levels up to 12 times background were observed. 

Although O.E. Collins (1956 data, presented in McLemore, 1983) indicated that the host rock for the 

radioactivity was limonite-stained, buff-colored 

sandstone, our field examination showed that the most 

radioactive rock was limonite-stained fine-grained trachyte from within a foot of the contact with the 

sedimentary rocks. It was not clear in the field, whether 

the anomalously radioactive trachyte is from the chill 

zone of the intrusion or from minor offshoots of the 

trachyte into the sandstone at the contact. In addition, at 

most places examined, a caliche (calcium carbonate) 

zone up to 4 or 5 in. thick was found adjacent to the 

anomalously radioactive trachyte at the contact. It is not 

known whether the uranium occurs as a uranium mineral 

or is dispersed in other minerals within the rock.

The most widespread lithologic units within both 

study areas are the late Quaternary Carrizozo basalt lava 

flows. The flows are 44 mi long, range in width from Vz to 

5 mi, and are up to 160 ft thick (Alien, 1951; Weber, 

1964). Because of their black color and great length, the 

Carrizozo flows are one of the most remarkable features 

seen on the composite color Landsat satellite image of 

New Mexico (see Highway geological map, New Mexico 

Geological Society, 1982). Although generally referred 

to as one flow, the Carrizozo actually consists of two 

basalt flows (Renault, 1970), of which only the upper 

flow is exposed in the study areas (except in the sinkhole 

in the northern part of the Carrizozo study area). The 

flows appear to have erupted from a vent at Little Black 

Peak and flowed southwards down the Tularosa Valley 

(pi. 1). Little Black Peak consists of a small, wellpreserved cinder cone and several other older subdued 

craters that sit at the summit of a broad shield of basaltic 

spatter and flow basalt. The Carrizozo basalt flows have 

not been dated, but on the basis of a lack of erosion and 

the preservation of fine surface features of the flows and 

of the Little Black Peak cinder cone, Weber (1964) 

estimated an age of 1,000-1,500 years before present. In 

addition to the Carrizozo flows, older Quaternary flow 

rocks of the Broken Back basalt flow (Smith, 1964) are 

present near the northwestern margin of the Little Black 

Peak Study Area (figs. 1, 2; pi. 1). Detailed studies of 

these basalts and their chemistry are presented in 

Renault (1970) and Paris (1980).

Uttie Black Peak and Carrizozo Lava Flow Wilderness Study Areas El 1
Table 1. Concentrations of selected trace elements in trachyte samples from in and near the Little Black Peak Wilderness 

Study Area, Lincoln County, New Mexico

[Concentrations in parts per million (ppm). All elements analyzed by X-ray fluorescence by Betsi Esposito, USGS; <, less than; number in 

parentheses, lower limit of detection. The following elements were analyzed for but not detected (detection limits in ppm in parentheses): Bi (2), 

Cd (10), Sb (6), Sn (6), U (8)]

Sample 

No.

Cu Zn 

(20) (26)

Pb 

(5)

As 

(1)

Rb 

(3)

Sr 

(3)

Ba 

(5)

Zr 

(2)

Mo 

(1)

Th 

(6)

Ga Y 

(6) (2)

Nb 

(2)

La 

(4)

Ce 

(4)

Nd 

(7)

Interior

D003 39

D015 34

DO 17 <20

Chill zone

97 40 15 259 78 <5 792 6 36 23 51 204 140 191 54

123 41 15 236 77 12 1237 6 49 31 55 203 138 184 48

102 33 15 207 51 47 388 3 43 26 43 225 150 190 47

D012

D016

D018

27

30

23

117

93

122

40

42

38

16

14

15

166

115

107

117

524

215

89

265

198

904

2258

1241

18

13

19

32

26

44

29

26

25

55

56

49

171

61

196

133

61

132

184

96

174

51

36

47

SAMPLE DESCRIPTIONS

Sample D003 was taken from the Mancos Shale-trachyte contact In a road cut on U.S. Highway 380, all other 

samples were taken from the Dakota Sandstone-trachyte contact the kipuka in the Little Black Peak Wilderness 

Study Area.

Geochemistry

Because of the lack of established drainage within 

the Carrizozo basalt field, no stream-sediment samples 

could be taken, nor were rock samples of the flow taken 

because of lack of evidence for mineralization of the 

basalt. Ten reconnaissance stream-sediment samples 

were taken along the western margin of the flow to check 

for possible mineralization of the sedimentary rock units 

which dip eastward toward and underlie the basalt. The 

samples were analyzed for 31 elements by six-step optical 

emission semiquantitative spectrography (Grimes and 

Marranzino, 1968). These analyses revealed no 

anomalous element concentrations nor has any 

mineralization been reported within 5 mi of the western 

border of the study areas (Griswold, 1959; Smith, 1964; 

Weber, 1964; Krason and others, 1982).

Fourteen rock-chip samples were taken from the 

interior and chill zone of the trachyte. Six of these 

samples were selected for trace element analysis (1 from 

the Mancos Shale-trachyte contact on U.S. Highway 380, 

2 from the kipuka trachyte interior, and 3 from the 

contact with the Dakota Sandstone within the exploration 

trenches chosen by locating rock with the highest 

readings on the scintillometer). These samples were 

analyzed with an air-path Kevex X-ray fluorescence unit, 

which used radionuclide sources to irradiate the 

powdered samples. The results are presented in table 1. 

The trace element concentrations are typical of alkalielement-rich syenitic and trachytic quartz-poor igneous 

rocks (Gerasimovsky, 1974), and none of the 

concentrations are considered to be significantly

anomalous. The high content of zirconium (table 1), in 

particular, indicates that the trachyte has an alkaline 

composition (Watson, 1979). The lower amounts of 

rubidium and higher contents of strontium, barium, and 

niobium in the chill zone samples suggests some 

chemical zonation in the trachyte. No detectable uranium 

was found in the samples; however, a slight concentration 

of molybdenum in the chill zones samples was observed. 

O.E. Collins (1956 data presented in McLemore, 1983) 

reported 0.009-0.028 percent uranium and 0.03-0.07 

percent vanadium in radioactive samples from the kipuka, and Berry and others (1982) reported 207 ppm 

uranium from a sample from the Highway 380 locality.

Geophysics

The complete Bouguer gravity map of Healey and 

others (1978), along with their first- and third-order 

residual maps, display large gravity lows that reflect the 

great thickness of sedimentary fill in the Tularosa Basin 

(fig. 4). A regional gradient that extends from the 

southeast to the northeast over the Carrizozo region (fig. 

4), reflects the transition from a basement high with 

Tertiary intrusions and volcanics on the eastern flank of 

the Tularosa Basin to the central part of the basin. Steep 

gravity gradients to the west of the study areas may 

reflect the presence of major normal faults along the 

western flank of the basin (fig. 4; Kelley and Thompson, 

1964; Woodward and others, 1975). In the vicinity of the 

study areas, the gravity anomaly may not be fully defined 

owing to a lack of gravity stations.

E12 Mineral Resources of Wilderness Study Areas West-Central New Mexico
A magnetic high located in the northern part of the 

Little Black Peak study area (anomaly A, fig. 6) occurs 

over the area containing Little Black Peak and 

presumably reflects the underlying intrusive vent. Two 

other similar highs beneath the Carrizozo flow in the 

southern part of the Little Black Peak and in the 

northern part of the Carrizozo Lava Flow study areas 

(anomalies B and C, fig. 6) suggest additional vents for 

the Carrizozo lava flows, other than the one at Little 

Black Peak, or may indicate one or more concealed 

shallow older intrusive masses beneath the flow. The 

trachyte intrusions, shown on plate 1, have no magnetic 

expression in figure 6. The lack of any magnetic high 

associated with the trachyte is in line with the very IQW 

magnetic susceptibility readings for two typical samples 

of the trachyte (averaging 200 emu, electromagnetic 

units).

On the basis of a series of 1:1,000,000 scale color 

composite maps developed from aerial gamma-ray 

survey data of the U.S. Department of Energy, J.S. Duval 

(USGS, written commun., 1986) reported that the rocks 

of the Little Black Peak Wilderness Study Area have an 

overall low radioactivity with concentrations of 1.0-1.8 

percent potassium, 1.5-2.0 ppm equivalent uranium, and 

1-6 ppm equivalent thorium. Similarly, the rocks of the 

Carrizozo Lava Flow Wilderness Study Area have overall 

low radioactivity with concentrations of 1.0-1.8 percent 

potassium, 1.6-2.5 ppm equivalent uranium, and 1-7 

ppm equivalent thorium. There are no radiometric 

anomalies within or near the study areas.

Mineral and Energy Resource Potential

Uranium Associated with Alkaline Rocks

There are no known occurrences of metallic 

minerals in or near the Little Black Peak or Carrizozo 

Lava Flow study areas. Metallic and non-metallic mineral 

deposits associated with alkaline Tertiary intrusive rocks 

have been mined east and southeast of the study areas 

(Griswold, 1959; Kranson and others, 1982). The closest 

mining districts associated with these intrusives are the 

White Oaks district, 5 mi east of the Little Black Peak 

study area, and the Nogal mining district, 10 mi southeast 

of the Carrizozo Lava Flow study area (fig. 4). These 

districts have produced iron, gold, silver, zinc, copper, 

fluorspar, molybdenum, and rare-earth elements (Griswold, 1959). The trachyte of the Little Black Peak study 

area is interpreted to be related to these Tertiary intrusives, and, although the trachyte intrusion has uranium 

mineralization associated with it, there are no other 

mineral occurrences or geochemical anomalies. The 

uranium is concentrated in very minor amounts 

immediately along the contact of the trachyte with its host

sedimentary rocks. A low resource potential for uranium 

in the contact zone is assigned with a certainty level of C.

Resources Associated with Magnetic Highs

The cause of the aeromagnetic highs beneath the 

southern part of the Little Black Peak study area and the 

northern part of the Carrizozo Lava Flow study area (fig. 

6) is unknown. Two possible interpretations are that they 

result from one or more Tertiary intrusive masses or are 

basaltic intrusive rocks related to the Carrizozo lava 

flows. If the anomalies are due to Tertiary intrusions 

buried beneath the Carrizozo lava flows, then there 

would be some likelihood for the occurrence of metals 

and non-metals known to be associated with such 

intrusions. In particular, Tertiary intrusions elsewhere in 

the Carrizozo region are associated with replacement 

iron deposits that consist chiefly of magnetite, which 

could be the cause of one or more of the anomalies 

(Griswold, 1959). If the source of the anomalies is due to 

basaltic intrusive rocks associated with the Carrizozo 

flows, then the probability for any type of associated 

mineral deposits would be extremely low. However, 

detailed geophysical studies and (or) drilling will be 

needed to determine the cause of the aeromagnetic high. 

Therefore, the resource potential is unknown, with 

certainty level A, for metals and nonmetals in areas of the 

magnetic anomalies.

Sediment-hosted Uranium and Copper

Terrestrial, lagoonal, and shallow-marine clastic 

sedimentary rocks, including redbed clastic and evaporite 

sedimentary rocks, occur throughout much of the Pennsylvanian to Cretaceous age stratigraphic units beneath 

both study areas. This type of sedimentary rock assemblege is known to host stratiform base metal and uranium 

deposits elsewhere in the Western United States 

(Gustafson and Williams, 1981; Nash and others, 1981). 

Stratiform copper and uranium deposits are known to 

occur in these units elsewhere in New Mexico, 

particularly in northwestern New Mexico (Woodward 

and others, 1974; North and McLemore, 1986; McLemore and Chenoweth, in press). These deposits can also 

contain anomalous concentrations of silver, lead, zinc, 

and vanadium (North and McLemore, 1986). Within 50 

mi of the study areas five minor sediment-hosted copper 

and uranium deposits, for which there is no known 

production, occur within the Abo and Yeso Formations. 

The closest of these occurrences is sediment-hosted 

copper in the Abo Formation of the Esty (or Oscuro) 

district 24 mi west of Carrizozo (McLemore and Chenoweth, in press). The occurrence of these types of 

deposits within such rocks depends on a number of 

factors including adequate permeability, a reducing

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas E13
106° 15'

34°

Off

106°00' 105°45'

33° 

45'

33° 

30'

APPROXIMATE BOUNDARY OF

THE LITTLE BLACK PEAK

WILDERNESS STUDY AREA

APPROXIMATE BOUNDARY OF

THE CARRIZOZO LAVA FLOW

WILDERNESS STUDY AREA

10 MILES

Figure 6. Aeromagnetic contour map of the Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas, New 

Mexico, and vicinity (from Cordell, 1983). Contour interval, 20 gammas. Anomalies labeled A, B, and C are discussed in 

the text.

E14 Mineral Resources of wilderness Study Areas-West-Central New Mexico
environment containing organic material and sulfurbearing material, and a source region from which to 

mobilize the copper and uranium (Cox, 1986; TurnerPeterson and Hodges, 1986). There is no available 

evidence to indicate the presence of such deposits in the 

Pennsylvanian to Cretaceous sedimentary rocks beneath 

the study areas; however, compared to deposits in similar 

rocks elsewhere in New Mexico, the Pennsylvanian to 

Cretaceous section beneath the study areas is permissive 

for the occurrence of sediment-hosted copper and 

uranium deposits. Given the lack of detailed knowledge 

of the stratigraphic section beneath the study areas, lack 

of evidence for such mineralization, and lack of deposits 

in central New Mexico of these types with known past 

production, we assign a low resource potential with a 

level of certainty of B for the occurrence of sedimenthosted copper and uranium deposits beneath all of both 

study areas.

Gypsum

In the Carrizozo area, gypsum occurs as interbeds 

throughout the Yeso and San Andres Formations 

(Smith, 1964; Weber, 1964; Milner, 1978; King and 

Harder, 1985). In addition, as reported previously, 

gypsum beds are exposed within the Yeso and San 

Andres Formations in the southwestern part of the 

Carrizozo Lava Flow study area (Weber, 1964). Because 

both formations appear to underlie all of both study 

areas, both areas are assessed as having a moderate 

resource potential for gypsum with a confidence level 

ofC.

Salt

As logged by R.W. Foster (in Griswold, 1959) and 

by King and Harder (1985), the Yeso Formation in the 

Standard of Texas No. 1 Heard well, approximately 3 mi 

west of the Little Black Peak Wilderness Study Area (fig. 

4), contains a 900 ft section of salt (halite), interbedded 

with shale, sandstone, and anhydrite. The lateral extent of 

this salt section is unknown but could extend beneath the 

study areas (Kelly and Thompson, 1964) (fig. 5). Cuttings 

from the Heard well were also examined for potash, but 

the results were negative (Weber, 1964). Milner (1978) 

also reported that the upper Yeso and lower San Andres 

contain numerous evaporite beds in western Lincoln 

County, although no detailed information is presented 

for the immediate vicinity of the study areas. On this 

basis, both study areas have a moderate resource 

potential for salt at a certainly level of C.

Oil and Gas

Prior to 1983, seven oil and gas exploration holes 

were drilled within 3 mi of the study areas (fig. 4; Foster,

1978; Krason and others, 1982). Three of these holes had 

slight shows of hydrocarbons, and the others were dry. At 

least 22 other test holes drilled elsewhere in Lincoln 

County prior to 1978 were dry (Havenor, 1964; Foster, 

1978). In addition, another nine deep tests were 

completed to basement during 1984 and 1985 (Broadhead, 1985,1986) in central and eastern Lincoln County 

to test the Yeso Formation and underlying Abo 

Formation. All nine wells were without hydrocarbon or 

gas shows. In the vicinity of the study areas, the Abo, 

Yeso, and San Andres Formations and the Dakota 

Sandstone are considered to have the highest oil and gas 

potential (Havenor, 1964; Foster, 1978; King and 

Harder, 1985). In particular, the San Andres is 

considered to have the best potential based on porosity 

and petroliferous odor (Havenor, 1964). Negative factors 

for the occurrence of petroleum resources are the 

destructive thermal effects of the Tertiary and 

Quaternary magmatism within the study areas and the 

surface exposure of the favorable host units which would 

allow for the incursion of meteoric (ground) waters and 

the flushing of hydrocarbons (Foster, 1978; Milner, 1978; 

Ryder, 1983; King and Harder, 1985). Although the oil 

and gas resources of the region cannot be considered to 

be fully explored, available data are sufficient to indicate 

that the mineral resource potential for oil and gas in both 

study areas is low with a certainty level of C.

Coal

Low-grade coal is present within sedimentary rocks 

of the Upper Cretaceous Mesaverde Group in the Sierra 

Blanca coal field east of both study areas (fig. 4) (Griswold, 1959; Arkell, 1983); however, the Mesaverde 

Group does not underlie either study area. Smith (1964) 

reported that "locally, thin coal seams are found in the 

shaly central portion" of the Dakota Sandstone in the 

eastern part of the Sierra Blanca coal field east of the 

Little Black Peak study area. Coal is not reported from 

any of the other sedimentary rock units that underlie the 

study areas. On this basis, the resource potential for coal 

is assessed as low in both study areas with a certainty 

ofB.

Geothermal Energy

Although the Carrizozo lava flows are very recent, 

no hot spring activity has been reported in either study 

area, and Krason and others (1982) report low heat flow 

for the region (1.44 heat flow units). The study areas are 

assigned a low resource potential for geothermal energy 

sources with a certainty level of B.

Little Black Peak and Carrizozo Lava Flow Wilderness Study Areas E15
Recommendations for Further Work

The mineral potential for metals and nonmetals is 

unknown in areas of magnetic highs. Further work is 

needed to determine the source of the magnetic 

anomalies and to better define mineralization associated 

with that source. Such work should be based on initial, 

more detailed geophysical studies.

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Arkell, B.W., 1983, Geology and coal resources of the Cub 

Mountain area, Sierra Blanca Coal Field, New Mexico: 

Socorro, New Mexico, New Mexico Institute of Mining 

and Technology, M.S. thesis, 104 p.

Berry, V.P., Nagy, P.A., Spreng, W.C., Barnes, C.W., and 

Smouse, D., 1982, Uranium resource evaluation, 

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Energy Report GJQ-014(82), 22 p.

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New Mexico in 1984: New Mexico Geology, v. 7, 

p. 35-39.

___ 1986, Oil and gas discovery wells drilled in New Mexico 

in 1985: New Mexico Geology, v. 8, p. 36-40.

Clippinger, D.M., 1946, Building blocks from natural 

lightweight materials of New Mexico: New Mexico 

Bureau of Mines and Mineral Resources Bulletin 24, 

25 p.

Cordell, Lindrith, 1983, Composite residual total intensity 

aeromagnetic map of New Mexico: National Oceanic and 

Atmospheric Administration, National Geophysical 

Data Center, scale 1:500,000.

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Cox, D.P., and Singer, D.A., eds., Mineral deposit 

models: U.S. Geological Survey Bulletin 1693, p. 205.

Custer, Thomas, 1975, Technical examination and 

environmental analysis record for the potential sale of 

lava from the malpais near Carrizozo: U.S. Department 

of the Interior, Bureau of Land Management Mineral 

Report, 23 p. [report on file at the Roswell, New Mexico, 

office of the U.S. Bureau of Land Management].

Dane, C.H., and Bachman, G.O., 1958, Preliminary geologic 

map of the southeastern part of New Mexico: U.S. 

Geological Survey Miscellaneous Investigations Map 

1-256, scale 1:500,000.

Elston, W.E., 1967, Summary of the mineral resources of 

Bernalillo, Sandoval, and Santa Fe Counties, New Mexico: State Bureau of Mines and Mineral Resources 

Bulletin 81, 81 p.

Paris, K.B., 1980, A geochemical model for the magmatic 

history of the Carrizozo basalt field, South Central New 

Mexico: Socorro, New Mexico, New Mexico Institute of 

Mining and Technology, M.S. thesis, 149 p.

Foster, R.W., 1978, Oil and gas evaluation of White Sands 

Missile Range and Fort Bliss Military Reservation, 

South-Central New Mexico: New Mexico Bureau of 

Mines and Mineral Resources Open-File Report 92, 

60 p.

Gerasimovsky, V.I., 1974, Trace elements in selected groups of 

alkaline rocks, in Sorensen, H., ed., The alkaline rocks: 

New York, John Wiley and Sons, p. 402-411.

Goudarzi, G.H., compiler, 1984, Guide to preparation of 

mineral survey reports on public lands: U.S. Geological 

Survey Open-File Report 84-787, 42 p.

Grimes, D.J., and Marranzino, A.P., 1968, Direct-current arc 

and alternating-current spark emission spectrographic 

field methods for the semiquantitative analysis of 

geologic materials: U.S. Geological Survey Circular 591, 

6 p.

Griswold, G.B., 1959, Mineral deposits of Lincoln County, New 

Mexico: New Mexico Bureau of Mines and Mineral 

Resources Bulletin 67, 117 p.

Gustafson, L.B., and Williams, Neil, 1981, Sediment-hosted 

stratiform deposits of copper, lead, and zinc, in Skinner, 

B J., ed., 75th Anniversary Volume: Economic Geology, 

p. 139-178.

Havener, K.C., 1964, Oil and gas tests in Lincoln County, New 

Mexico, in Ash, S.R., and Davis, L.V., eds., Guidebook of 

the Ruidoso Country: New Mexico Geological Society 

Fifteenth Field Conference Guidebook, p. 155-158.

Healey, D.L., Wahl, R.R., and Currey, F.E., 1978, Gravity 

survey of the Tularosa Valley and adjacent areas, New 

Mexico: U.S. Geological Survey Open-File Report 

78-309, 37 p.

Jagnow, David, 1973, Geology and speleogenesis of Crockett's 

Cave, New Mexico: Bureau of Land Management, 

Roswell District Office, Roswell, New Mexico, 

unpublished report, 31 p. [report on file at the Roswell, 

New Mexico, office of the U.S. Bureau of Land 

Management].

Kelly, V.C., and Thompson, T.B., 1964, Tectonics and general 

geology of the Ruidoso-Carrizozo region, central New 

Mexico, in Ash, S.R., and Davis, L.V., eds., Guidebook of 

the Ruidoso Country: New Mexico Geological Society 

Fifteenth Field Conference Guidebook, p. 110-121.

King, W.E., and Harder, V.M., 1985, Oil and gas potential of 

the Tularosa Basin Otero platform Salt Basin graben 

area, New Mexico and Texas: New Mexico Bureau of 

Mines and Mineral Resources Circular 198, 36 p.

Krason, Jan, Cruver, S.K., and Wodzicki, Antoni, 1982, 

Geology, energy and mineral resources assessment of the 

Carrizozo area, New Mexico: U.S. Department of the 

Interior, Bureau of Land Management unpublished 

report, 68 p. [report on file at the Roswell, New Mexico, 

office of the U.S. Bureau of Land Management].

Logsdon, MJ., 1982, Gypsum resources of New Mexico, in 

Austin, G. S., ed., Industrial rocks and minerals of the 

Southwest: New Mexico Bureau of Mines and Mineral 

Resources Circular 182, 111 p.

McLemore, V.T., 1983, Uranium and thorium occurrences in 

New Mexico: Distribution, geology, production, and 

resources, with selected bibliography: New Mexico 

Bureau of Mines and Mineral Resources Open-File 

Report OF-183, 174 p.

McLemore, V.T., and Chenoweth, William, in press, Uranium 

resources in New Mexico: New Mexico Bureau of Mines 

and Mineral Resources, Resource Map 18, scale 

1:1,000,000.

E16 Mineral Resources of Wilderness Study Areas West-Central New Mexico
Milner, Sam, 1978, Genesis, provenance, and petrography of 

the Glorieta Sandstone of eastern New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Circular 

165, 25 p.

Moore, S.L., Foord, E.E., Marvin, R.F., and Taggart, J.E., Jr., 

1986, Structure and petrology of the Tertiary igneous 

complex of the Sierra Blanca region, Otero County, New 

Mexico [abs.], in Southwest Section of American 

Association of Petroleum Geologists Transactions and 

Guidebook of 1986 Convention, Ruidoso, New Mexico: 

New Mexico Bureau of Mines and Geology, p. 151.

Nash, J.T., Granger, H.C., and Adams, S.S., 1981, Geology and 

concepts of genesis of important types of uranium 

deposits, in Skinner, BJ., ed., 75th Anniversary Volume: 

Economic Geology, p. 63-116.

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geological map: New Mexico Geological Society, 

Socorro, New Mexico, scale 1:1,000,000.

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occurrences in New Mexico: New Mexico Bureau of 

Mines and Mineral Resources, Resource Map 15, 32 p., 

scale 1:1,000,000.

Osburn, J.A., 1979, Evaluation of scoria deposits in New 

Mexico: New Mexico Bureau of Mines and Mineral 

Resources Annual Report for the Fiscal Year July 1, 

1978 to June 30, 1979, p. 75-80.

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New Mexico Bureau of Mines and Mineral Resources 

Circular 113, 22 p.

Ryder, R.T., 1983, Petroleum potential of wilderness lands in 

New Mexico, in Miller, B.M., ed., Petroleum potential of 

wilderness lands in the western United States: U.S. 

Geological Survey Circular 902-1, 32 p.

Smith, C.T., 1964, Reconnaissance geology of the Little Black 

Peak Quadrangle, Lincoln and Socorro Counties, New 

Mexico, in Ash, S.R., and Davis, L.V., eds., Guidebook of 

the Ruidoso Country: New Mexico Geological Society 

Fifteenth Field Conference Guidebook, p. 92-99.

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map of Little Black Peak fifteen minute quadrangle, New 

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the Ruidoso Country: New Mexico Geological Society 

Fifteenth Field Conference Guidebook, scale 1:62,500.

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Mexico: Geological Society of America Bulletin, v. 83, p. 

2341-2356.

Turner-Peterson, C.E., and Hodges, C.A., 1986, Descriptive 

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eds., Mineral deposit models: U.S. Geological Survey 

Bulletin 1693, p. 209-210.

U.S. Bureau of Land Management, 1985, Little Black Peak 

(LBP)/Carrizozo Lava Flow (CLF), in New Mexico 

Statewide Wilderness Study, Volume 3: Appendices 

Wilderness Analysis Reports, Appendix 36/37, p. 

36/37-1 to 36/37-36.

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Principles of a resource/reserve classification for 

minerals: U.S. Geological Survey Circular 831, 5 p.

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Experimental results and applications to trace element 

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Mexico, in Ash, S.R., and Davis, L.V., eds., Guidebook of 

the Ruidoso Country: New Mexico Geological Society 

Fifteenth Field Conference Guidebook, p. 100-109.

___ 1979, Valley of Fires (New Mexico State Parks Series): 

New Mexico Geology, v. 1, no. 2, p. 27-28.

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Chapin, C.E., Zitinski, R.E., and Shaffer, W.L., 

compilers, 1975, Tectonic map of the Rio Grande region 

from New Mexico Colorado border to Presidio, Texas, 

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Geological Society Annotated Field Conference 

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W.H., and Schumacher, O.L., 1974, Sandstone copper 

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Zelten, J.E., 1986, Mineral investigation of a part of the Little 

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County, New Mexico: U.S. Bureau of Mines Open File 

Report MLA 42-86, 21 p.

Uttle Black Peak and Carrizozo Lava Flow Wilderness Study Areas E17

APPENDIX
DEFINITION OF LEVELS OF MINERAL RESOURCE POTENTIAL 

AND CERTAINTY OF ASSESSMENT

Definitions of Mineral Resource Potential

LOW mineral resource potential is assigned to areas where geologic, geochemical, and geophysical characteristics define a geologic environment in which the existence of resources is unlikely. This broad 

category embraces areas with dispersed but insignificantly mineralized rock as well as areas with few 

or no indications of having been mineralized.

MODERATE mineral resource potential is assigned to areas where geologic, geochemical, and geophysical 

characteristics indicate a geologic environment favorable for resource occurrence, where interpretations 

of data indicate a reasonable likelihood of resource accumulation, and (or) where an application of 

mineral-deposit models indicates favorable ground for the specified type(s) of deposits.

HIGH mineral resource potential is assigned to areas where geologic, geochemical, and geophysical characteristics indicate a geologic environment favorable for resource occurrence, where interpretations of 

data indicate a high degree of likelihood for resource accumulation, where data support mineral-deposit 

models indicating presence of resources, and where evidence indicates that mineral concentration has 

taken place. Assignment of high resource potential to an area requires some positive knowledge that 

mineral-forming processes have been active in at least part of the area.

UNKNOWN mineral resource potential is assigned to areas where information is inadequate to assign low, 

moderate, or high levels of resource potential.

NO mineral resource potential is a category reserved for a specific type of resource in a well-defined 

area.

Levels of Certainty

U/A

UNKNOWN

POTENTIAL

H/B

HIGH POTENTIAL

M/B 

MODERATE POTENTIAL

L/B

LOW

POTENTIAL

H/C

HIGH POTENTIAL

M/C 

MODERATE POTENTIAL

L/C

LOW

POTENTIAL

H/D

HIGH POTENTIAL

M/D 

MODERATE POTENTIAL

L/D

LOW POTENTIAL

N/D

NO POTENTIAL

t

<

p

1

u 

oc

C

uu 

O

B C 

LEVEL OF CERTAINTY

A. Available information is not adequate for determination of the level of mineral resource potential.

B. Available information suggests the level of mineral resource potential.

C. Available information gives a good indication of the level of mineral resource potential.

D. Available information clearly defines the level of mineral resource potential.

Abstracted with minor modifications from:

Taylor, R. B., and Steven, T. A., 1983, Definition of mineral resource potential: Economic Geology,

v. 78, no. 6, p. 1268-1270. 

Taylor, R. B., Stoneman, R. J., and Marsh, S. P., 1984, An assessment of the mineral resource potential

of the San Isabel National Forest, south-central Colorado: U.S. Geological Survey Bulletin 1638, p.

40-42. 

Goudarzi, G. H., compiler, 1984, Guide to preparation of mineral survey reports on public lands: U.S.

Geological Survey Open-File Report 84-0787, p. 7, 8.
RESOURCE/RESERVE CLASSIFICATION

ECONOMIC

MARGINALLY 

ECONOMIC

SUBECONOMIC

IDENTIFIED RESOURCES

Demonstrated

Measured j Indicated

Reserves

 1 

Marginal Reserves 

I

Demonstrated 

Subeconomic Resources

Inferred

Inferred Reserves

Inferred 

Marginal Reserves

Inferred 

Subeconomic 

Resources

UNDISCOVERED RESOURCES

Probability Range

 (or) 

Hypothetical i Speculative

1

\ 

\

1

Major elements of mineral resource classification, excluding reserve base and inferred reserve base. Modified from McKelvey,1972, Mineral 

resource estimates and public policy: American Scientist, v.60, p.32-40, and U.S. Bureau of Mines and U.S. Geological Survey, 1980, 

Principles of a resource/reserve classification for minerals: U.S. Geological Survey Circular 831, p.5.
GEOLOGIC TIME CHART 

Terms and boundary ages used in this report

EON

Phanerozoic

Proterozoic

Arch can 

pre-Ar<

ERA

Cenozoic

Mesozoic

Paleozoic

Late Proterozoic

Middle Proterozoic

Early Proterozoic

Late Archean

Middle Archean

Early Archean 

jhean*

PERIOD

Quaternary

Tertiary

Neogene 

Subperiod

Paleogene 

Subperiod

Cretaceous

Jurassic

Triassic

Permian

Carboniferous 

Periods

Pennsylvanian

Mississippian

Devonian

Silurian

Ordovician

Cambrian

 3800? -

EPOCH

Holocene

Pleistocene

Pliocene

Miocene

Oligocene

Eocene

Paleocene

Late 

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late

Early

Late 

Middle 

Early

Late 

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Middle 

Early

Late 

Middle 

Early

 _

BOUNDARY AGE 

IN 

MILLION YEARS

-0.010

- 1.7

- 5

+}A

_ "JO

-55

__ CC

- 96

_ *JAC

-A* 240

&9U

-~ 330

- 360

- 410

jlOC

- 500

U~ 570'

aw

- 1600

^2500

-3000

L. ?400

1 Rocks older than 570m.y. also called Precambrian. a time term without specific rank.

2 Informal time term without specific rank.

*U.S. GOVERNMENT PRINTING OFFICE: 1989-673-047/86062