A HYDROGEOLOGIC MAP OF THE DEATH VALLEY 

REGION, NEVADA AND CALIFORNIA, DEVELOPED 

USING GIS TECHNIQUES

U.S. GEOLOGICAL SURVEY 

Water-Resources Investigations Report 95-4016

Prepared in cooperation with the 

NEVADA OPERATIONS OFFICE, 

U.S. DEPARTMENT OF ENERGY, under 

Interagency Agreement DE-AI08-92NV10874
A Hydrogeologic Map of the Death Valley Region, 

Nevada and California, Developed Using GIS 

Techniques

by Claudia C. Faunt, Frank A. D'Agnese, and A. Keith Turner

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 95-4016

Prepared in cooperation with the 

NEVADA OPERATIONS OFFICE, 

U.S. DEPARTMENT OF ENERGY, under 

Interagency Agreement DE-AI08-92NV10874

Denver, Colorado 

1997
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Gordon P. Eaton, Director

The use 9* firm, trade, and brand names in this report is for identification purposes only and does 

not constitute endorsement by the U.S. Geological Survey.

For additional information write to:

Chief, Hydrologic Investigations Program

Yucca Mountain Project Branch

U.S. Geological Survey

Box 25046, Mail Stop 421

Denver Federal Center

Denver, CO 80225-0046

Copies of this report can be purchased 

from:

U.S. Geological Survey 

Branch of Information Services 

Box 25286 

Denver, CO 80225-0286
CONTENTS

Abstract ...................................................................................................................................................................^ 1

Introduction ................................................................................................................................................................^ 1

Purpose and Scope ...................................................................................................................................................... 2

Physical Setting ........................................................................................................................................^ 2

Regional Hydrogeology .............................................................................................................................................. 2

Recharge ........................................................................................................................................................... 3

Discharge .......................................................................................................................................................... 4

Data Sources and Digitization Procedures ........................................................................................................................... 5

Geographic Information Systems ............................................................................................................................... 5

Data Quality Assurance .............................................................................................................................................. 5

Geographic Coordinate System .................................................................................................................................. 5

Data Sources and Data Entry Procedures ................................................................................................................... 6

Existing Digital GIS Files ................................................................................................................................. 6

Published Map Information .............................................................................................................................. 6

Tabulated Data .................................................................................................................................................. 7

Digitizing Procedures ................................................................................................................................................. 7

Digital Representations of the Regional Hydrogeologic Units ............................................................................................ 8

Geologic Information ................................................................................................................................................. 8

California Geologic Maps ................................................................................................................................ 8

Nevada Geologic Map ...................................................................................................................................... 8

Combining Nevada and California Maps ................................................................................................................... 10

Classification of Hydrogeologic Units ................................................................................................................................. 10

Playa Deposits of Quaternary Age (Qp) ..................................................................................................................... 12

Valley Fill of Quaternary-Tertiary Age (QTvf) .......................................................................................................... 12

Volcanic Rocks of Quaternary-Tertiary Age (QTv) ................................................................................................... 12

Volcanic Rocks of Tertiary Age (Tv).......................................................................................................................... 12

Volcanic and Volcaniclastic Rocks of Tertiary Age (Tvs) .......................................................................................... 13

Granitic Rocks of Tertiary-Late Jurassic Age (TJg)................................................................................................... 13

Sedimentary and Metavolcanic Rocks of Mesozoic Age (Mvs) ................................................................................ 13

Carbonate Rocks of Paleozoic Age (P2) .................................................................................................................... 13

Clastic Rocks of Paleozoic-Precambrian Age (PI) .................................................................................................... 13

Igneous and Metamorphic Rocks of Precambrian Age (pGgm)................................................................................. 14

Hydrologic Properties of Hydrogeologic Units .................................................................................................................... 14

Summary .................................................................................................................................................................^ 17

References Cited .............................................................................................................................................................^ 17

PLATE

[Plate is in pocket]

1. Hydrogeologic map of the Death Valley region, Nevada and California; and maps showing 

A, hydrogeologic units of the Death Valley region; and B, problems with joining map sheets

FIGURES

1. Map showing location of the Death Valley region, Nevada and California............................................................... 3

2. Diagram showing observed configurations of ground-water flow in the Great Basin................................................ 4

3. Map showing index of sources of geologic data......................................................................................................... 6

4. Graph showing hydraulic-conductivity distributions estimated for rock types in the Death Valley region............... 15

CONTENTS III
TABLES

1. Correlation of hydrogeologic units with geologic units in the Death Valley region .............................................. 9

2. Correlation of hydrogeologic units with other hydrogeologic units in the Death Valley region ........................... 11

3. Estimated hydraulic conductivity of hydrogeologic units in the Death Valley region........................................... 16

CONVERSION FACTORS

Multiply By To obtain 

Length

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

Area 

square kilometer (km2 ) 0.3861 square mile (mi2 )

IV CONTENTS
A Hydrogeologic Map of the Death Valley Region, 

Nevada and California, Developed Using 

GIS Techniques

By Claudia C. Faunt, Frank A. D'Agnese, and A. Keith Turner

ABSTRACT

In support of Yucca Mountain site characterization studies, a hydrogeologic framework was 

developed, and a hydrogeologic map was constructed for the Death Valley region. The region,

covering approximately 100,000 km2 along the 

Nevada-California border near Las Vegas, is characterized by isolated mountain ranges juxtaposed 

against broad, alluvium-filled valleys. Geologic 

conditions are typical of the Basin and Range 

Province; a variety of sedimentary and igneous 

intrusive and extrusive rocks have been subjected 

to both compressional and extensional deformation. The regional ground-water flow system can 

best be described as a series of connected intermontane basins in which ground-water flow 

occurs in basin-fill deposits, carbonate rocks, clastic rocks, and volcanic rocks. Previous investigations have developed more site-specific 

hydrogeologic relationships; however, few have 

described all the lithologies within the Death 

Valley regional ground-water flow system.

Information required to characterize the 

hydrogeologic units in the region was obtained 

from regional geologic maps and reports. Map 

data were digitized from regional geologic maps 

and combined into a composite map using a geographic information system. This map was simplified to show 10 laterally extensive hydrogeologic 

units with distinct hydrologic properties. The 

hydraulic conductivity values for the hydrogeologic units range over 15 orders of magnitude due 

to the variability in burial depth and degree of fracturing.

INTRODUCTION

Yucca Mountain, located near the western 

boundary of the Nevada Test Site (NTS) in southern 

Nevada, has been selected as a potential site for a 

high-level, nuclear-waste repository. In cooperation 

with the U.S. Department of Energy (DOE), the 

U.S. Geological Survey (USGS) is evaluating the site 

characteristics at Yucca Mountain for its suitability as a 

repository.

Because of the potential for radionuclides to be 

transported by ground water from the repository to the 

accessible environment, studies are being conducted to 

characterize the Death Valley regional ground-water 

flow system (Bedinger and others, 1989c) of which 

Yucca Mountain is a part. Analysis of the regional flow 

system will help to define the hydrologic conditions at 

Yucca Mountain and allow for subsequent detailed 

site-scale hydrologic modeling. In addition, characterizations of the present, past, and future hydrologic 

regimes at Yucca Mountain and its surrounding areas 

are required to adequately assess the potential for radionuclides to reach the accessible environment within 

the first 10,000 years following repository closure. 

Such characterizations can only be constructed after 

the current regional ground-water flow system has been 

analyzed.

The purpose of this study is to develop a conceptual hydrogeologic framework using regional geologic 

and hydrologic data and to develop a digital hydrogeologic map showing the surface expressions of the 

framework. This hydrogeologic framework is being 

developed for ground-water flow modeling. The scope 

of this study is limited in that the details of the geology 

were obtained from published regional maps that contain geological details typically shown on 1:250,000 

and 1:500,000 scale maps. Synthesis was done using 

geographic information systems (GIS).

Abstract 1
Purpose and Scope

This report focuses on the initial phase of 

regional ground-water flow characterization, the development of a hydrogeologic framework. A hydrogeologic map of the area was produced in digital format to 

depict the surface expressions of the hydrogeologic 

system. The report describes the geometry, composition, and physical properties of the materials forming 

the natural hydrogeologic system, and it serves as an 

important information source for the development of 

numerical ground-water flow models. The selection of 

required numerical modeling parameters is facilitated 

by using attribute data stored in the data base that 

accompanies the hydrogeologic map.

Physical Setting

The Death Valley region, defined in this report 

by the area between lat 35°N., long 115°W., and 

lat 38°N., long 118°W., bounds the Death Valley 

regional ground-water unit (outlined on fig. 1), as 

defined by Bedinger and others (1989c). The geographic extent of the study area is shown in figure 1 and

includes about 100,000 km2 .

The Death Valley region includes Las Vegas, 

Nevada, and several large prominent valleys, namely 

Amargosa Valley, Pahrump Valley, and Death Valley 

(fig. 1). The region also includes several major mountain ranges including the Panamint Range, the Spring 

Mountains, the Sheep Range, the Amargosa Range, the 

Kawich Range, the Kingston Range, the Pahranagat 

Range, the Timpahute Range, and the Last Chance 

Range (fig. 1). Yucca Mountain, the site of a proposed 

high-level radioactive-waste repository, is approximately at the geographic center of the Death Valley 

region on the western boundary of the NTS (fig. 1).

The Death Valley region has a semi-arid to arid 

climate and is located within the southern Great Basin, 

a subprovince of the Basin and Range physiographic 

province. Elevations range from 86 m below sea level 

at Death Valley to 3,600 m above sea level in the Spring 

Mountains; thus, the region includes a great variety of 

climatic regimes, and associated ground-water 

recharge and discharge conditions.

The region is characterized by isolated mountain 

ranges rising abruptly from broad, alluvium-filled 

desert basins. The valley bottoms are occupied by 

local depositional centers usually marked by playa 

lakes, which act as catchments for surface-water runoff 

(Grose and Smith, 1989). The Amargosa River, an 

intermittent stream whose drainage basin covers about

fy

15,000 km , discharges into the south end of the Death 

Valley salt pan (fig. 1), the largest of these playa lakes 

(Hunt and others, 1966). Most of the basins, however, 

seldom contain standing water. Some of the playas 

affected by faulting contain springs where ground 

water is forced to the surface by juxtaposed lake 

sediments (Bedinger and others, 1989a; 1989c).

The Death Valley region displays the record of a 

long and active geologic history, including intermittent 

marine sedimentation, large-scale compressive deformation, plutonism, volcanism, extensional tectonics, 

and terrestrial sedimentation (Mifflin, 1988). Consequently, rock types, ages, and deformational structures 

are highly variable, and in many areas, impressive 

diversities exist in juxtaposed rock types. As a consequence, subsurface conditions are highly variable and 

complex. The bedrock geologic conditions beneath 

alluvial basins are only approximately known in much 

of the region.

The area contains clastic and crystalline rocks of 

Precambrian and Cambrian age; Paleozoic clastic and 

carbonate rocks; Mesozoic clastic and intrusive rocks; 

varied fluvial, paludal, pond, and playa sedimentary 

rocks of Pliocene age; volcanic rocks of Tertiary age; 

and alluvium, colluvium, and eolian dunes of 

Quaternary age (Waddell, 1982).

Regional Hydrogeology

Conceptualization of the ground-water flow system requires identification and assessment of system 

elements, including: (1) definition of hydrogeologic 

units, (2) distribution of hydrologic properties of the 

units, (3) distribution and characteristics of geologic 

structures, and (4) estimates for recharge, discharge, 

and boundary fluxes.

In an idealized desert-basin flow system, water 

generally moves downward in recharge areas, then laterally toward discharge areas, and finally upward in 

discharge areas (Eakin and others, 1976) (fig. 2). 

Although these general characteristics for flow exist, 

conditions for idealized flow are rarely met in natural 

hydrologic environments, particularly in geologically, 

climatically, and ecologically complex regions. Therefore, to correctly interpret a natural flow system, all 

deviations from the ideal must be considered.

The conceptual model used is derived from those 

proposed by Bedinger and others (1989a; 1989c), 

Winograd and Thordarson (1975), and Waddell (1982). 

Conceptually, the ground-water flow system can be 

thought of as a series of connected intermontane 

basins, shown on figure 2, in which localized groundwater flow occurs in basin-fill deposits, clastic rocks,

2 A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using GIS Techniques
118° 117° 116° 115°

25 50 MILES 

EXPLANATION

DEATH VALLEY REGIONAL FLOW SYSTEM BOUNDARY

Figure 1. Location of the Death Valley region, Nevada and California.

carbonate rocks, and volcanic rocks (P.O. Sinton, 

U.S. Geological Survey, written commun., 1987).

Local and regional faults have altered the rocks 

and are an important component of the hydrogeologic 

framework. As a result, the regional flow system 

may be characterized as largely fault- and fracturecontrolled. The dominant flow direction is from the 

north, northeast, and east to the south and southwest, 

and shows interbasinal flow (P.O. Sinton, U.S. Geological Survey, written commun., 1987; Downey and others, 1990; Hunt and Robison, 1960; Hunt and others, 

1966).

Recharge

The Death Valley ground-water basin is not an 

isolated basin. Ground-water flow in the region typically is not coincident with topographic basins; flow 

patterns are quite complex and reflect the presence of a 

large carbonate aquifer and the effects of structural and 

lithologic controls in the compartmentalization of flow 

into local, subregional, and regional subsystems 

(Bedinger and others, 1989c). Regional interbasinal 

ground-water movement in the area is affected by the 

deformed nature of the great thicknesses of Paleozoic

INTRODUCTION
AREAS OF GROUND-WATER EVAPOTRANSPIRATION

Phreatophytes Discharging playa

Figure 2. Observed configurations of ground-water flow in the Great Basin (from Eakin and 

others, 1976).

carbonate and clastic rocks. Major wrench, thrust, and 

normal faults and folds have been shown to exert 

marked control on this ground-water movement 

(Winograd and Thordarson, 1975). Most of the ground 

water that traverses the boundaries of the basin does so 

as interbasinal flux.

Aside from interbasinal flux, precipitation in the 

topographically high areas within the region is a major 

source of recharge to the ground-water flow system 

(Prudic and others, 1993). Recharge of this kind dominantly occurs on the mountains that rim the basin. 

Smaller quantities of recharge occur through return of 

irrigation and domestic-use waters, as well as seepage 

of spring discharge back into the ground-water system 

(Rice, 1984); however, these lesser components are 

small compared to regional infiltration and interbasinal 

flux and may be considered negligible.

Much of the infiltration is from winter and spring 

storms that produce abundant snow in the mountains, 

which are capable of sustaining a significant snow pack 

that melts and infiltrates as recharge. During spring 

melt, the water seeps slowly into the permeable bedrock or flows off to adjacent drainages where water 

seeps into alluvium (Prudic and others, 1993). Additional recharge may occur during infrequent, large 

storms that cause local runoff to stream channels where

water infiltrates in concentrated areas along the channel. These recharge events are locally significant, but 

are less so at regional scales. Both snowmelt and 

storm-runoff water percolate through bedrock in 

outcrop areas of extensively fractured carbonate, clastic, and volcanic rocks. In areas where well-developed 

clayey soils have formed on tuff and argillaceous 

rocks, less infiltration occurs.

Discharge

Natural ground-water discharge is by springs, 

evaporation in areas where the water table is near the 

land surface, and through transpiration by plants. The 

Death Valley salt pan has long been interpreted as the 

ultimate discharge area for the Death Valley regional 

ground-water flow system (Eakin and others, 1951, 

Eakin and others, 1963; Winograd and Thordarson, 

1975). Two other major discharge areas are the springs 

at Ash Meadows and Oasis Valley (Winograd and 

Thordarson, 1975). Artificially induced discharge 

occurs in the form of ground-water pumping for agricultural, commercial, and residential uses (Bedinger 

and others, 1989c).

4 A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using CIS Techniques
DATA SOURCES AND DIGITIZATION 

PROCEDURES

comprehensive system and almost any type of 2D analysis can be accomplished.

The creation of conceptual models and maps of 

geologically and hydrologically complex regions 

requires careful data management and quality controls 

(Turner, 1992). The identification, acquisition, and 

conversion of suitable data, and proper processing and 

analysis procedures for these data, are critical for successful characterization and conceptualization. A geographic information system (GIS) was used to manage, 

store, and analyze the digitized data that were used to 

develop a hydrogeologic map of the Death Valley 

region.

Geographic Information Systems

GISs are used to map and analyze essentially 

two-dimensional (2D) land surface phenomena. A GIS 

is not just a computer system for displaying geometric 

data; rather a GIS is an analytical tool that links spatial 

data with geographic information (Environmental Systems Research Institute, 1992). As a result, in addition 

to geometric data, a GIS needs descriptive data and an 

ability to analyze and compare multiple data sets, both 

geometrically and analytically. A GIS allows you to 

identify the spatial relationships between map features.

All GISs have an internal linkage between the 

data, or attributes, and the geometry. All maps and 

GISs generalize the geometry to some extent. Maps 

and GISs convey information by representing features 

with 2D graphic components: points, lines, and areas. 

ARC/INFO is the GIS used in this study (Environmental Systems Research Institute, 1992).

ARC/INFO is a vector-based GIS that provides 

digitizing capability, interactive graphics editing, data 

storage and management (INFO), and graphical manipulation functions as well as sophisticated overlay operators and geographic analysis tools. Each layer or map 

in ARC/INFO is called a coverage. A coverage consists of topologically linked geographic features and 

their associated descriptive data. A coverage can contain several feature classes, including points (nodes, 

vertices, labels, and/or tics), lines (arcs), and/or areas 

(polygons). ARC/INFO stores the descriptive information for a feature in an INFO data file. This data file is 

a tabular data file, in which a record (row) stores all the 

information about one occurrence of a feature (point, 

arc, or polygon), and an item (column) stores attribute 

information (Environmental Systems Research Institute, 1992). In ARC/INFO, all of the attribute data are 

linked to a single map and cannot be directly related to 

other maps without additional analyses. It is a very

Data Quality Assurance

Data quality-assurance and control procedures 

require that: (1) data be safeguarded, secure from 

any form of data modification, and (2) data must 

always retain information documenting their origins 

(Turner, 1992). The original data usually cannot be 

used directly in building a coherent data base because 

data collected at different times, by different people, 

using different methods, will not be consistent. To 

ensure consistency in the developed data base, three 

processes were conducted: (1) data validation, (2) data 

parsing, and (3) data regionalization.

Validation includes the identification of both 

"errors" and "blunders." Errors include incorrect values occurring in the original data caused by instrument 

or equipment failures, such as "dropped bits" during 

electronic data transmission. Blunders include human 

mistakes resulting from mislabeling, mislocation, or 

misidentification of data (Turner, 1992).

Data parsing involves the review and conversion 

of descriptive data to consistent, standard terminology 

and formats (Turner, 1992). For example, rock unit 

definitions may change over time, or different geoscientists may use different terms to describe the same 

unit. Parsing develops a consistency in the data so that 

they are usable during characterization (Turner, 1992).

Finally, data must be regionalized, or adjusted to 

represent appropriate levels of detail in order to accomplish the purposes of the map (Turner, 1992). Data 

should be neither too detailed, nor too generalized, to 

satisfy the study objectives with maximum efficiency.

The specifics of these processes are discussed in 

the "Digitizing Procedures" section. D'Agnese and 

others (1994) give a more detailed description of the 

processes for the California sheets. Cartier and others 

(1993) describe similar processes for the Lake Tahoe 

basin.

Geographic Coordinate System

In any study involving the integration of disparate data types from numerous sources, care must be 

taken to make sure the data all have a consistent, standardized coordinate system. Without such a system, 

the locations of various data items cannot be assessed. 

Because the development of the hydrogeologic map 

involved a large geographic region, distortions

DATA SOURCES AND DIGITIZATION PROCEDURES
required to represent the curved surface of the Earth 

on flat maps had to be considered.

Accordingly, all data were projected to the standard Universal Transverse Mercator (UTM) coordinate 

system, Zone 11, defined by the transverse Mercator 

projection. The east-west and north-south directions in 

the UTM are measured in meters. The UTM coordinate system was used because:

1. It has been demonstrated as a useful coordinate 

system for regional studies at scales of approximately 1:250,000 to 1:500,000 (Snyder, 

1987);

2. Most of the geology for the area was obtained 

from maps using UTM;

3. The entire map area fits in a single zone; and

4. The distortions in area and distance are acceptable 

for project needs.

Data Sources and Data Entry Procedures

The data acquired for analysis were of three 

types: existing digital GIS files, published maps, and 

tabulated data in reports and files. These data were 

acquired from standardized archives, national data 

bases, and published reports.

Existing Digital GIS Files

Existing digital GIS data files were already in a 

GIS format and have corresponding structured data 

attribute tables that were directly useful in data analysis 

and characterization. Data conversion requirements 

for these data were rather straightforward, and 

consisted primarily of importation into the desired GIS 

from an archived format. One such data file was available a digital representation of the USGS geologic 

map of Nevada (Stewart and Carlson, 1978) developed 

by Turner and Bawiec (1991). This map was acquired 

as an archived GIS file compatible with ARC/INFO.

Published Map Information

Published maps represent the second major data 

type. Published geologic map sheets for the California 

portion of the Death Valley region were the major nondigital maps used. Parts of four l:250,000-scale geologic maps cover the California portion of this region. 

They are part of the geologic report of California, produced by the Division of Mines and Geology, California Department of Natural Resources (Bacon, 1971). 

These map sheets are:

1. Death Valley sheet (Streitz and Stinson, 1974);

2. Kingman sheet (Jennings, 1961);

3. Mariposa sheet (Strand, 1967); and

4. Trona sheet (Jennings and others, 1962).

The areas covered by these maps are shown in 

figure3.

118° 117 116°

Mariposa sheet (Strand, 1967) 

Death Valley sheet (Streitz and Stinson, 1974) 

Trona sheet (Jennings and others, 1962) 

Kingman sheet (Jennings, 1961)

Nevada State Geologic Map (Stewart and 

Carlson, 1978)

Figure 3. Index of sources of geologic data.

Data digitization, conversion, and preprocessing 

procedures required to develop a suitable digital map 

from these published maps were the most timeconsuming procedures involved in the study. These 

maps were converted to a digital format by a process 

that involves digitizing/scanning, editing (arc-node 

aligning), and attribution (Seller and others, 1990). 

Also, because these maps were not originally generated 

for this report, they required parsing and regionalization during the conversion process.

6 A Hydrogeologlc Map of the Death Valley Region, Nevada and California, Developed Using GIS Techniques
Tabulated Data

Published or tabulated data include tables of data 

in reports or in public-access data bases. These data 

include lithologic names and hydraulic conductivity. 

Data conversion and preprocessing of published or 

tabulated data generally involve two forms of data 

manipulation: data entry of manuscript or published 

data into computer compatible format, or data reformatting of existing digital files and data bases. In this 

study, both forms of public-access data were used. 

Lithologic names were included with the Nevada geologic map in digital format and were reformatted where 

necessary. The lithologic names for the California 

geologic maps were entered into the data base. Hydrogeologic units were entered into each data base so that 

the geologic units could be combined into the proper 

hydrogeologic units.

Digitizing Procedures

A procedure for transferring map documents to a 

digital file format, described in Soller and others 

(1990), formed the basis for all data digitization. Maps 

showing geological boundaries and fault traces were 

scanned by using a raster-to-vector scanner. This process was similar to that described by Bawiec and others 

(1992) during their development of the digital version 

of the geologic map of Nevada (Turner and Bawiec, 

1991). The processing removed artifacts of the scanning process, transformed the files into a suitable 

geographic coordinate system, and edited the files to 

achieve accurate topology. The procedure can be summarized as follows:

1. Geologic unit contacts, faults, and control points 

were obtained from black-and-white copy.

2. The black-and-white copies of geologic contacts 

and fault traces were converted to digital format by a raster scanner. The digital files were 

then converted into a sequence of individual 

ARC/INFO coverages.

3. The resulting digital map coverages were manually reviewed and corrected for scanning errors 

such as gaps in lines, stray lines, and incorrect 

depictions of line intersections. Control points 

were converted to geographic registration 

points (ARC/INFO tics). The map coverages 

were then geographically registered into 

Zone 11 of the Universal Transverse Mercator 

coordinate system.

4. For the geologic units coverages, the digital

boundaries, represented by lines (or "arcs" in 

ARC/INFO terminology), were further analyzed to represent polygonal information defining the extent of each geologic map unit. 

ARC/INFO uses rules of planar enforcement to 

construct a topologically correct sequence of 

polygons from such boundary lines. This 

requires a point to be placed within each polygon representing a geologic unit area, and these 

points are to be identified or labeled with an 

alphanumeric code representing that geologic 

unit. Using ARC/INFO commands, the coverages were analyzed (by the ARC/INFO "clean" 

and "build" commands) until no errors in 

topology were identified. For the fault coverages, construction of polygon topology was not 

required.

5. Tables containing appropriate attributes were 

constructed within the ARC/INFO system.

6. Each of the coverages was plotted at the original 

map scale (1:250,000). The plots were then 

overlaid on the manuscript sheets and checked 

for discrepancies. Because the final scale of 

the map was to be 1:500,000, errors less than 

250 m on the ground were not corrected, in 

accordance with accepted geographic standards (Goodchild, 1993;Nebert, 1989). For 

the geologic maps, each of the digital geologic 

map units were plotted in appropriate colors 

and their agreement with the published maps 

was checked.

Certain criteria were used to decide which geological 

information to include and exclude. Only the geologic 

boundaries, unit identification, and fault data were 

included in the digitization procedure. Symbols such 

as anticlines, synclines, strikes, and dips were not 

included. Dashed contacts and faults were treated as 

solid lines and were not separately identified in the 

data base. Fault traces were encoded as simple fault 

lines and were not attributed with attitude or type. The 

map control points did not always agree with those 

contained on the original scale-stable bases. To eliminate any further confusion and to produce a more geographically correct digital file, the resulting map was 

scaled during digitization to fit the calculated control 

points. The result is that the digital map will not agree 

exactly at all locations with the original source materials.

DATA SOURCES AND DIGITIZATION PROCEDURES 7
DIGITAL REPRESENTATIONS OF THE 

REGIONAL HYDROGEOLOGIC UNITS

The conceptual model of the regional hydrogeologic systems used is based on the models of Bedinger 

and others (1989a; 1989c), Winograd and Thordarson 

(1975), and Waddell (1982). As shown conceptually in 

figure 2, these authors concluded that the Death Valley 

ground-water flow system is a series of connected 

intermontane basins in which ground water flows in 

basin-fill deposits, carbonate r,ocks, clastic rocks, and 

volcanic rocks. Therefore, the characterization of the 

framework through which the water flows is important 

to understanding the ground-water flow system.

Since this report is directly concerned with characterization of the regional hydrogeologic system of 

the Death Valley region, only data specific to the 

project goals and objectives were gathered for data 

base incorporation. As a result, detailed large-scale 

maps were not included in the data acquisition process.

Geologic Information

The surface bedrock geology provides the basis 

for the hydrogeologic map. Exposure of the geologic 

units was taken from regional geologic coverages. 

Parts of four l:250,000-scale geologic maps cover the 

California portion of this region (Jennings, 1961; 

Jennings and others, 1962; Strand, 1967; and Streitz 

andStinson, 1974). Part of the l:500,000-scale 

geologic map for the State of Nevada (Stewart and 

Carlson, 1978) was used for the rest of the area. The 

locations and, extent of these map sheets are shown in 

figure 3.

California Geologic Maps

The hydrogeologic map covers a nearly triangular section of southeastern California bounded by the 

Nevada-California border on the northeast, by 

long 118°W on the west, and by lat 35°N on the south 

(fig. 3). Although the various map sheets in the 

Geologic Report of California (Bacon, 1971) generally 

correspond to standard 1:250,000-scale topographic 

map quadrangles and take their names from these 

quadrangles, the sheets were extended in some cases 

(where they border adjacent states) to encompass small 

parts of adjacent quadrangles. One such extension 

occurs within the Death Valley region. The Mariposa 

sheet (Strand, 1967) was extended eastward from the 

Mariposa topographic map quadrangle to include a 

small triangular portion of California on the Goldfield, 

Nevada, topographic map quadrangle.

D'Agnese and others (1994) developed a digital 

version of this portion of the California geologic maps. 

The process used is summarized as follows. For the 

Death Valley (Streitz and others, 1974), Trona 

(Jennings and others, 1962), and Kingman (Jennings, 

1961) sheets, black-and-white map copies plotted on 

stable-base acetate materials, one showing the geologic 

unit boundaries and the other the faults (each containing geographic control points), were obtained from the 

California Division of Mines and Geology. These copies show the geologic boundaries and faults exactly as 

they are shown on the original published maps of the 

Geologic Report of California (Bacon, 1971). Such 

materials were not available for the Mariposa sheet 

(Strand, 1967); thus, for the small part of this sheet that 

was required, the geologic boundaries and the faults 

were traced from a library copy of the published paper 

map sheet onto two separate scale-stable masters, 

along with appropriate control points.

Inevitably, judgments were made in creating 

these digital map files. Small unlabeled units on the 

source map were combined with nearby units. Whenever possible, this was done after consulting a larger 

scale, more detailed, geologic map of the area. The 

geologic unit polygons on these digital map files were 

attributed to correspond to the geologic units used by 

the geologic report of California (Bacon, 1971).

Within the region of interest, the geologic materials range in age from Precambrian to Holocene and 

are composed of metamorphic rocks, carbonate and 

clastic sedimentary rocks of both marine and continental origin, and plutonic and volcanic igneous rocks. 

The diverse geology in the California portion of the 

Death Valley region is defined by 51 geologic units 

(table 1). These unit names were stored as attributes in 

the appropriate ARC/INFO tables.

Nevada Geologic Map

To complete the geologic coverage of the 

Death Valley region, the USGS digital geologic map of 

Nevada (Turner and Bawiec, 1991), which corresponds 

to the published Nevada State geologic map (Stewart 

and Carlson, 1978), was acquired and imported from 

its archived file format into ARC/INFO GIS. The data 

set was an early release version and required some 

minor editing to correct "errors" and "blunders," such 

as improperly attributed entities. Once these corrections were made, the map projection was changed to 

the UTM projection. The area of interest, the portion 

of Nevada between lat 35°N., long 115°W, and 

lat 38°N., long 118°W, was extracted from the state 

coverage (fig. 3). This extracted digital map included 

58 geologic units (table 1).

8 A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using GIS Techniques
ada

9 *

.s

CO

o 

Q 

O

d S

E c a

3 'so

o 

o

O)

3 

o

3

o 

o

O) e 

f

o 

o

«

A 

^2

o

en

I

o.

DIGITAL REPRESENTATIONS OF THE REGIONAL HYDROGEOLOGIC UNITS 9
Combining Nevada and California Maps

The California maps were in Universal Transverse Mercator coordinates; the Nevada map was 

initially in Lambert Conformal Conic coordinates but 

was converted to Universal Transverse Mercator coordinates. The four California maps were merged first, 

then the Nevada map was merged with the California 

coverages. After merging, the edges of the various 

maps were compared and matched. Boundaries were 

dropped between areas on adjacent map sheets with 

identical hydrogeologic units. The resulting combined 

maps form a hydrogeologic map for the entire Death 

Valley region (pi. 1).

Numerous limitations are inherent in the creation 

of these digital map files. They include, but are not 

limited to:

1. The maps are, at best, accurate only to the scale of 

the original digitized map, in this case 

1:250,000 for California and 1:500,000 for 

Nevada.

2. The geologic units along the borders of the original California geologic report (Bacon, 1971) 

map sheets do not match exactly (quadrangle 

boundary-line faults). This is especially true of 

the Death Valley sheet (Streitz and Stinson, 

1974), which was remapped and reissued later 

than the other sheets. Even more severe differences are found along the Nevada-California 

border because the California and Nevada 

mapping used different sets of geologic units, 

reflecting different emphases concerning geologic conditions in the two states (state 

boundary-line faults). Due to the variety of 

map scales and authors, it was beyond the 

scope of this study to resolve the differences on 

the original map sources. The location or classification of geologic features does not match 

across many of the borders between adjacent 

maps. Hence, "state boundary-line and quadrangle boundary-line faults" are apparent in 

several areas when the maps were joined 

(pi. \A). When the original geologic units were 

combined into hydrogeologic units, a number 

of these problem areas were resolved (pi. \B). 

The remaining discrepancies, inherited from 

the source maps, remain in the composite coverage. Cartier and others (1993) discuss a similar problem encountered in the Lake Tahoe 

Basin.

CLASSIFICATION OF HYDROGEOLOGIC 

UNITS

The rocks and deposits forming a hydrogeologic 

system can be classified into hydrogeologic units. A 

hydrogeologic unit is a unit that has considerable lateral extent and has reasonably distinct hydrologic properties because of its physical (geological and structural) 

characteristics (Maxey, 1968).

Since the overall study objective was to develop 

an understanding of the hydrogeology, hydrogeologic 

units were used for simplification. Although the major 

geological features were retained, many of the smaller 

geologic units were grouped into larger entities by generalizing both lithologic and hydrologic properties of 

the bedrock-geology units. The geologic units found 

on the regional geologic maps that compose each of 

these hydrogeologic units are summarized in table 1.

Winograd and Thordarson (1975) divided and 

combined the various geologic units at the NTS, based 

on hydrologic properties. Waddell (1982) further 

described these hydrogeologic units while constructing 

a numerical ground-water flow model. These authors 

used hydrogeologic units to describe the aquifers and 

confining units. These units are similar to, but not 

exactly the same as, the hydrogeologic units used 

here. Bedinger and others (1989a; 1989c) expanded 

Winograd and Thordarson's hydrogeologic units while 

describing the hydrogeology of the Death Valley 

region. Grose (1983) and Grose and Smith (1989) 

subsequently developed cross sections for the Death 

Valley region based on the hydrogeologic units defined 

by Bedinger and others (1989a; 1989c).

Grose (1983) and Grose and Smith (1989) 

defined and correlated 44 hydrogeologic units. 

Because their study area was larger than the Death 

Valley region defined in this report, 12 of these 44 units 

are not included in this map area. Many of the remaining units have similar hydrologic properties (Bedinger 

and others, 1989b) or were not considered important on 

the regional scale. As a result, only 10 hydrogeologic 

units are defined for the Death Valley region (tables 1 

and 2). The abbreviations for the hydrogeologic units 

were modified from those used by Grose (1983). 

Plate 1 shows the surface expressions of the hydrogeologic units. Table 2 summarizes the correlation of the 

hydrogeologic units with the units described by 

Winograd and Thordarson (1975), Bedinger and others 

(1989a), Grose (1983), and Grose and Smith (1989).

10 A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using CIS Techniques
g

3 

O

I

O 

30 

O 

O

m 

O

O 

O 

O

c

Table 2. Correlation of hydrogeologic units with other hydrogeologic units in the Death Valley region

[Sources: Waddell (1982) and Bedinger and others (1989a; 1989c)]

Hydrogeologic unit

Hydrogeotogic unit

(from Winograd and Thordarson, 1975)

Major hydrogeologic unit

(from Bedinger and others, 1989a)

Playa deposits of Quaternary age (Qp) 

Valley fill of Quaternary-Tertiary age (QTvf) 

Volcanic rocks of Quaternary-Tertiary age (QTv) 

Volcanic rocks of Tertiary age (Tv) 

Volcanic and volcaniclastic rocks of Tertiary age (Tvs) 

Granitic rocks of Tertiary-Late Jurassic age (TJg) 

Sedimentary and metavolcanic rocks of Mesozoic age 

(Mvs) 

Carbonate rocks of Paleozoic age (P2)

Clastic rocks of Paleozoic-Precambrian age (PI) 

Igneous and metamorphic rocks of Precambrian age 

(pCgm)

Valley-fill aquifer

Valley-fill aquifer

Lava-flow aquifer

Welded tuff aquifer, bedded tuff aquifer

Tuff aquitard, lava-flow aquitard

Granitic stock minor aquitard

Upper carbonate aquifer, 

Upper clastic aquitard, and 

Lower carbonate aquifer 

Lower clastic aquitard

Basin fill 

Lava flows 

Ash-flow tuff

Undifferentiated volcanic rocks 

Crystalline rocks (upper part) 

Coarse-grained clastic rocks

Carbonate rocks

Fine-grained clastic rocks 

Crystalline rocks (lower part)
Playa Deposits of Quaternary Age (Qp)

The lacustrine confining beds, lake bed sediments of Quaternary age, are a relatively homogeneous 

deposit composed of mainly clay-sized particles. The 

unit includes fine-grained playa deposits, lacustrine 

limestone, and evaporites. Accordingly, the unit can 

exhibit matrix flow from the permeable unconsolidated 

deposits and fault and fracture-controlled flow in consolidated deposits (Downey and others, 1990). The 

lacustrine beds were deposited contemporaneously 

with the younger alluvial sediments. As a result, the 

deposits grade into each other. In some of the valleys, 

the lacustrine confining beds are several hundred 

meters thick.

Volcanic Rocks of Quaternary-Tertiary 

Age (QTv)

The volcanic rocks, including lava flows and 

undifferentiated volcanic rocks of Tertiary and Quaternary age, underlie the valleys and crop out extensively 

in many of the mountains. The lava flows are primarily 

basalts, andesites, and rhyolites of Tertiary and Quaternary age. Columnar jointing and platy fractures are 

common in the flows, which vary from vesicular to 

dense. Secondary openings are developed along fractures and bedding planes. Individual flows generally 

are less than 33 m thick; some are less than 1 m thick 

(Bedinger and others, 1989a). Aggregate thicknesses 

are as much as 1,000 m (Bedinger and others, 1989a).

Valley Fill of Quaternary-Tertiary Age 

(QTvf)

The alluvial sediments of Quaternary-Tertiary 

age are a heterogenous mixture of volcanic and sedimentary rock detritus ranging from clay to boulder 

size. The heterogeneous mixture includes units of 

fine-grained playa and lake beds containing evaporites 

(of limited areal extent), boulder-cobble-pebble debris 

flow and fan deposits, and volcanic tuffs. Accordingly, 

they may exhibit matrix flow in the permeable unconsolidated materials, but fault- and fracture-controlled 

flow in more indurated materials (Downey and others, 

1990). The valley fill (including fluvial deposits) 

accumulated largely in structural basins. As a result, 

the valley fill deposits range in thickness from zero at 

margins of valleys to several hundred meters in valley 

lowlands. The fill in many basins is greater than 

1,300 m thick and may be as thick as 2,000 m 

(Bedinger and others, 1989a). The basin fill forms the 

major aquifer system in many of the valleys.

These basin fill aquifers constitute a regional 

system because of the similarities between basins and 

because they are the most developed source of ground 

water in the region. Some basins are topographically 

and hydraulically closed by low-permeability bedrock, 

while others are part of multibasin flow systems connected by perennial streams or by flow through the 

basin fill or permeable bedrock (fig. 2). Well yields 

within the basin fill seem to be related to physiographic 

setting (Plume and Carlton, 1988). The hydrologic 

properties of these deposits can differ greatly over short 

distances, both laterally and vertically, because of 

abrupt changes in grain size, and the degree of sorting 

and consolidation.

Volcanic Rocks of Tertiary Age (Tv)

These volcanic rocks include tuffs and undifferentiated volcanic rocks of Tertiary and Quaternary age. 

They underlie the valleys and crop out extensively in 

northern and central portions of the area (pi. 1), including the Yucca Mountain area, where tuffs of Tertiary 

age are widespread. These units have an aggregate 

thickness of more than 4,000 m. The composition and 

structure of these volcanic tablelands, and their position and mode of emplacement, drastically affect 

regional ground-water flow by altering flow paths, 

providing numerous avenues of recharge, and altering 

water-table gradients.

This hydrogeologic unit includes densely welded 

to nonwelded, bedded, reworked, and air-fall tuffs. 

Welded ash-flow tuffs characteristically have an interstitial porosity of about 5 percent or less (Bedinger and 

others, 1989a); thus, the commonly moderate to large 

hydraulic conductivity of welded ash-flow tuffs is 

largely a function of secondary openings along joints, 

bedding planes, and partings within the flows. Where 

these welded tuffs are not fractured or jointed, they 

tend to form confining beds; thus, welded tuffs can only 

transmit significant quantities of water where they are 

fractured.

In contrast, nonwelded ash-flow tuffs may have a 

large interstitial porosity, but low hydraulic conductivity and can function as confining beds. Fractures and 

joints are virtually absent in nonwelded ash-flow tuffs 

(I.J. Winograd, U.S. Geological Survey, written 

commun., 1971). Hence, the nonwelded tuffs generally act as confining units. These nonwelded tuffs, 

however, have limited areal extent.

12 A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using CIS Techniques
Volcanic and Volcaniclastic Rocks of 

Tertiary Age (Tvs)

The clastic and tuffaceous aquifers and confining 

beds are comprised of tuffs and associated sedimentary 

rocks. They include up to 1,500 m of a variety of nonwelded to welded ash-flow tuff, ash-fall tuff, tuff breccia, breccia flow deposits, tuffaceous sandstone, 

siltstone, mudstone, freshwater limestone, and minor 

amounts of densely welded tuff. Despite the widely 

differing origins of these rocks, this unit usually has 

matrices consisting of zeolite or clay minerals (Winograd and Thordarson, 1975), which results in low 

hydraulic conductivity. Some of the limestone and 

densely welded tuff may not have zeolitic or clayey 

matrices, but are believed to have low hydraulic conductivity (Winograd and Thordarson, 1975). These 

rocks usually separate the more permeable volcanic 

rocks (Tv) from the Paleozoic carbonate rocks (P2).

Granitic Rocks of Tertiary-Late Jurassic 

Age (TJg)

Granitic rocks of Mesozoic and Tertiary age are 

widespread throughout the southern portion of the 

region (pi. 1). They outcrop in many mountain ranges 

and underlie most of the southern portion of the region 

at depth (Bedinger and others, 1989a). Ground water 

is thought to occur in these crystalline rocks only where 

they are fractured. Because the fractures are poorly 

connected, these rocks are believed to act mostly as 

confining units.

Sedimentary and Metavolcanic Rocks of 

Mesozoic Age (Mvs)

The clastic rocks of Mesozoic age are predominantly continental fluvial, lacustrine, and eolian deposits and clastic and carbonate sedimentary rocks. These 

rocks form extensive outcrops on the sides of the 

Spring Mountains where they have been thrusted. The 

rocks have a variable thickness due to the extensive 

thrust faulting and are some of the more permeable 

rocks in the Death Valley region; however, they are not 

widespread. Some of these rocks are also found in the 

southwestern portion of the Death Valley region 

(Bedinger and others, 1989a).

Carbonate Rocks of Paleozoic Age (P2)

Limestone, dolomite, and calcareous shales of 

Paleozoic age underlie many valleys and outcrop along

the flanks of and throughout some mountains. These 

carbonate rocks cover an extensive portion of the area 

around Death Valley, extending to the north and east 

(pi. 1). They are often interbedded with siItstones and 

shales and locally interrupted by volcanic rocks in the 

north. These carbonate rocks, which have an aggregate thickness of about 8,000 m, are probably the most 

permeable rocks in the area. Where hydraulically connected, they contribute significantly to interbasinal 

movement of water. This interbasinal movement 

includes: (1) movement of water within the groundwater basin between topographic basins (fig. 2); and 

(2) the entrance of ground water from basins to the 

northeast. Many of the springs in the area are associated with the carbonate rocks. Intergranular flow is not 

significant in these rocks; the large transmissivity is 

primarily due to fractures and solution channels 

(Winograd and Thordarson, 1975). Hydraulic tests of 

carbonate-rock aquifers throughout eastern and southern Nevada indicate that faults can increase their 

transmissivity by factors of 25 times or more 

(Dettinger, 1989).

Clastic Rocks of Paleozoic-Precambrian 

Age(P1)

Siltstone, quartzite, shale, sandstone, and some 

metamorphic rocks of later Precambrian and Paleozoic 

age form clastic confining units. These rocks vary in 

aggregate thickness with a maximum thickness of 

about 3,500 m. These rocks have negligible interstitial 

ground-water movement but frequently are highly fractured and locally brecciated (Winograd and 

Thordarson, 1975). At shallow depths, these fractures 

and breccias can be conduits to flow, converting these 

clastic rocks into locally important shallow aquifers.

Clastic rocks in the region differ hydrologically 

from carbonate rocks in two important ways. First, 

secondary porosity rarely develops along bedding 

planes in any of the clastic rocks because of the low 

solubility of their constituents including quartz, mica, 

and clay minerals. Second, the clastic rocks deform 

more plastically than the carbonates and, as a result, 

fractures may become sealed or isolated during deformation (Winograd and Thordarson, 1975). In these 

rocks, the fractures may be sealed by continued deformation caused by the same process that formed them or 

by later plastic deformation. Open fractures in interbedded competent rocks may be sealed by plastic 

deformation of the less competent interbedded strata 

(Winograd and Thordarson, 1975).

CLASSIFICATION OF HYDROGEOLOGIC UNITS 13
Igneous and Metamorphic Rocks of 

Precambrian Age (pGgm)

Crystalline metamorphic and igneous rocks of 

Precambrian age are widespread throughout the southern part of the region, cropping out in many mountain 

ranges and underlying most of the area at depth 

(Bedinger and others, 1989a). Hydrologically, this unit 

behaves similarly to the other crystalline rocks in the 

region (TJg). Ground water is thought to occur only 

locally in these crystalline bodies where the rock is 

fractured. Because the fractures are poorly connected, 

these rocks are believed to act mostly as confining 

units.

HYDROLOGIC PROPERTIES OF 

HYDROGEOLOGIC UNITS

Numerous site-specific, in-situ, and laboratory 

tests conducted throughout the region are needed to 

define the hydrologic properties of rocks in the Death 

Valley region (Bedinger and others, 1989b). Bedinger 

and others (1989b) conducted a rather extensive search 

of the literature on the hydrologic properties of rocks in 

the Death Valley region. Their review indicated that 

hydrologic properties can range over 15 orders of magnitude in the Death Valley region. They concluded that 

it was appropriate to evaluate these properties by defining ranges of values for hydraulic conductivity for the 

major units in the region (Bedinger and others, 1989b). 

They also discussed the effects of lithology, depth, and 

degree of fracturing on the hydrologic properties.

Bedinger and others (1989b) compiled values of 

hydraulic conductivity and porosity for 14 rock types 

widely represented in the Death Valley region and 

developed a generalized log-normal plot showing the 

distributions of the hydraulic conductivity values 

(fig. 4). Although these hydraulic conductivity plots 

were developed from generalizations, they represent a 

good first approximation of the ranges of hydraulic 

conductivity values in the region. Using the information from figure 4 and the effects of depth and faulting, 

the hydrologic properties are summarized in table 3.

Recent hydrogeologic investigations in the 

Death Valley region have not included any quantitative 

assessment of the hydraulic role of faults. As a result, 

little quantitative information is available concerning 

the influence of regional fault zones on ground-water 

flow patterns; however, the conceptual model used in 

this study suggests that regional fault zones may have 

a considerable influence on the regional ground-water 

flow system.

Bedinger and others (1989b) believed that the 

Death Valley regional ground-water flow system is 

influenced by deep ground-water flow paths. Therefore, they examined the effects of depth on the hydrologic properties of the hydrogeologic framework in the 

region. They suggested that increased jointing near the 

surface, caused by stress release by erosional unloading and weathering, may yield larger hydraulic 

conductivity and porosity values for rocks at shallow 

depths; however, Bedinger and others (1989b) found 

that adequate quantitative data were not available in the 

Death Valley region. Most existing well-yield and specific capacity tests relate to relatively shallow depths in 

alluvial aquifers (Bedinger and others, 1989b). Constrained by these limitations, Bedinger and others 

(1989b) searched for and evaluated all available hydrologic property data from a variety of locations. By 

comparison, with known regional geological conditions, these results were used to estimate hydrologic 

properties in the Death Valley region. Bedinger and 

others (1989b) reached the following conclusions:

1. At depths below 150 to 300 m, weathering and 

fractures due to release of confining pressures 

by erosional unloading probably are not significant.

2. At increased depths, overburden pressures tend to 

decrease the apertures of joints or fractures and 

the size of pores and, therefore, porosity and 

intrinsic permeability tend to decrease.

3. In some areas, solution-type voids and relict cavernous conditions may withstand overburden 

pressures in crystalline carbonate rocks, 

allowing these features to remain open at 

depths up to 2,000 to 3,000 m.

4. Surface faults and fractures are good indicators of 

the orientation and position of permeable zones 

at depths up to 1,000 m.

5. Large, regional, crustal fault zones are good indicators of areas of significant increased hydraulic conductivity at great depths. The regional 

hydraulic conductivity as a result of fractures is 

dependent not only on the presence of open 

fractures, but also on rock type, fracture orientation, and the history of tectonic stress in the 

region.

14 A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using GIS Techniques
99

qn 90

60

« 50

40

2 30

20

10

BOI-LLJ

z

OX£ -

a.

10 10 10-' 10-' NT 10-' ID- 10"' 10' 10U 10'

HYDRAULIC CONDUCTIVITY, K, IN METERS PER DAY

10"

EXPLANATION

BASALT

1-Moderately dense to dense lava flows

2-Fractured cavernous basalt

BASIN FILL

1-Fine-grained basin fill

2-Coarse-grained basin fill

CARBONATE ROCKS

1-Dense to moderately dense carbonate rocks

2-Fractured, karstic carbonate rocks

CLASTIC ROCKS

1-Fine-grained clastic rocks

2-Coarse-grained clastic rocks

METAMORPHIC ROCKS

1-Unweathered metamorphic and intrusive 

rocks with fracture permeability, greater 

than 300 meters below land surface

2-Unweathered metamorphic and intrusive 

rocks with fracture permeability, less than 

300 meters below land surface

3-Weathered metamorphic and intrusive rocks

TUFF

1-Nonwelded to partially welded, bedded tuff

2-Welded, moderately fractured to dense tuff

3-Fractured, welded tuff

Figure 4. Hydraulic-conductivity distributions estimated for rock types in the Death Valley region (from Bedinger 

and others, 1989b).

HYDROLOGIC PROPERTIES OF HYDROGEOLOGIC UNITS 15
"o) o

<D

_g> "S

"1

<D

Q

<D

SI

c.

tn"c

13

"1

o

1

>» SI "o

1*

o

 o

8

o

"5

i_f.

9

c3

E

to

CO

jO>

«

2r

o

w

o

oo

o

^

 S

o

"e

«

8)

1

CQ

1

1

^

 *3

^

^

1

0

E

1

5

I

§

%

JJ

y. J

i

&

A

Is*

 o

1

i

.M,

3

§

O

I!

iCO

'JJE

S 

&

<

c

_g

Q.

o

(A

S

'E

3

o

f

1

 o2

^

1*c

fe

1

tfc

en

£ 

t

^

O

X

tN

^

^J

P^

§

 *-;

tl_!

- §

 o

<u x>

s

^

^

f

<

oT

o

0

*o

12 en

 §

cd"

E

^ 

1

0

c

i-i

1

C4

«fc

en

O, 

3

S

|

X

 '

^

en

^ .^ CQ en

r^ O

<2 0

"O .y S 3

*4> C

1 5

11

c« r£ 3"! '^ ^ C3

S 5=

3 0

ini o

^1

o

1^aT

'1I

£1

1

3o^

*0

£ 

>^

s

^

O (D

O O

E E

o o

11

^ ~* 

99 

o O

X X

i

&

m m

V A

 O ^> O 0

x-^ CX x-^

ex « ex

II

o 

o AVA\/ 

, §

o o

X X

i

X

r-M^1 999 

OOO

9

O

m -M 

99 

OO

r-rs 

99 

O

- =3 s ajg

3

 o 

o

X X

m vo

I . I s

II

-

5

o

X X

I

t

o

<

o o 

m o

HI

r->fs 

99 

OO

I

5.S

g

5

§>

16 A Hydrogeologic Map of the Death Valley Region, Nevada and California, Developed Using GIS Techniques
SUMMARY

A regional hydrogeologic map was constructed 

for the Death Valley region, Nevada and California. 

The study area is characterized by isolated mountain 

ranges juxtaposed against broad, alluvium-filled 

valleys. Geologic conditions are typical of the Basin 

and Range province in which a variety of sedimentary 

and igneous intrusive and extrusive rocks have been 

subjected to both compressional and extensional 

deformation. The regional ground-water flow system 

in the area can best be described as a series of connected intermontane basins, in which ground-water 

flow occurs in valley fill deposits, carbonate rocks, 

clastic rocks and volcanic rocks. Previous investigations have developed more site-specific hydrogeologic 

relationships; however, few have described all the 

lithologic types within the Death Valley regional 

ground-water flow system.

ARC/INFO GIS was used to digitize, manage, 

store and analyze geologic data used to develop the 

hydrogeologic map. ARC/INFO is a vector-based GIS 

system that provides digitizing capability, interactive 

graphics editing, data storage and management, and 

manipulation functions as well as sophisticated overlay 

operators and geographic analysis tools. All digital 

map data entered into this system underwent a series of 

data quality checks to assure data accuracy.

The data acquired for map development included 

existing digital GIS files, published maps, and tabulated data in reports and public-access files. All maps 

requiring digital data entry were digitized following 

methods developed by Seller and others (1990). Once 

in digital formats, regional geologic maps were converted to a common coordinate system and combined 

into one map. The regional geologic map units were 

then reclassified into 10 hydrogeologic units. Each of 

these hydrogeologic units has considerable lateral 

extent and reasonably distinct hydrologic properties. 

Because the hydrologic properties of these units are 

also influenced by depth and degree of fracturing, the 

hydraulic conductivity values of these hydrogeologic 

units can range over 15 orders of magnitude.

REFERENCES CITED

Bacon, Forrest, 1971, California's geologic report complete: 

California Geology, v. 24, no. 6, California Division of 

Mines and Geology, p. 99-103.

Bawiec, W.J., Traudt, O.K., Ambroziak, R.A., and Arndt, 

R.E., 1992, The evolution of a digital geologic coverage From paper to CD-ROM: U.S. Geological Survey Bulletin 2016, chap. E, p. E1-E8.

Bedinger, M.S., Langer, W.H., and Reed, J.E., 1989a, 

Ground-water hydrology, in Bedinger, M.S., Sargent, 

K.A., and Langer, W.H., eds., Studies of geology and 

hydrology in the Basin and Range Province, Southwestern United States, for isolation of high-level radioactive waste Characterization of the Death Valley 

region, Nevada and California: U.S. Geological Survey 

Professional Paper 1370-F, p. F28-F35.

Bedinger, M.S., Langer, W.H., and Reed, I.E., 1989b, 

Hydraulic properties of rocks in the Basin and Range 

Province, in Bedinger, M.S., Sargent, K.A., Langer, 

W.H., Sherman, F.B., Reed, I.E., and Brady, B.T., eds., 

Studies of geology and hydrology in the Basin and 

Range Province, Southwestern United States, for isolation of high-level radioactive waste Basis of characterization and evaluation: U.S. Geological Survey 

Professional Paper 1370-A, p. A16-A18.

Bedinger, M.S., Sargent, K.A., and Langer, W.H., 1989c, 

Studies of geology and hydrology in the Basin and 

Range Province, Southwestern United States, for isolation of high-level radioactive waste Characterization 

of the Death Valley region, Nevada and California: 

U.S. Geological Survey Professional Paper 1370-F, 

49 p.

Cartier, K.D., Peltz, L.A., and Smith, J.L., 1993, Development and documentation of spatial data bases for the 

Lake Tahoe basin, California and Nevada: U.S. Geological Survey Water-Resources Investigations Report 

93-4182, 50 p.

D'Agnese, F.A., Faunt, C.C., Turner, A.K., 1994, Preliminary digital geologic maps of the Mariposa, Kingman, 

Trona, and Death Valley sheets, California, U.S. Geological Survey Open-File Report 94-318, 22 p.

Dettinger, M.D., 1989, Distribution of carbonate-rock aquifers in southern Nevada and the potential for their 

development Summary of findings: Carson City, 

Nev., 1985-88, Program for the study and testing of 

carbonate-rock aquifers in eastern and southern 

Nevada, Summary Report no. 1, 37 p.

Downey J.S., Kolm, K.E., and Gutentag, E.D., 1990, Selection of geohydrologic boundaries for ground-water 

flow models: Waste Management '90', v. 2, Tucson, 

Ariz., p. 725-734.

Eakin, T.E., Maxey, T.E., Robison, G.B., Fredericks, J.C., 

and Loeltz, O.B., 1951, Contributions to the hydrology 

of eastern Nevada: Nevada State Engineers, Water 

Resources Bulletin, no. 12, p. 171.

Eakin, T.E., Schoff, S.L., and Cohen, P., 1963, Regional 

hydrology of a part of southern Nevada A reconnaissance: U.S. Geological Survey Trace Elements Investigations 833, 40 p.

SUMMARY 17
Eakin, T.E., Price, Don, and Harrill, J.R., 1976, Summary 

appraisals of the Nation's ground-water resources 

Great Basin region: U.S. Geological Survey Professional Paper 813-G, 37 p.

Environmental Systems Research Institute, 1992, Understanding GIS the ARC/INFO method: Redlands, 

Calif, Environmental Systems Research Institute.

Goodchild, M.F., 1993, Data models and data quality 

Problems and prospects, in Goodchild, M.F., Parks, 

B.O., and Steyaert, L.T., eds., Environmental modeling 

with GIS: New York, Oxford University Press, 

p. 94-103.

Grose, T.L., 1983, Thirty-two geologic cross sections, Clark, 

Esmeralda, Lincoln, Mineral and Nye Counties, 

Nevada, and adjacent areas in California: Nevada 

Bureau of Mines and Geology Open-File Report 83-13.

Grose, T.L., and Smith, G.I., 1989, Geology, in Bedinger, 

M.S., Sargent, K.A., and Langer, W.H., eds., Studies of 

geology and hydrology in the Basin and Range Province, Southwestern United States, for isolation of highlevel radioactive waste: U.S. Geological Survey Professional Paper 1370-F, p. F5-F19.

Hunt, C.B., and Robinson, T.W., 1960, Possible interbasin 

circulation of ground water in the southern part of the 

Great Basin: U.S. Geological Survey Professional 

Paper 400-B, p. B273-B274.

Hunt, C.B., Robinson, T.W., Bowles, W.A., and Washburn, 

A.L., 1966, Hydrologic basin, Death Valley, California: 

U.S. Geological Survey Professional Paper 494-B, 

138 p.

Jennings, C.W., 1961, Geologic map of California Kingman sheet: California Division of Mines and Geology, 

scale 1:250,000, 1 sheet.

Jennings, C.W., Burnert, J.L., and Troxel, B.W., 1962, Geologic map of California Trona sheet: California Division of Mines and Geology, scale 1:250,000, 1 sheet.

Maxey, G.B., 1968, Hydrogeology of desert basins: Ground 

Water, v. 6, no. 5, p. 10-22.

Mifflin, M.D., 1988, Region 5, Great Basin, in Back, 

William, Rosenshein, J.S., and Seaber, P.R., eds., 

Hydrogeology: Boulder, Colo., Geological Society of 

America, The Geology of North America, v. O-2, 

p. 69-78.

Nebert, D.D., 1989, Review of edgematching procedures for 

digital cartographic data used in geographic information systems (GIS): U.S. Geological Survey Open-File 

Report 89-579, 12 p.

Plume, R.W., and Carlton, S.M., 1988, Hydrogeology of the 

Great Basin region of Nevada, Utah, and adjacent 

states: U.S. Geological Survey Hydrologic Investigations Atlas 694-A, 1 sheet.

Prudic, D.E., Harrill, I.E., and Burbey, T.J., 1993, Conceptual evaluation of regional ground-water flow in the 

carbonate-rock province of the Great Basin, Nevada, 

Utah, and adjacent States: U.S. Geological Survey 

Open-File Report 93-170, 103 p.

Rice, W.A., 1984, Preliminary two-dimensional regional 

hydrological model of the Nevada Test Site and vicinity: Richland, Wash., Pacific Northwest Laboratory, 

SAND83-7466, 44 p.

Snyder, J.P., 1987, Map projections A working manual: 

U.S. Geological Survey Professional Paper 1395, 

383 p.

Seller, D.R., Stettner, W.R., Lanfear, K.J., and Aitken, D.S., 

1990, A user's manual for a method of map scanning 

and digital editing for thematic map production and 

data-base construction: U.S. Geological Survey 

Circular 1054, 38 p.

Stewart, J.H., and Carlson I.E., 1978, Geologic map of 

Nevada: U.S. Geological Survey Map, scale 

1:500,000, 2 sheets.

Strand, R.G., 1967, Geologic map of California Mariposa 

sheet: California Division of Mines and Geology, 

scale 1:250,000, 1 sheet.

Streitz, Robert, and Stinson, M.C., 1974, Geologic map of 

California Death Valley sheet: California Division of 

Mines and Geology, scale 1:250,000, 1 sheet.

Turner, A.K., 1992, Applications of three-dimensional geoscientific mapping and modeling systems to hydrogeological studies, in Turner, A.K., ed., Three-dimensional 

modeling with geoscientific information systems, 

NATO ASI Series C: Dordrecht, The Netherlands, 

Klwer Academic Publishers, Mathematical and 

Physical Sciences, v. 354, p. 327-364.

Turner, R.M., and Bawiec, W.J., 1991, Digital geologic coverage of Nevada A digital representation of the 1978 

geologic map of Nevada: U.S. Geologic Survey Digital 

Data Series 2.

Waddell, R.K., 1982, Two-dimensional, steady state model 

of ground-water flow, Nevada Test Site and vicinity, 

Nevada-California: U.S. Geological Survey WaterResources Investigations Report 82-4085, 77 p.

Winograd, I.J., and Thordarson, William, 1975, Hydrologic 

and hydrochemical framework, south-central Great 

Basin, Nevada-California, with special reference to the 

Nevada Test Site: U.S. Geological Survey Professional 

Paper712C,p. C1-C126.

18 A Hydrogeoiogic Map of the Death Valley Region, Nevada and California, Developed Using GiS Techniques

U.S. GOVERNMENT PRINTING OFFICE: 1997 - 673-263 / 32009 REGION NO. 8