Further Studies of the 

Distribution of Uranium 

in Rich Phosphate Beds 

of the Phosphoria 

Formation

GEOLOGICAL SURVEY BULLETIN 1009-D

A CONTRIBUTION TO THE GEOLOGY OF URANIUM

FURTHER STUDIES OF THE DISTRIBUTION OF URANIUM 

IN RICH PHOSPHATE BEDS OF THE PHOSPHORIA 

FORMATION

By M. E. THOMPSON

ABSTRACT

Five sets of "close" samples (narrow and contiguous samples across a lithologic 

unit) from beds of high phosphate content of the Phosphoria formation in Idaho, 

Utah, and Wyoming were analyzed chemically for F and C02. Very good correlations between F, COj, and P20g were found in several of the samples.

The size of phosphate pellets was measured in thin sections of two sets of close 

samples. Frequency histograms and cumulative curves were plotted from these 

size measurements, but when compared with uranium concentration for each 

sample, no significant correlation between size and uranium concentration was 

discovered.

Analyses of these samples for PjOg, CaO, organic matter, and equivalent uranium are presented in a previous report by this writer (U. S. Geol. Survey Bull. 

988-D). In two sets of samples a good correlation was found between equivalent 

uranium and each of the other components. The samples in these two sets have 

a uranium content that is relatively high for the Phosphoria formation, and they 

show considerable range in PjOs content.

INTRODUCTION

In connection with the Geological Survey's work on behalf of the 

Division of Raw Materials of the U. S. Atomic Energy Commission, a 

study was made of the distribution of uranium in rich phosphate beds 

of the Phosphoria formation of Permian age in the Northwestern 

United States. This study is described in a previous report. 1 The 

present report concerns a further investigation of the problem.

In the previous investigation, a study was made of special "close" 

samples from the rich phosphate beds. A "close" sample is defined as 

one of a set of small, contiguous samples taken across a stratigraphic 

unit, the set being representative of the entire unit. Sets of close 

samples, with from 12 to 31 samples to a set, were taken across a layer 

of the phosphate-rich rock. The thickness of the layers that were 

sampled ranged from 0.5 foot to 1.2 feet, and the thickness of the individual samples was on the order of half an inch. Chemical analyses of 

the groups of close samples for U, CaO, P205, organic matter, and loss 

on ignition, radiometric analyses for equivalent uranium, and Rosiwal

' Thompson, M. E., 1953, Distribution of uranium In rich phosphate beds of the Phosphoria formation: 

U. S. Qeol. Survey Bull. 988-D.

107
108 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

analyses of some of the samples for mineral content are given in the 

previous report. Comparisons were made between the proportions of 

the various components, and positive correlations were found between 

PzC^ and uranium content in the groups of close samples whose uranium 

content was higher than average. A positive correlation between 

uranium and organic matter was obtained in the group of close 

samples with the lowest average uranium content. Negative correlations were found between uranium and organic matter in three groups 

of close samples whose uranium content was higher than average.

In the present report, the problem has been pursued along two lines, 

as follows:

1. Analyses of F and C02 (table 1) were made in order to determine 

if the concentration of uranium is related to the nature of the apatite 

in the phosphate rock.

TABLE 1. Chemical and radiometric analyses, in percent, of close samples from 

phosphate rock of the Phosphoria formation in Idaho, Utah, and Wyoming

[Analyses of F and COj by Harry Levine, David Deibler, and Henry Mela, Jr.]

Sample no. F CDs eU PjO.

Brazer Canyon, Utah

WT-304 30...................... ........................ ...............

29... ............................ .. ...................

28 __ -- __ -._-_ .

27... _ . _ ..... _ . ...

26........ .................. ...................................

25.. ...........................................................

94

23.............................................................

22.............................................................

21............................................................

20.......... ...................................................

19... ........................... ... .....................

18............................... .......................... ....

17................. .......................... ..................

16 

15 - . .. .. . -

10

12........................ .................. ...................

11.................. ............................... ...........

w................'................ .............................

9.. . __ . ... .....

8 . ._ . . 

7.........-......-...-.....-..............-.--- ....... .. _

6.......... ....... ................. .......-......... ...... .

5.............-..-.......-..-..............................:..

4.. .

WT-605 3.......................

2 . .-. _ ....

1.............. ............ . .......................

WT-603 24.............................................................

23........... ..... . ..................

22...... .......................................................

21 . - - -: -

20... ................... ................... ........ ..

19 

18... ... ....... ............ ..,........... ......... ------

17... ............................................ ..............

16...... .. 

1.38

3.10

3.38

3.62

3.66

3.58

3.64

3.77

3.48

3.55

3.57

1.88

1.84

3.14

2.88

2.58

2.68

2.66

2.90

3.28

3.24

3.36

3

OA

3.14

3.55

3.95

3.77

3 on

3.73

3.42

3.71

3.39

3.95

3.93

1.44

1.92

I

fift

1.78

1.62

1.62

1.48

1.74

1.62

1.60

2.08

1.40

1.40

1.12

1.84

1.84

1.58

1.42

1.60

1.56

1.67

1.78

2.12

2.10

2

f)A

2

f\A

2.04

2.30

2.34

2.74

2.42

2.08

2.48

2.70

2.32

2.58

0.014

.014

.011

.010

.014

.015

.017

.029

.014

.015

.013

.011

.012

.010

.023

.015

.011

.012

.010

.010

.008

.010

.009

.010

009 .'010

.014

10.85

23.36

10 oft

29.51

32.77

33.58

32.09

32.76

33.70

31.21

30.78

31.31

32.91

15.59

14.96

26.73

24.37

21.89

23.86

23.05

23.37

29.04

28.50

29.50

29.91

28.88

28 47

27.57

32.15
DISTRIBUTION OF URANIUM IN PHOSPHORIA FORMATION 109

TABLE 1. Chemical and radiometric analyses, in percent, of close samples from 

phosphate rock of the Phosphoria formation in Idaho, Utah, and Wyoming Con.

Sample no. F OOi eU P>0.

Brazer Canyon, Utah Continued

WT-603 15. ..._ - . 

H.._. . . .. ....................................... . ...

13... ., . 

12.... ...... ........ ...... ....... ...... .......... . 

11...... . ...... ........ .. . .... .

10..., ... ........ ... ................. , ... .

9... .. ............................... ....... .......

8... ......--. ....... ...... ...... .... ......... ..

7..-. ... ...................... ......:.... 

6 . . .. . ........... .. ............ ..

8.... .................... ....... ....... ............. ....

4.... ........ ............................... .. ........

3..... ...................................................... ..

z..... ...................................................... ..

I..... ........................................................

3.73

3.81

3.81

3.77

3.81

3.65

2.02

1.08

1.16

1.34

1.46

2.78

3.14

l.«4

.72

2.32

2.26

2.24

2.42

2.18

2.64

1.56

.08

.36

.42

.70

1.20

1.68

1.12

.50

Trail Canyon, Utah

[Entries marked with asterisks are determinations of U, not eU]

WT-36S 26 

25.. . .

24.. 

23... ... .

22.. ....... .... . 

21.. -- - . 

20....-.. ...... ........... ...... . . . .

19...---....---. .......... . .. .

18.. . 

17.. 

16 . -

15 . 

14............ . ....

13 

12............ 

11 ........ . .. . 

10.. -- - --.

9 .... 

8 . -

7 . -

6 

5 

4 

3 -

2 . . ....

1: .. ... .........

3.43

3.24

3.42

3.34

3.35

3.35

3.35

3.14

2.08

2.80

2.04

2.76

2.06

2.76

2.82

2.84

2.60

2.76

2.08

2.56

2.16

2.06

3.42

3.58

3.36

3.30

1.66

1.83

1.66

1.50

1.76

2.04

2.12

1.56

2.08

4.32

2.74

1.63

1.74

1.78

2.10

1.76

2.02

1.00

1.66

1.42

1.00

2.66

2.16

2.86

. 2.14

.018

.017

.014

.017

.000

.011

.006

.005

.004

.006

.005

.005

.005

.005

.005

.007

.007

.000

 .007

 .012

 .000

 .010

 .006

 .008

 .006

'.006

33.0

20.8

32.6

32.4

32.0

32.8

32.2

33.5

31.1

27.5

29.1

27.3

28.8

27.2

20.3

27.0

24.1

27.7

29.3

26.2

20.8

19.9

33.0

35.1

32.9

30.7

Coal Canyon, Wyoming

WT-700 12 ..

11......... . ..

10 ......... __ ...

9 

8-.. 

7... . . . . 

6 

a..... . - 

3........ . 

2...... . 

1...... . . 

3.34

3.79

3.85

3.73

3.59

3.58

1.24

1.62

1.92

.50

.66

.88

1.70

1.60

1.68

1.68

1.68

1.46

.42

.70

1.06

.20

.08

.42

0.039

.044

.045

.040

.048

.065

.021

.022

.025

.006

.006

.011

31.45

32.71

34.35

33.55

33.15

31.37

7.64

0.50

16.21

.83

.73

3.71
TO' THE GEOLOGY OF URANIUM

TABLE 1.-^Chemical and radiometric analyses, .in .percent of close samples from\ 

phosphate rock of the Phosphoria formation in Idaho, Utah, and Wyoming-^ Con."

Sample no. F COa eU PiOj

Reservoir Mountain, Idaho

WT-910 SI.......--.:..................................................

30..... . 

29....................:........................................

28-. - . . ....

27.............................................................

26... ... .:- _._ . 

25..................:..........................................

24....-....-.......- 1...... .....................................

23.......... ....::i:.... ......................................

22....................... ...................................

21..... - -'.... ....... .............. .........

20..... -' ... ...... ...... ... . 

19... . . .. 

18 . ... .-...... .......

17........ .. ...... ................. ...

16 .. 

15.... ...... ................... _ ........ ."... ......

14... ....... ..;.... :..... ....... ..i. ...-.-.: . . IX. :.--J.L: ;~...

n...,-.. ............................................. .........

12...... ... .............................................

 : :'' 11.'... ................ .........................

': ' io ..--.--..... ... :'__ ........ .......__ . 

9.'... ....... ..... ..... ..... . ..............

8 - ............. .................

7...-...... I.... ......... ......... ...............

6.............................................................

' 5...--.-. ^..:..... I..-:... ............... ...... .. ...........

4.:...... i'i.-: . _ ............... ..... .........

3.:. ..:;:...... . ... ......... . .........

2.J... ...! ..:..... : . ........................................

1........ . ... .......... .... .... ..

3.61

3.81

3.65

3.79

3.63

3.75

3.73

3.71

3.71

3.65

3.63

3.63

3.65

3.63

3.79

3.63

3.67

1 3. 85

3.67

3.73

3.81

3.73

3.75

3.85

3.59

3.69

3.67

3.77

3.73

3.85

3.77

2.76

2.62

2.52

2.58

2.50

2.56

2.72

2.32

2.44

2.38

2.72

2.34

2.36

2.26

2.44

2.36

2.38

2.44

2.74

2.34

2.18

2.00

2.28

1.96

2.56

2.26

2.10

2.26

2.30

2.32

2.22

0.007

fins ,

.008

007

.008

.011.

.011

.008

.009

.010

.022

.019

.017

.017

.015

.012

.016

.021

.023

.025

.030

.030

.026

.023

.022

.018

.013

.013

,013

.019

.022

33.60

35.48

34.32

35.46

34.62

34.79

34.32

35.61

35.49

32.81

33.38

33.57

34.09

35.30

35.22

34.42

33.32

34.41

32.81

33.29

35.80

34.72

34.47

34.71

32.58

33.78

33.23

33.06

31.14

31.89

32.05

Laketown Canyon, Utah

WT-509 25.. ........... .. .......... ............. ...... ..........

94

23.,. , ..-.... - 

:, 22 . 

: 21.... ...... . .. _ ........ 

20 

;, 19 

 ;- 17 - - _ 

..: IB.:. .... 

14 . 

1Q ,','.> 

12...... .................. ............ ... .. . ...- 

11 

10:1.. :: . 

: 9 . ..--... ... 

: 7'.... ...._......

. : 6.;. _ . - -- .

fi....... ...................-, - »- 

: 4---. -.-.. .'-

3:1...... ........ ... ...... -

2.L . .. . .. . . .

0.012

.012

.009

.008

:009

.008

.012

.017

.011

003

.006

.010

.013

.017

.013

.009

009

.007

(M.009

.010

.005

36.20

34.80

34. 4C

33. 8(

32. 1C

33. 8C

35. 2C

OQ Of]

34. 8C

10.6

24. OC

35. 2C

35. 2C

34. M

35.2C

35 Of

oe t\t

33. 8C

34 SI

34. (X 36. a

29. «
DISTRIBUTION OF, URANIUM-IN PHOSPHOR^ .FORMATION 111}

2. Because -the rich phosphate.'beds of thes-Phosphoriai formation 

have a typically'oolitic or pelle'tal* texture/ the-size of-, tlie pellets in 

thin sections, of two sets of close samples was .measure^ for comp^ri,- 

son with ..uranium content. .It was hope4-tjiat the sigiiificahc.e ojf 

variations of pellet size might be more easily discovered in these 

samples, 'because a:number, of chemical analyses 'had. already been 

obtained on these or similar samples'with the intention of making 

comparisons of uranium content with other components.

As in the earlier report, the order of correlation of the various components was expressed numerically by means of the correlation coefficient. The formula used is that given by Snedecor,2 -.- ''

; : vis*,2 ) .czatf)

where Xi and x2 are iidividual values of the two components being 

compared. The following is summarized from Snedecor: The " expression . , ; . .:: . .

. 2 ) (Sx2') . . . ' . / . . .

is designed to vary between minus 1 and plus 1, according1 to the' 

closeness of the relationship of. the two, components. Where there is 

a direct correlation between two sets of values, the points plotted on t 

a scatter diagram tend to lie in a band extending from lower left, to 

upper righ.t and are not scattered randomly over the whole field. 

These points are confined to an ellip.tical -area with the rriajor axis inclined toward the right. Negative values of. r indicate an inclination . 

of the ellipse pf points downward toward the right, .large values of 

one variate being associated with small values of the other. The 

thinness, of the ellipse of points exhibits the magnitude of .r, and theinclination of the axis to the right or left shows; its sign.1 A good correlation, either positive or negative, is fairly obvious from a graph. 

If the number of samples is small, a single point can 'make a great 

difference. Judgment about the degree of correlation should be 

made in the light of other correlations in the same field. 

rFrom the point of view of a statistician, the number of samples' 

used in this investigation was probably too small to give dependable, 

results. Therefore, only the strongest correlations should be regarded 

as significant: those where r is well over 0.5 or well under 0.5. ,

;>. Snedecor, Q. W., 1946, Statistical methods applied to experiments In agriculture and biology* 'jj. :138.'. , 

Ames, Ipwa State College Press. . .

.. S03767 54 2
112 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

The localities from which sets of close samples were collected are 

fully described in the earlier report. They are listed in table 2.

TABLE 2. Location of analyzed samples of phosphate rock of the Phosphoria

formation

Name of section

Reservoir Mountain.

Brazer Canyon .......

Laketown Canyon...

County and State

Rich County, Utah.....

Rich County, Utah.....

Field unit no.

RAH-183-47L. ..

RAH-184-47'.. .. 

4769-DFD".... ..

2061 ............ ..

RAH-105-47«._ ..

RAH-106-47*.. .. 

RAH-107-47*.. .. 

Equivalent to 

RWQ-3827.*

Laboratory nos.

WT-tfi"? 1 _ WT 1AH "ft

WT-910-1 WT-910-31 - - - WT-700-1 WT-700-12. -

WT-605-1 WT-605-3. 

WT-604-3 WT-604-30... 

WT-603-1 WT-603-24... 

WT-509-1 WT-509-25...

Thickness 

(feet)

0

0

1.0

.5

.1

1.0 

1.2 

1.0

> McKelvey, V. E., Armstrong, F. C., Qulbrandsen, R. A., and Campbell, R. M., 1953, Stratigraphic 

sections of the Phosphoria formation In Idaho, 1947-48, part 2: U. S. Qeol. Survey Circ. 301.

» Davidson, D. F., Smart, R. A., Pelrce, H. W., and Weiser, J. D., 1953, Stratigraphic sections of the 

Phosphoria formation in Idaho, 1949,part 2: U. S. Geol. Survey Circ. 305.

 McKelvey, V. E., Smith, L. E., Hoppln, R. A., and Armstrong, F. C., 1953, Stratigraphic sections of 

the Phosphoria formation in Wyoming, 1947-48: U. 8. Qeol. Survey Circ. 210.

«Smith, L. E.. Hosford, Q. F., Sears, R. S., Sprouse, D. P., and Stewart, M. D., 1952, Stratigraphic 

sections of the Phosphoria formation In Utah, 1947-48: U. S. Qeol. Survey Circ. 211.

 Cheney, T. M., Smart, R. A., Waring, R. Q., and Warner, M. A., 1953, Stratigraphic sections of the 

Phosphoria formation In Utah, 1949-51: U. S. Qeol. Survey Circ. 306.

Figures 9 through 13 are scatter diagrams in which F and C02 are 

plotted against P20s for each set of close samples. The correlation 

coefficients relating equivalent uranium and P206 that were given in 

the earlier report are repeated in table 3 together with correlation 

coefficients relating CO3 and F with P2O6 and with equivalent uranium. 

Correlation coefficients for the set of samples from Reservoir Mountain 

were not calculated because of the small variation in P20s content.

TABLE 3. Correlation coefficients relating various components and average percent

eU in four sets of close samples from pho&phaterock of the Phosphoria formation

Sample No.

WT-700... ..................... ... . . .....

WT-603..-. .......................... .................

WT-604, 605............................................ WT-365... ..-....... ._.. - 

Average 

percent eU

0.031 

.020

.013'

.008

Correlation coefficients

uyp.o.

+0.9 +.8-

+.2 -M

COi/FiO|

+0.98 

+.93 

+.52 

+.29

F/FiO«

+0.99 

+. 99 

+.98 

+.95

Although material from the Phosphoiia formation has been 

described as oolitic, these samples are more properly referred to as 

pelletal in view of the absence of concentric structures in the pellets.

The rocks are dark b-own to black, except for the samples from the 

Reservoir Mountain trench which contain less organic material. 

The phosphatic material in these samples is chiefly pelletal phosphate
z

UJ 

O

5

14 21 28 35 

PERCENT P205

V V 

7 14 21 -28 ,35 

PERCENT,P205 ra+0>95

FIGURE 9. Scatter diagrams of Trail Canyon samples. WT-365.

of the type referred to in the older literature as cellophane, but 

more properly designated carbonate-fluprapatite. Where thin sections of the samples were made and examined, most of the pellet 

material was found to be nearly isotropic, and very little of the 

secondary or recrystallized variety (francolite) was seen. The 

accessory minerals in the samples are chiefly quartz and mica, with 

clays and calcite.
 114 ' : 'vcoiTTRiBUTibisrs 1 'T6 THE GEO'LOGY OF URANIUM

8 2 

tr

UJ 

0.

. <*

14 21 28 

PERCENT P205

35.

z

UJ

0 3 <r °

UJ

o.

<5SC*»*

, ^w

0"-> ,7 14 21 28 :35

.. * PERCENT P205 ' |

 FiatJBE 10. Scatter diagrams of Keservolr Mountain samples WT-910. ;.

;l - ..-.: ,

The predominant phosphate mineral in the Phosphoria formation is 

a fluorine-bearing apatite.., Therefore, it is not surprising that'.jail 

of the sets of samples show ar strong correlation between F anji^Os.

The analyses of all the samples show, however, an excess of F oyer the

amount required by the fluqrapatite formula CaioCPO^eF? computed 

on the basis of PgOs content.

Fluoritffis not an uncommon mineral in the Phosphoria formation,

but it was not ot>serv~ecrin the rock layers from \vhich these samples

were, taken,, and examination of .a number of thin sections^ made from 

the samples failed to, reveal ike presence of any visible nuorite.

There has been much discussion as to the exact nature of the phosphate mineral! in the Phosphoria formation. According .to K. 'I>.

, Jacob,3 it! is an apatite with excess fluorine and with a small amount of 

carbonatq. . ,. ,. .

«Jacob, K. D., and others, 1933, The composition and distribution of phosphate rqqk; with special reference 

to the United States: U. S. Dept. Agriculture Tech. Bull. 364, p. 72-75,
DISTRIBUTION' OF URANIUM : IN'PHO&PHORIA FORMATION 115

CM 

O 

O

 

14 21

PERCENT PO2 W5

28 35

r=+0.98

' 4-

UJ

o 

a: 2

UJ

14 21 

PERCENT P2 05

28 ' 35

..!_.... . ....:....... ....... . r' 3 40.99i

FIGURE 11. Scatter diagrams of Coal Canyon samples WT-700.

X-ray studies 4 of a number of carbonate-bearing fluorapatites have 

shown that they : are>'a'" Structurally! distinct-variety, different from 

either fluorapatite or hydroxylapatite. X-ray powder patterns of 

pn6sphatic ma'terial from the Phbsphoria formation match the type 

pattern of the carbonate-bearing fluorapatites; that is, they show the 

same difference from fluorapatite -or hydroxylapatite as do the 

carbonate-bearing fluorapatites. ' \ ' 

«;Altschiiler, Z. S., :and Glsne'y, P; A.,,195R, X-ra^ .^ 

jQ.eol. Soo. America Bull., v. 63, no. 12, pt. 2,' " ' ' '

of the nature of carbonate-apatite (abs.):
116 'CONTRIBUTIONS TO THE GEOLOGY .OF URANIUM

CM

o 2 

o

UJ

o

<r ui 

o.

J_______I

14 21 28 35 

PERCENT P205

r'4-0.93

4 -

tu 

o 

o: ui 

a.

O 7 14 21 28 35

PERCENT P90c

* D r**O.S§ 

FlQUBB 12. S6att6r diagrams of Brazer Canyon samples WT-603.

In two sets of close samples there is a very good correlation between

CO2 and PgOs, and it seems probable that the phosphate-bearing mineral in these samples is a carbonate-bearing fluorapatite.

Two general statements may be made concerning the distribution 

of uranium in these samples:

1. The samples with high percent of equivalent uranium show much
DISTRIBUTION OF URANIUM IN PHOSPHORIA FORMATION 117

evJ« O 2 

o

z

UJ

o tr

UJ

a.

I

 ,

.

14 21 28 35

PERCENT PgOs

n + 0.52

3 

u.

07 14 21 28 35

PERCENT P2 05

r»4-0.98

FIOURE 13. Scatter diagrams of Brazer Canyon samples WTMW4 and WT-605.

better correlation of equivalent uranium and P206 (WT-700, WT603).

2. The samples that show good 'correlation of equivalent uranium 

and P206 show better correlation of C02 with P206 (WT-700, WT-603).

PELLET SIZE AND URANIUM CONTENT

It has been suggested that the size of the pellets in phosphate rock 

might have a direct relation to the concentration of uranium in the 

rock and that the size of a pellet might also reflect either the length 

of time required for the pellet to form or the conditions under which it 

formed. As a corollary to the above, it has been suggested that the 

longer the period required for a pellet to form, or the longer it was
118 ! / CONTRIBUTIONS, TO THE GEOLOGY OF URANIUM ; y ,.

in contact with ocean waters, the more uranium it might have absorbed 

from the sea water.

To determine if a correlation exists between pellet size and uranium 

content, the size of pellets was measured in thin sections of two sets of 

samples. One set was from Laketown Canyon, Utah (WT-509), and 

the other was from Trail Canyon, Idaho (WT-365). These particular 

sets were chosen because neither contained enough organic matter to 

obscure the pellets. Twenty-four thin sections, which were cut normal 

to the bedding of the rock, were prepared for each set. It was observed 

that the pellets were distinctly flattened in the bedding plane. By 

means of a micrometer ocular, the longest and shortest observed 

dimensions of each pellet were measured. There was little variation of 

the measurements of the shortest dimension of the pellets.

The 25 samples from Laketown Canyon, Utah, which were not 

referred to in the previous report, were taken from the phosphatic 

shale member of the Phosphoria formation. They cover a thickness of 

1 foot and are numbered from lowest to highest stratigraphically. The 

lowest sample/no. 1, was taken 2 feet above the Wells formation. This 

group of samples was analyzed for P205 and equivalent uranium. The 

results of these analyses, together with the results of some of the 

chemical and radiometric analyses of samples that were taken earlier, 

are presented in table 1.

Traverses were made across each thin section of the Laketown 

Canyon and Trail Canyon samples, and all grains passing under one 

line on the micrometer ocular were measured until 100 grains had been 

measured in each thin section. A correction was not made for the fact 

that the grains were measured in thin sections of indurated rock, 

because only the variation in size of the pellets was needed, not the 

absolute size. Measurements of the longest dimensions of the pellets 

were plotted in frequency histograms', and ,the related cumulative 

curves were plotted. The arithmetic and geometric quartile deviations 

of the measurements for each sample were obtained from the graphs of 

the cumulative curves.. Figure 14 shows a typical frequency histogram 

and the related cumulative curve. The first and third qiiartiles are'

indicated on the figure. , , ; , . No obvious relationship was found between the concentration' of

uranium arid the size measurements. Different properties of the' 

frequency histograms- and cumulative; curves. for each; sample were 

compared with .the concentration of uranium without discovering a 

significant; correlation.. Figures 15 and 16, are scatter diagrams showing the comparison of various properties of the, size measurements 

with uranium con tent. ( . The coefficients of correlation that were 

obtained for the two sets of samples are summarized as follows;
DISTRIBUTION OF'URANIUM IN PHOSPHORIA'FORMATION 119

Size measurement properties 

Modes of longest dimensions of pellets___.___________.:

Means of longest dimensions of pellets_________________

Arithmetic quartile deviations of longest dimensions of

pellets.____________________ _ _.!____ ______ 

Geometric quartile deviations of longest dimensions of

pellets______'_.-,____--__-_ -___-_-_-___-_..-_;--

Coefficients of correlation 

WT-86B WT-609

0. 53 0. 22 

.45' . 004

.17 

.007

Arithmetic quartile deviation

Geometric quortile deviation

3d Quortile 

, °3

0.62 053 0.44 0.35 0.26 0.09

GRAIN SIZE IN MILLIMETERS

FIGURE 14. A typical frequency histogram and cumulative curve showing 1st and 3d quartlles, the median 

and the mode. Sample WT-365-7; 0.012 percent eU.
120 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Arithmetic quortile deviotion Geometric quortile deviation

 

* (

r . : 4

§ 0.01

ec

£

f

 

 *!« **

i 1*1 i

8 10 I.I 1.2

Mean long diameter Peok of frequency curve

0.09 0.18 0.26 0.35 mm 0.09 OJ8 0.26 0.35 mm

r«+0.4S rt+0.93

FIOURE 15. Scatter diagrams showing comparison of various size measurements with uranium content,

Trail Canyon samples WT-365.

Arithmetic quortile deviation Geometric quortile deviation.

UUI7

2

io...

s

 

 

 

. . . 

 ****? 

 

1 1 1 '

dOI »

5

»-

Q Q0| 

O

^

. .

B

0 

* »% * 

1 1 1 1

10 20 1.4 1.5 1.6

Mean long diameter

0.02 0.02

Peak of frequency curve

0.18 0.35 053mm 0.10 0.35 053 0.70 mm

r»+0.004 r:+0.22

FIGURE 16. Scatter diagrams showing comparison of various size measurements with uranium content, 

Laketown Canyon samples WT-509.
DISTRIBUTION OF URANIUM IN PHOSPHORIA FORMATION 121

The coefficients of correlation of variation in uranium content with 

variation in the arithmetic and geometric quartile deviations of the 

longest dimensions of the pellets were not calculated for WT-509 

samples, because it was obvious from inspection of scatter diagrams 

that no marked relationship exists.

Figures 17 and 18 show some of the variously shaped histograms 

that were obtained from samples with the same percent of equivalent 

uranium.

20 

is 

10

5

J2 20

u 15

U.

o 10

oc

| 5

z

_

_

_

-

1 1 1 1 1 ,

0.70 0.62 053 0.44 035 0.26 0.18 0.09

GRAIN SIZE IN MILLIMETERS

FIOURK 17. Various frequency distribution curves obtained from samples with the same percent equivalent 

uranium. From bottom to top, the samples are WT-365-4, -17, -20, Trail Canyon.
122 'CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

CJ25 

a.

fe 20

IT

£ 15

* 10 

5

10

5

0.86 0.70 0.62 0.53 0.44 0.35 0.26 0.18 0.09

GRAIN SIZE IN MILLIMETERS

FIQUBE 18. Various frequency distribution curves obtained from samples with the same percent equivalent 

uranium. From bottom to top, the samples are WT-509-6, -20, -22, Laketown Canyon.

The original size and shape of the phosphate pellets may have been 

considerably changed since the time of their formation. Perhapsj 

also, the two sets of samples that were chosen are not typical of the 

pelletal phosphate of the Phosphoria formation. However, the 

measurements show little, if any, relation between the concentration 

of uranium and pellet size, and they give little reason for believing 

that pellet size has an influence upon, or reflects, the concentration of 

uranium in phosphate rock.
INDEX

Page Page 

Altsohuler, Z. S., cited._.................... 115 Minerals, accessory........................... 113

Apatite....................................... 114

Pellet size, coefficients of correlation for....... 119

Brazer Canyon, Utah........................ 112 measurements ........ .......... 118

relationship to uranium concentration.. 117- 

Carbonate-fluorapatite....................... 113 118,122

Chemical analyses___...._..._.... 108-110 Phosphatic shale member of Phosphoria forCisney, E.A..cited.......................... 115 mation........................... 118

Coal Canyon, Wyoming________...... 112

Coefficient of correlation, equation for........ Ill Radio-metric analyses....................... 108-110

for pellet size............................ 119 Reservoir Mountain, Idaho................... 112

Cellophane ..................... 113 g defined..................... 107

Correlation, CO, and P2 0.................. 116,117 '

FandP8 0. .................... 114

uranium and organic matter_..._.... 108 , . , ...

, °n explained__..__... ...-..--...... Ill uranium and PaOs..._--._._..--___.-_--._ 117 ~ , n w .. . ... Snedecor, O. W., cited..... ...------...-.. Ill

Fluorapatite............................ 114,115,116 Trail Canyon, Idaho......................... 112

Fluorlte...................................... 114

Francolite .... ........ .......... 113 Uranium, concentration compared to pellet

size............................ Ill

Hydroxylapatite.............................. 115 distribution in samples.................. 116

Jacob, K. D., cited........................... 114 Wells formation.............................. 118

Laketown Canyon, Utah__................ 112 X-ray studies ............. . .... 115

O

123