Saline Minerals of the 

Green River Formation

GEOLOGICAL SURVEY PROFESSIONAL PAPER 405
Saline Minerals of the 

Green River Formation

By JOSEPH J. FAHEY

With a section on

X-RAY POWDER DATA FOR SALINE MINERALS OF THE GREEN RIVER 

FORMATION

By MARY E. MROSE

GEOLOGICAL SURVEY PROFESSIONAL PAPER 405

A study of the mode of occurrence of the 

saline minerals, their paragenetic 

relationship, and the economic importance 

of the trona

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1962
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEW ART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C.
CONTENTS

Abstract. _________________________

Introduction- ___--_-______----_-__

Location. ___--__-_____-_---__-

Exploration- _--_-____-_-_-____

Acknowledgments. ____ _ ____________

Drill core of the John Hay, Jr., well !_ 

Description ___________________

Continuity.. _ _________________

Mining operation. -_-_____--_____-_

Development of mine. _________

Soda ash __ _________-___-_--

Rocks containing the saline minerals. 

Definition __ _ ________________

Selection of samples _ _ -_-__-__

Chemical analysis _ _ _ ________________

Spectrographic analysis. __-_-_-________

Particle size. _ ________________________

Mineral analysis.. _-__-_-_-__-____-___

Organic matter. ______._...____.______

Saline minerals. __________________________

Distribution___________.__ ____________

Shortite. _ -_---__-____---____________

Name of mineral __ ______________

Occurrences. _____________________

Crystallography __________________

Optical and physical properties. ____

Chemical properties _ _ ___________

Spectrographic analysis. __ _________

Industrial use. ___________________

Genesis. _ ________________________

Composition of sediments. _____

Compaction of sediments. 

Flow lines. __________________

Size of crystals. _-_-_____.____

Consolidated shortite aggregate. 

Pyrite inclusions.... __________

Temperature of formation. 

Trona. ______________________________

Occurrences. __ ___________________

Crystallography. _________________

Optical and physical proper ties. -___ 

Chemical properties .---__-________

Spectrographic analysis _ _ ________

Industrial use. __---___-__________

Nahcolite.. . _________________________

Name of mineral. _.__--______-.__

Occurrences. _____________________

Optical and physical properties. 

Chemical properties.. _____________

Spectrographic analysis _ . ________

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Saline Minerals Continued

Northupite __ __________________

Occurrences. __ __--_----_-__--

Crystallography ______________

Optical and physical properties. 

Chemical properties.__________

Spectrographic analysis. _______

Genesis. ______.____.-_____-_.

Bradleyite _____._-.-_--_-_-____-.

Name of mineral.____---_____- 

Occurrences. __-_----------__-

Optical and physical propertiesChemical properties. ___._____.

Spectrographic analysis_______-

Pirssonite... _._________-_---_-__-

Name of mineral.____________

Occurrences. ______--___--_---

Crystallography --------------

Optical and physical propertiesChemical properties. __________

Spectrographic analysis......--

Gaylussite. ________--_---_-_____-

Name of mineral__.__-___-.- 

Occurrences.. . __-_-_-_-_____-

Crystallography _----------__-

Optical and physical properties.

Chemical properties.-__-_-__--

Spectrographic analysis...

Paragenesis of the saline minerals_-__-_-

Gosiute Lake__._-____-______.--

Shortite to northupite._-______-__-

Shortite to pirssonite to northupite.. 

Shortite to pirssonite._____________

Shortite to gaylussite to northupite . 

Shortite to gaylussite._____________

Shortite to trona plus dolomite.___. 

Trona to northupite...------------

Shortite to bradleyite_____--_----_

Main trona bed.___________-_-_-____--

Areal extent.______---_---_-__---------_-----_

Composition. _ ________-___-____-----_._-_------

Chemical.____-__-____--___-_--_-_-____-___

Mineralogical. _____________________________

Organic matter.____________________________

Length of time of deposition. ________._.________-_-_-

X-ray powder data for the saline minerals of the Green 

River formation, by Mary E. Mrose. _______________

Experimental techniques_______________________

Literature cited.______________-_______----_-____--__

in

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IV CONTENTS

ILLUSTRATIONS

Page

FIGURE 1. Index map showing location of the Green River formation in Wyoming, Colorado, and Utah----__---______-__ 2

2. Locations of exploratory wells and the Westvaco mine, Sweetwater County, Wyo____----_______-______-_-___ 4

3. Photograph of a working face in the Westvaco mine_ ____________________________________________________ 12

4. Closeup of face in figure 3_-_________________________-___-_--_-----_---_----------__-__-_-__--________ 13

5. Photograph of buildings of the Westvaco mine______________-_-_-_-____-_---__-_-_______-_____-_-_______ 13

6. PCo2 -T diagram of the system Na_COrNaHCOrH20__ ------.---------------- ------------- -_---_____ 19

7. Histogram showing the percentages of shortite, trona, and northupite in the John Hay, Jr., well 1_--_________- 20

8. Diagrammatic representation of the pragenesis of six saline minerals- -_--_-____________-__--__----_----____ 21

9. Photomicrograph of the sequence shortite to bradleyite_--------_------------_-_------------------------_- 22

10. Photograph of bradleyite on low-grade oil shale_______-____-_-______---__-__________-----__-_------___-_ 22

11. Authigenic crystals of bradleyite_____________________________________________________________________ 22

12. Crystals of shortite. _-_-_-_______ __________________________________________________________________ 23

13. Large crystals of shortite in place__-_____-____---------------_-------------_-----------------------_--- 23

14. Photomicrograph showing flow lines around pseudomorphs after shortite__-_-______-__-_____--_-_-_--_____ 25

15. Photomicrograph showing flow lines around pseudomorphs after shortite____________________________________ 26

16. Polished section showing crystals of shortite cutting bedding____________-___________________--_-----______ 26

17. Photomicrograph showing crystals of shortite in matrix showing no bedding.________________________________ 26

18. Photomicrograph of massive shortite-___ _ ________ _ _- __-______-_______-______-_-__---_----______ 27

19. Photomicrograph of large crystals of shortite____________________________________________________________ 27

20. Photograph of pearly-white trona___________________-_____-___---__--__--_-_-___-_-_-_-__-_-------_____ 29

21. Photograph of radiating crystals of trona_______________________________________________________________ 29

22. Photomicrograph of interlocking crystals of trona_____________-_-___---_-_-___-----_---_____---------___- 29

23. Photograph of nahcolite_______________________________________________________________________ _ ______ 31

24. Photograph of euhedral crystal of northupite____-__-_-_-______-____-_-------_-----_-_.--_-------_-_-_-__ 32

25. Photomicrograph showing the symmetry of northupite_________-_-_______-._-______________-_-----_--_____ 33

26. Photograph of northupite with oolitic structure...------------------------------------------------------- 33

27. Photomicrograph of northupite with oolitic structure..--- --------------------------------------------- 33

28. Photomicrograph of liquid inclusion with gas and solid phase. ______-__--_-_-----_-____--_-------_--__-__ 33

29. Photomicrograph showing northupite replacing dolomitic shale. -___-______-_________--_____ _ - _____ 34

30. Phase-equilibrium diagram of the system Na2 CO3 CaCOs H2 0__________________________________________ 37

31. Photomicrograph showing sequence shortite to northupite-__________-_____-_---__ _ -_ _----- -______ 39

32. Photomicrograph showing sequence shortite to pirssonite to northupite-____________________________________ 40

33. Photomicrograph showing sequence shortite to pirssonite-________________________________________________ 40

34. Photomicrograph showing sequence shortite to gaylussite to northupite_____________________________________ 41

35. Photomicrograph showing sequence shortite to gaylussite____--_____-___--_ -------__-_ ----- --------- 41

36. Photomicrograph showing sequence shortite to trona_-______-_----_-____-_________-_-___ _- -_-_-___-__ 42

37. Photomicrograph showing sequence trona to northupite-- ___________________________ _ ____________ _ _____ 42
CONTENTS V

TABLES

Page

TABLE 1. Production figures and value of soda ash produced in the United States from 1948 through 1957.______________ 13

2. Color of samples from the drill core of the John Hay, Jr., well 1 matched to Robert Ridgway's Color Standards and

Nomenclature, ___ __________________________________________________________________________________ 14

3. Chemical analyses of samples from the drill core of the John Hay, Jr., well l_________-___--_-_________-_-_-_ 15

4. Quantitative speetrographic analyses for minor elements in samples from the drill core of the John Hay, Jr., well 1_ 15

5. Particle-size analysis of 14 samples of oil shale from the drill core of the John Hay, Jr., well l____________-_____ 16

6. Semiquantitative estimation, by means of X-ray diffraction patterns, of the minerals present in the clay and silt

fractions of samples from the John Hay, Jr., well l_______-_________-_____---_______-__----____-_--_____ 16

7. Solubility in hydrochloric acid of the clay, silt, and sand fractions of samples from the drill core of the John Hay,

Jr., well !-____-______________-__________________________________________ ___________.._..__.__ 17

8. Optical and physical properties of the saline minerals________________-___-__-_________-__-_--___--___--___ 24

9. Chemical analyses of shortite, pirssonite, gaylussite, and northupite from the John Hay, Jr., well 1._____________ 24

10. Speetrographic analyses of saline minerals from the Green River formation from the John Hay, Jr., well 1_______ 24

11. Chemical analyses of trona and nahcolite____--___________________-______---____--__--------------------_ 30

12. The tonnage of soda ash used in 1957 by industries in the United States.- __________________________________ 30

13. Chemical analyses of bradleyite----____________________________________________-___--_-_-_-_-_-_-_----_ 35

14. Speetrographic determination of lithium in channel samples from each foot, top to bottom, of the main trona bed at

locations C and D, about 500 feet apart.____________________________-______________--_--__-_-_-_-----_ 43

15. Chemical analysis of channel samples of each foot from top to bottom of the main trona bed at locations A and B,

about half a mile apart--__----____-______-_____________-__-____________________----------__--------- 43

16. Density and composition of bulk samples from the top, middle, and bottom of the main trona bed at locations E

and F, about a quarter of a mile apart_-__-______________-____________-_-___----_-_--------_-_-------- 44

17. Length of time of deposition of the trona bed, based on the percentage of water-insoluble material in the vertical

section. ___________________________________________________________________________________________ 45

18. X-ray powder data for shortite, Na2Ca2 (CO3)3, from the John Hay, Jr., well l____________--_-_--__-------____ 46

19. X-ray powder data for trona, Na3H(CO3)2-2H2 O, from the John Hay, Jr., well l______________-__-_-------_-_ 46

20. X-ray powder data for nahcolite, NaHCO3 , from the oil shale mine of the Bureau of Mines, near Rifle, Colo__-__ 47

21. X-ray powder data for northupite, Na3 MgCl(CO3) 2 , from the John Hay, Jr., well !______.____________________ 47

22. X-ray powder data for bradleyite, Na3 Mg(PO4 ) (CO3), from the Westvaco mine, Sweetwater County_-_--______ 48

23. X-ray powder data for pirssonite, Na2Ca(CO3 ) 2 -2H2O, from the John Hay, Jr., well 1_________________________ 48

24. X-ray powder data for gaylussite, Na2Ca(CO3) 2 -5H2O, from the John Hay, Jr., well l______________________--_ 49

SALINE MINERALS OF THE GREEN RIVER FORMATION

By JOSEPH J. FAHEY

ABSTRACT

A mineralogical study was made by the U.S. Geological Survey 

of the drill core from the John Hay, Jr., well 1, in Svveetwater 

County, Wyo., about 18 miles west of the City of Green River. 

The well penetrated the Wilkins Peak member of the Green 

River formation of early and middle Eocene age. This study, 

begun in 1939, revealed a unique assemblage of carbonate minerals in a fine-grakred dolomitic marlstone tha,t ranges in content 

of organic-matter from about 1 to 30 percent. The investigation also established the presence of an economically important 

bed of trona about 10 feet thick, and subsequent drilling showed 

it extended over an area of at least 60 square miles. As a 

result of this disclosure the Westvaco mine was opened in 1947; 

by 1957 it was delivering about two-thirds of the natural soda 

ash produced in the United States.

The distribution of the six saline minerals shortite, trona, 

northupite, pirssonite, gaylussite, and bradleyite that are present in large quantities in the Wyoming area of the Green River 

formation, was first shown in the log of the drill core of the 

John Hay, Jr., well 1. A seventh saline mineral, nahcolite, is 

present in quantity in the Uinta Basin of Utah and the Piceance 

Creek basin of Colorado.

Shortite (Na2CO3 -2CaCO3 ) was first found in the core of the 

John Hay, Jr., well 1. It is present in this well between depths 

1,251 feet and 1,806 feet 6 inches, a vertical distance of 555 

feet 6 inches. Shortite marks the saline zone, within which, 

and only within which, the other five saline minerals are found. 

It constitutes a visually estimated 10 percent of this saline zone.

Trona (Na2CCyNaHCO3 -2H2 O), the next most abundant of 

the saline minerals, was found between depths of 1,300 feet and 

1,665 feet and makes up in volume about 9.7 percent of this 

interval; which is equivalent to 6.4 percent of the saline zone. 

The trona is concentrated chiefly in four strata, the approximately 10-foot main bed, the bottom of which is at a depth of 

1,600 feet 4 inches, and constitutes the ore body of the Westvaco mine; a 2-foot 3-inch bed at a depth of 1,619 feet 9 inches; 

a 4-foot bed at 1,646 feet; and a 6-foot 1-inch bed, the bottom 

of which is at a depth of 1,659 feet 3 inches.

The areal extent of the trona is estimated to be as much as 

2,000 square miles. How much of this is suitable for economic 

exploitation must remain unknown until many more test holes 

have been put down. The known area of the trona bed that is 

currently being mined at Westvaco is about 60 square miles, 

from which can be produced more than 650 million tons of soda 

ash.

Northupite (Na2CO3 -MgCO3 -NaCl) is the saline mineral that 

is third in abundance in the Wilkins Peak member at the site of 

the John Hay, Jr., well 1. It occurs between the depths 1,327 to 

1,560 feet and occupies 5.2 percent of this interval, which is equivalent to 2.2 percent of the saline zone that is marked by the 

presence of shortite. Crystals of northupite are rarely found; it 

usually occurs massive, filling cracks and vugs in the shale.

Nahcolite (NaHCO3 ) is present in great quantities in the shales 

of the Green River formation of Colorado and Utah, but it has 

been found only once in the Wyoming area, and that was as tiny 

crystals in a small crack in the shale. At Rifle, Colo., at the site 

of the oil shale mine of the U.S. Bureau of Mines, it is found in 

lenses, some of which are more than 10 feet across. In Utah, 

nahcolite occurs associated with shortite.

Bradleyite (Na3PCyMgCO3), like shortite, was first found in 

the drill core of the John Hay, Jr., well 1. It occurred at a depth 

of 1,342 feet 10 inches in intimate association with clay and 

shortite. During the sinking of the No. 1 shaft of the Westvaco 

mine, bradleyite was found in low-grade oil shale at a depth of 

1,245 feet, and later tiny crystals were recovered from the residue 

obtained when samples of trona from the main trona bed of the 

Westvaco mine were leached.

Pirssonite (Na2CO3 -CaCO3 -2H2O) is present between depths 

of 1,310 and 1,391 feet in the drill core of the John Hay, Jr., well 

1. It makes up about 10 percent of the interval between 1,310 

and 1,320 feet and occurs massive in the shale.

Gaylussite (Na2CO3 -CaCO3 -5H2 0) occurs in the drill core of 

the John Hay, Jr., well 1, between depths of 1,261 and 1,350 feet. 

It constitutes about 10 percent of the intervals 1,266 feet to 1,267 

feet 6 inches and 1,268 feet to 1,270 feet. As with pirssonite, no 

crystals of gaylussite have been found in the shale; only masses 

filling cracks have been seen.

Tables of indexed X-ray powder data are given for the seven 

saline minerals; these include the first published data for natural 

nahcolite, northupite, and pirssonite.

Shortite, in all instances, is the primary mineral of the six 

saline minerals present in the Wyoming area. It is seen in thin 

sections being replaced by the other five saline minerals. Northupite replaces not only shortite, but also trona, pirssonite, and 

gaylussite. Trona, pirssonite, and gaylussite have not been 

observed replacing one another.

Chemical and spectrographic analyses were made on 14 samples of measured sections from the drill core of the John Hay, Jr., 

well 1. The color of each sample before grinding was matched 

to plates in Robert Ridgeway's "Color Standards and Nomenclature". The size distribution was determined on each of the 14 

samples, recording the clay (<C2joi), silt (2/j, to 64/*), and the sand 

(>64joi) fractions. A mineral analysis was made by means of 

X-ray diffraction patterns, and each mineral present was reported 

in parts in ten.

Organic matter was separated from a sample of very rich oil 

shale from the drill core of the John Hay, Jr., well 1. The index 

of refraction of the organic matter was found to be 1.58, the 

specific gravity 1.01 at 4°C, and a Kjeldahl determination 

showed that it contained 2.18 percent nitrogen.

Analyses were made of the trona bed at two localities about 

half a mile apart. Each foot from the top to the bottom of the 

bed at each location was sampled, and the trona determined by 

leaching. The water-insoluble portion, composed chiefly of dolo1
SALINE MINERALS OF THE GREEN RIVER FORMATION

mite and detrital material, was treated with hydrochloric acid, 

and the detrital material weighed. Organic matter was determined on six 1-kg samples, from two other localities, and found 

to range from 0.001 percent to 0.142 percent.

The length of time of deposition of the trona bed, determined 

on samples from two locations about half a mile apart in the 

Westvaco mine, was found to be 973 and 1,463 years, respectively. 

This divergence is not an alarming one because of the errors inherent in the method used in which the quantity of the waterinsoluble material of a vertical column of the trona bed is compared to a similar column of the sedimentary rock, estimated to 

have required 3,000 years per vertical foot for deposition.

INTRODUCTION 

LOCATION

The Green River formation is composed of lacustrine 

sediments of early and middle Eocene age in the Bridger 

and Washakie Basins north of the Uinta Mountains in 

southwestern Wyoming, the Piceance Creek Basin in 

northwestern Colorado, and the Uinta Basin in northeastern Utah (fig. 1). The fluviatile sediments of the 

Wasatch formation underlie these deposits, and occupy 

approximately the lower third of the Eocene epoch.

106°

FIGURE 1. Index map showing location of the Green River formation (shaded areas) in Wyoming, Colorado, and Utah. (From Bradley, 1931, p. 2.) Arrow indicates site

of the John Hay, Jr., well 1, Sweetwater County, Wyo.
INTRODUCTION

In the Wyoming area the Green River formation is 

overlain by the Bridger formation which, like the 

Wasatch, is of fluviatile origin. Bridger sediments also 

overlie the Green River rocks in the Uinta Basin and 

are, in turn, covered by the fluviatile sediments of the 

Uinta formation. In the Piceance Creek basin in 

Colorado the rocks of the Green River formation are 

the youngest rocks exposed, except in an area where 

they are overlain by 400 feet of sandy beds of fluviatile 

origin that appear to be lithologically and stratigraphically equivalent to the basal beds of the Bridger formation of the Uinta Basin (Bradley, 1931, p. 19).

EXPLORATION

In 1938 the Mountain Fuel Supply Co., a subsidiary of 

the Ohio Oil Co., drilled the John Hay, Jr., well 1. This 

well on government land in the SE1/4NW1/4 sec. 2 

(1,920 feet from the north line and 2,120 feet from the 

west line), T. 18 N., R. 110 W., about 18 miles west of 

the city of Green River, Sweetwater County, Wyo. 

was put down in the search for oil and gas in the Green 

River formation. Neither oil nor gas was found, and 

the drill core was stored in a shed behind the offices 

of the Mountain Fuel Supply Co. in Rock Springs, Wyo. 

One year later (in the spring of 1939) Howard I. Smith, 

of the U.S. Geological Survey, suggested to Dr. William 

T. Nightingale, chief geologist of the Mountain Fuel 

Supply Co., that a mineralogical examination of portions of the core would be of scientific interest. Dr. 

Nightingale thought well of the suggestion, and 30 feet 

of the core was selected and sent to Washington for 

study.

In this 30 feet of core, trona and the rare mineral 

northupite were identified. Also a new mineral, an 

anhydrous carbonate of sodium and calcium, was found 

and named shortite. (See p. 24.)

It was decided that this unique assemblage of saline 

minerals warranted further investigation, so again the 

Survey was favored by Dr. Nightingale, who, when told 

that a study of the paragenesis of the saline minerals in 

the oil shale would be desirable, released to the Survey 

all the drill core that penetrated the Wilkins Peak member of the Green River formation, which represented a 

thickness of 627 feet.

In this core a stratum of trona 10 feet thick was found 

at a depth of about 1,600 feet below the surface. A note 

published in Science by Walter C. Mendenhall, then 

director of the U.S. Geological Survey, announced the 

finding of this trona bed (Mendenhall, 1940).

As a result of this report the Union Pacific Railroad 

drilled four wells, spaced several miles apart. The core 

from each of these wells showed the 10-foot thick trona 

bed at the depth reported by the Survey. This strongly

indicated that a potentially economic bed of trona extended over an area of many square miles.

Several years later three wells were drilled and cored 

by the Westvaco Co.; the Westvaco No. 1 was about 

2 miles north of the John Hay, Jr., well 1, and Westvaco 

wells 2 and 3 were about 2 miles north-northwest of 

Westvaco well 1. By means of these test holes the 

depth and thickness of the trona bed was again confirmed and its areal extent further established.

The Westvaco Co. in 1947 sank a shaft in close proximity to their No. 2 and No. 3 test holes. The locations 

of the 20 wells drilled up to and including the year 1956, 

and the location of the Westvaco mine, are shown in 

figure 2. The shaft of the mine, having a diameter of 

12 feet and lined with concrete, penetrated down 

through the trona bed. Room and pillar mining was 

started and the trona brought to the surface was ground 

and converted by calcination to sodium carbonate, the 

soda ash of commerce, in a pilot plant that had a 

capacity of 200 tons per day.

The soda ash produced was not pure sodium carbonate, but contained as much as 10 percent of waterinsoluble material, chiefly clay with some calcium and 

magnesium carbonates. These impurities rendered the 

soda ash unsuitable for some of the many uses of this 

very important heavy chemical that is second only to 

sulfuric acid in tonnage used by industry in the United 

States. This condition was overcome in 1954 by the 

installation of a solution plant wherein the trona was 

dissolved in hot water, the insoluble material filtered 

off, and pure sodium carbonate produced by precipitation, filtration, and calcination. Thus a new industry, 

born of a mineralogical and geochemical investigation, 

was established in southwestern Wyoming.

ACKNOWLEDGMENTS

Grateful appreciation is expressed for the assistance 

by many friends, both in and out of the Geological 

Survey, whose contributions, suggestions, and sound 

advice have been helpful in writing this paper. Chief 

among those in the Survey is Wilmot H. Bradley, 

whose counsel and constructive criticism stemmed from 

the vast store of information that he acquired through 

his many years of study of the Green River formation. 

Also of great assistance were Daniel E. Appleman who 

made the calculations of the interplanar spacings, and 

Frank Reed and John Mergner who so skillfully cut the 

thin sections that were used in determining the paragenetic relationship of the water-soluble saline minerals.

From the time the No. 1 shaft of the trona mine was 

put down in 1947, the members of the technical staff 

at Westvaco have been most kind and cooperative, 

both in the mine where the trona bed was sampled and 

studied, and in the many conferences and discussions
SALINE MINERALS OF THE GREEN RIVER FORMATION

R. 110 W. R. 109 W.

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A John Hay Jr., Well 1 (1938)

B Union Pacific Well 1 (1940)

C Union Pacific Well 2 (1940)

D Union Pacific Well 3 (1942)

E Union Pacific Well 4 (1942)

F Westvaco Well 1 (1944)

G Westvaco Well 2(1945)

H Westvaco Well 3(1946)

I Westvaco Well 4 (1948) 

J Westvaco Well 5 (1954) 

K Westvaco Well 6(1954) 

L Westvaco Well 7 (1954) 

M Westvaco Well 8(1954) 

N Westvaco Well 9 (1954) 

0 Westvaco Well 10(1955) 

P Westvaco Well H (1955)

Q Westvaco Well 12 (1956) 

R Westvaco Well 13 (1956) 

S Potash Company of America

Well 1 (1949) 

T Potash Company of America

Well 2 (1950) 

U Westvaco Mine (1947)

FIGURE 2. Locations of exploratory wells and the Westvaco mine in Sweetwater County, Wyo.
DRILL CORE OF THE JOHN HAY, JR., WELL 1

pertaining to problems of mutual interest. Among 

these were Dr. Max. Y. Seaton, Guilford Gaylord, J. 

Ward Downey, and John Jacobucci, who were on the 

staff at the time the mine was started; also later C. A. 

Romano, N. E. McDougal, Lewis Smith, Dr. William 

Bauer, Robert Love, L. K. Marshall, Keith Norseth, 

and John A. Anderson. Time and space do not permit 

a detailed outline of the great help so willingly given by 

these pioneers in trona mining. Without this help 

much of the information contained in this paper could 

not have been presented.

DRILL CORE OF THE JOHN HAY, JR., WELL 1 

DESCRIPTION

The core of the John Hay, Jr., well 1 was obtained by 

drilling in a brine saturated with sodium carbonate, and 

marking the depths as each 10-foot section of the 2-inch 

diameter core was brought to the surface. The core 

was then placed longitudinally in shallow trays and 

stored in a shed in the yard of the Mountain Fuel Supply Co. at Rock Springs, Wyo. In the summer of 1939 

that part of the core that penetrated the Wilkins Peak 

member of the Green River formation was transferred 

to 4 boxes each containing 6 trays, the total weight 

being 1,600 pounds and sent to the Geological Survey 

in Washington, D.C., for detailed examination.

To obtain a fresh uncontaminated surface for mineral 

examination the core was split longitudinally, using a 

core splitter that would open sections as much as 5 

inches long. Identification of the saline species usually 

required no more than the use of a hand lens. Examination of an oil-immersion mount was made with the 

petrographic microscope when the identification of a 

mineral was in doubt. Thin sections and polished sections were used to determine genetic and paragenetic 

relations.

In this report the term "lean" will be used to mean 

oil shale that, upon distillation, yields up to 5 gallons of 

distillate per ton, "medium grade" between 5 and 15 

gallons per ton, "rich" between 15 and 30 gallons per 

ton, and the term "very rich" will be applied to shale 

that would yield more than 30 gallons of distillate per 

ton. A sample was designated as to grade by visual 

examination and estimation of density. This was 

based on the distillation of many samples of each category (lean, medium grade, rich and very rich) in order 

to recognize these differences in organic content.

The terms "shale" and "oil shale," as applied to the 

Green River formation are erroneously used, as will be 

discussed later in this report. Fissility, that property 

which characterizes a shale, is lacking in all but a small 

percentage of these sediments.

The shale of this drill core is a compact bedded rock, 

containing varying amounts of organic matter, in which 

the saline minerals and pyrite, loughlinite, and searlesite have precipitated. The composition of the shale 

varies from predominantly argillaceous material to 

microcrystalline dolomite with detrital quartz and feldspar. A thin section or semiquantitative chemical 

analysis is usually required to distinguish between the 

argillaceous shale and that composed chiefly of 

dolomite.

CONTINUITY

The log of the drill core of the John Hay, Jr., well 

1 shows that shortite is present continuously between 

1,251 feet and 1,806 feet 6 inches, a vertical distance 

of 555 feet 6 inches. The other saline minerals reported in the log are also found only between these 

depths. In the vertical distances of 555 feet 6 inches 

there was obtained 489 feet 8 inches of core. The 

65 feet 10 inches of missing core is indicated in the log 

by 23 breaks ranging in length from 6 inches to 16 

feet. The longest unbroken section is between 1,592 

feet 6 inches and 1,810 feet, a length of core of 217 

feet 6 inches. Another long unbroken section is 

between 1,375 feet and 1,510 feet, a length of 135 feet, 

and another between 1,526 feet and 1,587 feet 9 inches, 

a length of 61 feet 9 inches.

In the section of the core between 1,587 feet 9 inches 

and 1,600 feet 4 inches, a vertical distance of 12 feet 

7 inches, massive trona is found in beds of 1 foot 3 

inches and 7 feet 10 inches with a 1-foot break between the beds and a 2-foot-6-inch break immediately 

above the smaller bed. Because of the solubility of 

the trona, it well may be that it occupied the positions 

where the breaks of 1 foot and 2 feet 6 inches are recorded in the log and was lost. If such is the case, 

the trona bed at this horizon is 12 feet 7 inches thick, 

approximately 2 feet thicker than it is found to be in 

the Westvaco mine about 4 miles to the north.
6 SALINE MINERALS OF THE GREEN RIVER FORMATION

Log of John Hay, Jr., well 1

Depth interval Thickness 

Ft in Ft in Remarks

1, 183 0 01 Sandstone with a minor quantity of dolomite. 

1, 183 1

Break, 10 ft 11 in

1, 194 0 60 Dense dark-gray shale containing calcite crystals as much as 4 mm thick. The first 3 ft of the 

1, 200 0 shale is lean, the next foot is medium grade and the lower 2 ft lean.

Break, 8 in

1,200 8 9 Dark dense medium-grade shale having many small crystals of calcite. 

1, 201 5

Break, 3 ft 4 in

1, 204 9 53 Same as 1,200 ft 8 in to 1,201 ft 5 in 

1, 210 0

Break, 2 ft 0 in

1, 212 0 30 Same as 1,204 ft 9 in to 1,210 ft 0 in 

1, 215 0

Break, 2 ft 0 in

1,217 0 5 About 50 percent lean shale and 50 percent calcite. 

1,217 5

Break, 7 in

1, 218 0 1 Calcite with minor quantity of lean shale. 

1,218 1

Break, 3 ft 11 in

1, 222 0 16 Lean shale containing crystals of calcite. 

1, 233 6

Break, 6 in

1, 224 0 30 Lean oil shale with small crystals of calcite. A few small lenses (1 cm diameter) of pyrite are 

1, 227 0 present.

Break, 13 ft 0 in

1, 240 0 17 Crystals of calcite and pyrite in lean shale. 

1, 241 7

Break, 1 ft 5 in

1, 243 0 10 Same as 1,240 ft 0 in to 1,241 ft 7 in 

1,244 0

Break, 4 ft 0 in

1, 248 0 5 Same as 1,243 ft 0 in to 1,244 ft 0 in 

1,248 5

Break, 2 ft 4 in

1, 250 9 17 Medium-grade oil shale containing crystals of calcite. Shortite is found at 1,251 ft 0 in and 

1, 252 4 continues to the end, constituting about 2 percent of this section.

Break, 7 in

1, 252 11 2 Small crystals of shortite (about 2 percent) in medium-grade shale. No calcite present. 

1, 253 1

Break, 1 ft 8 in

1, 254 9 13 Rich brown oil shale containing crystals of shortite (about 15 percent). 

1,256 0

Break, 5 ft 0 in

1, 261 0 10 Lean light-green shale with shortite (about 5 percent) and gaylussite (about 5 percent). Good 

1, 262 0 contacts show gaylussite replacing shortite. Tiny crystals of pyrite are present throughout

the section.

Break, 2 ft 0 in

1, 264 0 10 Same as 1,261 ft 0 in to 1,262 ft 0 in. 

1, 265 0

Break, 1 ft 0 in

1, 266 6 16 Lean light-green shale containing shortite (about 5 percent) and gaylussite (about 10 percent). 

1, 267 0 The sequence shortite to gaylussite is present. Also gaylussite is found in thin veins not in

contact with shortite. Pyrite is sparingly present.

Break, 6 in

1, 268 0 20 Lean light-green shale with shortite (about 5 percent) and gaylussite (about 10 percent). 

1,270 0
DRILL CORE OF THE JOHN HAY, JR., WELL 1

Depth interval 

Ft in

Thickness 

Ft in

1, 271

1,271

1, 274

1, 276

1, 278

1,278

1, 279

1, 279

1,283

1,283

1, 284

1, 287

1, 290

1,295

1, 296

1,298

1, 300

1,305

1,310

1,320

1, 335

1,338

1, 338

1, 340

1, 340

1, 350

1, 305 0

1, 309 0

10

1, 320 0 10

1, 330 0

10

Remarks

Break, 1 ft 0 in

Lean light green shale containing blebs of shortite (about 15 percent). Gaylussite (5 percent) is 

found in veins filling cracks in the shale.

Break, 2 ft 6 in

Lean light-green shale with shortite (about 20 percent) and gaylussite (5 percent). At 1,275 ft 

8 in to 1,275 ft 10 in a 2-inch stratum of massive shortite is found. A small quantity of the 

rare mineral bromlite is found at 1,276 ft 0 in. Thin sections show the sequence shortite to 

gaylussite to bromlite and dolomite.

Break, 2 ft 0 in 

Massive trona.

Break, 9 in

Colorless trona (about 70 percent) cut by 1-inch stratum of very rich black shale at 1,279 ft 4 

in. Rich brown shale containing shortite (about 5 percent) is found at the bottom of the 

section. Pyrite is present.

Break, 3 ft 6 in

Lean greenish shale containing small crystals of shortite (about 25 percent).

Break, 1 ft 4 in

Medium-grade greenish-yellow shale that grades into very rich dark-brown shale. Shortite 

(about 10 percent) is present. In the last foot the crystals of shortite are oil soaked apparently 

with oil derived from the very rich oil shale.

Break, 2 ft 6 in

Lean shale containing small crystals of shortite (about 10 percent).

Break, 1 ft 0 in

Lean shale containing small crystals of shortite (about 15 percent), some of which fill cracks in 

the shale that cut the bedding.

Break, 1 ft 6 in

Lean shale varying from light green through tan to brown in color. Shortite (about 10 percent) 

occurs as small crystals throughout the section. A few thin seams of trona (about 1 percent) 

are found between 1,301 ft 4 in and 1,302 ft 6 in. Very small crystals of dolomite are present 

at 1,302 ft 0 in where shortite is being replaced by trona and dolomite, as shown in thin section. A few tiny crystals having a high birefringence and high index of refraction with a 

small optic angle (2V) are seen in this thin section. The mineral may be bromlite or aragonite.

No break 

Lean shale containing small crystals of shortite (about 15 percent). Pyrite is abundant.

Break, 1 ft 0 in

Greenish lean shale containing shortite (about 10 percent) and pirssonite (about 10 percent). 

Magnesite and pyrite are present. The transition shortite to pirssonite plus magnesite is 

seen throughout the section.

No break

Greenish lean shale containing shortite (about 10 percent), pirssonite (about 5 percent), trona 

(about 10 percent), and northupite (less than 1 percent). A 1-foot stratum of white massive 

trona occurs at 1,324 ft 10 in to 1,325 ft 10 in. The northupite is found between 1,327 ft 0 in 

and 1,328 ft 0 in.

Break, 5 ft 0 in

Lean shale containing shortite (about 50 percent) and northupite (about 5 percent). Between 

1,336 ft 0 in and 1,337 ft 0 in, well-formed octahedra of northupite are found.

Break, 6 in

Lean shale containing crystals up to 3 mm across of shortite (about 30 percent) and fine-grained 

northupite (about 35 percent) containing residual crystals of shortite.

No break

Lean light-brown shale containing shortite (about 20 percent), northupite (about 15 percent), 

pirssonite (about 1 percent), gaylussite (about 0.5 percent), and trona (about 0.5 percent). 

Nodules of northupite, some of which contain residual fragments of shortite, have flow lines 

in the shale around them. The sequence shortite to northupite and dolomite is found at 

1,340 ft 8 in and also shortite to pirssonite to northupite and dolomite. At 1,342 ft 10 in a

596568 O -62
O SALINE MINERALS OF THE GREEN RIVER FORMATION

Depth interval Thickness 

Ft in Ft in Remarks

1-inch stratum is composed approximately of 55 percent bradleyite, 30 percent shortite, and 

15 percent clay. Bradleyite is found in a 1^-inch stratum at 1,343 ft 7 in with shortite and 

clay. Pyrite is sparsely present throughout the 10-foot section.

No break

1, 350 0 20 Lean shale containing crystals of shortite (about 10 percent) and trona (about 1 percent). 

1, 352 0

Break, 8 ft 0 in

1, 360 0 10 0 Lean shale containing shortite (about 10 percent), trona (about 7 percent), and northupite 

1, 370 0 (about 2 percent). From 1,364 ft 6 in to 1,366 ft 0 in very small crystals of shortite fill

cracks in the shale that are normal to the bedding. A 6-inch stratum of pure white trona is 

present at 1,367 ft and is oriented in such a way that the cleavage is normal to the bedding. A 

2-inch stratum of massive trona occurs at 1,369 ft 10 in.

Break, 5 ft 0 in

li 375 0 50 Lean shale containing shortite (about 30 percent) and northupite (about 7 percent). At 1,379 

1, 380 0 ft 6 in the sequency shortite to northupite is observed.

No break

1, 380 0 10 0 Lean shale containing shortite (about 35 percent) and northupite (about 25 percent) with tiny 

1, 390 0 crystals of pyrite throughout. Thin sections cut at 1,380 ft 4 in and 1,382 ft show shortite

being replaced by northupite.

No break

1, 390 0 50 Greenish lean shale containing shortite (about 15 percent), trona (about 2.5 percent), northupite 

1. 395 0 (about 1 percent), and pirssonite (about 0.5 percent). The sequence shortite to pirssonite is

found at 1,390 ft 2 in. At 1,390 ft 8 in, three small grains of tychite were found. A 1^-inch 

stratum of trona is present at 1,392 ft 6 in. A minute quantity of an unidentified mineral 

was found at 1,392 ft 3 in. It is insoluble in H2 0, soluble in HC1, has parallel extinction and 

negative elongation with indices w 1.554 and e = 1.497.

No break

1. 392 0 17 0 Light-green lean shale containing shortite (about 20 percent) and northupite (about 5 percent). 

1, 409 0 The sequence shortite to northupite is found in thin sections cut at 1,401 ft 6 in and 1,407 ft 1 in.

No break

1, 409 0 10 0 Rich brown oil shale containing shortite (about 35 percent) and northupite (about 15 percent). 

1» 419 0 In the first 2 feet milky northupite constitutes about 60 percent of the core. The northupite

occurs as round nodules that grew in the soft mud, producing flow lines. A thin section at 

1,411 ft 2 in shows northupite replacing shortite and shale.

No break

1)419 0 50 Lean brown shale containing shortite (about 10 percent) and northupite (about 10 percent). 

1,424 0

No break

1) 424 0 60 Lean greenish shale containing shortite (about 7 percent) and northupite (about 1 percent)- 

1, 430 0 In the first 4 feet euhedral crystals of northupite are present.

No break

1, 430 0 60 Lean greenish shale broken by a stratum 1-foot thick of rich brown shale at 1,431 ft to 1,432 ft. 

1) 436 0 Shortite (about 10 percent) and northupite (about 10 percent) are found throughout. At

1,431 ft 8 in, a }Cinch stratum ot rich brown oil shale contains oolitelike inclusions of northupite. 

The round blebs of northupite have in cross section, concentric rings made up of microscopic 

liquid inclusions that give the appearance of oolitic structure. At 1,431 ft 8 in, a small amount 

of authigenic chert with index of refraction of 1.550 was found.

No break

1» 436 0 60 The section contains shortite (about 15 percent), trona (about 5 percent), and northupite (about 

1, 442 0 2 percent). The first 2 feet are composed of light-green lean shale that grades to rich brown

shale 1 foot thick. Lean green shale makes up the remaining 3 feet of the section. At 1,439 

ft 4 in, a crack about 1 mm thick is filled with tiny authigenic crystals of quartz. At 1,441 

ft 9 in, a very small amount of the mineral thermonatrite (Na2C03-H2 0) was identified.

No break

1, 442 0 70 The first 2 feet is composed of rich dark-brown oil shale, and the remaining 5 feet of the section 

1- 449 0 is lean light green shale. Northupite (15 percent) and shortite (5 percent) are found throughout. Thii) sections at 1,442 ft 6 in and 1,442 ft 8 in show northupite replacing shortite and 

shale.

No break
DRILL CORE OF THE JOHN HAY, JR., WELL 1

Depth ut interval Thickness

ft in Ft in Remarks

1.449 0 10 Greenish shale containing shortite (about 15 percent).

1.450 0

No break

1, 450 0 10 0 Lean greenish shale contains shortite (about 10 percent), trona (about 6 percent), and northupite 

1, 460 0 (about 3 percent). A thin section at 1,454 ft shows northupite replacing shale. Trona is concentrated between 1,454 ft 4 in to 1,455 ft 8 in.

No break

1, 460 0 10 0 The lean greenish shale is cut by a 6-inch stratum of dense black rich oil shale at 1,462 ft 6 in. 

1, 470 0 Shortite (about 10 percent), northupite (about 6 percent), and trona (about 4 percent) are

present. At 1,462 ft 6 in is found a 2-inch stratum of massive white trona. From 1,466 ft 6 

in to 1,466 ft 8 in, the greenish shale contains large plates of searlesite. Trona, northupite, 

and pyrite are also present. Tiny plates of biotite are found for 3 inches at 1,468 ft 5 in. Massive trona occurs in a 4-inch stratum beginning at 1,468 ft 8 in.

No break

1, 470 0 50 Greenish lean shale contains crystals of shortite (about 10 percent), northupite (about 1 percent), 

1) 475 0 and trona (about 1 percent). A thin stratum of searlesite is found at 1,473 ft 0 in. Thin sections cut at 1,470 ft 1 in and 1,470 ft 3 in, show northupite replacing trona.

No break

1, 475 0 50 Medium-grade shale contains shortite (about 25 percent), northupite (about 15 percent), and 

1, 480 0 trona (about 3 percent). The northupite occurs as glassy nodules up to 5 mm in diameter.

At 1,475 ft 3 in a thin section shows northupite replacing shortite and shale, leaving at the 

contact with the shale, long strings of low birefringent material that is insoluble in cold (1 +1) 

HCl, has positive elongation and parallel extinction. A 2-inch stratum of nearly pure trona 

occurs at 1,479 ft 0 in.

No break

1, 480 0 10 0 Medium-grade tan-colored oil shale is found in first 5 feet. The remainder of the section is lean 

1, 490 0 greenish shale. Shortite (about 25 percent), northupite (about 15 percent), and trona (about

3 percent) are present. A J^-inch stratum of searlesite occurs at 1,480 ft 0 in and another at 

1,485 ft 0 in. At 1,481 ft 0 in a thin stratum contains plagioclase, feldspar, biotite, and volcanic ash. Five inches of white massive trona begins at 1,481 ft 8 in. Northupite replaces 

shortite and trona between 1,482 ft 7 in and 1,485 ft 0 in.

No break

1, 490 0 10 0 Lean shale contains shortite (about 13 percent) and trona (less than % percent). At 1,491 ft 3 

1, 500 0 in a small vug contains many very small crystals of nahcolite. A thin section at 1,491 ft 10

in shows trona replacing shortite. Thin sections show that two %-inch strata between 1,494 

ft 3 in and 1,494 ft 5 in are probably altered ash. volcanic From 1,494 ft 4 in to 1,498 ft 1 

in well-formed crystals of shortite up to 1 cm across are present.

No break

1, 500 0 10 0 Lean gray shale containing shortite (about 5 percent). Cracks in the shale normal to the bedding 

I. 510 0 and as much as 2 feet long, are filled by tiny crystals of shortite. These may have been mud

cracks.

Break, 16 ft 0 in

I. 526 0 40 Medium-grade oil shale containing crystals of shortite (about 15 percent). 

If 530 0 No break

1) 530 0 10 0 Medium-grade oil shale containing crystals of shortite (about 15 percent). A polished section 

1. 540 0 normal to the bedding at 1,535 ft 0 in showed sharp folding. A thin section cut at the same

place showed shortite being replaced by an unidentified mineral of high birefringence and upper 

index about 1.55. The fragments of this mineral were very small. No cleavage was evident.

No break

1) 540 0 10 0 Lean greenish shale containing crystals of shortite (about 15 percent) and massive trona (about 

!> 550 0 2 percent). A few crystals of northupite are present at 1,544 ft 0 in. A 2^-inch stratum of

pure trona is found at 1,548 ft 0 in.

No break

1> 550 0 10 0 Greenish lean shale containing shortite (about 20 percent) both massive and as crystals, trona 

1) 560 0 (about 15 percent), and northupite (about 1 percent). Trona is present scantily at the top

of the section and increases with depth to a 13-inch stratum beginning at 1,557 ft 9 in of dark 

brown trona, the color due to organic matter. A thin section at 1,559 ft 9 in shows shortite 

and trona being replaced by northupite.

No break
10 SALINE MINERALS OF THE GREEN RIVER FORMATION

Depth interval Thickness 

Ft in Ft in Remarks

1, 560 0 16 Lean shale containing trona (about 50 percent), shortite (about 5 percent), and northupite (about 

1, 561 6 1 percent). A 9-inch stratum of yellow-colored trona is found at the top of this 1^-foot section.

At 1,560 ft 2 in, a lens of brownish northupite is in the trona where a thin section shows northupite replacing trona. Ghost crystals of trona are present in the northupite.

No break

1,561 6 86 Medium-grade light-brown oil shale containing crystals of shortite (about 10 percent). 

1, 570 0 No break

1, 570 0 10 0 Lean greenish shale cut by an 8-inch stratum of very rich oil shale beginning at 1,576 ft contains 

1, 580 0 crystals of shortite (about 5 percent).

No break

1, 580 0 79 Lean shale containing shortite (about 5 percent) and massive trona (about 5 percent). The 

1, 587 9 trona is present in two strata, one 2 inches thick, and the other 3 inches thick from 1,587 ft

6 in to 1,587 ft 9 in.

Break, 2 ft 6 in

1, 590 3 13 Massive trona. 

1,591 6

Break, 1 ft 0 in

1, 592 6 7 10 Massive trona. 

1, 600 4

No break

1, 600 4 11 8 Medium grade and rich oil shale containing shortite (about 10 percent) and trona (about 10 

1, 612 0 percent). A small amount of searlesite is present, the plates of which are separated by thin

veins of loughlinite.

No break

1, 612 0 40 Lean greenish oil shale containing a 1-foot thick stratum of brown rich oil shale. Crystals of 

1, 616 0 shortite (about 10 percent) are present throughout.

No break

1, 616 0 40 Medium-grade oil shale containing shortite (about 10 percent) and trona (about 55 percent). 

1, 620 0 A stratum of massive trona 2 ft 3 in thick is present from 1,617 ft 6 in to 1,619 ft 9 in. At

1,619 ft a tiny bleb of aragonite was identified.

No break

1, 620 0 10 0 Lean greenish oil shale with about 2 ft of medium-grade shale. Shortite (about 5 percent) is 

1, 630 0 present throughout the section. A small amount of loughlinite is present at 1,620 ft 6 in and

searlesite at 1,621 ft 3 in.

No break

1» 630 0 10 0 The section is composed of 5 ft of lean greenish shale and 5 ft of brown medium-grade oil shale. 

1, 640 0 Shortite (about 5 percent) and trona (about 2 percent) are present. Loughlinite is sparingly

present between 1,633 ft 0 in and at 1,639 ft 0 in. A 2-inch stratum of trona is found at 1,635 

ft. Pyrite is found to as much as about 5 percent in the medium-grade brown shale between 

1,635 ft 2 in and 1,638 ft 6 in.

No break

1) 640 0 10 Lean greenish shale containing crystals of shortite (about 5 percent). 

1, 641 0

No break

1) 641 0 90 The section contains lean greenish shale, rich dark-brown shale, shortite (about 5 percent) and 

1, 650 0 trona (about 45 percent). Between 1,642 ft 0 in to 1,646 ft 0 in is a 4-ft bed of massive trona.

No break

I- 650 0 10 0 The section is composed of trona (about 65 percent), shortite (about 3 percent), and both lean 

1> 660 0 and rich oil shale. The first 3 ft is lean shale. From 1,653 ft 2 in to 1,659 ft 3 in is found a

6 ft 1 in bed of massive trona followed by 5 in of dark brown rich-oil shale containing 

crystals of shortite. A 4-in bed of reddish brown massive trona is present from 1,659 ft 8 

in to 1,660 ft 0 in. A thin section cut at 1,659ft Sin at the contact between the rich oil shale 

and the trona shows the shale being replaced by the trona.

No break

1> 660 0 10 0 The upper two-thirds of the section is medium-grade oil shale and the lower one-third is lean 

1; 670 0 greenish shale. Shortite (about 5 percent) and trona (about 3 percent) are present. Loughlinite is found from 1,665 ft to 1,665 ft 5 in. Pyrite is present in the lower part of the section.

No break
DRILL CORE OF THE JOHN HAY, JR., WELL 1 11

Depth Vti interval Thickness

Ft in Ft in Remarks

1, 670 0 50 Lean shale containing crystals of shortite (about 10 percent). Small veins of loughlinite are 

1, 675 0 found between 1,672 ft 6 in and 1,673 ft 0 in.

No break

1, 675 0 50 Lean gray shale containing crystals of shortite (about 5 percent). 

1, 680 0

No break

1, 680 0 10 0 Shortite (about 5 percent) is present throughout the section. The lean shale is divided by a 

1, 690 0 2-ft bed of medium-rich shale beginning at 1,684 ft 2 in.

No break

1, 690 0 10 0 Lean greenish shale containing crystals of shortite (about 10 percent) and crystals of pyrite. 

1,700 0

No break

1, 700 0 40 Lean brown shale containing large crystals of shortite (about 10 percent). 

1,704 0

No break

1, 704 0 60 Lean brown shale containing large crystals of shortite (about 5 percent). 

1, 710 0

No break

1,710 0 10 0 Lean greenish shale divided by a bed of medium-grade shale from 1,711 ft to 1,712ft 0 in. Large 

1, 720 0 shortite (about 5 percent) crystals up to 3 cm across are present.

No break

1, 720 0 50 Lean shale, both greenish and brown, containing shortite (about 5 percent). 

1,725 0

No break

1, 725 0 50 Lean greenish shale with poorly formed crystals of shortite (about 15 percent) up to \% cm across. 

1, 730 0

No break

1, 730 0 10 0 Lean greenish shale containing poorly formed crystals of shortite (about 10 percent) up to \yz cm 

1,740 0 across.

No break

1, 740 0 10 0 Shortite (about 3 percent) is present throughout the section. The first 6 ft is composed of 

1, 750 0 lean shale, both greenish and brown in color. From 1,746 ft 0 in to 1,746 ft 4 in a greatly

altered bed of volcanic ash containing tiny crystals of pyrite is found. This may be a good 

horizon marker. The remainder of the section is made up of lean brownish shale containing 

large crystals of pyrite (about 2 percent).

No break

1, 750 0 60 Lean shale, both brown and greenish, containing large poorly formed crystals of shortite (about 

1, 756 0 5 percent). Pyrite is present in the upper 2 ft of the section.

No break

1, 756 0 40 Lean greenish shale with a few large crystals of shortite (about 1 percent) as much as 2 cm across1, 760 0

No break

1, 760 0 10 0 Lean greenish shale divided by a bed of medium-grade shale from 1,761 ft 0 in to 1,763 ft 0 in. 

1,770 0 Shortite (about 1 percent) is present.

No break

1, 770 0 10 0 The first 3 ft is composed of lean greenish shale. From 1,773 ft 0 in to 1,777 ft 6 in medium-grade 

1, 780 0 oil shale is found. The remainder of the section is lean greenish shale. Shortite (about 1

percent) and pyrite are present.

No break

1, 780 0 30 Lean greenish shale containing a few blebs of shortite (about 0.5 percent) and tiny crystals of 

1,783 0 pyrite.

No break

1, 783 0 70 The first foot is made up of rich black oil shale. The remaining 6 ft of the section is composed 

1, 790 0 of lean greenish shale. Shortite (about 1 percent) and tiny crystals of pyrite are present.

No break

li 790 0 10 0 The first 9 ft of this section is composed of lean light-green shale containing an occasional bleb 

1, 800 0 of shortite (about 0.1 percent). From 1,799 ft to 1,800 ft the medium-grade oil shale contains

no salines. Tiny crystals of pyrite are sparingly present.
12 SALINE MINERALS OF THE GREEN RIVER FORMATION

Depth D, interval

Ft

1,800

1,810

1,820

1,820

1.970

1.971

1.991

1.992

Thickness 

Ft in

10 0

Remarks 

No break

The first 2l/2 ft of the section is composed of medium-grade oil shale, the next 4 ft of lean shale 

and the remainder of dark medium-grade shale. Shortite (about 0.1 percent) and pyrite 

are present. The greatest depth at which shortite is found in the John Hay, Jr., well, 1 is 

1,806 ft 6 in.

Break, 10 ft 3 in 

Lean dense black shale.

Break, 149 ft 6 in 

Lean greenish shale containing blebs of calcite.

Break, 20 ft 4 in

Limestone containing gastropods.

MINING OPERATION

DEVELOPMENT OF MINE

Since the first shaft of the Westvaco mine was put 

down in 1947 to the trona bed, 1,600 feet below the 

surface, many problems that presented themselves in 

the mining of the trona and converting it to soda ash 

(sodium carbonate) have been solved. A pilot plant 

with a capacity of 200 tons per day was first installed 

in which the crushed 'trona brought up from the mine 

was calcined, sieved, and bagged. This product contained from 5 to 10 percent of extraneous material 

derived from the detrital minerals and the dolomite in 

the trona bed, and did not meet the requirement of 

the most lucrative market, for which a minimum 

purity of 99.9 percent for the soda ash must be 

maintained.

By 1952 the pilot plant had served its purpose and a 

great expansion program was started which by 1954 

resulted in a solution plant with a capacity of 300,000 

tons of soda ash per year. The buildings were so built 

that doubling this capacity could be brought about 

with a minimum of effort.

In the new plant the crushed trona is dissolved in 

hot water, the insoluble material filtered off, and the 

sesquicarbonate precipitated, filtered, and calcined to 

lorm the soda ash of commerce. This product of 

better than 99.9 percent purity was by 1958 being 

produced at a rate of more than 400,000 tons per year.

The expansion and development of the underground 

workings kept pace with processing advancement on 

the surface. By 1959, more than 100 miles of corridors, 

crisscrossed to facilitate room and pillar mining, had 

been cut into the trona bed.

Working faces in the mine, one of which is shown in 

figures 3 and 4, are undercut, drilled horizontally to a 

depth of 9 feet, and loaded with dynamite. Each 

round of explosive knocks down almost 50 tons of 

trona. After the blast, loading machines move up to 

the face, their crablike arms sweep the ore onto a 

moving belt that carries it to electrically driven cars

equipped with rubber tires. These cars shuttle back 

and forth to a conveyor belt that carries the ore to a 

crusher at the bottom of a 1,600-foot shaft. Twin 

skips hoist the trona to the surface at the rate of 6 tons 

per minute.

A noteworthy feature of the Westvaco mine is the 

absence of wooden supports underground. Roof bolts 

driven vertically into the overhead shale support the 

square-cut main entries. The other development openings are arched and usually require no roof bolts. The 

absence of timber makes more room for the movement 

of equipment.

SODA ASH

The trona of the Green River formation will probably 

be a source of soda ash for hundreds of years. Each 

square mile of the trona bed contains more than 16 

million tons of trona, from which it is estimated, after 

deducting for impurities in the trona bed, and the inFIGURE 3. Photograph of a working face in the Westvaco mine, 

table 22 was obtained from this location.

B in
ROCKS CONTAINING THE SALINE MINERALS 13

FIGURE 4. Closeup of face in figure 3, showing stratification in the trona bed. The 

handle of the pick crosses a half-inch stratum of shale.

complete recovery by room and pillar mining, about 

9 million tons of soda ash can be produced.

Four products are now marketed by Westvaco: 

crude trona (crushed), soda ash (dense), soda ash 

(light) and sultron, a specialty product used in the 

desulfurization of steel.

With this development of the trona resources as a 

foundation, the manufacture of other basic chemicals 

from nearby natural resources may be planned to 

provide the intermountain area with more basic 

chemicals at new low economic levels.

Figures for the production in this country of both 

the synthetic soda ash, produced from sodium chloride 

brines by the Solvay process, and the soda ash produced from natural sources are listed in table 1. The 

tonnages of soda ash used by the various industries in 

this country are recorded in table 12.

A photograph (fig. 5) of the calcining house, the 

screen house, and the superstructure of shaft 1, shows 

only a small part of the surface development of the 

new mine that produces the trona and the plant that 

converts it to soda ash.

TABLE 1. Production figures and value of soda ash produced in

the T Tnited States from 1948 through 1957 

[From the Minerals Yearbook, v. 1, 1957, U.S. Bureau of Mines]

Year

1954_ _______ ___________-______________

1955_ 

1956. -

Manufactured short 

tons

4, 403, 809

4, 879, 396

4 906 971

4, 650, 588

Natural 

short tons

613, 594

Value

i $6, 905, 367

10, 627, 460

13. 536, 345

1 Exclusive of Wyoming in 1948-49.

2 Preliminary figures.

FIGURE 5. Photograph showing the calcining house, the screen house, and the superstructure of shaft 1 of the Westvaco mine.

ROCKS CONTAINING THE SALINE MINERALS 

DEFINITION

To understand better some of the many problems 

that were faced in the study of the genesis and paragenesis of the saline minerals, a careful look at the 

rocks in which they occur was taken. The saline minerals of the Green River formation that are found 

north of the Uinta Mountains in the Wyoming area 

are exclusively in the Wilkins Peak member of this 

formation. The term "oil shale," applied in the description of these sediments, and so used in this report, 

is firmly established in the literature of the Green 

River formation. However, from a look at the definition of shale, in which fissility is the physical property 

that characterizes the structure, one must conclude 

that the term "oil shale" is incorrectly used when 

applied to all but a very small percentage of the 

Wilkins Peak in which the saline minerals occur.

Regarding the term "shale", Lewis (1924, p. 568) 

says:

It implies no particular composition except so far as certain 

materials of fine texture lend themselves to the development of 

the characteristic structure. This structure, or fissility, may be 

defined as the capacity of clayey strata for splitting into somewhat uneven flakes, thin chips, and wedgelike fragments approximately parallel to the bedding.

The American Geological Institute's Glossary of 

Geology and Related Sciences, 1957, on page 262 states:

Shale includes the indurated, laminated or fissile claystones 

and siltstones. The cleavage is that of bedding and such other 

secondary cleavage or fissility that is approximately parallel to 

the bedding. The secondary cleavage has been produced by 

the pressure of overlying sediments and plastic flow.
14 SALINE MINERALS OF THE GREEN RIVER FORMATION

In a vertical section through the Wilkins Peak 

member, only rarely would one see strata that could 

be classified as oil shale. Bradley (1931, p. 22) in his 

paper on the oil shale of Colorado and Utah points 

out that most of the oil shale of the Green Kiver 

formation could not be regarded strictly as shale, but 

instead it is practically a magnesian marlstone rich in 

organic matter.

The Wilkins Peak sediments that vary in content of 

dolomite from approximately 20 to 75 percent do not 

fit into the category of any single rock type. They 

vary, with increasing dolomite, from magnesian marlstone to argillaceous dolomite.

SELECTION OF SAMPLES

To determine the variations in chemical composition, 

physical properties, and mineral content of the "oil 

shale", 14 samples were chosen from the drill core of 

the John Hay, Jr., well 1, care being taken to select 

material having a minimum amount of saline minerals. 

The criteria used in deciding what intervals of the drill 

core should be sampled were chiefly the depth, the 

color, the visually estimated content of organic material, and the amount of acid insoluble portion, the 

latter having been previously determined semiquantitatively by treatment of a roughly weighed sample 

with dilute hydrochloric acid. On all these samples 

the color was recorded, and on six the bulk specific 

gravity was determined. The samples were then 

ground to pass an 80-mesh sieve.

COLOR

A freshly broken surface was used to determine the 

color of each of the 14 samples of oil shale. Comparison 

was made, in daylight from a north window, with the 

plates in Kobert Kidgway's Color Standards and Nomenclature, and the results are recorded in table 2. 

There was no noticeable variation in the color within 

the individual section of core from which each of the 

samples was taken. The color of the samples after 

grinding was not recorded.

CHEMICAL ANALYSIS

Complete quantitative chemical analyses were made 

of 14 samples from the drill core of the John Hay, Jr., 

well 1 and these are listed in table 3. For all but 

6 of the 20 constituents determined, the classical 

methods of Hillebrand, Lundell, Bright and HofTman 

(1953) were used. An ion-exchange column was employed to isolate sodium and potassium, lithium was 

determined spectrographically, and carbon dioxide was 

collected and the volume at standard conditions converted to mass by applying the appropriate factor 

(Fahey, 1946).

TABLE 2. Color of samples from the drill core of the John Hay, 

Jr., well 1, matched to Robert Ridgway's "Color standards 

and nomenclature"

Laboratory No.

148137______-____--

148138- -

148139_ ______ _

148142 ___ 

148143_ . 

148144__._ .

151391 - 

151392. ___ .. ._

151393 __ _ ____

151396. ____ 

Depth

From 

Ft in

1, 275 0 

1, 320 0 

1,390 0 

1,623 6 

1,646 0 

1,710 0 

1,711 0 

1,712 0 

1,365 0 

1,624 0 

1,654 6 

1,663 0 

1,668 0 

1,700 0

ToFt in

1,276 0 

1,321 0 

1,391 0 

1,624 6 

1,647 0 

1,711 0 

1,712 0 

1,713 0 

1.365 3 

1,624 1 

1,654 7 

1,663 3 

1,668 1 

1,700 3

Plate

XL. _

XL._____.

XXXII___

XLIXLVI___.. 

XL_______

XL.._____

XL. 

XL.______

XXXII.. _ 

XVIII.. ._ 

XLVI - 

LIT 

XLVI-- 

Name

Pale olive buff. 

Pale olive buff.. 

Pale turtle green. 

Yellowish glaucous. 

Fuscous. 

Pale olive buff. 

Deep olive buff. 

Olive buff. 

Olive buff. 

Pale turtle green. 

Pale Veronese green. 

Chaetura drab. 

Pearl gray. 

Grayish olive.

Organic matter was determined by treating the 

sample for about 2 hours on the steam bath with 

(1 + 1) HC1 and filtering, using a 4lH Whatman 

filter paper. The residue was then transferred from 

the paper, by means of a stream of water, to a 100-ml 

platinum crucible, to which was then added about 

20-ml (1 + 1) HC1 and 70 ml of HF. A well-fitting 

cover was placed on the crucible and it was allowed 

to remain on the steam bath over night. The residue 

was then filtered on 41H paper, using a polyethylene 

funnel and beaker, and washed well with hot (1+3) 

HC1. The residue was transferred to a 25-ml platinum 

crucible by means of a stream of water, the water was 

removed by evaporation on the steam bath and the 

crucible, plus contents, was then allowed to remain 

overnight in an oven at 90° C. After cooling in a 

desiccator and weighing, the organic matter was burned 

off and determined by difference. A correction must 

be applied for the sulfur of the pyrite present after 

determining iron in the residue following the burning 

off of the organic matter.

The water lost above 110° C (H2O+110° C) was 

determined by slowly burning off the organic matter 

of a sample in a platinum crucible and then heating 

over night in a furnace held at 900° C. The loss of 

weight after correcting for the organic matter, the 

CO2 , theH2O-110°C,the sulfur of the pyrite, and the 

oxidation of the FeO present to Fe2O3 , is a measure 

of theH2O+110°C.

Because of the inertness of the organic matter, 

FeO can be determined in the usual manner. An 

excellent end point is obtained when titrating with 

twentieth-normal permanganate.

The specific gravity was determined by using a 

fused silica Adams-Johnston pycnometer. The interstitial air was removed by allowing the sample in 

the pycnometer (about half filled with boiled and
ROCKS CONTAINING THE SALINE MINERALS 15

TABLE 3. Chemical analyses (in percent) of samples from the drill core of the John Hay, Jr., well 1, Sweetwater County, Wyo. 

[Joseph J. Fahey, analyst. Samples are listed by laboratory number. Depths of sample? given in table 2]

SiOi. ..........................

A.\tO s ... ...........................................

FeiOz.... ................. - ...

FeO-- . ......

TIOz - -

PtOi... .......... .. ..

CaO-___._. _______ .....

MgO. --. __.-___._ ...

BaO. ............ ....

MnO. .........................

NazOi...... -_--.__-.--______-____ ...

KsO 1 . ... - -

Li 2O2 ----. _

SO 3 .... _ .

S-._.____ .....

Cl.. ..... .. .

C0 2 _. --._._- ... -

H2O-11C0C__._ ._ ..... Hao+no°c. ........... . . .

Organic matter.. ._ _ ...... . _ . ...

Oxygen correction for Cl and S3 __ -..--.......

Specific gravity at 4° C ___ ... .. . .... .

148137

1 98

95

.10

°2

91 37

.02

12.15

2.07

.04

.37

.30

29.76

7.78

.81

1.07

100. 04 -.16

99.88

148138

97 QA

1 92

.80

.24

.17

1 °. O9

A Qfi

no

10.84

4. ^7

nfi

.00

1 flQ

.85

20.22

1 7Q

K on

101.29 -.46

100.83

148139

On QQ

1 Q 4

90

10

.00

9 OK

12 03

2.75

03

.00

.08

2.38

14.44

4.40

6.76

100. 78 

-.56

100. 22

148140

O£ Q1

3 W7

8970

10

.04

17.89

no

0 «Q

.04

.00

QQ

.21

26.49

2 09

100. 06

99.91

148141

3.42

1 89

.14

.01

8 m

02

no

A 4.Q

.04

21.11

100. 35

100. 22 

2.091

148142

or no

c or

00

1 °5

01

no

12 89

.00

.10

1 4*.

09

.34

.06

.93

99.81

99.71 

2.593

148143

on Qfl

2.74

2

4 0

I

ns

25

13.06

7.77

nn

04

2 39

04

.00

2.17

.05

.50

52

100. 68 -.25

100. 43 

2.342

148144

OQ nn

8 64

50

1.10

.22

.01

.00

.09

2.80

.07

.23

19.80

.56

5.77

100. 96 

-.07

100. 89 

2.518

151391

1.14

1.00

.02

16.75

10.64

.00

.08

2 47

.02

.00

.88

.47

21.82

1.17

1.32

10.49

100. 50 -.32

100. 18 

2.458

151392

27.38

6.33

1.42

.25

.01

14.03

.08

5.63

3.70

.09

.00

.63

.31

20.86

2.40

2.22

o.43

100. 15 -.23

99.92 

2.560

151393

3.82

.31

.68

.13

.02

2.54

.04

.00

.03

.25

33.10

.69

1.16

3.21

100. 69 -.06

100. 63 

2.697

151394

04 97

4.78

2.45

.65

.17

.00

8.32

.00

.04

1.98

2 22

.04

.00

1.57

.06

15.00

.95

1.29

25.32

100. 87 -.16

100. 71 

1.978

151395

31.87

7.67

.83

1.05

.01

7.31

.02

4.93

.02

.00

.30

.10

21.57

1.51

1.79

1.45

100. 58 -.10

100. 48 

2.648

151396

24.80

3.23

.12

.01

18.01

12.98

.00

1.04

1.94

.09

.00

.52

.05

27.28

.44

1.06

7.04

100. 72 -.14

100. 58 

2.519

1 Determined by Laura Reichen using ion-exchange method.

2 Determined by Janet Fletcher by means of visible spectrum.

8 The sulfur correction was made on the basis of the sulfur present as pyrite.

cooled distilled water) to remain under a bell jar at 

reduced pressure until no bubbles were forced to the 

surface by gentle tapping.

SPEC TRO GRAPHIC ANALYSIS

The 14 samples from the John Hay, Jr., well 1 

were examined quantitatively for minor elements 

spectrographically and the results are given in table 4. 

Each sample was ignited before placing it in the arc. 

Sixteen minor elements were found and 24 more were 

looked for but not detected.

PARTICLE SIZE

Each sample was ground in a jaw crusher and rolls 

and a 5-gram portion (2 grams of sample 148139) 

of each was dispersed in distilled water. Particles

larger than 64^ (sand fraction) were removed by wet 

seiving and the clay (<C2;u) and silt (2-64/z) were 

separated by repeated centrifuging and decanting. 

The fractions obtained were dried and weighed and 

their proportions calculated as percentages. The 

loss in weight from the original sample is presumed to 

be due to the loss of water-soluble material. The 

consolidated nature of the shales makes it improbable 

that the figure shown in table 5 represent the true 

particle size distribution in the shale. The sand 

fractions of most of the samples contain aggregates of 

finer material.

MINERAL ANALYSIS

The proportions of the minerals in the clay and silt 

fractions listed in table 5 were semiquantitatively

TABLE 4. Quantitative spectrographic analyses for minor elements in samples from the drill core of the John Hay, Jr., well 1, Sweetwater County, Wyo.

[Janet D. Fletcher, analyst. Samples are listed by laboratory number. Depths of samples given in table 2]

Laboratory

Cu 1

Mo -----

Pb. - ....... ......

Mn - ..- 

Co ............ ......

NL ......... ........

Cr _ ... .

V- ----._.

So. ..----......_.- ....

Y. ..

TL. ...................

Zr. ......

Sr. ....................

Ba_. ............. ..... Li 2

B_

148137

0 02^

.001

.02

.0007

.003

.002

.08

.003

02

.002

148138

0.047

0

.002

.04

nni

.009

0002

2

.005

09

.03

02

148139

0 24

0

.07

.001

.005

flAO

007

QQQO

f\AO

02

149140

O

rvoo

0

AfiO

nAQ

.006

.0002

0

.009

.003

09

no

02

rvnn

148141

0.014

022

.002

.03

.01OOO9

.002

09

.0,5

02

148142

0.021

0

no

fino

.005

flflQ

0

0

2

.004

.08

no

.04

.02

148143

O noc

.004

.005

.006

nni

.05

.009

148144

0

0

.003

.004

0

o

.003

.1

.02

.03

009

151391

0 0072

0

.02

.001

.003

.004

.005 000°

0

.06

.01

.003

151392

0

.07

.006

0

.002

.08

.04

.04

.01

151393

0.027

0

0

.05

.001

.004

.005

.006

0

0

.1

.004

.2

.006

.02

.01

151394

0.033

.001

0

.07

.001

.004

.004

.009

.0002

0

.1

.007

.2

.01

.02

.008

151395

0.018

.002

0

.03

.0009

.003

.005

.U08

0

0

.08

.002

.2

.04

.01

.008

151396

0.013

.002

0

.02

.001

.005

.004

.009

0

0

.09

.003

.08

.04

.04

.007

1 Two significant figures for Cu are given because results were obtained on highly diluted samples.

2 A special exposure in the visible region was made to obtain better sensitivity for lithium.

Note. 0 in unit column means element not detected. All samples were ignited prior to analysis.

Looked for but not found: Ag, Au, Hg, Pd, Os, Ir, Pt. W., Ge, Sn, As, Sb, La, Be, Bi, Zn, Cd, Tl, In, Th, Nb, Ta, U, and P.
16 SALINE MINERALS OF THE GREEN RIVER FORMATION

TABLE 5. Particle-size analysis, in percent, of 14 samples of oil 

shale from the drill core of the John Hay, Jr., ivell 1, Sweetwater 

County, Wyo.

[John C. Hathaway, analyst. Depths of samples given in table 2]

TABLE 6. Semiquantitative estimation, by means of X-ray diffraction patterns, of the minerals present in the clay and silt fractions 

of samples from the John Hay, Jr., well 1, Sweetwater County, 

Wyo.

Laboratory 

No.

148137 

148138 

148139 . 

148140 

148141..........-....--..--.. ...

148142 _ _

148143...... -.-. . --------

148144 

151391 

151392 

151393 . --.

151394 _.-

151395 

151396 .

Sand 

(>64M)

26

15

1 fi

10

53

23

66

47

64

44

72

24

70

Silt 

(2-64M)

37

33

61

KQ

25

46

19

32

28

29

31

20

49

19

Clay 

K»

11

28

5

4

27

7

10

8

10

14

20

7

Difference 

(H20 

soluble)

26

24

19

10

18

4

8

0

6

11

3

7

4

estimated by means of their X-ray diffraction patterns, 

and are reported as parts in ten in table 2. X-ray 

diffraction patterns were made for each sample as 

follows:

Clay fraction:

1. Oriented aggregate, air dried.

2. Oriented aggregate, treated with ethylene 

gylcol.

3. Oriented aggregate, heated at 400° C in 

diffractometer furnace.

4. Oriented aggregate, heated at 500° C in 

diffractometer furnace.

5. Randomly oriented powder, air dried.

6. Randomly oriented powder, treated with formic 

acid.

7. Randomly oriented powder, treated with hot

concentrated HC1. 

Silt fraction:

1. Randomly oriented powder, air dried.

2. Randomly oriented powder, treated with formic 

acid.

3. Randomly oriented powder, treated with hot 

concentrated HC1.

As the estimates of minerals present, listed in table 

10, are derived from the relative intensities of the 

diffracted lines, and as many factors in addition to the 

quantity of a mineral affect the diffraction intensity, 

the estimates are not intended to give more than a very 

general indication of the relative amounts of the various 

minerals present. A measure of the acid-soluble portion 

(table 7) of the sand, silt, and clay fractions of samples 

151391 to 151396, inclusive, listed in table 5, was obtained by treating on the steam bath with (1 + 1) HC1 

for about 30 minutes a weighed sample of each fraction, 

filtering on a preweighed fine-mesh sintered-glass filter, 

drying overnight in an oven held at 90° C, and weighing. 

The difference between the weight of the sample and

[John C. Hathaway, analyst

Laboratory 

No. Fraction

148137-. Clay «2M)___

Silt (2-64^)---

148138- _ Clay. _ _______

Silt

148139-- Clay_. -------

Silt

148140. _ Clay.. ------ -

Silt

148141-. Clay----...--

Silt

148142__ Clay.- -------

Silt

148143__ Clay__-___--_

Silt

148144__ Clay._ ------

Silt.-. -----

151391 Clay__ _ -_

Depths of samples

Minerals present

Orthoclase

Calcite,

Dolomite _ 

Loughlinite

Mica _.__

Quartz _

CalciteQuartz

Orthoclase __

Orthoclase _

Mica-__-___

LoughliniteCalcite.

Calcite_.

Quartz

Orthoclase

Dolomite

Mica_- _

Loughlinite- _ 

Aragonite (residue

shortite) .

Orthoclase _

Mica_

Loughlinite.

Aragonite __ __

Orthoclase _

Dolomite.

Quartz _ _

Orthoclase __

Loughlinite

Mica ___

Dolomite

Quartz _

Orthoclase

Calcite_ _

Dolomite

Mica 

Orthoclase _

Calcite _ _

Quartz. __

Loughlinite

Dolomite

Calcite __

Quartz _

Orthoclase __

Dolomite

Mica

OrthoclaseQuartz _______-_--

Montmorillonite _ -

Dolomite__

Quartz

Orthoclase

Dolomite

Orthoclase _

Mica __

Quartz

Dolomite

Quartz

Orthoclase __

Dolomite

Quartz

Mica

Orthoclase __

Dolomite

Quartz

Orthoclase _

Mixed layered

montmorillonite.

Dolomite

Quartz _ _ _

given in table 2]

Estimated

amount 

(parts in 10)

_____ 3

9

_____ 1

2(?)

_____ 1

_____ Tr.

_____ 4

2

_____ 1

1

_____ 5

_____ 2

_____ Tr.

_____ 3

__ _ 2

2

9

_____ Tr.

4 

from 3

_____ 2

_____ Tr.

_____ 4

_____ 3

2

_____ 3

2

_____ 1

2

Tr.

6

_____ 2

___ _ Tr.

Tr.

_____ 3

_____ 2

_____ 2

_ _ _ 1

_____ 1

_____ Tr.

4

_____ 3

____ 2

__ __ Tr.

3

_____ 3

_____ 2

1

____ Tr.

6

_____ 3

____ Tr.

____ 4

____ 2

2

1

6

_ __ 2

1

____ 3

2

1

6

2

1

mica- 2

____ 5

1
ROCKS CONTAINING THE SALINE MINERALS 17

TABLE 6. Semiquantitative estimation, by means of X-ray diffration patterns, of the minerals present in the clay and silt fractions 

of samples from the John Hay, Jr., well 1, Sweetwater County, 

Wyo. Continued

[John C. Hathway, analyst. Depths of samples given in table 2]

Laboratory

No. Fraction

151392._ Clav

Silt.

Minerals -present 

Feldspar. ________ _ _ . _ _

Calcite_ _______________

Dolomite__ ____________

Quartz. _______________

Calcite. _______________

Feldspar(?) ____________

Mixed layered micamontmorillonite. 

Dolomite ______________

Quartz- - ______________

Feldspar, _____________

Montmorillonite____ _

151393.- Clay.

Silt.. 

151394__ Clay.

Silt.. 

151395__ Clay.

Quartz. _ ______________

Oalcite_ _______________

Feldspar. _____________

Mixed layered micamontmorillonite. 

Dolomite. _ ____________

Feldspar. _____________

Dolomite, _ ____________

Feldspar. _____________

Dolomite____ __________

Quartz. _ ______________

Feldspar. _____________

Mixed layered micamontmorillonite. 

Dolomite. _ ____________

Quartz_ _ ______________

Feldspar. _____________

151396._ Clay.

Feldspar. 

Quartz. __ 

Dolomite. 

Dolomite_ 

Quartz- _- 

Calcite. _ _ 

Feldspar.

Silt.

Quartz. _ _ Mica *_ _- 

Feldspar. 

Dolomite_ 

Quartz ___ 

Feldspar.

Estimated

amount

(parts in 10)

1

Tr. 

5 

2

2 

Tr.

3

3 

1 

1

Tr. 

5 

2 

1 

1 

3

3 

3 

7 

2 

6 

1 

1 

Tr.

5

3

1

4

2

1

2 

4 

3 

1 

1 

4 

3 

1 

1 

6 

o

i May have small number of interstratified montmorillonite layers,

the residue is recorded in table 7 as percent of the clay, 

silt, and sand fractions soluble in (1 + 1) HC1. This 

soluble portion was made up chiefly of the carbonates 

present in each sample.

ORGANIC MATTER

The organic matter contained in the Green River 

formation is the contribution of countless numbers of 

tiny organisms that, having finished their life cycle, 

sank to the muddy bottom of the lake, and were buried 

and changed through millions of years to form this vast 

accumulation of fossil fuel. The "oil shale" constitutes 

a tremendously large source of energy that awaits only 

propitious economic conditions to perform the thousands of tasks now done by crude petroleum.

The concentration of organic matter in the Wilkins 

Peak sediments ranges from less than 1 percent to

TABLE 7. Solubility in hydrochloric acid of the clay, silt, and 

sand fractions of samples from the John Hay, Jr., well 1, Siveetwater County, Wyo.

[Joseph J. Fahey, analyst. Depths of samples are given in table 2. Particle-size 

analyses are given in table 5]

Laboratory

No. Solubility of fraction in (1+1) HC1

151391____ Clay, 50 percent of 8 percent = 4 percent 

Silt, 58 percent of 28 percent=16 percent 

Sand, 58 percent of 64 percent = 37 percent

57

151392_ ___ Clay, 39 percent of 10 percent^ 4 percent 

Silt, 53 percent of 29 percent = 15 percent 

Sand, 55 percent of 55 percent = 30 percent

49

151393.___ Clay, 40 percent of 14 percent= 6 percent 

Silt, 78 percent of 31 percent = 24 percent 

Sand, 81 percent of 44 percent = 36 percent

66

151394_ ___ Clay, 70 percent of 5 percent = 4 percent 

Silt, 40 percent of 20 percent = 8 percent 

Sand, 36 percent of 72 percent = 26 percent

151395_ - _ _ Clay, 27 percent of 20 percent^ 

Silt, 52 percent of 49 percent = 

Sand, 70 percent of 24 percent =

151396. __. Clay, 44 percent of 7 percent^ 

Silt, 62 percent of 19 percent : 

Sand, 61 percent of 70 percent:

38

= 5 percent 

=25 percent 

= 17 percent

47

= 3 percent 

=12 percent 

=43 percent

58

probably more than 30 percent. In the 14 chemical 

analyses listed in table 3, the lowest content of organic 

matter is 1.07 percent and the highest is 25.32 percent. 

A sample from the drill core of the John Hay, Jr., well 1, 

which was obviously high in organic matter, was selected 

to serve as a source of organic matter on which the 

specific gravity could be determined and the index of 

refraction measured. This sample contained 26.88 

percent organic matter and had a bulk specific gravity 

of 1.898 at 25° C. This was determined on the Jolly 

balance by using a piece that weighed between 16 and 

17 grams, the entire surface of which had been made 

smooth by applying fine sandpaper. This was done to 

eliminate the possibility of air entrapment in tiny 

surficial cavities, which would result in a figure for the 

specific gravity that would be lower than the correct 

one.

The organic matter and the pyrite were separated 

from the other material of the sample by treatment as 

follows:

1. A sample weighing 10 grams that had been ground 

to pass a 200-mesh sieve was treated in a beaker 

with about 100 ml of (1 + 1) HC1 and allowed to
18 SALINE MINERALS OF THE GREEN RIVER FORMATION

remain on the steam bath for about 1 hour. This 

removed the carbonates.

2. The solution was filtered using a 41H Whatman 

filter paper and washed with warm dilute HC1. 

The residue was transferred with a stream of 

water to a platinum crucible of 100-ml capacity, 

and 5 ml of concentrated HC1 and 50 ml of HF 

were added. A well-fitting cover was applied and 

the crucible was allowed to remain on the steam 

bath overnight.

3. It was filtered on 41H Whatman paper using a 

polyethylene funnel and beaker, washed with 

warm dilute HC1 and the residue was returned to 

the same crucible and 50 ml of dilute HC1 was 

added. It was covered and heated on the steam 

bath about an hour.

4. The residue which consisted of the organic matter 

and the pyrite was filtered on a 41H Whatman 

paper, washed with warm water, and transferred 

with a stream of water back to the same crucible.

5. The crucible and contents were placed on the steam 

bath until the water was evaporated and then 

transferred to an oven held at 80° C and allowed 

to remain overnight. After cooling, the residue 

was lightly ground to destroy caking and passed 

through a 200-mesh sieve.

The specific gravity of the organic matter plus pyrite 

was found to be 1.064 at 4° C. A 0.5480-gram sample 

was used and placed in a fused-silica Aclams-Johnston 

pycnometer of 25-ml capacity. The sample was 

covered with boiled and cooled distilled water to which 

a drop of aerosol wetting agent had been added. The 

pycnometer and contents were then placed under a bell 

jar and the pressure reduced to about 3 cm of mercury 

and held there for about 2 hours. During this time the 

pycnometer was repeatedly agitated to cause air bubbles 

trapped by the fine-grained organic material to rise to 

the surface of the water. The pycnometer was then 

removed from the bell jar to a water bath held at 33° C 

and allowed to remain there until the temperature of 

the pycnometer and contents reached the temperature 

of the bath. This required about 45 minutes. The 

pycnometer was then filled with boiled distilled water 

that had been brought to the temperature of the bath, 

and the cap of the pycnometer was immediately put on. 

After the pycnometer was dried with a soft towel and 

allowed to remain on the balance pan for 45 minutes, 

its weight, plus the weight of the sample and water 

contained therein, was obtained. Likewise, without 

the vacuum treatment, the figure for pycnometer plus 

water was obtained. From these figures and the 

weight of the sample the specific gravity at 33°C was 

obtained and computed to 4° C by applying the proper 

factor.

The pyrite content of the organic material was found 

by determining the iron and computing to FeS2 . This 

gave the figure 6.28 percent pyrite. On another sample 

sulfur was determined that when computed gave the 

figure 6.70 percent pyrite. The figure 6.28 percent 

was arbitrarily selected on the reasoning that the 

organic matter may have contained the sulfur equivalent of the difference between 6.70 and 6.28 percent 

pyrite. An X-ray powder pattern confirmed the presence of pyrite.

The specific gravity of the pj^rite in the organic 

matter was assumed to be 5.000. Using this figure, 

the percent of pyrite present, and the determined 

specific gravity of the organic matter plus the pyrite, 

the specific gravity of the organic matter was computed, 

as follows:

6.28 100.00-6.28_ 100 .

5.000+ x "1.064

x=1.01, which is the specific gravity of the organic 

matter at 4° C.

The index of refraction of the organic matter is 1.60. 

A 0.2500-gram sample was treated for about an hour 

with CS2 +Br+HNO3 , after which it was filtered, 

washed, and dried overnight on the steam bath, and 

allowed to remain for 4 hours in an oven at 80° C. The 

sample was then cooled in a desiccator and was found 

to weigh 0.3410 grams, an increase of 36 percent over 

the original 0.2500 gram weight. The index of refraction dropped 0.01 to 1.59. The increase in weight was 

undoubtedly due to oxidation and possibly bromination 

of organic compounds that make up the heterogeneous 

mixture of saturated and unsaturated hydrocarbons.

Nitrogen was determined by the Kjeldahl method on 

a %-gram sample of the organic matter, and found to 

be 2.04 percent. After correcting for the 6.28 percent 

pyrite, the pure organic matter was found to contain 

2.18 percent nitrogen.

SALINE MINERALS 

DISTRIBUTION

The term "saline mineral" as used in this report, 

refers to those minerals having sodium occupying one 

or all of their cation positions, and the carbonate radical 

supplying all or part of the negative charge. Saline 

minerals found in more than trace quantities in the 

Green River rocks are shortite (Na2CO3 -2CaCO3 ), 

pirssonite (Na2CO3 .CaCO3 -2H2O), gaylussite (Na2CO3 - 

CaCO3 -5H2O), trona (Na2CO3 -NaHCO3 -2H2O), nahcolite (NaHCO3 ), northupite (Na2CO3 .MgCO3 -NaCl), 

and bradleyite (Na3PO4 -MgCO3 ). Traces of tychite (2Na2CO3 -2MgCO3 .Na2SO4 ) and thermonatrite 

(Na2CO3 -H2O) also have been found.
SALINE MINERALS 19

During the long period of time required for the 

deposition of the sediments that are now the Green 

Kiver formation, there were great variations in the 

conditions that brought about precipitation of the saline 

minerals. Changes in the composition and concentration of the lake waters caused by successive periods 

of rainfall and drought, varying amounts of carbon 

dioxide made available by decaying organic matter on 

and above the lake bottom, variations in the temperature of the brine at the bottom of the lake all of 

these, singly and collectively, determined which of the 

saline minerals was precipitated at any given horizon. 

In the PCO2-T diagram (fig. 6) of the system NaHCO3- 

Na2CO3-H2O, it is seen that at a given partial pressure of 

CO2 , trona precipitates at a higher temperature than does 

nahcolite. A rise in temperature of less than 1°C could 

cause the precipitation of trona instead of nahcolite. 

If temperatures were the only factor, this would indicate

- 5000

Thermonatrite + Solution

20 30 40 

 >- Temperature in degrees centigrade

FIGURE 6. PCOs-T diagram of the system NaaCOs-NaHCOs-H^O. (From Carnegie Institute of Washington Yearbook 1957, p. 182.)

596568 O 65
20

125C

Percent shortite 

10 20 30

1800 

FIGUBE 7. Histogram showing the percentages of shortite, trona, and northupite in the drill core of the John Hay, Jr., well 1, Sweetwater County, Wyo.

that a warmer climate prevailed north of the Uinta 

Mountains when the sediments were laid down in 

Gosiute Lake in what is now the Wyoming area where 

trona is found in great abundance than to the south 

of these mountains in the Uinta Basin of Utah, and in 

the Piceance Creek basin of Colorado, where nahcolite 

(Ertl, 1947) is common and trona has rarely been found 

and then only in a few tiny isolated crystals. However,

other factors such as the partial pressure of CO2 , the 

depth of the lake, the thickness and translucence of 

the relatively fresh stratum of water above the brine, 

which in limnological parlance is called the epilimnion, 

probably played a greater part than the climate in the 

precipitation of trona and nahcolite.

It is in the sediments to the north of the Uinta 

Mountains, in the Wyoming area, that the greatest
SALINE MINERALS 21

concentration of saline minerals is found. These are 

recorded in the log of the John Hay, Jr., well 1, and 

the quantitative distribution of the three most abundant 

of these minerals, shortite, trona, and northupite, is 

graphically shown in the histogram (fig. 7).

As recorded in this log, shortite is ubiquitous between 

the depths 1,251 feet and 1,806 feet 6 inches, a vertical 

distance of 555 feet 6 inches. This is in sharp contrast 

to the saline-mineral content of the sediments of the 

Piceance Creek basin in Colorado, where the presence 

of shortite has never been reported, and the only saline 

mineral found is nahcolite (Ertl, 1947).

In the Uinta Basin, shortite (Erickson, 1952) and 

nahcolite are the only saline minerals that have been 

reported in greater than trace quantities. The shortite 

occurs abundantly as individual crystals in the shale, 

and nahcolite is likewise liberally distributed throughout these sediments. Massive nahcolite has not been 

reported in the Uinta Basin, but at the site of the oilshale mine near Rifle, Colo., in the Piceance Creek

Shortite 

Na2C03 2CaC03

basin, lenses of this mineral as much as 10 feet in 

diameter are not uncommon.

Pirssonite and gaylussite are found between depths 

of 1,261 and 1,390 feet, and constitute about \% and 

K percent, respectively, of this 129-foot thickness of 

sediments. Each of these minerals occurs as anhedral 

ctystals that are seen, in thin section, replacing shortite, 

and frequently in turn being replaced by northupite 

(fig. 8).

Bradleyite (Fahey and Tunnell, 1941) was found in 

a 1-inch stratum at a depth of 1,342 feet 10 inches in 

the core of the John Hay, Jr., well 1, in intimate association with shortite and clay. A thin section (fig. 9) 

shows crystals of shortite in the process of replacement 

by bradleyite. During the sinking of the No. 1 shaft 

of the Westvaco mine, about 4 miles north of the John 

Hay, Jr., well 1, bradleyite (fig. 10) was found in lowgrade oil shale from a depth of 1,245 feet. Authigenic 

subhedral crystals of bradleyite (fig. 11) have been 

found in minute quantities in the residue obtained when

Northupite

Na2C03 - MgC03 - H 20

Pirssonite northupite 

Na2C03 - CaC03 - 2H 20

Gaylussite - northupite 

Na 2C03 CaC03 5H20

Trona northupite 

Na2C03 - NaHC03 - 2H 20

Bradleyite 

Na3 P04 -MgC03

FIGTJKE 8. Diagrammatic representation of the paragenetic sequence of six saline minerals of the Green River formation

in Wyoming.
22 SALINE MINERALS OF THE GREEN RIVER FORMATION

FIGURE 9. Photomicrograph of thin section from drill core of the John Hay, Jr., 

well 1, depth 1,342 ft. 10 in., showing the sequence shortite to bradleyite. Planepolarized light. X15.

trona from the Westvaco mine was dissolved in water 

(Mrose, Fahey, and Chao, in preparation).

Three small grains of tychite (2Xa2OO3 -2MgCO3 - 

Na2SO4), the sulfate analogue of northupite, were found 

at a depth of 1,390 feet 8 inches in the core of the John 

Hay, Jr., well 1. A very small amount of thermonatrite 

(Na2CO3 -H2O) was identified at a depth of 1,441 feet 

9 inches. Identification of these two minerals was 

made by their indices of refraction.

SHORTITE 

NAME OF MINERAL

The mineral shortite (Fahey, 1939), which has the 

formula (Na2COs'2CaCO3), was found in the drill core 

of the John Hay, Jr., well 1 in 1939 and was named in 

honor of Dr. Maxwell N. Short, a geologist who had 

been a member of the U.S. Geological Survey until he 

joined the faculty of the University of Arizona. His 

name was given to this new carbonate in recognition of 

his excellence as a teacher of mineralogy and for his 

untiring efforts to stimulate in the chemists, who were 

his associates while he was a geologist of the U.S. 

Geological Survey, an interest not only in minerals but 

also in the optical and physical methods used in their 

identification.

OCCURRENCES

The Wilkins Peak member of the Green River formation in southwestern Wyoming, formerly called the

FIGURE 10. Photograph of bradleyite (light-colored area at top center) on low-grade 

oil shale. From a depth of 1,245 ft, shaft 1, Westvaco mine.

Laney shale member (Bradley, 1959), contains the zone 

in which the saline minerals occur. In the core of the 

John Hay, Jr., well 1 that pierces these sediments, the 

upper limit of this saline zone at the depth 1,251 feet 

and the lower limit at 1,806 feet 6 inches, is marked by 

the mineral shortite. Between these depths shortite is 

omnipresent and constitutes a visually estimated 10 

percent of this vertical column of sedimentary rock 

(fig. 7). A simple calculation leads to the astounding 

figure of approximately 125 million tons of shortite 

under each square mile of this area. Shortite occurs as 

individual undeformed crystals in the dolomitic sediments and presents a unique pattern of saline deposition. 

The only other known location of shortite is also in 

the Green River formation but, in the Uinta Basin in 

northeastern Utah, it is found abundantly in association 

with nahcolite (Erickson, 1952).

FIGURE ll. Authigenic crystals of bradleyite from the trona bed of the Westvaco

mine.
SALINE MINERALS 23

CRYSTALLOGRAPHY

Shortite occurs as orthorhombic hemimorphic crystals that range in size from about 2 mm to as much as 

3 cm in the longest direction of the crystal, which is 

usually parallel to the b axis. Less frequently the small 

crystals will have their longest direction parallel to the 

a axis. These crystals, referred to in the original description (Fahey, 1939, p. 515) as nearly equant, are 

much less common than those having the tabular habit.

The crystals (figs. 12 and 13) are simple in habit, 

bounded by only five well-developed faces, the front 

and back pinacoids (100) and (100), two domes (Oil) 

and (Oil), and the base (001). There is a distinct 

cleavage parallel to the brachypinacoid (010) that does 

not occur as a crystal form.

Each of the crystal faces other than the base forms a 

smooth uninterrupted plane. No crystal has been observed that shows terraced growth lines on these faces 

such as one sees on crystals of quartz. This could be 

interpreted as indicating that during the growing period 

of the crystal there were no environmental changes of 

sufficient magnitude to halt the growth of the crystal 

temporarily. However, it is most unlikely that such an 

interpretation would be correct, because shortite is 

found throughout the saline zone that has a vertical 

thickness of 555 feet and which was deposited through 

a period of approximately 1 million years. It is 

evident then that environmental changes, even though 

they may have temporarily halted the growth of an 

individual crystal of shortite, did not produce terraced 

growth lines on the crystal faces.

OPTICAL AND PHYSICAL PROPERTIES

Shortite varies from colorless to a pale yellow. The 

yellow color is due to minute traces of organic matter 

that cause a light amber fluorescence in ultraviolet light 

of wavelength 2,537A.

FIGURE 12. Crystals of shortite, small and medium sizes.

FIGURE 13. Large crystals of shortite in place, in sections of core from the John Hay,

Jr., well 1.

The indices of refraction are:

«______________________!. 531

fl-_-_____--------------1.555 ±0.002

7____________________-_!. 570

2F=75°, optically negative (calculated). 

The dispersion is r<C v (slight). 

The optical orientation is:

X, a (acute bisectrix) =c 

F,/8 =a 

Z, j (obtuse bisectrix) =b

Optical and physical properties of the seven saline 

minerals are listed in table 8.

Shortite is strongly pyroelectric, has a vitreous luster 

and a conchoidal fracture. Rarely will a blow cause the 

crystal to break along the cleavage parallel to the 

brachypinacoid (010). The hardness is reported as 3 

in the original description of the mineral (Fahey, 1939, 

p. 516). A redetermination of the hardness indicates 

that it is nearer to 3}£ and it is so recorded. The 

specific gravity was determined as 2.629 by the 

pycnometer method, using water as the liquid medium. 

At 25° C, water attacks shortite so slowly that no measurable error was introduced by differential solution.

CHEMICAL PROPERTIES

The chemical analysis of shortite is given in table 9. 

Shortite is soluble in cold dilute acids with effervescence, 

and is differentially decomposed by water, the sodium 

carbonate going into solution and the calcium carbonate 

remaining in the solid phase as calcite and forming a 

pseudomorph of the original crystal.

When a crystal of shortite is heated in a test tube to 

about 200°C, inversion takes place accompanied by 

violent decrepitation. By means of an X-ray powder 

pattern taken of this residual material, calcite was identified as one of the phases. It was not established
24 SALINE MINERALS OF THE GREEN RIVER FORMATION

TABLE 8. Optical and physical properties of the saline minerals 

[Determined by Joseph J. Fahey]

/3.-.- _-. .-. ..-_.-_-.-_._-_._.--_______

2V (calc.)- ____ .... .. ..... __ ....... ___ .......

Shortite 

(orthornombic)

1.531

1.555

1.570

0.039 75°

r<v

3H

Pirssonite 

(orthorhombic)

1.504

1.509

1.573

0.069 27°

r<v

3-3H

Gaylussite 

(monoclinic)

1 M.<^

i 51 d

1.524

0.079 40°

2^-3

Trona 

(monoclinic)

1.417

1 494

1.543

0.126 74°

2.147

2J4-3

subconchoidal

Nahcolite 

(monoclinic)

1.375

1.498

1.583

0.208 74°

2.238

2H

Bradleyite 

(monoclinic)

1.487

1 Pi4.fi

1.560

0.073 50°

N"G£8itiVG

r<»

1 2 720

3H

Northuplte 

(isometric)

n- 1.513

2.407 3H-4

i Determined on Herman balance by Mary E. Mrose.

whether the other material present was one or more of 

the many polymorphs of sodium carbonate, or a phase 

containing both sodium and calcium carbonate.

SPECTROGRAPHIC ANALYSIS

The spectrographic analysis (table 10) was made on 

a powdered sample of shortite, using d-c arc excitation 

in which a steady current of 16 amperes was maintained 

between the graphite electrodes. The spectra in the 

region, 2,350A to 4,750A were recorded on spectroscopic plates, using a grating spectrograph having a 

reciprocal linear dispersion of 5A per millimeter. The 

spectral lines of shortite and the synthetic standards 

were evaluated by means of a nonrecording densitometer.

The elements looked for but not found are recorded in 

table 10 where it is seen that the copper content of 

shortite and that of the five other saline minerals is very 

nearly the same. Shortite contains the same percentage 

of tin, manganese, chromium, beryllium, and barium as 

the other saline minerals, with the following exceptions: 

Gaylussite contains more tin, chromium, and barium; 

the percentage of manganese in northupite is greater by 

two orders of magnitude; and trona has a higher content 

of beryllium. The 0.10 percent strontium in shortite is 

higher than the strontium percentage of any of the 

other saline minerals.

INDUSTRIAL USE

The composition of shortite is such that it could be 

used as a replacement for all or part of the limestone 

and soda ash that are necessary constituents in the 

manufacture of the more common types of commercial 

glass. However, although it is the most abundant 

saline mineral in the Wilkins Peak member of the 

Green River formation, the cost of recovery for industrial use probably would be» prohibitive. Even 

though this were not so, the presence of inclusions of 

pyrite would raise the iron content beyond the range 

allowable in the manufacture of any but the cheaper 

grades of colored glasses.

Shortite could by utilized as a source of sodium 

carbonate by leaching with hot water. This, too, 

would require concentration and be much more costly 

than would the extraction of sodium carbonate from 

thick beds of trona. It must be concluded, then, 

that it is unlikely shortite will be of economic value.

GENESIS 

COMPOSITION OF SEDIMENTS

The sediments that make up the Wilkins Peak member of the Green River formation in southwestern

TABLE 10. Spectrographic analyses (in percent) of saline minerals 

from the Green River formation from the John Hay, Jr., well 1, 

Sweetwater County, Wyo.

TABLE 9. Chemical analyses, in percent, of shortite, pirssonite, 

gaylussite, and northupite from the John Hay, Jr., well 1, Sweetwater County, Wyo. 

[Joseph J. Fahey, analyst]

Na2O _ .........................

CaO. __ -_ .__-___._ __

MgO... .-..... ...............

CO». ...... _. 

CL. _- -.__ _- ____________

H»0 --.. ___- ._ 

Insoluble (HC1).............._...

TYttal

Total. _ ..................

Depth... ........ _ ..........ft..

Shortite

19.91 

36.34 

.04 

42.90

.66

99.85

99.85

1,649

Pirssonite

25.45 

22.75 

.18 

35.38

14.70 

1.40

99.86

99.86

1,391

Gaylussite

20.80 

19.20 

.00 

29.39

29.97 

.50

99.86

99.86

1,261

Northupite

36.59 

.04 

15.98 

35.72 

14.01 

.04 

.68

103. 06 

3.16

99.90

1,452

[Harry Uastron, analyst]

C

.-.

Sn...... .. .

Mn_ .... .

Fe 

Or... .... -

Ti-_ 

Be 

Mg__ 

r_ __-____._._ 

Ba .-_ 

Shortite

0. 0005 

<.002 

<.0002 

.008 

<.0004 

.013 

.001 

<.0002 

.022 

Major 

.10 

<. 0002

Trona

0.0005 

<.002 

<.0002 

.003 

<.0004 

 COOl 

 COOl 

.0012 

<.001 

<.0002 

<.0002 

<.0002

Nahcolite i

0. 0003 

<.002 

<.0002 

.002 

<.0004 

<.001 

 COOl 

<.0002 

<.001 

<.0002 

<.0002 

<. 0002

Pirssonite

0.0005 

<.002 

<.0002 

.023 

<.0004 

.052 

.004 

<.0002 

.080 

Major 

.068 

.0080

Gaylussite

0.0006 

.004 

<.0002 

.050 

.0006 

.14 

.004 

<.0002 

.20 

Major 

.022 

.0004

Northupite

0.0004 

<.002 

.048 

.17 

<.0004 

.012 

 COOl 

<.0002 

Major 

.052 

.0009 

<.0002

i From the Bureau of Mines' oil-shale mine near Rifle, Colo.

NOTE. Looked for but not found: Ag, Au, Hg, Ru, Rh, Pd, Ir, Pt, Mo, W, Re, 

Qe, Pb, As, Sb, Bi, Te, Zn, Cd, Tl, In, Co, Ni, V, Ga, Sc, Y, Yb, La, Zr, Th, Nb, 

Ta, U, Li, P, B. 

The above results have an overall accuracy of ±15 percent except near limits of 

detection where only one digit is reported.
SALINE MINERALS 25

Wyoming differ vertically in their content of organic 

matter, dolomite, and detrital minerals. The content of organic material in these rocks ranges from less 

than 1 percent to approximately 30 percent. Dolomite, computed from the 14 analyses in table 3, ranges 

from 22 to 68 percent. Throughout the vertical 

column there are undoubtedly strata having less than 

22 percent dolomite, and it is probable that 68 percent 

is not the highest percentage of dolomite in these 

sediments. The content of detrital minerals, chiefly 

quartz, feldspar, and montmorillonite, ranges from a 

lower limit of approximately 20 percent, but in some 

samples may be as high as 50 percent. This great 

variation in the composition of samples taken at many 

depths between the top and the bottom of the saline 

zone reflects the equally variable composition of the 

bottom muds that, when compacted, became the 

sediments as they are today. It was in these muds 

that shortite precipitated and grew as individual 

crystals, probably after partial compaction due to 

the gradual addition of the overlying sediments. At 

this stage much of the brine had been squeezed out, 

and in the beds that contained a relatively high amount of 

organic matter a condition of sticky plasticity was 

attained.

COMPACTION OF SEDIMENTS

As several thousand feet of overburden was added 

to the partly compressed semiplastic bottom mud in 

which shortite had participitated, and as the individual 

crystals completed their growth, all the brine was 

squeezed out and the sediment tightly pressed around 

the crystals of shortite. The overburden was made 

up of the Laney shale member of the Green River 

formation, formerly called the Morrow Creek member 

of the Green River formation (Bradley, 1959), and 

the fluviatile sediments of the Bridger formation.

FLOW IINES

Many thin sections were cut normal to the bedding 

in order to study the effect of the compaction of the 

sediments around the crystals of shortite. The following conditions were observed:

1. Flow lines bending around crystals of shortite in 

sediments that were moderate to high in content 

of organic matter. In these specimens there are 

less than average amounts of dolomite, and enough 

montmorillonite and flat-lying flakes of mica to 

lend tensile strength to the bedding laminae, 

which flow around the crystal instead of being 

broken or cut by it. A good example of such 

flow is seen in a thin section (fig. 14) cut from a 

specimen obtained by W. H. Bradley from an 

outcrop in the canyon of the Green River, close 

to the tunnel of the old oil-shale mine about half

FIGURE 14. Photomicrograph taken with plane-polarized light showing flow lines 

around pseudomorphs after shortite. Specimen collected by W. H. Bradley from 

the canyon of the Green River, about half a mile upstream from Green River, Wyo.

a mile west of the city of Green River. The 

photomicrograph, taken in plane-polarized light, 

shows the bending of the bedding around pseudomorphs of crystals of shortite. The sodium 

carbonate of the original shortite has been leached 

by rain water, and the residual calcite now forms 

a pseudomorph in each of the crystal cavities. 

The photomicrograph has a magnification of 15 

diameters and shows very little tearing of the 

bedding that was pressed around the crystals of 

shortite during the compaction of the sediments.

2. Absence of flow lines in sediments that are low in 

content of organic matter. An example of this 

condition is seen in a photomicrograph (fig. 15) 

of another thin section from Bradley's specimen. 

The upper half of the pseudomorph is embedded 

in sediment low in organic matter and relatively 

high in dolomite. No flow lines are evident. 

This is in sharp contrast to the appearance of 

the lower half of the crystal that is embedded in 

sediment such as described above in condition 1 

where the content of organic matter is moderate 

to high and flow lines are readily discernible.

3. Absence of flow lines in sediments with a moderate 

to high content of organic matter. These samples have a smaller percentage of montmorillonite 

and clay than those that show flow lines as described under condition 1, and hence the laminae, 

lacking the tensil strength afforded by flat-lying 

minerals, are cut by the crystals of shortite upon 

compaction of the sediments. This condition is 

shown in a photograph of a polished section from
26 SALINE MINERALS OF THE GREEN RIVER FORMATION

FIGURE 15. Photomicrograph showing flow lines around pseudomorphs after

shortite.

the core of the John Hay, Jr., well 1 (fig. 16), 

and in the photomicrograph (fig. 17) of a thin 

section cut from the core of the Westvaco well 3 

at a depth of 1,464 feet 2 inches. In the polished 

section the randomly oriented crystals of shortite 

are seen cutting the bedding. The photomicrograph of the Westvaco core shows poorly defined 

bedding and only faintly visible flow lines, both 

around and cut by the crystals of shortite. The 

magnification is 15 diameters and was made in 

plane-polarized light. These two pictures indicate that at the time of compaction the sediments

3cm

FIGURE 16. Photograph of polished section of core from the John Hay, Jr., well 1, 

depth 1,695 ft to 1,695 ft 3 in, showing randomly oriented crystals of shortite cutting 

across the poorly defined bedding.

FIGURE 17. Photomicrograph of thin section from the drill core of Westvaco well 

3, depth 1,464 ft 2 in, showing crystals of shortite in matrix with no bedding. Planepolarized light.

readily flowed, owing to the high percentage of 

organic matter, but no bedding was developed 

because of the relatively small amount of clay 

and mica present.

SIZE OF CRYSTALS

Crystals of shortite found in medium- to rich-oil 

shale rarely attain a size as great as 1 cm in the longest 

direction (fig. 12). This condition is also found in most of 

the lean shale, as observed in the core of the John Hay, 

Jr., well 1. In this core, however, at depth 1,700 to 

1,725 feet, the crystals are much larger, some measuring 

3 cm across (fig. 13). These crystals have a lightyellow color that is due to traces of organic matter. 

This is in contrast to the colorless condition of almost 

all the smaller crystals found in the medium-rich oil 

shale.

The large light-yellow crystals are very fragile. It is 

unusual to find one of these large crystals unbroken 

when the core is split longitudinally for visual examination. During this same treatment, small crystals fall 

out of the shale or with very little difficulty may be 

picked out intact.

CONSOLIDATED SHOETITE AGGREGATE

In the drill core of the John Hay, Jr., well 1, consolidated aggregates of shortite crystals have been found 

in only a few places. These occur as flat-lying beds 

not more than one inch thick. A thin section (fig. 18) 

cut from the core at a depth 1,382 feet 6 inches, shows
SALINE MINERALS 27

FIGURE 18. Photomicrograph of thin section from the drill core of the John Hay, 

Jr., well 1, depth 1,382 ft 6 in, showing massive shortite. Crossed nicols. X15.

small randomly oriented, subhedral and probably 

anhedral crystals of shortite. The magnification is 

15 diameters. The picture was taken under crossed 

nicols. Dark areas are caused by crystals in the extinction position. There is little, if any interstitial 

filling by detrital material or dolomite.

The rare occurrence of these aggregates of crystals 

of shortite indicates that at the time of formation very 

unusual conditions obtained, causing crystals of shortite 

to be abraded by rolling and tumbling and finally concentrated to form thin monomineralic beds. It is 

unlikely that the rounded edges arid dearth of crystal 

faces found in the crystals that make up these thin 

beds were due to differential solution during the periodic flushing of the lake that removed chlorine and 

potassium from the system. Had this been so, the 

crystals of shortite would be rimmed by calcite that 

would remain after the sodium carbonate had been removed by leaching. No calcite has been seen in the 

thin section.

There is no evidence of cementing material between 

the individual crystals that make up the shortite aggregates. However, fractures caused by a hammer 

blow cut across individual grains much as when quartzite is broken. It must be assumed then that surface 

welding of adjacent crystals, because of the pressure 

resulting from several thousand feet of overburden 

acting during a long interval of time, caused the consolidation of the rock.

In sharp contrast to the tightly packed small rounded 

crystals that characterize the shortite aggregates, a 

polished section (fig. 19) of the drill core of the John

Hay, Jr., well 1, at depth 1,710 feet 4 inches to 1,710 

feet 6 inches, shows large sharp-edged crystals of 

shortite. These crystals make up at least 75 percent 

of the specimen and undoubtedly grew in place. The 

other 25 percent is composed of detrital material that 

contains a small amount of organic matter.

PYBITE INCLUSIONS

An estimated 10 percent of the many hundreds of 

crystals of shortite examined contain either single cubes 

of pyrite as much as 2 mm across, or twinned crystals 

of pyrite approximately the same size. Less commonly, 

crystals of shortite are seen with pyrite only partly 

embedded and protruding from one of the faces of a 

crystal of shortite. This would seem to indicate that 

the crystal of shortite grew around the older cube of 

pyrite rather than that the pyrite was later and had 

penetrated the crystal of shortite as rutile enters a 

crystal of quartz.

TEMPERATURE OF FORMATION

Ingerson (1947, p. 376) in his paper on liquid inclusions in geologic thermometry states:

The fundamental assumption has not changed since Sorby's 

time that a liquid inclusion cavity was just filled with fluid at 

the temperature and pressure under which it was formed. These 

conditions, and the composition of the solution, determine the 

degree of filling of the cavity as it is observed at room temperature. If a crystal containing such inclusions is heated, the liquid 

will expand and fill the cavity at the temperature of formation 

if the original pressure did not exceed significantly the vapor 

pressure of the solution.

A close approximation of the temperature of formation of shortite was made by observing liquid inclusions 

in polished "thick" thin sections of crystals of shortite 

and applying the technique of Ingerson and other work3 cm

FIGURE 19. Photograph of polished section from the drill core of the John Hay, 

Jr., well 1, depth 1,710 ft 4 in to 1,710 ft 6 in, showing large crystals of shortite.
28 SALINE MINERALS OF THE GREEN RIVER FORMATION

ers in that field. These "thick" thin sections were 

made by cementing the crystal to a glass slide and 

grinding to a thickness of about half a millimeter. 

The ground surface of the crystal was then polished. 

As it was necessary that the entire operation be done 

at room temperature, cement was used rather than 

canada balsam, because the balsam requires heating to 

about 90°C in making thin sections.

Many liquid inclusions were observed under the 

microscope in the "thick" thin sections. These inclusions ranged in size from about 0.07 mm to 0.005 mm 

in the longest direction. By actual count about 95 

percent of the inclusions contained only the liquid 

phase. The remaining 5 percent contained both the 

liquid and the gas phase. It was observed that the 

volume occupied by the gas phase ranged from less 

than 5 percent to at least 50 percent of the volume of 

the cavity. Single inclusions containing the two phases 

were frequently found in clusters of cavities wherein 

only the liquid phase was present. It was therefore 

assumed that the inclusions containing the gas phase 

had acquired the gas by leakage. The temperature of 

crystallization of the shortite, as indicated by the cavities having only the liquid phase, was probably within 

10°C of room temperature which was 27°C. This 

would mean that shortite crystallized at a temperature 

no higher than 40°C. However, if supercooling of the 

tiny liquid inclusions took place, the correct figure may 

be considerably higher than this.

TBONA 

OCCURRENCES

The earliest known and most used by man of the 

saline minerals present in the Green River formation is 

trona (NaaCOg-NaHCOs^HaO). It is found in many 

saline lake deposits and efflorescences throughout the 

world, including the ancient deposits of natural sodium 

carbonates near Memphis, in the lower Nile River 

valley. Other African locations are Lake Mandara in 

the province of Tezzan, Tripoli; the Oasis of Bilma in 

the Sahara Desert; and the Otjiwalundo Salt Pan in 

South West Africa. In Asia it is found in Iran, Armenia, and the alkali deserts of Mongolia and Tibet. 

On the continent of Europe trona has been reported as 

efflorescences on lava on Mount Vesuvius, and in the 

Szegedin district, Hungary. In Venezuela it is associated with gaylussite in the mud of an alkali lake at 

Lagunillas, 48 miles southeast of the City of Merida.

Trona occurs in many alkali lakes in the western part 

of the United States. Deposits are located at Soda 

Lake, Butterfield Marsh, and Double Springs Marsh in 

Nevada. Searles Lake in San Bernardino County and 

Borax Lake in Lake County are the two best known 

locations in California.

The largest known deposit of trona in the world is in 

the Wilkins Peak member of the Green River formation 

in Sweetwater County, Wyo. Here a stratum that 

approximates 10 feet in thickness and is at a depth of 

about 1,600 feet at the site of the John Hay, Jr., well 

1, has an area of many tens, and probably many hundreds, of square miles. Below this 10-foot bed of trona 

are beds 6, 4, and 2 feet thick, each having an areal 

extent at present unknown. Many strata as much as 

1 foot thick lie both above and below this main trona 

bed, between depths of 1,300 and 1,665 feet. Trona 

comprises 6.4 percent (fig. 7) of the saline zone that is 

555 feet thick at the site of the John Hay, Jr., well 1.

The temperature of formation of the trona is estimated to be between 20° and 40 °C by the liquid-inclusion technique.

CRYSTALLOGRAPHY

Trona crystallizes in the monoclinic system and has 

a perfect cleavage parallel to the front pinacoid (100). 

The crystal habit ranges from finely crystalline aggregates, which make up the main trona bed, to large 

radiating crystals up to 4 cm in length which form 

rosettelike clusters in the shale at various places above 

the main trona bed. About a dozen strata, also at 

shallower depths than this bed and ranging in thickness 

from 2 to 13 inches, are composed of pearly-white trona, 

the whole mass of which has the same orientation 

throughout, as would a large fragment of a single 

crystal. The c axis is normal to the bedding of the 

shale. Figure 20 shows such a crystal fragment that 

was brought up from a depth of 1,370 feet during the 

excavation of the No. 1 shaft of the Westvaco mine. 

A large radiating crystal cluster (fig. 21) was obtained 

from a depth of 1,350 feet in the same shaft.

A specimen from the main trona bed (fig. 22) shows 

the tiny interlocking crystals that make up this 10-foot 

stratum and lend a quality of toughness that often 

prevents fracture after many lusty blows of a geologist's 

hammer. The photomicrograph was taken under 

crossed nicols and shows a large crystal of shortite 

(dark area) at the extinction position.

OPTICAL AND PHYSICAL PROPERTIES

Trona ranges in color from pearly white through 

yellow to brown. The pearly-white trona as much as 

13 inches thick, is that found in the beds referred to 

above. The trona is fibrous and oriented as a single 

crystal with the c axis and the fibers normal to the 

bedding. The yellow and brown color of the main 

trona bed and the large radiating crystal clusters, is due 

to contamination by trace quantities of organic matter. 

Like the yellow shortite, the yellow and brown trona 

fluoresces in ultraviolet light of 2,537 A wavelength.
SALINE MINERALS 29

FIGUKE 20. Photograph of pearly-white trona from the Westvaco No. 1 shaft; 

depth 1,370 feet.

The indices of refraction are: 

a=1.417 

0= 1.494 ±0.002 

7=1.543.

2V 74° negative (calculated). 

Other optical properties are given in table 8.

The hardness of trona is between 2% and 3; the 

fracture can best be described as uneven to subconchoidal, and the luster is vitreous. A piece of clear 

pearly-white trona had the specific gravity 2.147 at 

25° C, determined by means of the Jolly balance and 

absolute alcohol for the liquid medium.

CHEMICAL PROPERTIES

Trona is soluble in water and when treated with 

acid vigorously give off CO2 . When heated, water is 

driven off, followed by CO2 , as the sodium bicarbonate 

is converted to sodium carbonate. This occurs at 

270° C. The sodium carbonate melts at 850° C.

The chemical analysis given in table 11 was made on 

clear pearly-white trona, the same as that on which the 

specific gravity was made, and on which the indices of 

refraction were determined. The high order of purity 

of the sample is indicated by the small amount (0.02 

percent) of insoluble material and by the spectrographic 

analysis given in table 10.

FIGUKE 21. Photograph of radiating crystals of trona from the Westvaco No. 1 

shaft, depth 1,350 feet.

In the PCo2-T diagram (fig. 6) of the system Na2CO3 

NaHCO3 H2O the phase boundary between trona and 

nahcolite is shown. Trona is stable only above 21.4°C, 

whereas nahcolite, at higher concentrations of CO2 , 

forms throughout the 0 to 60°C range of the diagram.

SPECTROGRAPHIC ANALYSIS

The spectrographic analysis was made on a powdered 

sample of trona in the way described for shortite.

The percentages of the elements present in minor 

quantities are Cu, 0.0005; Sn, <0.002; Mn, <0.0002; 

Fe, 0.003; Cr, <0.0004; Al, <0.001; Ti, <0.001; Be, 

0.0012; Mg, <0.001; Ca, <0.0002; Sr, <0.0002; and

FIGURE 22. Photomicrograph of thin section from the trona bed of the Westvaco 

mine showing tiny interlocking crystals. Crossed nicols. X15.
30

TABLE 11. Chemical analyses of trona and nahcolite 

[Joseph J. Fahey, analyst]

Na.

COs _-___ -__ - 

HCO3

H20________________. ___________

Insoluble (H2O) __ ______________

Total

Trona ' 

(percent)

30.47 

26. 66 

27. 11 

16. 11 

.02

100. 37

Nahcolite 2 

(percent)

27.33

72.87

.00

100. 20

1 From the John Hay, Jr., well 1, Sweetwater County, Wyo.

2 From the Bureau of Mines oil-shale mine near Rifle, Colo.

Ba, <0.0002. The above results have an overall 

accuracy of ± 15 percent except near limits of detection 

where only one digit is reported. The elements looked 

for but not found in the spectrographic analysis of trona 

are listed in table 10. Trona and nahcolite, the two 

saline minerals that are completely water soluble, have 

almost the same spectrographic analysis except for 

beryllium. Trona was found to contain 0.0012 percent 

beryllium whereas nahcolite had less than 0.0002 percent 

beryllium reported.

INDUSTRIAL USE

Trona of the Green River formation in southwestern 

Wyoming affords an enormous source of sodium carbonate (soda ash). Soda ash is second only to sulfuric acid 

in tonnage used by industry in the United States, most 

of which is produced synthetically by the Solvay process 

from sodium chloride brines. The manufacture of glass 

and soap, the softening of water, and the production of 

metallic sodium and sodium chemicals are only a few 

of the many uses of sodium carbonate. (See table 12.)

NAHCOLITE 

NAME OF MINERAL

Naturally occurring sodium bicarbonate was first 

described by F. A. Bannister, of the British Museum of 

Natural History, and was named nahcolite (Bannister, 

1929) at the suggestion of his colleague L. J. Spencer, 

who said that the name, derived from the chemical 

formula of sodium bicarbonate, would serve as a memory aid in recalling the composition of the new mineral.

TABLE 12.- -The tonnage of soda ash used in 1957 by industries in 

the United States

[From the Minerals Yearbook, v. 1,1957, U.S. Bureau of Mines]

Industry Tons

Glass-_________ 1,590,000

Caustic and bicarbonate- _____ 696, 000

Water treatment __ 120, 000

Other chemicals. __ 1, 383, 000

Soap________ 80,000

Other cleaners- _ _ _ 160, 000

Industry Tons 

Pulp and paper_ _ _ 339, 000 

Metal processing __ 614,000 

Exports and miscellaneous ______ 672,000

Total______ 5,654,000

OCCURRENCES

Nahcolite was first found in an efflorescence from 

hot springs in an old Roman underground conduit at 

Stufe de Nerone about 9 miles west of Naples in the 

Phlegrean Fields. Because it occurred in such small 

crystals intimately mixed with thermonatrite, trona, 

and thenardite, no separation of the new mineral was 

made.

The presence of nahcolite was first indicated by a 

complete analysis of the crusts and proper allotment of 

the constituents to the three identified saline minerals. 

Three such analyses showed an excess of sodium bicarbonate of 20, 20, and 25 percent. An examination 

with the petrographic microscope readily identified the 

new mineral with artificially prepared sodium bicarbonate. Thus, though the new mineral was not separated and purified, its presence was established by 

chemical and optical means.

Nahcolite was found in 1937 in the same area in an 

incrustation in a lava grotto (Quercigh, 1937). There 

also the mineral was not isolated and thoroughly investigated. An earlier report of naturally occurring 

sodium bicarbonate (Walther, 1922) at Little Mogadi 

dry lake, 40 km south of Mogadi Lake in British East 

Africa, was presented but no confirmatory evidence 

was given.

Nahcolite was first isolated and studied by Dr. 

William F. Foshag, of the U.S. National Museum 

(Foshag, 1940). The material he used was part of a 

drill core from a stratum containing saline minerals in 

Searles Lake, San Bernardino County, Calif., between 

depths of 122 and 289 feet. The associated minerals 

were gaylussite, trona, thenardite, borax, northupite, 

and burkeite. Many of the beds of nahcolite consisted 

of loosely friable crystal aggregates or porous masses 

with crystal-lined vugs. He found that single crystals 

rarely were greater than 1 cm long.

IE the Green River formation, nahcolite (Ertl, 1947) 

is present in the oil-shale mine of the Bureau of Mines 

at Anvil Points, 10 miles west of Rifle, Colo. It occurs 

in cleavable masses as concretions as much as 10 feet 

in diameter in the oil shale. A fragment from one of 

these concretions is seen in figure 23. Nahcolite is also 

found in layers as much as 4 inches thick intercalated 

between rich oil-shale beds. It was found in only one 

place in the John Hay, Jr., well 1, and there only as a 

trace quantity.

OPTICAL AND PHYSICAL PROPERTIES

Nahcolite has a vitreous luster and is colorless unless 

pigmented by extraneous material. The color of the 

mineral from the concretions in the oil-shale mine of 

the Bureau of Mines near Rifle, Colo., is usually reddish 

brown due to the presence of organic matter, but locally
31

3cm

FIGURE 23. Photograph of nahcolite from the oil-shale mine of the Bureau of Mines 

at Anvil Points, 10 miles west of Rifle, Colo.

the color ranges from colorless through white, yellow, 

brown to black. The mineral, when found in layers 

between oil-shale beds, is usually white and translucent 

and occurs as fibrous crystals with the c axis normal to 

the bedding.

The indices of refraction are:

«=1.375

jg=1.498 ±0.002

7=1.583.

2V= 74° negative (calculated).

Optical properties are listed in table 8.

Nahcolite is harder than gypsum but is easily 

scratched by calcite; hence the hardness is estimated 

to be 2%. It has a conchoidal fracture and perfect (101) 

cleavage. A good (111) cleavage and distinct (100) 

cleavage are present. As with trona, the specific 

gravity (2.238 at 25°C) was determined by means of 

the Jolly balance using absolute alcohol as the liquid 

medium.

CHEMICAL PROPERTIES

Nahcolite is readily soluble in water. It is vigorously 

attacked by the common acids giving off CO2 . When 

it is heated to 270°C, water and CO2 are driven off, 

and the more stable sodium carbonate is formed.

The analysis in table 11 was made on a sample prepared from the pure white translucent nahcolite found 

in layers between oil-shale beds in the oil-shale mine 

of the Bureau of Mines, 10 miles west of Rifle, Colo. 

The purity of the sample is indicated by the lack of a 

measurable quantity of insoluble material as shown 

in this analysis. The optical and physical constants 

were also determined on this sample.

The stability range of nahcolite shown in the PCo2-T 

diagram (fig. 6) is between 0° and 60°C. At a given 

CO2 pressure on the phase boundary between nahcolite 

and trona, an increase in temperature would cause 

trona. to precipitate, whereas a decrease in temperature 

would make nahcolite the stable phase.

SPECTROGRAPHIC ANALYSIS

The spectrographic analysis was made on a powdered 

sample of nahcolite, by the method used for shortite.

The percentages of the elements present in trace 

amounts are Cu, 0.0003; Sn, < 0.002, Mn, < 0.0002; 

Fe, 0.002; Cr, < 0.0004; Al, < 0.001; Ti, < 0.001; 

Be, < 0.0002; Mg, < 0.001; Ca, < 0.0002; Sr, < 0.0002; 

and Ba, <C 0.0002. These results have an overall 

accuracy of ±15 percent except near the limits of 

detection where only one digit is reported. The 

elements looked for but not found are recorded in 

table 10. Here it is seen that in both nahcolite and 

trona the Mg and Ca percentage is < 0.001 and < 0.0002 

respectively. In view of the fact that these two 

water-soluble minerals crystallized from a brine that 

was contemporaneously yielding dolomite, such small 

traces are noteworthy.

NORTHUPITE 

OCCURRENCES

Searles Lake, San Bernardino County, Calif., that 

most bountiful source of both rare and common saline 

minerals, is the original locality of the mineral northupite (Na2CO3 -MgCO3 -NaCl). It was described by Foote 

(1895) and named in honor of C. H. Northup of San 

Jose, Calif., who found the first specimens of this 

mineral in a boring known as the "New Well" in 

Searles Lake. According to Mr. Northup, the mineral 

was formed in a stratum of clay about 450 feet below 

the surface.

The second location of northupite is Borax Lake, 

Lake County, Calif., where it was found by Vonsen 

(1935) in association with pirssonite and gaylussite 

in massive trona.

The Wilkins Peak member of the Green River formation is the third recorded locality of northupite, and it is 

here the third most abundant saline mineral, only 

shortite and trona being present in greater quantities. 

At the location of the John Hay, Jr., well 1, northupite 

is present between the depths 1,327 and 1,560 feet, 

and comprises a visually estimated 5.2 percent of 

this 233-foot interval, or 2.2 percent of the 555-foot 

thick saline zone. Like pirssonite and gaylussite, 

it has not been found at depths below the main trona 

bed.

CRYSTALLOGRAPHY

Northupite crystallizes in the isometric system as 

octahedra. Euhedral crystals are rare in the Green

596568 O 62 - 4
32 SALINE MINERALS OF THE, GREEN RIVER FORMATION

River formation. They vary in size up to about 4 mm 

across. A photograph of one of these crystals, magnified 8 times (fig. 24) shows the octahedron in low-grade 

shale. This specimen was found at a depth of 1,245 

feet during the sinking of the first shaft of the Westvaco 

mine in 1947.

A photomicrograph (fig. 25) of a thin section of a 

cluster of small crystals of northupite, taken in planepolarized light, shows in several of these crystals the 

symmetry of the octahedron, marked by collodial clay 

that was entrapped as the crystals grew. The thin 

section was cut from the core of the John Hay, Jr., 

well. 1, at a depth of 1,336 feet 6 inches.

OPTICAL AND PHYSICAL PROPERTIES

Northupite is usually colorless in ordinary light, 

but a pale yellow color due to traces of organic matter in 

the massive crystalline material is not uncommon. Such 

material fluoresces in ultraviolet light of 2,537 A 

wavelength. Crystal fragments are translucent and 

have a vitreous luster.

The index of refraction of northupite is : ?i=1.513. 

An anomalous birefringence has been noted in a few 

oil-immersion mounts, but this is unusual.

The fracture of northupite is conchoidal, and it 

has a hardness of 3% to 4. The specific gravity, 

2.407, was determined on material passing an 80-mesh 

seive and retained on 100-mesh. A fused silica AdamsJo hnston pycnometer was used.

CHEMICAL PROPERTIES

The chemical analysis of northupite is given in table 

9. The analyzed sample was prepared by grinding

FIGUBE 24. Photograph of a euhedral crystal of northupite. X8.

shale that contained northupite to pass a 10-mesh 

sieve, and then hand-picking the crystal fragments of 

northupite which, in turn, were ground to pass an 80- 

mesh sieve. The specific gravity, index of refraction, 

and the chemical analysis were all made on this sample, 

as was also the X-ray powder diffraction pattern.

Northupite is readily soluble in acids with effervescence of carbon dioxide. It is very slowly differentially 

decomposed by cold water and more rapidly by hot 

water. The sodium carbonate and the sodium chloride 

are dissolved, leaving the magnesium carbonate in the 

solid phase. When heated in the closed tube, northupite decrepitates violently and fuses to a very viscous 

liquid.

SPECTROGRAPHIC ANALYSIS

The spectrographic analysis was made on a powdered 

sample of northupite, by the method used for shortite.

The percentages of the elements present in trace 

amounts are Cu, 0.0004; Sn, <0.002; Mn, 0.048; Fe, 

0.17; Cr, <0.0004; Al, 0.012; Ti, <0.001; Be, <0.0002; 

Ca, 0.052; Sr, 0.0009; and Ba, <0.0002. These results 

have an overall accuracy of ±15 percent except near 

the limits of detection where only one digit is reported. 

The elements looked for but not found are recorded in 

table 10, where also it is seen that the percentages of 

manganese and iron are higher in northupite than in 

any of the other five saline minerals listed. The calcium content of northupite is greater by a factor of 

more than 200 than that of the two water-soluble saline 

minerals trona and nahcolite.

GENESIS

Northupite occurs as euhedral crystals and globular 

masses. The crystals are rare, probably constituting 

less than 0.01 percent of all the northupite present, and 

are invariably in shale low in organic matter, and with 

a relatively high percentage of dolomite. The massive 

northupite is found in shale of medium to low content 

of organic material.

The euhedral crystals of northupite probably formed 

in the fluid mud at the bottom of the lake, and in that 

same mud after much of the brine had been squeezed 

out by the gradual addition of overburden that brought 

about a condition of sticky plasticity or semifluidity in 

the partially compressed sediment. That the crystals 

grew in this fluid mud is indicated by the entrapped 

colloidal clay (fig. 25) that marks the symmetry of the 

octahedron and also by the perfectly formed crystals, 

none of which shows any distortion that could have 

resulted from pressure applied to the growing crystal 

in a fixed nonfluid environment.

Massive northupite is found filling vugs and cracks 

in medium- to low-grade oil shale, and in thin section 

has been seen replacing shortite (fig. 31), pirssonite
SALINE MINERALS 33

FIGURE 25. Photomicrograph of thta section from the drill core of the John Hay, 

Jr., well 1, depth 1,336 ft 6 in, showing the symmetry of crystals of northupite 

marked by collodial clay. Plane-polarized light. X35.

(fig. 32), gaylussite (fig. 34), and trona (fig. 37). In 

no instance has northupite been observed being replaced by any of the other saline minerals.

The drill core of the John Hay, Jr., well 1, at a 

depth of 1,431 feet 8 inches, contains many small 

round masses of northupite (fig. 26) that, when sectioned, show imperfect concentric circles, giving 

somewhat the appearance of oolitic structure. A 

photomicrograph (fig. 27) magnified to 20 diameters, 

and taken in plane-polarized light, shows that the 

concentric rings are made up of a great many tiny 

liquid inclusions. A "thick" thin section of a group 

of these pseudo-oolites was cut and cemented without 

heating. A microscope examination of this thin section 

showed many liquid inclusions with no gas phase, and 

others with a liquid and gas phase, the latter occupying 

as much as about 50 percent of the volume of the

FIGURE 26. Photograph of a section of core from the John Hay. Jr., well 1, depth 

1,431 ft. 8 in., showing round masses of northupite that have an oolitic structure.

FIGURE 27. Photomicrograph of thin section from the drill core of the John Hay, 

Jr., well 1, depth 1,431 feet 8 inches. Tiny liquid inclusions in concentric rings 

give the appearance of oolitic structure. Plane-polarized light. X20.

cavity. A few cavities containing a solid phase in 

addition to the liquid and gas phase (fig. 28) were 

observed.

From the above it was concluded that the gas phase 

resulted from a leakage of the liquid from the cavity, 

and those cavities containing only the liquid phase 

gave evidence of the temperature of formation of 

the northupite. Hence this temperature was estimated 

to be within 10° C of the temperature of the room

FIGURE 28. Photomicrograph of the thin section of figure 26 showing liquid 

inclusion containing a gas and solid phase. Plane-polarized light. X800.
34 SALINE MINERALS OF THE GREEN RIVER FORMATION

when the observations were made, or roundly between 

20° C and 40° C. This is the temperature range, 

determined in the same manner, within which both 

shortite and trona were estimated to have formed.

In a thin section (fig. 29) cut from the drill core of 

the John Hay, Jr., well 1, at a depth of 1,454 feet, 

northupite is seen replacing the highly dolomitic 

shale. The magnification is 10 diameters and the 

photomicrograph was taken in plane-polarized light. 

The dark areas are the remnants of the shale in which 

traces of the bedding can be seen.

Northupite is the only chlorine-containing saline 

mineral that has been found in more than trace quantities in the drill core of the John Hay, Jr., well 1. 

Although it is the third most abundant saline mineral 

present in the Wilkins Peak shale, only shortite and 

trona being present in greater amounts, the quantity 

is much too small to have fixed all the chlorine that 

was brought into the lake by the streams. Periodic 

flushing of the lake was probably the means by which 

the greater part of the chlorine and also most of the 

potassium was removed.

BRADLEYITE

The second new mineral that was found in the Green 

River formation was bradleyite (Fahey and Tunell, 

1941), an anhydrous carbonate-phosphate of sodium 

and magnesium (Na3PO4 'MgCO3 ). It was named in 

honor of Wilmot H. Bradley, geologist of the U.S. 

Geological Survey, in recognition of his many contributions to our knowledge of the Green River formation.

OCCURRENCES

Bradleyite was first found in the drill core of the 

John Hay, Jr., well 1 at a depth of 1,342 feet 10 inches

FIGURE 29. Photomicrograph of thin section from the drill core of the John Hay, 

Jr., Well 1, depth 1,454 feet, showing northupite replacing the dolomitic shale. 

Plane-polarized light. X10.

in a horizontal layer 1 inch thick. This layer contained 

about 60 percent bradleyite, 30 percent shortite, and 

10 percent detrital material. A small percentage of 

organic matter was present, which yielded tiny droplets 

of oil when heated in the closed tube.

Immediately above the bradleyite the core consists 

mainly of shortite and northupite with a minor quantity 

of clay, while below is found brown clay containing 

much shortite and northupite. Both above and below 

the stratum containing the bradleyite, the northupite 

is later than the shortite.

In 1947, 6 years after the bradleyite was found in 

the drill core of the John Hay, Jr., well 1, bradleyite 

was found in shale at a depth of 1,245 feet during the 

sinking of the No. 1 shaft of the Westvaco trona mine. 

Bradleyite is seen in figure 10 at the top center of the 

specimen of shale as fine-grained light-colored material. 

It contains less shortite and clay than the bradleyite 

found in the John Hay, Jr., well 1, but the presence 

of several percent of finely divided chert was visually 

estimated in thin section.

Tiny crystals of bradleyite were found by Charles 

Milton, geologist of the U.S. Geological Survey, in the 

residue obtained when a quantity of several kilograms 

of trona from the Westvaco trona bed was leached. 

Laborious hand-picking by Milton produced about 90 

mg of these crystals on which a chemical analysis was 

made and the optical, physical, and X-ray constants 

were determined (Mrose, unpublished data).

OPTICAL AND PHYSICAL PROPERTIES

The bradleyite from the core of the John Hay, Jr., 

well 1 (Fahey and Tunell, 1941, p. 647) was extremely 

fine-grained, most individual particles being less than 

0.002 mm across. The a and 7 indices of refraction 

were determined as 1.49 and 1.56 respectively. No 

determination of the ft index was attempted.

The indices of refraction were measured on the 

bradleyite picked by Milton from the residue obtained 

upon leaching trona from the Westvaco mine and found 

to be

a= 1.487 

P= 1.546 

7=1.560 

2F=50°,

±0.002

optically negative (calculated) 

2F 49°, optically negative (measured) 

Optic axial plane J_ to (010) Y /\ c = 7°

X b axis=elongation

Habit: flattened crystal || to (001).

The optical orientation was determined on the universal 

stage by Edward C. T. Chao, of the U.S. Geological 

Survey. (See table 8 for optical properties.)
SALINE MINERALS 35

Bradleyite has a vitreous luster and a conchoidal 

fracture. The hardness is 3 1/2. The specific gravity 

2.720 was the average of seven determinations made 

on the Berman balance by Mary Mrose, X-ray crystallographer, on tiny subhedral crystals picked by Milton 

from the trona residues. The value 2.720 agrees with 

that of 2.734 determined by an indirect method on the 

original material from the core of the John Hay, Jr., 

well 1. It also checks the figure 2.725 obtained by 

applying the Gladstone-Dale equation (Fahey and 

Tunell, 1941, p. 647).

CHEMICAL PROPERTIES

Cold water very slowly attacks bradleyite dissolving 

the sodium phosphate and leaving a residue of magnesium carbonate. Hot water produces the same effect 

but in a much shorter time. The common acids dissolve bradleyite, with evolution of carbon dioxide. In 

the closed tube bradleyite becomes opaque but does 

not melt.

A chemical analyses of two samples of bradleyite are 

listed in table 13. Sample A was from the drill core 

of the John Hay, Jr., well 1, and included 14.46 percent 

of clay that was recorded as insoluble in HC1. Sample 

B weighed 80.2 mg and was from the residue obtained 

by Milton upon leaching material from the trona bed 

of the Westvaco mine.

SPECTROGRAPHIC ANALYSIS

The spectrographic analysis was made on powdered 

bradleyite from sample B (table 13) by the method 

used for shortite.

The percentages of the elements found in trace 

amounts are Mn, 0.1; V, 0.01; Ti, 0.2; Ca, 0.4; Sr, 

0.05; Ba, 0.7; Sc, 0.004; and Si, 0.5. The elements 

looked for but not found are Ag, Au, Hg, Pd, Pt, Mo, 

W, Re, Ge, Sn, Pb, As, Cu, Sb, Nb, Bi, Zn, Cd, Tl, 

Co, Ni, Cr, Ga, Y, Yb, La, Ce, Nd, Zr, Th, Ta, U, Be, 

and B.

A comparison of the spectrographic analysis of 

bradleyite with those of the six other saline minerals 

listed in table 10 shows that the elements copper, tin, 

chromium, and beryllium are among the elements that 

were looked for but not found in the bradleyite, but 

are present in trace quantities in the other six saline 

minerals. Bradleyite contains 0.7 percent barium 

whereas pirssonite and gaylussite contain 0.0080 and 

0.0004 percent, respectively, and the other four saline 

minerals have less than 0.0002 percent of this element. 

The relatively high percentages of iron, aluminum, 

copper, and silica found in bradleyite are probably due 

to the presence of foreign material in the samples.

TABLE 13. Chemical analyses of bradleyite

[Joseph J. Fahey, analyst]

K2 (X___ ---___ 

P2 06 ___. _______

C02 -------

Insoluble in HC1. 

H2 0__. _________

Fe2 08 __ -__ 

A12 08 ___ _____

Sample A 

(percent)

12.91

31. 62

.00

22. 03

15.80

14. 46

.30

. 52

. 24

.36

Sample B 

(percent)

14. 3

1 35. 3

1 . 0

26. 1

15. 8

1. 9

. 5

2.6

1. 5

.6

. 2

. 1

S08

.02 

.46 

.35

Total.. 99.07 99.7

1 Alkalies determined by Laura E. Reichen. 

3 Determined spectroscopically by Harry Rose.

Sample A. From drill core of John Hay, Jr., well 1.

Sample B. Analysis made on 80.2 mg of individual crystals obtained from the trona

bed of the Westvaco mine.

PIRSSONITE 

NAME OF MINERAL

Pirssonite (Na2CO3 -CaCO3-2H2O) was described and 

named in 1896 by J. H. Pratt in honor of his friend and 

associate, Professor L. V. Pirsson of the Sheffield Scientific School at Yale University (Pratt, 1896).

OCCURRENCES

The new mineral was found very sparingly associated 

with northupite in material from a bore hole drilled into 

the sediments of Borax Lake, San Bernardino, Calif., 

which was discovered in 1863 by John W. Searles. 

The name Borax Lake was later changed to Searles 

Lake to avoid confusion with Borax Lake in Lake 

County, Calif. (Bailey and Aubury, 1902).

The second occurrence was in the Otjiwalundo Salt 

Pan, South West Africa (Foshag, 1933), where it was 

found associated with trona, thenardite, and sulphohalite.

M. Vonsen, an amateur mineral collector, in 1935 

recorded the third locality of pirssonite (Vonsen, 1935) 

He found it embedded in trona with gaylussite and 

northupite near the western shore of Borax Lake, Lake 

County, Calif.

The fourth location at which pirssonite has been 

reported is the Wilkins Peak member of the Green 

Kiver formation in Sweetwater County Wyo. It 

occurs here with shortite and northupite.
36

Pirssonite was found between depths 1,310 and 

1,391 feet in the drill core of the John Hay, Jr., well 

1, about 18 miles west of the town of Green River, Wyo. 

It was visually estimated to make up 10 percent of the 

drill core between 1,310 and 1,320 and 5 percent of the 

core between 1,320 and 1,330 feet. In the core, between depths 1,340 and 1,350 feet, pirssonite is found 

in association with gaylussite and bradleyite in addition to shortite and northupite.

CRYSTALLOGRAPHY

Pirssonite crystallizes in the orthorhombic system. 

No crystal faces were observed on samples of pirssonite from the core of the John Hay, Jr., well 1. The 

mineral forms as masses in vugs and cracks in the shale. 

It is usually found replacing shortite and then being 

replaced by northupite, both replacements taking place 

within the area covered by a photomicrograph of the 

thin section (figs. 32 and 33).

OPTICAL AND PHYSICAL, PROPERTIES

Most of the pirssonite found in the shales of the 

Green River formation is transparent. In ordinary 

light it ranges from colorless to a very pale yellow 

owing to traces of organic matter.

The indices of refraction are:

a= 1.504 

0 = 1.509 ±0.002

7=1.573

217=27° positive (calculated).

Optical properties are listed in table 8.

Pirssonite is brittle and has a vitreous luster and a 

conchoidal fracture. The hardness is 3 to 3%. An 

Adams-Johnston fused silica pycnometer was used to 

determine the specific gravity on a sample that passed 

80-mesh and was retained on a 100-mesh sieve. The 

value 2.382 for the specific gravity was obtained.

CHEMICAL PROPERTIES

Pirssonite is differentially soluble in water, leaving 

calcium carbonate in the solid phase. It is readily dissolved in acids, vigorously giving off carbon dioxide. 

When heated in the closed tube it loses its water and 

fuses.

The phase-equilibrium diagram (fig. 30) of the 

system Na2CO3 CaCO3 H2O (Bury and Redd, 1933) 

shows that at one atmosphere of pressure pirssonite 

forms between 37.5° C and 103.2° C in a saturated 

solution of sodium carbonate in the presence of sodium 

carbonate and calcium carbonate in the solid phase. 

Under these conditions equilibrium was attained in 

7 to 14 days.

The sample for chemical analysis was prepared by 

hand-picking clear fragments of pirssonite from coarsely 

crushed shale that contained this mineral and then

grinding to pass an 80-mesh sieve. Though great care 

was taken to prepare the sample as free as possible 

from contaminating shale, the chemical analysis in 

table 9 shows that 1.40 percent was insoluble in acid.

SPECTRO GRAPHIC ANALYSIS

The spectrographic analysis was made on a powdered 

sample of pirssonite, by the method used for shortite.

The percentages of the elements measured on the 

spectrographic plate are: Cu, 0.0005; Sn, <0.002; 

Mn, <0.0002; Fe, 0.23; Cr, <0.0004; Al, 0.052; Ti, 

0.004; Be, <0.0002; Mg, 0.080; Sr, 0.068; and Ba, 

0.0080. These results have an overall accuracy of 

±15 percent except near the limits of detection where 

only one digit is reported. The elements that were 

looked for but not found are listed in table 10. As 

is seen in the spectrographic analysis the barium 

content of pirssonite is greater than that of any of the 

other saline minerals.

GAYLUSSITE 

NAME OF MINERAL

The pentahydrate of sodium and calcium carbonate 

(Na2CO3 -CaCO3 -5H2O) was described and named gaylussite (Boussingault, 1826) in honor of the great 

French chemist L. J. Gay-Lussac. The mineral was 

found in the mud of an alkali lake at Lagunilla, a 

small Indian village located about 48 miles southeast 

of the City of Merida, Venezuela.

OCCURRENCES

In addition to the original location gaylussite has 

been found in many places throughout the world in 

alkali lakes, including Taboos-nor (Salt Lake) in the 

eastern Gobi Desert, Mongolia.

Gaylussite is present in the United States at several 

sinks in the Carson Desert near Ragtown, Nev., at 

Independence Rock in the Sweetwater Valley, Wyo., 

and Mono Lake, Lake County, Calif. It has been 

found with northupite and pirssonite embedded in trona 

near the western shore of Borax Lake, Lake County, 

Calif., and at Searles Lake, San Bernardino County, 

Calif.

Gaylussite is found associated with shortite, northupite, pirssonite, and trona in the Wilkins Peak member 

of the Green River formation. At the site of the John 

Hay, Jr., well 1, it is found between depths 1,261 feet 

and 1,350 feet. Between 1,266 feet and 1,267 feet 6 

inches and the 2-foot stratum between 1,268 feet and 

1,270 feet, gaylussite is visually estimated to constitute about 10 percent of the core.

CRYSTALLOGRAPHY

Gaylussite crystallizes in the monoclinic system. In 

the Wilkins Peak member of the Green River formation,
SALINE MINERALS 37

100'

-a 50° -

Na2C03 , percent 

FIGURE 30. Phase equilibrium diagram of the system NaaCOs CaCOa ~H.iO (Bury and Redd, 1933).

gaylussite, like pirssonite, is found only massive in vugs 

and cracks in the shale. In thin section it is seen replacing shortite and in turn being replaced by northupite 

(fig. 34). Another thin section shows gaylussite replacing portions of several crystals of shortite (fig. 35).

OPTICAL AND PHYSICAL PROPERTIES

Gaylussite is transparent to translucent. Like pirssonite, it ranges from colorless to a pale yellow that is 

due to traces of organic matter.

The indices of refraction are:

a=1.445

0=1.514 ±0.002

7=1.524.

2 V= 40° negative (calculated).

Optical constants are listed in table 8.

Like pirssonite, gaylussite is brittle and has vitreous 

luster and a conchoidal fracture. The hardness is 2% 

to 3. It slowly loses water in dry air, reverting to the 

lower hydrate pirssonite.

The specific gravity (2.037 at 25° C) was determined 

by using a fused silica Adams-Johns ton pycnometer on 

material that passed an 80-mesh sieve and was retained 

on 100-mesh. Water saturated with sodium carbonate 

was the liquid medium.

CHEMICAL PROPERTIES

When heated in the closed tube, gaylussite decrepitates, loses water, and fuses to a white mass. It is 

readily dissolved in acids with effervescence of carbon 

dioxide, and is differentially soluble in water, leaving 

calcium carbonate in the solid phase.
38 SALINE MINERALS OF THE GREEN RIVER FORMATION

Gaylussite is one of the stable phases (Bury and 

Redd, 1933) in the system sodium carbonate-calcium 

carbonate-water (fig. 30) from 15° to 40° C. These 

authors also found that gaylussite is in equilibrium with 

pirssonite between 37.5° and 40° C. In the 10-foot 

stratum between depths of 1,340 and 1,350 feet in the 

core of the John Hay, Jr., well 1, gaylussite and pirssonite are found, suggesting that the temperature of 

of deposition of this stratum was for at least part of the 

time during diagenesis between 37.5° and 40°C.

The chemical analysis was made on carefully handpicked material and is given in table 9.

SPECTROGRAPHIC ANALYSIS

The spectrographic analysis was made on a powdered 

sample of gaylussite, by the method used for shortite.

The percentages of the elements measured on the 

spectrographic plate are Cu, 0.0006; Sn, 0.004; Mn, 

< 0.0002; Fe, 0.050; Cr, 0.0006; Al, 0.14; Ti, 0.004; 

Be, <0.0002; Mg, 0.20; Sr, 0.022; and Ba, 0.0004. 

These results have an overall accuracy of db 15 percent 

except near the limits of detection, where only one 

digit is reported. The elements looked for but not 

found are listed in table 10. In this tabulation it is 

shown that gaylussite contains a higher percentage of 

tin, chromium, and aluminum than any of the other 

saline minerals and also has a higher content of magnesium than any of these minerals except northupite, of 

magnesium is a major constituent.

PARAGENESIS OF THE SALINE MINERALS 

GOSIUTE LAKE

The Green River formation north of the Uinta 

Mountains had its origin in a lake of vast size that was 

named Gosiute Lake by Clarence King (1878, p. 446). 

This name was used by Bradley (1929, p. 88) in his 

study of the varves and climate of the Green River 

epoch.

During its long life span Gosiute Lake left in its 

bottom muds a chronological record of events and conditions of that time. Bradley has read much of this 

record and in his papers has shown that the climate was 

similar to that now found in our Gulf States, and that 

the heavy rains of the springtime were followed by low 

precipitation during the fall months. He deduced that 

for long periods of time the lake had no outlet, that 

solar evaporation balanced the inflow of the streams, 

and that an abundant flora and fauna grew in the lake 

waters. This, and much more, was obtained from the 

varves and fossils of the Green River rocks.

The aggregate of saline minerals found in the oil 

shale gives clues to other conditions of that time. The 

mineral trona (Na2CO3-NaHCO3 -2H2O), because of its 

bicarbonate ion, could have precipitated only in the

presence of abundant carbon dioxide. This was furnished by the decaying organic remains of plants and 

animals that, having passed through their life cycle, 

sank to the bottom ooze, there to begin that series of 

changes the end product of which is oil shale.

From the meager knowledge we have of the stability 

relations of the complex alkaline brine of the lake, we 

find that on the phase boundary between nahcolite and 

trona (fig. 6) at a given pressure of carbon dioxide, a 

slight lowering of the temperature causes nahcolite to 

be the stable phase whereas only trona will precipitate 

if the temperature is raised. This suggests that when 

the trona beds in Wyoming were deposited, the temperature may have been too high for nahcolite to be precipitated, whereas at the time of deposition of the 

nahcolite in Colorado and Utah the temperature may 

have been too low for the precipitation of trona. Another factor which may and probably did play a part is 

the partial pressure of' carbon dioxide. At a given 

temperature at which trona is precipitating, nahcolite 

can be made the stable phase by sufficiently increasing 

the partial pressure of the carbon dioxide.

The variations of concentration, composition, and 

temperature of solution that define the stability range 

of shortite (Na2CO3 -2CaCO3 ) the most abundant of 

the saline minerals found in the shale are not known. 

However, whatever these conditions may be, they were 

maintained uninterruptedly throughout that vast period 

of time required for the deposition of sediment that, 

when compacted, formed oil shale having a thickness of 

more than 550 feet at the site of the John Hay, Jr., 

well 1. Between depths of 1,251 feet and 1,806 feet 

6 inches, shortite is found throughout the entire vertical 

column. This includes the four trona beds of approximately 10, 2, 4, and 6 feet in thickness, between the 

depths 1,590 feet 3 inches and 1,600 feet 4 inches; 

1,617 feet 6 inches to 1,619 feet 9 inches; 1,642 feet to 

1,646 feet; and 1,653 feet 2 inches to 1,659 feet 3 inches, 

respectively, throughout which crystals of shortite are 

sparsely distributed. Likewise the physical and chemical conditions that permit the precipitation of trona 

(fig. 6) were maintained for the duration of time required for the deposition of each of these four beds.

Sulfates in quantity greater than a trace are not 

found among the saline minerals. The sulfate in the 

waters of the streams flowing into the lake was reduced 

to sulfide in the strongly reducing environment brought 

about by decaying plant and animal remains. The 

small amount of iron that was in solution in the lake 

water was in turn precipitated by the hydrogen sulfide 

and formed pyrite, tiny crystals of which are present 

throughout the oil shale.

No potassium saline minerals are found in the salines 

of the Green River formation. Sodium and calcium in
PARAGENESIS OF THE SALINE MINERALS 39

combination with the carbonate radical, as in shortite 

(Na2CO3 -2CaCO3 ), pirssonite (Na2CO3 .CaCO3 .2H2O), 

and gaylussite (Na2CO3 -CaCO3 -5H2O) form more insoluble double salts than would potassium and calcium. 

Sodium is also found in the triple salt northupite 

(Na2CO3 -MgCO3 -NaCl) and in combination with 

phosphate in bradleyite (Na3PO4 -MgCO3 ). This absence of potassium among the Green River saline minerals is in sharp contrast to the abundance of potassiumcontaining minerals in the marine evaporites of Permian 

age in New Mexico and Texas. In these, the sulfate 

mineral, polyhalite (K2SO4 -A/[gSO4-2CaSO4-2H2O), is 

found in great quantities whereas no sodium analogue 

has been reported. Had there not been a periodic 

flushing of Gosiute Lake that removed the potassium, 

vast deposits of sylvite (KC1) would undoubtedly have 

been laid down, as in the Permian deposits of New 

Mexico and Texas.

During that long period between the precipitation of 

the shortite in the partly compressed mud that had 

been the lake bottom, and the final compaction of this 

mud to form oil shale, there was, percentagewise, very 

little alteration of the shortite. That which was 

observed in the many thin sections studied, is graphically outlined (fig. 8) to give a condensed picture of 

the paragenetic sequence of the six saline minerals 

found in the Wyoming area. Shortite alters to (figs. 

32-35), or is replaced by (figs. 9, 31, and 36), five saline 

minerals northupite, pirssonite, gaylussite, trona, and 

bradleyite. Shortite has in no instance been observed 

replacing any of the saline minerals. It is always the 

oldest mineral in the sequence. Pirsonnite (fig. 32), 

gaylussite (fig. 34), and trona (fig. 37) are replaced by 

northupite. No replacement of northupite or bradleyite has been observed. Eight photomicrographs of thin 

sections, cut from the core of the John Hay, Jr., well 1, 

have been selected to show the paragenetic relationships 

among the six saline minerals.

SHORTITE TO NORTHUPITE

The replacement of shortite by northupite is shown 

in a thin section (fig. 31) cut from the drill core of the 

John Hay, Jr., well 1, depth 1,339 feet 4 inches. The 

shortite crystals are corroded and embayed by the 

isometric mineral northupite that occupies the black 

area. The three prominent crystal remnants that are 

seen do not extinguish at the same time, hence are not 

parts of a single crystal. No evidence is presented on 

the thin section as to the size of the crystals of shortite 

before the replacement by northupite started. An 

examination of this thin section and many others showing the replacement of shortite by northupite, leads to 

the conclusion that the entire area seen in the photomicrograph had been occupied by randomly oriented

FIGURE 31. Photomicrograph of thin section from the drill core of the 

John Hay, Jr., well 1, depth 1,339 ft 4 in, showing the sequence shortite 

to northupite. Crossed nicols. X 25.

crystals of shortite before the replacement by northupite 

began.

SHORTITE TO PIRSSONITE TO NORTHUPITE

The thin section was cut from core of the John Hay, 

Jr., well 1 from a depth of 1,342 feet. The magnification is 25 diameters under crossed nicols.

The photomicrograph (fig. 32) shows randomly 

oriented crystals of shortite altering to pirssonite (P), 

which in turn is being replaced by the isometric mineral 

northupite (N). A crystal of shortite ($1) is almost in 

the extinction position and is rimmed by pirssonite. 

Other crystals of shortite (S2 , Ss, S5 , S&, and Ss) are in 

or near the extinction position and are rimmed and 

deeply embayed by the highly birefringent mineral 

pirssonite. Near the center of the picture the crystal 

of shortite ($4) is not in or near the extinction position 

and shows deep embayment by pirssonite. Likewise, 

at the top of the photomicrograph the crystal of shortite 

marked S7 is not in or near the extinction position and 

is deeply corroded by pirssonite. Throughout the 

section, the isometric mineral northupite (N} is seen 

replacing pirssonite. All the pirssonite that is marked 

by the letter (P) extinguishes at the same time under 

crossed nicols, thereby strongly indicating it to be the 

remainder of what had been a single crystal that has 

been partly replaced by northupite (N). The shale
40 SALINE MINERALS OF THE GREEN RIVER FORMATION

FIGURE 32. Photomicrograph of thin section from the drill core of the 

John Hay, Jr., well 1, depth 1,342 ft, showing the sequence shortite 

(Si through SB) to pirssonite (-P) to northupite (N). Sh indicates 

shale. Crossed nicols. X25.

(Sh) is dark brown in the thin section because of the 

presence of organic matter.

The chemical changes in the sequence shortite to 

pirssonite to northupite are shown by their formulas:

Na2C03 -2CaC03 ^Na2C03 -CaC03 .2H2O^ 

shortite pirssonite

Na2CO3 -MgCO3 .NaCl 

northupite

Each of the three minerals in the sequence contains 

one molecule of Na2C03 which is joined in northupite 

by a molecule each of MgCO3 and NaCl. The moles of 

CaCO3 per mole Na2CO3 diminishes from two in shortite 

to one in pirssonite to none in northupite. The CaCO3 

may have been reprecipitated to form the fine-grained 

dolomite that is seen in the thin section under higher 

magnification.

SHORTITE TO PIRSSONITE

The thin section was cut from core of the John Hay, 

Jr., well 1 from a depth 1,344 feet 4 inches. Magnification is 40 diameters with crossed nicols.

The photomicrograph (fig. 33) shows randomly 

oriented crystals of shortite that are rimmed and embayed by pirssonite. Two crystals of shortite (Si and 

SG) are in the extinction position and are shown rimmed 

and embayed by pirssonite (P). Near the position of 

extinction are crystals of shortite (S2} Sz and $7) that

are seen going over to pirssonite. Two crystals of 

shortite ($4 and S5 ) are not in or near the position of 

extinction, and are rimmed by pirssonite that is readily 

discernible because it has a much higher birefringence 

than shortite. The three small areas marked (Sh) are 

occupied by low-grade oil shale.

SHORTITE TO GAYLUSSITE TO NORTHUPITE

Core of the John Hay, Jr., well 1, from a depth of 

1,340 feet 10 inches was the source of the thin section. 

The magnification is 25 diameters with crossed nicols.

The photomicrograph (fig. 34) shows randomly 

oriented crystals of shortite being replaced by gaylussite 

that is in turn being replaced by northupite. The 

crystal of shortite (Si), oriented so that it is near the 

position of extinction, is seen in the process of replacement by gaylussite (GO that is going over to northupite 

(N), as is seen by the embayment of the gaylussite and 

the pitting that results in the small black areas in this 

highly birefringent mineral. Another crystal of shortite 

($2) is almost at maximum extinction and is embayed by 

gaylussite which is under attack by the northupite.

The molecular replacements are the same as those of 

the sequence shortite to pirssonite to northupite because 

gaylussite is composition ally different from pirssonite 

only because it has 5H2O whereas pirssonite has 2H2O 

as water of crystallization. Here also tiny crystals of 

dolomite can be seen under higher magnification.

FIGURE 33. Photomicrograph of thin section from the drill core of the 

John Hay, Jr., well 1, depth 1,344 ft 4in, showing the sequence shortite 

(Si through 87) to pirssonite (P). Sh indicates shale. Crossed nicols. 

X40.
PARAGENESIS OF THE SALINE MINERALS 41

FIGURE 34. Photomicrograph of thin section from the drill core of the 

John Hay, Jr., well 1, depth 1,340 ft lOln., showing the sequence shortite 

(Si, Sz) to gaylussite (G) to northupite (N). Crossed nicols. X 25.

SHORTITE TO GAYLUSSITE

The thin section was cut from core of the John Hay, 

Jr., well 1 from depth of 1,268 feet. The magnification 

is 40 diameters under crossed nicols.

Three randomly oriented crystals of shortite (fig. 35) 

are shown rimmed by gaylussite (G). The gaylussite 

was photographed near the extinction position to afford 

good contrast to the shortite ($). No northupite is 

present in this section. The dark area (Sh) is occupied 

by low-grade oil shale.

SHORTITE TO TRONA PLUS DOLOMITE

The thin section was cut from core of the John Hay, 

Jr., well 1 from a depth of 1,302 feet. The magnification is 25 diameters; the nicols are crossed.

Trona is seen replacing shortite with the formation 

of many tiny crystals of dolomite in figure 36. That 

which remains of a crystal of shortite (Si) is seen in a 

diagonal position. The dark area within this crystal's 

boundaries is occupied by the replacing mineral trona 

(T) in the extinction position. Very small crystals of 

dolomite, too small to give more than a point of light 

under crossed nicols at this magnification, are present 

throughout the area of the picture. Another crystal 

of shortite (S2) is also being replaced by trona. A third 

crystal of shortite ($3 ), almost in the extinction position, 

is embayed by trona. All the trona seen in the picture 

is occupying areas where there had been shortite, and

FIGURE 35. Photomicrograph of thin section from the drill core of the 

John Hay, Jr., well 1, depth 1,268 ft, showing the sequence shortite 

(S) to gaylussite (G). Sh indicates shale. Crossed nicols. X 40.

though these crystals of shortite were randomly 

oriented, all the replacing trona has the same orientation, all of it extinguishing at the same time. Though 

the trona forms a single crystal unit, it is obvious in this 

thin section, and in others, that the sequence is shortite 

to trona and not trona to shortite. Sharp boundaries 

and isolated remnant areas of the shortite crystals leave 

no doubt as to the paragenetic relationship.

The chemical composition of the solution that caused 

the replacement of shortite by trona, and the formation 

of the tiny crystals of dolomite, is not known. However, if a brine rich in magnesium and the bicarbonate 

ion were to have come in contact with shortite, the following reaction is not an improbable one :

3 (Na2C03 .2CaC03) + 6MgCO3+ CO2 

shortite

2 (Na2C03 -NaHC03 -2H20 + 6 (CaCO3 -MgCO3 ) 

trona dolomite

Until a phase equilibrium study is made, the conditions 

necessary for the replacement of shortite by trona must 

remain unknown.

TRONA TO NORTHUPITE

Core from the John Hay, Jr., well 1 from a depth of 

1,560 feet 2 inches furnished the material for the thin 

section that shows the transition of trona to northupite
42

FIGURE 36. Photomicrograph of thin section from the drill core of the 

John Hay, Jr., well 1, depth 1,302 feet, showing the sequence shortite 

(Si, Si, Sa) to trona (T). Crossed nieols. X 25.

(fig. 37). A magnification of 15 diameters was used 

with crossed nieols.

The black areas in the photomicrograph are occupied 

by the isometric mineral northupite. The embayment 

and pitting of the highly birefringent mineral trona, 

and the tiny remnant islands of trona slightly removed 

from the main mass, all indicate that the sequence is 

trona to northupite.

SHORTITE TO BBADLEYITE

The thin section (fig. 9) that shows bradleyite replacing shortite was cut from core of the John Hay, Jr., well 

1, from a depth of 1,342 feet 10 inches. The magnification is 15 diameters in plane-polarized light.

The ground mass is composed of approximately 80 

percent bradleyite and 20 percent clay. The randomly 

oriented particles of bradleyite are much too small to be 

distinguished at this magnification, the largest being 

approximately 0.002 mm in the longest direction. 

Much-corroded edges and the embayment of the crystals of shortite leave no doubt that the bradleyite is in 

the process of replacing the shortite. The tiny black 

areas in the picture are due to crystals of pyrite.

FIGURE 37. Photomicrograph of thin section from the drill core of the 

John Hay, Jr., well 1, depth 1,560 ft 2 in, showing the sequence trona to 

northupite. Crossed nieols. X 15.

MAIN TRONA BED 

ABEAL EXTENT

The number of square miles in southwestern Wyoming underlain by trona cannot be even approximately 

estimated from the data available at this time. Fragmentary reports of drilling in the area during 1959, in 

conjunction with data already at hand, indicate that 

trona may be present under an area of as much as 2,000 

square miles. This does not mean that the trona bed 

approximately 10 feet thick found at the Westvaco 

mine has such an extent. Nor does it necessarily 

follow that minable trona underlies the entire area. 

Many more test holes must be put down before the 

boundaries of the trona can be established and the 

thickness and quality of the beds determined.

The minimum area, underlain bjr the trona bed that 

is now being mined at Westvaco, was determined to be 

about 30 square miles. This determination was made 

from measurements of cores of the John Hay, Jr., well 

1 put down in 1938, and the Union Pacific wells 1 and 2 

drilled in 1940, and 3 and 4 drilled in 1941. Between 

1944 and 1956, 13 drill cores, Westvaco Nos. 1 to 13, 

were obtained. The Potash Co. of America put down
X-RAY POWDER DATA FOR THE SALINE MINERALS 43

their No. 1 and No. 2 wells in 1949 and 1950. These 

15 drill cores doubled the size of the proven trona area 

to about 60 square miles, and showed that the thickness 

of the main trona bed ranged from 7 to 16 feet.

It became evident as additional wells were drilled 

and the cores logged that minable trona extended far 

beyond the area in which the wells were located. On 

April 29, 1954, the Geological Survey made available 

for leasing 287,904 acres, or approximately 450 square 

miles, for prospecting for trona. This extended the 

area more than 20 miles to the south and west of T. 19 

N., R. 110 W., in which most of the exploratory wells 

have been drilled.

COMPOSITION

CHEMICAL

To determine variations in the chemical composition 

of the main trona bed between the top and the bottom, 

two locations (A and B) about half a mile apart, were 

selected. A representative sample of each foot of the 

main trona bed was taken. At location A nine samples 

were obtained and at location B, where the trona bed 

was less thick, eight were collected. A similar procedure was followed at two other locations (C, 10 

samples, and D, 9 samples) about 500 feet apart. The 

samples from C and D were examined spectrographically 

for lithium and the results are given in table 14.

TABLE 14. Spectragraphic determination of lithium in channel 

samples from each foot, top to bottom, of the main trona bed at 

locations C and D about 500 feet apart, Sweetwater County, Wyo.

[Harry J. Rose, analyst]

Sample

Cl ......

C2 ... 

C3 ... 

C4 

05 

C6 ..... ..... ..... ..

C7 

C8... . .................

C9 ..... ....... ... .

CIO 

Lithium 

(percent)

0.001

.002

.004

.004

.001

.0005

.0009

.0004

.0002

.0009

Sample

Dl. ... . ........ .....

D2 ... ....... .......

D3 . . . 

D4 

D5. .. . -

D6_ ..... ...... ..

D7. ..........

D8 ... ... ....

D9_ . .............

Lithium 

(percent)

0.004

.003

no9

.004

.0004

nnn^

.0008

.0003

.0003

Fifty grams of each of the samples from locations A 

and B were ground to pass a 100-mesh sieve and then 

placed in a 1-liter beaker to which was added about 

900 ml of distilled water. Each sample was repeatedly 

stirred, and after remaining on the steam bath overnight, the insoluble residue was filtered off, dried in an 

oven overnight at 80°C, and weighed. Aliquots of the 

filtrate were taken for the determination of P205 , SO3 , 

Cl, Br, and I, and the results are given in table 15. The 

percentage of the water-insoluble residue subtracted 

from 100 percent is a very close approximation of the 

trona present in the sample. Treatment of the waterinsoluble residue with (1 + 1) HC1 on the steam bath for

1 hour removed the dolomite. The insoluble residue, 

which was chiefly detrital material and a very small 

amount of organic matter, was filtered on a preweighed 

sintered glass filter, dried in an oven at 80°C for 2 

hours, and weighed.

At both locations A and B, as shown in table 15, 

less contaminating material is found in the middle, or 

near the middle, of the trona bed than at the top or the 

bottom. This is usually true in the main trona bed, 

though location E in table 16 is a notable exception. 

The phosphate, sulfate, and chloride, though present 

in very low percentages are, in most instances, higher 

where the concentration of water-insoluble material is 

greater.

TABLE 15. Chemical analysis of channel samples of each foot 

from top to bottom of the main trona bed at locations A and B 

about one-half mile apart, Sweetwater County, Wyo.

[Joseph J. Fahey, analyst]

Sample

Al..._ ... .......

A2 ... ... .....

A3 

A4 .... ... ... .

A5 .... .... 

A6 -

A7 - 

A8 . 

A9 .... 

Average ...

Bl ...... .

B2 .... 

B3 - 

B4 ... ....... .

B5 .

B6 

B7 -

B8 . ... ... ... .

Average ...

Insoluble in 

H2O (percent)

12.40

.38

14.18

1.40

.31

.14

1.00

.73

1.91

3.61

29.22

9.04

8.04

.61

.87

.08

.13

.77

6.10

Insoluble in 

(1+D 

HC1 

(per 

cent)

2.71

.21

6.13

.65

.16

.08

.47

.35

.39

1.24

13.18

4.14

3.58

.25

.24

.04

.08

.43

2.74

P2 05

(percent)

0.024

.002

.013

.014

.014

.015

.014

.015

.004

0.013

0.014

.026

.012

.014

.014

.006

.012

.013

0.014

SO3 

(percent)

0.015

.002

.008

.012

.008

<.002

<.002

.002

<.002

0.006

0.030

.028

.028

.012

.010

<. 002

.004

.006

0.015

Cl (percent)

0.10

.07

.16

.08

.06

.12

.07

.05

.09

0.09

0.50

.15

.12

.08

.05

.08

.15

.07

0.15

Br

(percent)

0.002

.002

.002

.002

.002

.002

.002

.002

.002

0.002

0.002

.002

.002

.002

.002

.002

.002

.002

0.002

I (percent)

0.0002

.0002

.0002

.0002

.0002

.0002

.0002

.0002

.0002

0. 0002

0. 0002

.0002

.0002

.0002

.0002

.0002

.0002

.0002

0. 0002

PaOs, SO3 , Cl, Br, and I were determined on the water-insoluble fraction.

The average concentration of trona in the trona bed 

at any given locality is not likely to be higher than about 

96 percent, which is found in the bed at location A. 

The percentage of trona at location B, which is approximately 93 percent, is closer to the average content of 

the trona bed.

MINERALOGICAL

A mass of trona weighing about 20 pounds was taken 

from the top, middle, and bottom of the trona bed at 

each of two locations E and F about a quarter of a mile 

apart. On these six samples the density was measured 

by cutting from each sample a rectangular solid that 

was approximately a cube, polishing each side with 

fine sandpaper, and measuring its dimensions in centimeters and its mass in grams. The mass of the six 

samples ranged from 73.692 g to 147.770 g. The 

density in grams per cubic centimeter is listed in table 

16.

596568 O 162 &
44 SALINE MINERALS OF THE GREEN RIVER FORMATION

TABLE 16. Density and composition of bulk samples from the top, 

middle, and bottom of the main trona bed at locations E and F, 

about a quarter of a mile apart, Siveetwater County, Wyo.

[Joseph J. Fahey, analyst]

Sample

E(top) _ _ . .-_

E (middle) 

E (bottom)...... ___ ._--.-----

F(top) -. 

F (middle).. --

Density 

(g per cc)

2.117

2.179

2.126

2.156

2.124

2.119

Insoluble 

inH2 O 

(percent)

1.55

3.06

.12

1.83

1.02

.74

Insoluble in 

(1+1) HC1 

(percent)

0.79

1.61

.06

.78

.41

.35

Organic 

matter 

(percent)

0.037

.142

.002

.014

.001

.001

The six samples from locations E and F were ground 

to pass a 100-mesh sieve and leached with water overnight on the steam bath in the same manner as previously described for samples A and B. The waterinsoluble residue was filtered off and dried at 80° C. 

An X-ray powder pattern showed the material to be 

predominantly dolomite. Treatment with (1 + 1) HC1 

removed the dolomite, and the residue, after it was 

filtered and dried, was examined under the petrographic 

microscope and found to be a mixture of quartz and 

clay. The organic matter of the original sample was 

concentrated in this small fraction.

Subhedral crystals, as much as 10 inches long, of the 

rare mineral searlesite (NaBSi2CVH2O) have been found 

sparsely disseminated throughout the main trona bed. 

The mineral is also present as micalike books in the 

shale, both above and below the trona bed. This is the 

third recorded location of searlesite (Fahey and Axelrod, 

1950). It was orginally found in clay from Searles 

Lake (Larsen and Hicks, 1914) as white spherulites 

about 1 mm in diameter. The second locality of searlesite is the Silver Peak Range, Esmeralda County, 

Nev. (Foshag, 1934), where it is found as prismatic 

crystals that seldom exceed 3 mm in length.

ORGANIC MATTER

To obtain an accurate measurement of the organic 

matter contained in the six samples from locations E 

and F, a 1-kg sample of each was taken and, after 

crushing to about pea size, was placed in a 2-liter 

beaker. To this was slowly added (1+2) HC1 until 

the carbonate was destroyed. After the solution was 

diluted it was filtered through a Whatman 41H paper 

and the residue washed with (1 + 9) HC1 and transferred, by means of a stream of water, to a 100-ml 

platinum crucible. A well-fitting cover was put on the 

crucible after 10 ml of HC1 and 50 ml of HF were added. 

After the solution remained on the stream bath overnight it was filtered through a Whatman 41H paper, 

using a polyethylene funnel and beaker. The residue 

was washed with distilled water and transferred by 

means of a stream of water to a preweighed platinum

crucible of 25-ml capacity. After taking to dryness on 

the steam bath, the crucible and contents were allowed 

to remain overnight in an oven held at 80° C. After 

cooling and weighing, the organic matter was burned 

off, the crucible weighed, and the organic matter recorded as the difference in the weights. The very 

small percentages of organic matter in the samples 

listed in table 16 necessitated taking a 1-kg sample. 

The color of the trona bed resembles that of maple 

sugar. This is due in great part to the organic matter 

which, though only present in trace quantities, pigments the trona bed.

LENGTH OF TIME OF DEPOSITION

Bradley, in his study of the varves of the Green 

River formation, found the average range in thickness 

in the sandstone, marlstone, and oil shale to be from 

0.037 to 1.16 mm (Bradley, 1929, p. 99). He considered each varve to represent a period of time of 1 

year and thus computed the time required to accumulate the material necessary to produce a thickness of 1 

foot of these sedimentary rocks ranged from 250 to 

8,200 years, with a weighted average of 2,200 years. 

In an oral communication (1960) Bradley estimated 

that 3,000 years was the length of time required for the 

deposition of a thickness of 1 foot of the sediments of 

the Wilkins Peak member of the Green River formation 

in which the saline minerals are found. This means 

that a period of time of about 3,000 years was required 

for the deposition of the detrital material and organic 

matter plus the minerals that precipitated from the lake 

water to form a thickness of 1 foot of rock. This rock 

material is composed chiefly of dolomite, other waterinsoluble minerals, the detrital minerals, and organic 

material.

To arrive at an approximate figure for the length of 

time required for the deposition of the trona bed, the 

period of time, 3,000 years, is used as that required 

for the accumulation of the material of which a thickness of 1 foot of the average rock of the Wilkins Peak 

member of the Green River formation is composed. 

If it is assumed that this rate of deposition of waterinsoluble material was maintained during the time that 

the trona bed was laid down, it seems that the length 

of time required for the deposition of a thickness of 

1 foot of trona would be proportional to the percentage 

of water-insoluble material present. Thus, if a 1-foot 

thick section of trona contained 10 percent of waterinsoluble material, the time required for deposition 

would be 10 percent of 3,000 years, or 300 years. 

Taking the percentage of water-insoluble material of 

the channel samples A and B (table 15) and applying 

the factor 3,000, a figure for the time required- for the 

deposition of the trona bed is obtained (table 17).
X-RAY POWDER DATA FOR THE SALINE MINERALS 45

TABLE 17. Length of time of deposition of the trona bed, based on 

the percentage of water-insoluble material in the vertical section

[Joseph J. Fahey, analyst]

Sample

Al. 

A2. 

A3.

A4. 

A5. 

A6. 

A7_ 

A8, 

A9.

Insoluble

in H%O Length of

(percent) time (years)

12.40 372

. 38 11

14. 18 425

1. 40 42

.31 10

. . 14 4

1. 00 30

.73 22

1.91 57

Total

Bl__. _____________________

B2.______

B3--____- __ _- _

B4

B5_. ______________________

B6._.___

B7__-_____________.-_____-

B8_._ _____________________

Total _------_--__-

29. 22

_____________ 9.04

8. 04

61

_____________ .87

_____________ .08

_____________ .13

__-_-_____.__ .77

973

877

271

241

18

26

3

4 

. 23

1,463

Table 17 shows that in both sample A and sample B 

there is a very large range in the time of deposition per 

foot of the trona bed between the top and the bottom 

of the column. However, the difference in total time 

of deposition between that at location A and that at 

location B, as indicated by this procedure, is not so 

great. Table 17 also shows a moderate rate of deposition at the bottom of the bed. This rate rapidly increased in the next several feet but by the time the top 

of the bed was reached the rate was very greatly reduced, indicating gradually diminishing conditions propitious to the precipitation of trona.

In this method for the estimation of the time duration 

of the deposition of the trona bed, there are inherent 

errors, chiefly among these being the uncertainty of the 

factor 3,000 for the years required for the deposition 

of a stratum 1 foot thick of water-insoluble material. 

Bradley estimated this figure as a weighted average. 

However, the correct factor for the water-insoluble 

material of the trona bed well may be one-half of 3,000, 

or it may be twice as great. This would place the 

correct figure for the time required for the deposition 

of the trona bed between 500 and 3,000 years, based on 

the data obtained from the channel samples of locations 

A and B. A 9-foot stratum of fine-grained sandstone, 

according to Bradley, would be laid down in about 

2,000 years whereas a rich oil-shale bed of the same 

thickness would require more than 70,000 years. In 

view of these figures, it is apparent that the time required for the deposition of the trona bed is probably 

a small fraction of the time required for the deposition 

of the same thickness of shale immediately above or 

below the trona bed.

X-RAY POWDER DATA FOR THE SALINE MINERALS OF 

THE GREEN RIVER FORMATION

By MARY E. MROSE

Indexed X-ray powder data are presented in this section for the following minerals from the Green River 

formation: Shortite, Na2Ca2 (CO3 )3, table 18; trona, 

Na3H(CO3 )2-2H2O, table 19; nahcolite, NaHCO3 , table 

20; northupite, Na3MgCl (CO3 ) 2 , table 21; bradleyite, 

Na3Mg(PO4 )(CO3 ), table 22; pirssonite, Na2Ca(CO3 ) 2 

 2H2O, table 23; and gaylussite, Na2Ca(CO3 ) 2 -5H2O, 

table 24. These saline minerals, with the exception of 

nahcolite and bradleyite, are from the John Hay, Jr. 

well 1, Sweetwater County, Wyo.; the nahcolite is from 

oil-shale mine of the Bureau of Mines, near Rifle, Colo.; 

the bradleyite, from Westvaco mine, Sweetwater 

County, Wyo. Powder data for natural nahcolite, 

northupite, and pirssonite are given for the first time.

EXPERIMENTAL TECHNIQUES

All the patterns for which X-ray powder data are 

given in tables 18 through 24 were made on chemically 

analyzed samples of the saline minerals, the analyses 

of which are listed in tables 9 and 11, and table 13 

(analysis B). For each powder pattern a spindletype mount having a diameter averaging 0.15 mm was 

made from the finely powdered mineral and a binder 

that consisted of a 10-percent solution of granular 

low-viscosity ethyl cellulose dissolved in toluene. 

The patterns were taken with Debye-Scherrer powder 

cameras (114.59 mm diameter) using the Straumanis 

and Wilson techniques with Cu/Ni radiation (XCuK«= 

1.5418 A, XCuKa! = 1.5405 A, XCuK«2 =1.5443 A). 

Two powder patterns were taken with each spindle: 

one, with the camera in a spot-focus position, for 

obtaining intensity data; the other, with the camera in 

a line-focus position, for best possible resolution for 

film measurement. The observed cut-off, that is, 

the lower limit measurable for 26, was approximately 

7.0° (12.6 A).

The films were measured with a Hilger-Watts 

film-measuring rule with a vernier precision of 0.05 mm. 

All measurements were corrected for film shrinkage. 

Intensities were estimated visually by direct comparison 

with calibrated intensity film strips of successive step 

line-exposures related to each other by a factor of -y/2-
46 SALINE MINERALS OF THE GREEN RIVER FORMATION

Indexed calculated interplanar spacings are listed 

for each mineral for comparison with the observed 

spacings. These data were calculated from the cell 

constants cited at the head of each table. Calculations 

were carried down to dhk i > 2.00 A for trona, nahcolite, 

bradleyite, and gaylussite; to dhkt > 1.570 A for 

northupite; and down to dhk i > 1.500 A for shortite 

and pirssonite. Cell constants originally given in 

kX units have been converted to A units for convenience of comparison with the observed spacings. 

All observed lines were found to be satisfactorily 

accounted for by the given X-ray cell data. Calculated 

interplanar spacings for nahcolite, northupite, and 

pirssonite were carried out on a digital computer by a 

program devised by Daniel E. Appleman.

Tables 18 through 24 also contain powder data 

found by other investigators for these saline minerals 

as well as for corresponding synthetic compounds; 

these are presented for comparative purposes.

TABLE 18. X-ray powder data for shortite, Na2Ca2 (CO3)3, from

the John Hay, Jr., well 1, Sweetwater County, Wyo. 

[Orthorhombic, Am-ml-C^*, o=4.961±0.005A, 6=11.03±0.02, c=7.12±0.011]

ASTM 

(Card 8-109) 2

Measured

/

75

75

75

60

50

50

50

50

50

100

75

50

50

75

60

50

75

20

10

50

75

20

35

20

dhkl

6.03

5.37

4.98

3.82

3.56

3.26

2.99

2.89

2.75

2.57

2.48

2.31

2.29

2.17

2.11

2.03

2.00

1.98

1.94

1.90

1.845

1.778

1.695

1.680

Mrose (unpublished data) '

Measured

(film 14139)

/

50

71

71

50

2

25

25

25

18

13

35

100

50

9

35

13

71

50

35

60

18

6

18

35

9

5

25

13

5

13

2

50

5

9

13

13

dhki

5.985

5.515

4.957

3.818

3.685

3.555

3.267

2.992

2.888

2.758

2.725

2.562

2.476

2.412

2.321

2.287

2.179

2.106

2.032

1.996

1.972

1.941

1.905

1.841

1.778

1.722

1.690

1.672

1.649

1.634

1.612

1.603

1.552

1.537

1.471

1.446

Calculated

dhki

5.981

5.516

4.960

3.818

3.687

3.560

3.267

2.990

2.891

2.758

2.729

2.561

2.480

2.410

2.320

2.291

2.261

2.180

I 2. 107 

I 2. 102

2.035

/ 1. 996 

I 1. 994

1.975

1.939

1.909

1.849

( 1. 844 

1 1. 839

1.780

1.723

/ 1. 694 

I 1. 694

1.675

1.653

/ 1. 637 

I 1. 633

1.616

I 1. 606 

I 1. 603

1.594

1.584

/ 1. 554 

I 1. 552

( 1. 539 

1 1. 536

1.500

hkl

Oil

020

100

111

120

002

031

022

102

040

131

122

200

140

013

211

220

042

051 

113

202

142 

033

231

151

222

133

240 

060

004

160

213 

024

104

300

242 

062

053

251 

124

311

320

233

162

071 

153

302

See footnotes at end of table.

TABLE 18. X-ray powder data for shortite, Na2Ca2 (CO3)3, from 

the John Hay, Jr., well 1, Sweetwater County, Wyo. Continued

ASTM 

(Card 8-109) 2

Measured

/ dhki

Mrose (unpublished data) *

Measured 

(film 14139)

/

5

6

9

2

5

3

9

3

2

9

9

2

9

18

2

2

5

3

5

6

2

5

6

3

1

3

6

3

9

1

2

3

1

1

1

3

2

3B

3B

3B

3

dhki

1.429

1.397

1.352

1.328

1.316

1.306

1.281

1.269

1.246

1.236

1.207

1.196

1.182

1.162

1.145

1.137

1.127

1.094

1.088

1.077

1.069

1.064

1.052

1.033

1.027

1.016

1.008

1.006

.9969

.9830

.9763

.9691

.9609

.9553

.9481

.9400

.9218

.9056

.8897

.8767

.8646

Calculated

dhki ftfcl

1 Single-crystal data obtained from a crystal of shortite from the John Hay, Jr. 

well 1, Sweetwater County, Wyo. (Mrose, unpublished data).

2 Powder diffraction data for shortite from the Green River formation, Sweetwater 

County, Wyo., by G. Gottardi, Institute di Mineralogia e Petrografia, Universita 

di Pisa, Italy. Camera diameter, 57.3 mm. Copper radiation, nickel filter (X= 1.541 

A). Cut-off at 8.0° (5.5 A). Intensities estimated visually.

3 Film corrected for shrinkage. Camera diameter, 114.59 mm. Copper radiation, 

nickel filter (X=1.5418 A). Lower limit 26 measurable: 7.0° (12.6 A). B=broad.

TABLE 19. X-ray powder data for trona, Na3H(CO3)2 > 2H2O, from 

the John Hay, Jr., well 1, Sweetwater County, Wyo.

Monoclinic, I2/c Chh, a=20.11±0.03 A, 6=3.49±0.01, c=10.31±0.01, /3=103°08' 1 ]

ASTM

(Card 2-0601)

Measured 2

I

80

70

40

60

60

100

60

60

100

dhki

9.42

4.87

4.00

3.43

3.20

3.06

2.95

2.78

2.66

Present study

Measured 3

(film 14141)

I

50

35

6

5

6

18

85

13

100

dhkl

9.804

4.920

3.990

3.442

3.262

3.196

3.075

2.763

2.650

Pabst (1959)

Measured *

I

ms

m

vs

w

w

ms

s

vw

mw

vs

dhki

9.88

4.92

4.12

4.00

3.43

3.21

3.08

2.79

2.76

2.659

Calculated

dhkl

9.79

5.02

4.95

4.90

4.11

3.99

3.44

3.30

3.26

3.20

3.17

f 3.08 

I 3.07

3.06

2.89

2.83

2.79

2.76

2.645

2.606

hkl

200

002

202

400

202

402

110

on

600

211

402

310 

602

211

112

111

112

312

411

510

See footnotes at end of table.
MAIN TRONA BED 47

TABLE 19. X-ray powder data for trona, Na3H(CO3 ) 3 -2H2 O, from 

the John Hay, Jr., well 1, Sweetwater County, Wyo. Con.

ASTM 

(Card 2-0601) 2

Measured

/

70B

70

40D

70

60D

40

40

60

70

70

60

20

40

20

40B

40

40

60

40

40B

40

40

20

50

40

40D

50

50

50

dhki

2.45

2.25

2.16

2.05

1.95

1.88

1.83

1.78

1.73

1.65

1.59

1.55

1.51

1.46

1.40

1.37

1.35

1.32

1.30

1.25

1.21

1.17

1.15

1.13

1.11

1.06

1.03

1.02

1.00

Present study 3

Measured

(film 14141)

/

9

18

6

35

6

35

5

9

6

2

25

9

13

9

5

3

18

25

5

5

25

5

3

2

13

5

9

3

3

3

3

6

9

3

2

2

5

9

3

2

3

2

2

2

3

2

3

2

5

2

1

1

2

1

1

1

3

2

2

2

2

2

Akkl

2.583

2.513

2.480

2.446

2.419

2.258

2.185

2.147

2.116

2.059

2.030

1.995

1.963

1.884

1.851

1.807

1.779

1.743

1.720

1.682

1.662

1.650

1.632

1.614

1.598

1.554

1.519

1.495

1.471

1.449

1.433

1.413

1.398

1.379

1.371

1.356

1.330

1.304

1.287

1.269

1.258

1.247

1.212

1.188

1.173

1.152

1.130

1.120

1.109

1.100

1.090

1.065

1.057

1.044

1.034

1.015

1.006

.9961

.9897

.9809

.9755

.9660

Plus additional

weak lines

Pabst (1959) *

Measured

I

w

mw

vw

ms

w

m

vw

w

w

w

m

m

mw

mw

w

dhkl

2.587

2.510

2.485

2.447

2.426

2.259

2.186

2.149

2.119

2.060

2.040

2.032

1.996

1.965

1.886

Calculated

dhkl

2.578

2.512

2.508

2.491

2.475

2.471

2.448

2.441

2.429

2.417

2.411

2.323

2.310

2.262

2.238

/ 2. 183 

I 2. 182

2.146

2.115

2.067

2.057

2.053

2.039

2.038

hkl

204

004

312

602

404

512

800

213

802

013

611

413

204

213

611

710 

512

712

613

114

314

404

811

413

Plus more than 30 additional lines

1 X-ray crystallographic data from Brown, Peiser, and Turner-Jones (1949).

2 Powder diffraction data by British Museum of Natural History for trona from 

Lake Magadi, Kenya Colony. Camera diameter not indicated. Copper radiation, 

aluminum filter (\=1.541 A). B=broad; D=diffuse.

s Film corrected for shrinkage. Camera diameter, 114.59 mm. Copper radiation, 

nickel filter (X=1.5418 A). Lower limit 20 measurable: 7.0° (12.6 A).

« Powder diffraction data for trona from Searles Lake, California. Camera diameter not indicated. Copper radiation, nickel filter.

TABLE 20. X-ray powder data for nahcolite, NaH(COs), from 

the oil-shale mine of the Bureau of Mines, near Rifle, Colo.

[Monoclinic, PZiln-Chh] <z=7.525±0.04 A, 6=9.72±0.04, c=3.53±0.03, 0=93°19'i]

Measured 2 

(film 14040)

/

6

13

5

2

15

6

25

100

13

90

2

2

5

13

2

18

2

18

5

13

5

15

3

2

2

9

5

6

3

dhkl

5.92

4.85

4.07

3.74

3.48

3.25

3.08

2.97

2.69

2.60

2.453

2.418

2.390

2.305

2.254

2.217

2.108

2.032

1.984

1.965

1.931

1.900

1.872

1.823

1.778

1.735

1.687

1.658

1.637

Calculated

dhkl

5.94

4.86

4.08

3.76

3.50

3.32

3.27

3.13

3.10

f 2.98

{ 2.98

I 2.97

2.71

2.63

2.56

2.453

2.430

2.425

2.424

2.388

2.328

2.312

2.302

2.251

2.226

2.225

2.101

2.054

2.052

2.040

hkl

110

020

120

200

210

Oil

101

101

Til

111

130

220

121

121

211

230

040

310

211

031

221

140

131

131

320

221

301

311

231

240

Measured 2 

(film 11040)

/

13

6

2

2

13

3

3

3

2

2

2

3

2

2

4

2

2

2

2

2

2

2

2

3

1

2

3

2

2

2

2

1

3

1

3

2

3

2

dhkl

1.613

1.580

1.559

1.539

1.522

1.480

1.465

1.442

1.422

1.399

1.372

1.354

1.343

1.334

1.298

1.284

1.272

1.246

1.236

1.221

1.211

1.208

1.196

1.182

1.159

1.151

1.139

1.127

1.113

1.098

1.088

1.078

1.069

1.047

1.042

1.032

1.029

1.014

Plus additional

weak lines

Calculated

dhki hkl

1 Single-crystal data from Laue and rotation methods by Zachariasen (1933); converted to angstrom units from the original values given by Zachariasen.

2 Film corrected for shrinkage. Camera diameter, 114.59 mm. Copper radiation, 

nickel filter (\=1.5418 A). Lower limit 20 measurable: 7.0° (12.6 A).

TABLE 21. X-ray powder data for northupite, Na3 MgCl(C03)2,

from the John Hay, Jr., well 1, Sweetwater County, Wyo.

[Isometric, Fd3m=0h <z=14.08 AI]

Measured 2 

(film 14090)

/

60

25

1

9

18

18

18

71

100

13

9

6

35

9

9

6

5

30

5

3

25

2

<^1

jj

5

dhkl

8.132

4.983

4.240

4.062

3.520

3.226

2.874

2.706

2.488

2.375

2.225

2.146

2.122

2.030

1.970

1.881

1.831

1.758

1.657

1.623

1.614

1.572

1.546

1.535

1.498

Calculated

dhki

8.130

4.980

4.244

4.063

3.520

3.230

2.874

f2. 709 

12. 709

2.489

2.380

2.347

2.226

2.147

2.123

2.033

fl. 971 

11.971

1.883

fl. 833 

11. 833

1.760

1.720

fl. 659 

11. 659

1.626

1.615

1.574

hkl

111

022

113

222

004

133

224

333

115

044

135

244

026

335

226

444

117 

155

246

137

355

008

337

066

288

555

266

048

Measured 2 

(film 14040)

I

2

1

2

1

5

<^l

<[1

2

2

<[1

5

2

2

2

3

2 

2

<[1

2 

2

2

1

2 

2

2

2

<1

<[1

5

2

dhki

1.240

1.229

1.205

1.192

1.189

1.171

1.159

1.142 

1.138

1.129

1.112

1.109

1.101

1.099

1.085

1.075

1.073 

1.069

1.061

1.052ai 

1. 050<*2

1. 037ai

1. 036a2

1. 015ai 

1. 015a2

1.007ai

1. 006a2

l.OOOai

. 9998a2

. 9S41ai

.9835a»

Calculated

d^i hkl

See footnotes at end of table.
48 SALINE MINERALS OF THE GREEN RIVER FORMATION

TABLE 21. X-ray powder data for northupite, Na3 MgCl(CO3)2, 

from the John Hay, Jr., well 1, Sweetwater County, Wyo. 

Continued

Measured 2

(film 14090)

7

2

13

5

3

5

5

5

2

1

9

dkhi

1.473

1.455

1.413

1.379

1.360

1.353

1.312

1.283

1.269

1.243

Calculated

d hkl hkl

Measured 2

(film 14040)

I

1

<1

2

1

2

2

3

2

dkhi

. 9744ai

. 9740a2

. 9650ai

. 9647a2

. 9499ai

. 9491a2

. 9393ai

. 9387aj

Plus additional

weak lines.

Calculated

dhki hkl

1 Converted to angstrom units from original value of 14.05 kX (Shiba and Watanabe, 

1931).

2 Shrinkage negligible. Camera diameter, 114.59 mm. Copper radiation, nickel 

filter (X=1.5418 A). Lower limit 20 measurable: 7.0° (12.6 A).

TABLE 22. X-ray powder data for bradleyite, Na3 Mg(PO4 )

(CO3),from the Westvaco mine, Sweetwater County, Wyo. 

[Monoclinic, P2i/m C22 h; a=8.85 A, 6=6.63, c=5.16 (all ±0.01 A), )8=90025'±05'',

Fahey and Tunell (1941)2

Measured

I

3

5

10

2

10

8

/2l

Vt

Vi

3

4

K

4

8

A1

6

A1

3

dftti

8.939

3.680

3.319

2.969

2.658

2.566

2.467

2.388

2.313

2.209

2.116

2.025

1.935

1.842

1.760

1.658

1.598

1.562

Mrose (unpublished data) 3

Measured (film 12960)

I

50

3

18

25

3

71

3

9

4

2

100

35

18

6

2

13

3

9

2

13

3

6

13

6

3

9

9

30

5

9

9

25

3

3

6

3

dhki

8.85

5.308

4.468

3.694

3.368

3.312

3.105

2.986

2.946

2.789

2.655

2.576

2.556

2.480

2.401

2.383

2.321

2.312

2.233

2.208

2.200

2.144

2.115

2.034

1.979

1.948

1.933

1.839

1.769

1.708

1.673

1.655

1.628

1.603

1.569

1.556

Calculated

dhki

8.850

5.306

4.472

4.443

4.425

4.072

3.707

3.691

3.680

3.371

3.347

3.315

3.104

3.005

2.988

2.950

2.789

2.695

f 2. 663

\ 2. 657

I 2. 653

2.580

2.569

2.553

2.482

2.472

2.404

2.395

2.382

2.364

2.358

2.324

2.316

2.236

2.222

2.212

2.204

2.144

2.119

2.107

2.099

2.039

2.036

2.032

2.031

/ 2. 028 

I 2. 023

hkl

100

110

101

101

200

Oil

111

111

210

201

201

020

120

211

211

300

021

310

121

121

200

002

301

301

102

102

012

311

311

221

221

112

112

502

202

400

320

130

212

212

410

401

022

031

321

401 

321

See footnotes at end of table.

TABLE 22. X-ray powder data for bradleyite, Na3 Mg(PO4) (CO3 ), 

from the Westvaco mine, Sweetwater County, Wyo. Continued

Fahey and Tunell (1941)2

Measured

I

4

3

4

2

2

1

H

IB

2

3

2

1

MA1

dhu

1.494

1.443

1.386

1.331

1.288

1.251

1.224

1.186

1.151

1.101

1.068

1.038

1.011

.987

Mrose (unpublished data) 3

Measured (film 12960)

I

3

6

4

2

4

4

3

18

4

4

4

4

3

4

6

dhki

1.550

1.501

1.489

1.470

1.455

1.443

1.418

1.389

1.329

1.292

1.254

1.193

1.103

1.072

1.058

Calculated

dhki hkl

1 X-ray crystallographic data obtained by Mrose (Mrose, unpublished data) by 

the Buerger precession method on crystals of bradleyite from the Green River formation, Westvaco mine, Sweetwater County, Wyo.

2 B=broad. Camera diameter and wavelength not indicated. Copper radiation, 

nickel filter.

3 Film corrected for shrinkage. Camera diameter, 114.59 mm. Copper radiation, 

nickel filter (X=1.5418 A). Lower limit 20 measurable: 7.0° (12.6 A).

TABLE 23. X-ray powder data for pirssonite, Na2Ca(CO3 )2- 

2H2O, from the John Hay, Jr., well 1, Sweetwater County, 

Wyo.

[Orthorhombic, Fdd2-D^2h = V^h \ <z=11.32 A, 6=20.06, c=6.00 ']

ASTM (Card 2-0157) "

Measured

I

100

40

90-

90-

7090-

90-

100

10

20

90-

70

90

10

60

70

90

60

dhki

5.14

4.17

3.18

2.88

2.72

2.66

2.57

2.49

2.35

2.22

2.13

2.10

2.02

1.96

1.89

1.82

1.77

1.71

Present study 3

Measured (film 14588)

I

71

60

18

6

25

50

50

6

35

90

80

100

13

25

5

3

35

25

18

71

3

18

6

9

25

50

3

13

dhkl

5.133

4.928

4.157

3.752

3.198

3.153

2.885

2.829

2.726

2.654

2.565

2.506

2.348

2.294

2.234

2.160

2.130

2.105

2.055

2.020

1.963

1.893

1.876

1.853

1.823

1.770

1.753

1.710

Calculated

dhkl

5.125

5.015

4.929

4.154

3.754

3.199

3.154

2.882

2.879

2.874

2.830

2.724

2.651

2.563

2.521

2.508

2.499

2.465

2. 343

2.293

2.233

2.160

2.133

2.107

2.077

2.055

2.019

2.017

1.960

1.904

1.891

1.889

1.877

1.873

1.854

1.828

1.822

1.768

1.766

1.760

1.753

1.724

1.708

hkl

111

040

220

131

240

151

311

331

260

022

400

420

202

222

171

080

351

440

242

280

062

460

371

511

262

191

531

422

113

442

2. 10. 0

133

480

551

620

391

282

153

640

313

462

1.11.1

333

See footnotes at end of table.
LENGTH OF TIME OF DEPOSITION 49

TABLE 23. X-ray powder data for pirssonite, NaoCa(COa)r 

2HoO, from the, John Hay, Jr., well 1, Sweetwater County, 

Wyo. Continued

ASTM (Card 2-0157) 2

Measured

7

30

30

30

20

60

30

30

60

20

40

20

10

dhkl

1.67

1.63

1.60

1.56

1.52

1.50

1.47

1.44

1.41

1.38

1.36

1.34

Present study 3

Measured (film 14588)

7

13

13

6

6

13

5

9

18

9

6

18

6

9

5

3

9

9

3

9

6

5

6

6

6

3

5

5

5

5

5

6

9

9

2

2

5

2

2

9

5

5

dhkl

1.702

1. 60S

1.640

1.627

1.602

1.579

1.555

1.521

1.505

1. 465

1.439

1.413

1.388

1.359

1.335

1.318

1.296

1.287

1.278

1.258

1.246

1.235

1.228

1.216

1.203

1.194

1.186

1.177

1.155

1.146

1.132

1.107

1.077

1.065

1.053

1.038

1.030

1.021

1.010

1.001

.9822

Plus additional weak

lines

Calculated

dhkl

1.703

1.672

1.643

1.637

1.623

1.617

/ 1. 603 

I 1. 600

1.597

1.591

1.584

1.577

1.557

1.535

1.522

1.521

/ 1. 508 

\ 1.504

hkl

571

0. 12. 0

660

4.10.0

173

353

2. 12. 0 

2. 10. 2

602

482

3.11.1

622

711

592

641

731

680 

373

1 X-ray crystallographic data obtained by Evans (1948) by the Buerger precession 

method on crystal of pirssonite from Searles Lake, Calif.

2 Powder diffraction data by Imperial Chemical Industries of Northwich, England, 

presumably on synthetic material. Camera diameter not indicated. Molybdenum 

radiation (X=0.709 A).

3 Film corrected for expansion. Camera diameter, 114.59 mm. Copper radiation, 

nickel filter (X=1.5418 A). Lower limit 29 measurable: 7.0° (12.6 A).

TABLE 24. X-ray powder data for gaylussite, Na2Ca(CO3) 2 - 

5H2O, from the John Hay, Jr., well 1, Sweetwater County, 

Wyo.

[Monoclinic, I2/a a=11.57±0.01 A, 6=7.765±0.005, c=11.20±0.01, /3=102°00'

ASTM (Card 2-0122)2

Measured

7

100 

50 

70

dhki

6.41

5.57 

4.45

ASTM (Card 

2-0528)2

Measured

/

60 

40

dhki

6.40 

4.45

Mrose (unpublished data) 3

Measured 

(film 14651)

7

100 

18

13 

25 

35

dhki

6.403 

5.662

5.471 

4.495 

4.428

Calculated

dhkl

6.402 

6.333 

5.659

5.476 

4.496 

4.429

hkl

110 

Oil 

200

002 

211 

112

TABLE 24. X-ray powder data for gaylussite, Na2 Ca(CO3)2'5H2O, 

from the John Hay, Jr., well 1, Sweetwater County, Wyo. 

Continued

ASTM (Card 2-0122)2

Measured

/

50

30

80

40

40

80

80

70

40

50

40

40

30

40

10

70

80

20

60

30

60

60

40D

40

40

dhki

3.90

3.56

3.18

3.02

2.91

2.70

2.61

2.49

2.40

2.32

2.26

2.19

2.15

2.12

2.02

1.98

1.91

1.85

1.81

1.78

1.71

1.67

1.60

1.53

1.50

ASTM (Card

2-0528)2

Measured

7

100

40

80

20

10

10

20

25

35

40

15

15

20

20

dhkl

3.19

2.71

2.63

2.50

2.40

2.32

2.20

2.12

1.99

1.92

1.85

1.83

1.72

1.67

Mrose (unpublished data) 3

Measured

(film 14651)

7

13

9

9

25

100

9

3

18

3

80

35

80

50

2

13

2

6

18

9

13

18

9

13

3

3

9

25

35

18

5

9

5

18

2

9

5

13

13

5

18

18

3

3

2

2

2

9

6

6

3

3

3

3

3

3

3

3

6

dhki

3.943

3.555

3.417

3.308

3.203

3.159

3 121

2.921

2.831

2.726

2.692

2.635

2.515

2.478

2.420

2.386

2.356

2.330

2.290

2.259

2.212

2.176

2.137

2.113

2.065

2.030

1.994

1.920

1.895

1.873

1.855

1.841

1.824

1.812

1.787

1.752

1.729

1.720

1.701

1.677

1.675

1.652

1.610

1.590

1.583

1.562

1.540

1.512

1.491

1.477

1.447

1.438

1.417

1.366

1.358

1.348

1.332

1.297

Calculated

dhki

4.421

3.989

3.939

3.882

3.582

3.555

3.413

3.393

3.305

3.202

3.168

3.161

3.120

2.917

2.829

2.759

2.739

2.723

2.708

2.695

2.682

2.670

2.646

f 2. 632 

I 2. 632

2.540

2.523

2.519

2.506

2.475

2.418

2.3S3

2.357

2.348

2.344

f 2. 333 

I 2. 325

1 2.287 

I 2. 286

2.261

2.253

2.249

2.238

f 2.213 

I 2.210

2.173

2.134

2.120

2.111

2.109

f 2. 073 

I 2. 061

2.034

hkl

202

211

112

020

202

121

121

310

013

220

022

312

213

222

400

402

004

321

411

204

123

312

213

222 

114

321

130

031

123

411

114

113

314

323

231

132 

402

420 

204

231

132

422

024

224 

404

510

330

215

033

015

332 

233

323

See footnotes at end of table.
50 SALINE MINERALS OF THE GREEN RIVER FORMATION

TABLE 24. X-ray powder data for gaylussite, Na2Ca(CO3 ) 2 - 

5H2O, from the John Hay, Jr., well 1, Sweetwater County, 

Wyo. Continued

ASTM (Card No.

2-0122)2

Measured

I dhkl

ASTM (Card No.

2-0528) 2

Measured

/ dhkl

Mrose (unpublished data) 3

Measured

(film 14651)

I

3

3

2

2

3

2

3

3

5

3

2

2

3

2

2

2

2

2

2

2

dhkl

1.281

1.261

1.248

1.238

1.218

1.202

1.179

1.166

1.152

1.130

1.112

1. 095

1.074

1.065

1.060

1.046

1.034

1.024

1.011

.9969

Calculated

dhki hkl

1 X-ray crystallographic data obtained by Mrose (unpublished data) by the Buerger precessio'n method on crystal of gaylussite from the Green River formation, Westvaco mine, Sweetwater County, Wyo.

2 Powder diffraction data for laboratory prepared materials. Camera diameter not 

indicated. Molybdenum radiation (X=0.709 A).

3 Film shrinkage negligible. Camera diameter, 114.59 mm. Copper radiation, 

nickel filter (X= 1.5418 A). Lower limit 20 measurable: 7.0° (12.6 A).

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