GEOLOGICAL SURVEY CIRCULAR 235 

SODIUM CARBONATE BRINE AND 

TRONA DEPOSITS IN SWEETWATER 

COUNTY, WYOMING 

UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

GEOLOGICAL SURVEY CIRCULAR 235 

SODIUM CARBONATE BRINE AND TRONA DEPOSITS IN 

SWEETWATER COUNTY, WYOMING 

By H. B. Lindeman 

Washington, D. C., 1954 

Free on application to the Geological Survey, Washington 25, D. C. 
0 Heleno 

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0 Billings 

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salt Lak~ ~--- -r -----------------·-

100 

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100 Miles 

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Figure 1. --Index map showing location of area of sodium carbonate brine and trona deposits, Sweetwater County, 

Wyo. 
SODIUM CARBONATE BRINE AND TRONA DEPOSITS IN 

SWEETWATER COUNTY, WYOMING 

By H. B. Lindeman 

Page 

Introduction•••••••••••••••••••••••••• 1 

Acknowledgments....................... 3 

Brine............... . . . . . . . . . . . . . . . . . . 3 

Green River area. • • • • • • • • • • • • • • • • • • • 3 

Eden area. • • • • • • .• • • • • • • • • • • • • • • • • • • • 3 

CONTENTS 

Brine--Continued 

Westvaco area •••••••••••••••••••••• 

Trona deposits ••••••••••••••••••••••• 

Economic factors••••••••••••••••••••• 

Page 

6 

6 

8 

Literature cited..................... 10 

ILLUSTRATIONS 

Page 

Figure 1. 

2. 

Index map showing location of area••••••••••••••••••••••••••••••••••••••• Facing 1 

General map showing relationship of prospected or developed sodium 

carbonate brine wells and trona deposits............................... 2 

3. 

4. 

5. 

Sodium carbonate brine wells, Grea~ River area........................... 4 

Sodium carbonate brine wells, Eden area•••••••••••••••••••••••••••••••••• 5 

Sodium carbonate brine wells and trona deposits, Westvaco area........... 7 

6. Generalized sections from well-log data•••••••••••••••••••••••••••••••••• 9 

INTRODUCTION 

This report presents a short review of 

the historical background, the more irnpor-· 

tant physical and chemical aspects, and some 

of the factors which may affect development 

of the sodium carbonate brines and trona 

deposits known to exist underground in 

Sweetwater County, Wyo. The area (fig. 1) 

lies in the southwestern part of the State 

and extends westward from the town of Green 

River for a distance of 20 miles and north-

\>.'ard for 35 miles. By higm1ay, the area is 

about 175 miles northeast of Salt Lake City, 

'C'tah; about 310 miles 1-rest of Cheyenne, Wyo.; 

and about 225 miles southeast of Pocatello, 

Idaho. Not all of the area is knorm to be 

underlain by brines or trona deposits, but 

to the date of this report they had been 

found at the locations shown on figure 2. 

The sodium carbonate brines occur at 

the town of Green River and near Eden, north 

of Green River, and sodium carbonate brines 

1 

and thick beds of the mineral trona 

(Na2C03•NaHC03•2H20) occur northwest of 

Green River. 

Deposits of sodium salts, whose existence in 't-~Jyoming was known in pioneer times, 

have been described by Chatard ( 1890), r1hose 

bulletin also contains an excerpt from a 

paper (vleeks, 1886) on glass-making materials and related soda deposits. The deposits discussed are dr,y or partly dr.y surface 

lakes and can, for the most part, be considered as sodium sulphate. A bulletin by 

Schultz (1909) on these and other deposits 

also contains a de~cription of sodium brines 

from wells drilled at the town of Green 

River. The geology has been further described by Sears and Bradley (1924). 

In the past 16 years brine deposits, 

in addition to those mentioned in the preceding paragraph, have been found, and 
25 N 

110W 109 108 105 104W 

24 

N 

22 

21 

20 

17 

111 w 110 106 105W 

16 N 

Townships are numbered north and west from the 6th Principal Meridian 

5 0 20 Miles 

Figure 2. --General map showing relationship of prospected or developed sodium carbonate brine and trona areas, 

. Sweetwater County, Wyo. 

2 
trona deposits have been discovered, part~ 

prospected, and partly developed in the area 

(Romano, 19.52) • Prospecting and developnent 

have proved the trona deposits to be of such 

remarkable quality, thickness, and extent as 

to constitute a major commercial mineral 

resource. Further prospecting and development of the brines will be necessary to 

establish their degree of economic importance. 

ACKNOWLEDGMENTS 

The writer is indebted to officials of 

the Union Pacific Railroad Co., Intermountain Chemical Corp., and the Wyoming Trona 

Corp. for making available certain information contained in this report. 

BRINE 

Brine is found at three localities 

(fig. 2) and further prospecting may prove 

its presence in adjacent areas. The three 

areas known to have potential producing 

characteristics are Green River (figs. 2, 3), 

Eden (figs. 2, 4), and Westvaco (figs. 2, .5). 

The Westvaco area also contains beds of the 

l'l".ineral trona. 

Green River area 

Before World War I, brine was discovered near the town of Green River (fig. 3). 

Brine pwnped from 13 wells drilled in the 

vicinity by the Western Alkali Corporation 

and Associates yielded sodium carbonate 

which was used in a local plant (Schultz, 

1909). None of these wells was drilled to 

a depth greater than 300 feet. 

In December 193.5 a well (MFS 1, £ig. 3) 

was drilled to a depth of 439 feet (fig. 6) 

in the Green River area by the Mountain Fuel 

Supply Co. A sample o£ brine {sp gr 1.046) 

from a depth of 162 feet was analyzed by the 

U. S. Geological Survey as follows: 

Gral'l"..s 

per liter 

Constituents: 

co3 ----------- 17.76 

HC03----------- .5.09 

Cl------------- 10 • .59 

s~------------ .78 Ca------------- 0 

¥~------------- .02 K-------------- .16 Na------------- 22.72 

B-------------- ----- Total----- .57.12 

Percent 

31.00 

8.90 

18.50 

1.38 

.03 

.28 

39.91 

Trace 

-

100.00 

3 

Conventional 

combinations: 

Grams 

per liter 

Na2co3-------- 31.3.5 

NaHC03-------- 6.97 

NaCl---------- 17.4.5 

Na2so4-------- .8.5 

MgS04--------- .12 

K2S04--------- ~ 

Total--- .57.09 

Eden area 

Percent 

.54.9.5 

12.20 

30 • .54 

1.49 

.21 

____&! 

100.00 

In 1938 soda brine was found at a depth 

of 4.50 to .500 feet in a well (John Hay, fig. 

4) being drilled for 'tvater near Eden. The 

brine was cased off and the well was deepened to a fresh-water producing aquifer. As 

a result of the inform tion thus obtained, 

the Wyoming Trona Corp. drilled a well in 

1949 (no. 1, fig. 4) for the purpose of testing the quality and quantity of the brine. 

At 477 feet the brine had sufficient artesian pressure to force it from a 4-inch pipe 

for a distance of approximately" 3 feet. 

After about 30 minutes the now diminished 

to an estimated 40 gallons per minute. The 

follow :ing analy"ses (in percent) of brine 

from this well were made by the U. S. 

Geological Survey: 

Sample 

Na2co3-------------- NaHC03--------------

Cl------------------

S04-----------------

Ca------------------

Mg------------------ K20-----------------

1 

3.68 

1.44 

.017 

.003 

.ooo 

.001 

.023 

2 

4.20 -

• 73 

.018 

.002 

.oo8 

.OOJ 

.o.5o 

Time taken (a.m.) -- 9 .3r;!/ 9 .3.5 

Date -------- Sept. 1, 1949 Sept. 1, 1949 

Depth (feet) ------- 477 477 

Color -------------- Brown Amber 

Specific gravity at 

2.5° c ------------- 1.0480 

!/ Taken imrnedia tely after opening 

valve for testing. 
I 

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J¥~ 

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----14---· --

1 N 

GREEN RIVER 

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MFS 1

0 

1 

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1 

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T. 18 N., R 107 W., 6th P.M. 

1000 0 

Wells I - 13 drilled by Western Alkali Corporation and Associates 

Well MFS I drilled by Mountain Fuel Supply Company 

Figure 3.--Sodium carbonate brine wells, Green River area, Sweetwater County, Wyo. 

4 
t 

24 

N. 

T. 

23 

N. 

R.107 W. R.I06W. 

• EDEN 

24 19 20 21 22 

N 

25 30 29 28 27 

1 

36 31 32 33 c. 34 

""' 

1 6 

0 

1 

5 John Hoy ~ 3 

02 

o.3 

12 7 8 9 ~ 

o6 

05 18. 17 16 15 

04 

24 19 20 21 22 

John Hoy Welt drilled by John Hoy 

Wells 1-6 drilled by Wyoming Trona Corporation 

5000 0 5000 Feet 

Figure 4. --Sodium carbonate brine wells, Eden area, Sweetwater County, Wyo. 

5 
Before March 1952 six wells had been 

drilled in the area (fig. 4) by the Wyoming 

Trona Corp. and brine was found in all wells 

at deptl:s of 400 to 600 feet (fig. 6). There 

was an artesian flow of brine from several 

of the wells, but their productive capacity 

had not then been fullY determined. 

A dark substance found in some of tls 

brine from these wells appears to come from 

a zone a few feet above the zone which contains the more abundant amber-colored brine. 

The exact stratigraphic location of the 

dark brown- and amber-urine zones has not 

been definitelY established. An analysis 

of the dark-colored brine ( sp gr 1.055) 

from the no. 1. well (fig. 4) was made by 

the Geological Survey with the following 

results: 

Grams 

per liter 

Solids (total dissolved at 180°)-- 70.01 

Sodium carbonate (alkalinity)----- 47 .o5 

Organic acids (organic matter)!/-- 7.70 

Westvaco area 

In 1944 the Westvaco Chlorine Products 

Corp., now tiE Intermountain Chemical Corp. 

drilled its nos. 1 and 2 wells in the West-' 

vaco area (C, D, fig. 5) for the purpose of 

testing the commercial possibilities of the 

brine and also to test the trona deposits 

lying about 800 feet below the brine horizon (fig. 6). Neither well could be made 

to produce more than 10 gallons of brine a 

minute and further testing was abandoned in 

favor of mining the trona beds. In several 

other wells drilled to test the trona beds 

in the area sodium carbonate brine was fomrl 

about 700 feet below the surface. Analyses 

of these brines are not available. 

TRONA DEPOSITS 

In January 1938 an oil test, John Hay 

no. 1 (N, fig. 5) drilled by the Mountain 

Fuel Supply Co. in the Westvaco area, 

resulted in the discovery of the first 

trona to be found at depth. Identification 

of the mineral was made by the Geological 

Survey in core samples, the occurrence being made public in several reports (Mendenhall, 1940; Smith, 1942; Harness and Coons, 

1942). Northup~te, pirssonite, and gaylussite were also found and, in addition, two 

new minerals, shortite (Na2co3.2Caco3) and 

bradleyite (Na3Poh•MgC03), were discovered 

(Fahey, 1939, 1941). 

!/ Complex naphthenic and resin acid s~ltsbp~obab~v formed by reaction of alka- lme rme with petroleum. 

6 

As a result of this trona discovery, 

several companies became interested in the 

Westvaco area. Before March 1952 these . companies had drilled the following 10 test 

holes and obtained samples of trona from 

them: Mountain Fuel Supply Co., John Hay 

no. 1; Westvaco Chlorine Product Corp. (now 

Intermountain Chemical Corp.), Westvaco 

nos. 1, 3, and 4; Union Pacific Railroad, 

nos. 1, 2, 3, and 4; and Potash Comp~ of 

America, nos. 1 and 2. Two other wells, 

Union Pacific Railroad no. 5 and Westvaco 

no. 2, were not drilled deep enough to 

penetrate the trona deposits. 

All of the wells (fig. 5) which were 

drilled to the necessary depth penetrated 

beds of trona as much as 11.6 feet in thickness in the Green River fonnation. The 

thick beds usually u1clude a few minor shale 

bands. Each well, with the exceptions noted 

previously, penetrated at least 1 trona bed 

of minable thickness. Since most of the 

wells penetrated more than 1 minable bed, it 

is believed tha. t well logs which show only 1 

may be inaccurate because of solution of the 

trona during the drilling process. For this 

report the use of actual well and shaft logs 

was not admissible and wells in the Westvaco 

area are represented by a generalized log 

(fig. 6). Four well logs show only 1 bed of 

trona while the other logs show from 3 to ll 

beds, each 1 foot or more thick, separated 

by strata of shale of vacying thickness. 

The trona beds shown in each log do not correspond to the other beds in thickness, purity, or elevation. Prospect holes are 

widely separated, and ~~ere ha~ not been a 

sufficient number drilled to demonstrate the 

continuity of any one trona bed or to determine possible areas where there may be so 

maqy shale bands in the trona bed as to discourage mining. 

In 1946 and 1947 visual information 

concerning the strata and deposits was 

obtained when the Westvaco Chlorine Products Corp. sank its no. 1 shaft (A, fig. 5). 

(See Romano, 1952) • The shaft was put down 

to a depth of 1,550 feet, 5o feet below a 

10-foot bed of trona, the thickest found at 

that location. Several beds of trona were 

found in the shaft, but only the 10-foot 

bed and two others within a distance of 200 

feet above it are of possible commercial 

importance. A detailed stratigraphic section of the shaft is not available for 

inclusion in this report. 

In the mine the upper 3 to 4 feet of 

the 10-foot bed is found consistently to 

contain several bands of shale, the thickest about 3 inches, and mining is confined 

to the part below tre shale bands. Roof 
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10,000 o 20,000 Feet 

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EX PLANATION 

Shafts • 

A- Westvaco no. I 

B- Westvaco no. 2 

0 

Wells 

C- Westvaco no. I 

0-Westvaco no. 2 

E- Westvaco no. 3 

F- Westvaco no. 4 

G -Union Pacific R.R. no. I 

H -Union Pacific R.R. no. 2 

I -Union Pacific R.R. no. 3 

J -Union Pacific R.R. no. 4 

K-Union Pacific R.R. no. 5 

L -Potash Co. of America no. I 

M'-Potash Co. of America no. 2 

N-John Hoy no. I 

Figure 5.--Sodi\D!l ca.rbcmate brine wells and trona_deposits, Westvaeo area., Sweetwater County, Wyo. 
support in the workin6s is obtained by bolting the upper 3 to 4 feet of interspersed 

trona and shale to the overlying stratum. 

The trona bed varies in thickness within 

narrow limits throughout the mine and lies 

relatively horizontal on a bed of low-grade 

oil shale. Water has been found in small 

quantities in the mine workings where crevices infrequently occur. A relatively small 

area has been found in the course of mine 

development where the bed contains so maQY 

shale bands that mining is uneconomical. 

Except for initial shaft developrrent, mining 

has been neither difficult nor excessively 

costly. Shaft no. 2 (B, fig. 5) for orehoisting purposes was recently completed at 

a point 1,100 feet west of shaft no. 1 and a 

solution refiner,y for the production of soda 

ash has been built at the mine site. 

The followmg approximate analysis of 

the trona ore was furnished by the Intermountain Chemical Corp.: 

Percent 

Na2C03-------------------- 45.30 

NaHC03-------------------- 35.90 

01------------------------ .09 

S~----------------------- .OJ 

Fe------------------------ .05 

Si02---------------------- 1.10 

Comoined water------------ 15.40 

Insolubles -------Y J.50-15.oo 

The insoluble fraction in the above analysis 

is composed of the following compounds, with 

approximate percents: 

Percent 

Si02---------------------- 27.0 GaO----------------------- 18.0 

MgO----------------------- 1).0 

C02----------------------- 25.0 

R203---------------------- 6.0 

K20----------------------- 4.5 

Fe203--------------------- 1.8 

Organic------------------- 2.0 

The crude ore generally is light amber in 

color. 

If it is assumed that all of the area 

within the dotted line on figure 5 contaL~s 

at least one minable bed of trona having a 

minimum thicla1ess of 7 feet, then an estimated 125 million tons of ore is contaL."l.ed 

within the bounds of that line. Also, if it 

may be assumed that a min:i..l'flUJl1 thic!mess of 

Jl feet of minable trona is contained in a 

second bed in that same area, th~n an additional 60 million tons of ore is available. 

The area is bounded by test wells tln t shmv 

JOi. Depends on the amount of contained 

sha • 

8 

one or more minable trona beds v.rhich probably extend for a consinerable distance outside the enclosed area$ The Potash CompaQY 

of America drilled its no. 2 well (M, fig. 5) 

at some distance east of the area first prospected, and a minable bed of trona t.;as found. 

ECONOMIC FACTORS 

The deposits are favorably situated 

with respect to most of the factors which 

may influence their development: other 

basic mineral resources, transportation, 

fuel supplies, and water. Although not so 

near to markets as might be desired, the 

deposits are not unfavorably located in 

that respect. 

The railroads, high~rays, main streams, 

land subdivisions, and wells are shown on 

the general map of the trona and brine 

region (fig. 2). The main line of the Union 

Pacific Railroad traverses the southern part 

of the area and divides near the western 

edge to form the Oregon Short Line Branch. 

U. S. Highway 30 also traverses the southern 

part of the area. Coal is available fron 

the neighboring Rock Springs and Kemmerer, 

W,yo., coal fields, and natural gas is produced from the Baxter basin and Church 

Buttes fields nearby in southwestern Wyoming. 

Precipitation in the area is slight, 

and, because of low humidity and prevailing 

strong winds, conditions should be favorable 

for concentration of brines by solar evaporation. The Green River and its tributaries Blacks Fork and Sandy Creek are within . 

or near the area (figs. 2, 5) and the water 

may be made available for industrial use. 

A considerable amount of oil shale, 

some of good quality, lies above, between, 

and below the trona beds. The log of the 

Union Pacific Railroad no. 2 well refers to 

a thin bed of gilsonite, and other logs shO"w 

the presence of bentonitic shales. The 

potash-bearing rock wyomingite is abundant 

in surface deposits near Rock Springs, Wyo. 

Extensive phosphate deposits exist a short 

distance to the west, in western Wyoming and 

eastern Idaho., where the phosphate industr.v 

is now well established. Important deposits 

of potassium, sodium, and magnesium salts 

are found in Utah. Ferrous and nonferrous 

smelting industries using ores produced 

locallY are established in Utah and Colorado. 

A large part of the area containing the 

trona beds is owned by the Union Pacific 

Railroad. In general, the railroad owns 

ever,y odd-numbered section (square mile) for 

20 miles on each side of its right-of-way 

and the State has title to sees. 16 and )6. 
Eden 

a reo 

o' 0 0 0 0 

0 oo .!./1..0 

--

:.....·_:_. 

500' 

1000' 

1500' 

Green River 

Shale: sandy, gray, 

green, brown; 

minor sandstone 

Artesian 

brine 

area 

Lime shell 

2--:-~ Shale: sandy 

Westvaco 

area 

·~:;:::: Shale: sandy, gray, 

"""-'----· green, brown; 

minor sandstone 

Sandstone; shaly 

sandstone; brine 

.' ·.~~ Shale: sandy, green, 

.-:-. brown, gray; trona 

and shortite crystals; oil shale 

Trona beds 

Shale; oil shale; 

trona and 

shortite crystals 

Figure 6. --Generalized sections from well-log data. sodium carbonate brine and trona deposits~ Sweetwater 

County~ Wyo. 

9 
Some of the land in the rema.ini.."lg 16 sections in each township has passed from 

Federal ownership. Leasing of Federal land 

has already yielded a substantial income 

from rentals and royalties. 

Minable trona was found in the easternmost well (M, fig. 5) several hundred feet 

above the elevation at which it was found 

in the other wells in the area. This fact 

gives rise to the speculation that further 

geologic investigation or drilling ~ 

indicate that trona beds can be reached at 

a shallower depth in the vicinity of the 

to'Wll of Green River. 

Sodium carbonate, or its chief manufactured product, soda ash, is a basic chemical having wide application in industr,y. 

If the deposits are considered in relationship to the other minerals found in the 

surrounding territory it may be inferred 

that resources exist which could result in 

the growth of an extensive chemical industry 

in this part of the United States • 

LITERATURE CITED 

Chatard, T. M., 1890, Natural soda--its 

occurrence and utilization: u. s. 

Geol. Survey Bull. 60, p. 27-101. 

Fahey, J. J., 1939, Shortite, a new carbonate of sodium and calcium: Am. Mineralogist, v. 24, no. 8, •p. 514-518. 

1941, Bradleyite, a new mineral, 

-sc:xiium phospha. te-magnesium carbonate, 

with X-ray analysis by George Tunell: 

Am. Mineralogist, v. 26, no. 11, p. 

646-650. 

Fahey, J. J., and Axelrod, J. M., 1950, 

Searlesite from the Green River formation of Wyoming: Am. Mineralogist, 

v. 35, nos. 11-12, •P· 1014-1020. 

Harness, C. L., and Coons, A. T., 1942, 

Sodium carbonate: U. S. Bur. Mines Inf. 

Circ. 7212. 

Mendenhall, W. c., 1940, Occurrence of a 

deposit of trona: Science, new ser., 

v. 91, no. 2349, p. 11-12. 

Romano, C. A., 1952, Trona in southwestern 

Wyoming: Colorado School of Mines, The 

Mines Magazine, v. 42, no. 3, p. 69-70. 

Schultz, A. R., 1909, Deposits of sodium 

salts in Wyoming: U. S. Geol. Survey 

Bull. 430-I, p. 570-589. 

Sears, J. D., and Bradley, W. H., 1924, 

Reiations of the Wasatch and Green River 

formations in northwestern Colorado and 

southern Wyoming, with notes on oil 

shale in the Green River formation: 

U. S • Geol. Survey Prof. Paper 132-F, 

p. 93-107. 

10 

Smith, H. I., 1942, Trona in Wyoming: 

Am. Inst Min. Met. Eng. Tech. Pub. 

1489. 

Weeks, J. D., 1886, Glass materials: 

Min. Res. U. S., 1885, p. 550-555. 

INT.-DUP. SEC., WASH., D.C •• 5'14 814