GEOLOGICAL SURVEY CIRCULAR 260

STRATIGRAPHIC SECTIONS OF THE 

PHOSPHORIA FORMATION IN 

MONTANA, 1948
UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

GEOLOGICAL SURVEY CIRCULAR 260

STRATIGRAPHIC SECTIONS OF THE PHOSPHORIA FORMATION

IN MONTANA, 1948

By M. R. Klepper, F. S. Honkala, O. A. Payne, and E. T. Ruppel

This report concerns work done partly 

on behalf of the U. S. Bureau of Reclamation and partly on behalf of the U. 8. 

Atomic Energy Commission, and is 

published with the permission of the 

Commission.

Washington, D. C., 1953

Free on application to the Geological Survey, Washington 25, D. C.
STRATIGRAPHIC SECTIONS OF THE PHOSPHORIA FORMATION

IN MONTANA, 1948

By M. R. Klepper, F. S. Honkala, O. A. Payne, and E. T. Ruppel

CONTENTS

Lot no. Page

Introduction......................... 1

Acknowledgments.................... 1

Stratigraphy of the Phosphoria

formation in Montana .............. 4

Stratigraphic sections................ 4

References ......................... 4

Tables of Stratigraphic sections

Anderson mine ................. 1287 5

Graveley mine ................. 1286 7

Canyon Creek no. 1............. 1237 9

Canyon Creek no. 2............. 1238 10

Melrose Adit no. 2 ............. 1239 11

Spectrographic analyses.... 12

Melrose Adit no. 1 ............. 1240 13

South Greenstone Gulch ......... 1250 14

Kelley Gulch. .................. 1249 16

Cave Creek.................... 1257 19

Lot no. Page

Tables of Stratigraphic 

sections Continued

Cedar Creek................... 1256 21

Sawtooth Peak ................. 1241 23

Upper French Creek............ 1248 27

Wadham Springs ...........1246-1247 28

Centennial Range

Trench no. 4 ................ 1251 31

Odell Creek ................... 1252 32

Centennial Range

Trench no. 1 ................ 1253 34

Centennial Range 

Trenches 

nos 2 and 3 ............. .1254-1255 36

Additional analyses of

sample OAP-505.......... 38

Luke mine..................... 1285 39

ILLUSTRATIONS

Figure 1. Outcrop of the Phosphoria formation in Montana and localities sampled.......

2. Generalized section of the Phosphoria formation at Sheep Creek (lot no. 1234).

Page

2

3

INTRODUCTION

The U. S. Geological Survey has measured and 

sampled the Phosphoria formation at many localities 

in Montana and other western states. These data will 

not be fully synthesized and analyzed for several years, 

but segments of the data, accompanied by little or no 

interpretation, are published as preliminary reports 

as they are assembled. This report, which contains 

abstracts of many of the sections in southwestern 

Montana (fig. 1), is one of this series and is the second 

report of data gathered in Montana during 1948. The 

field and laboratory procedures adopted in these investigations are described rather , fully in a companion 

report (McKelvey and others, 1953).

Many people have taken part in this investigation. 

The program of which this work is a part was organized 

by V. E. McKelvey. D. A. Bostwick, E. R. Cressman, 

J". E. Joyce, J. A. Kelleher, R. L. Konizeski, 

R. L. Parker, L. A. Thomas, and W. H. Wilson participated in the description of strata and collection of 

samples referred to in this report. The laboratory 

preparation of samples for chemical analysis was done 

in Denver, Colo., under the direction of W. P. Huleatt.

ignition analyses were made-for the Survey by the 

U. S. Bureau of Mines at the Northwest Electrodevelopment Laboratory, Albany, Oreg., under the 

supervision of S. M. Shelton and M. L. Wright. The 

Spectrographic analyses were made by D. M. Mortimer, 

also in this laboratory. Mostof the AlgOs, FegOs, and 

loss-on-ignition analyses were made in the Trace 

Elements Section laboratory of the Survey in 

Washington, D.. C., under the direction of J. C. Rabbitt, 

by chemists I. Barlow, A. B. Caemmerer, J. L. Greene, 

and N. Guttag.

Compilation of the data has been largely by 

R. P. Sheldon and F. D. Frieske under the supervision 

of R. W. Swanson. Organization of the tabular data 

has been largely by Anita Cozzetto.

ACKNOWLEDGMENTS

AllthePgOg, F, VgOs, and acid- insoluble 

analyses and some of the AlgOs, Fe2O3 ,, and loss-onSpecial thanks are due A. E. Weissenborn, 

who gave much advice and help'in carrying out the 

field program. Ths cost of the field and laboratory 

investigations has been borne partly by the Missouri 

River Basin Division of the Bureau of Reclamation 

and the Division of Raw Materials of the Atomic Energy 

Commission.
INDEX MAP

EXPLANATION

Outcrop of Phosphoria formation, 

dotted where questionable

Location and lot number of sample 

locality included in this report

°1341

Location and lot number of sample 

locality to be included in other reports

V

Recompiled and modified I 

from Clabaugh, 1946 I

46°

45°

Figure 1. Outcrop of the Phosphoria formation in Montana and localities sampled.

2
-

FE 

0

50 

100 

ISO 

2OO

250 

300 

349

PERCENT PjOs THICK- *£«*?* 

JO 20 10' 0 LITHOL06V IN FEET PERCENT DESCRIPTION

ET

^^

i

SSSSSS^Sff* 1

BBBH

_

I

J

1

" 1

^mns^^

L_ _J J *"'^ _f- J ' 

 I '- _k

r;*vvvf^

i JL JC V X

'j^'rV X

!>*>'»« if'

JC X X J-^

...... ...... ...... (^\^

JL r XL \

...... *,. .''...:.. T

 ji jtL_ ir^~~~

 ::..:: ::.: . ::.:" >

x^jc-yjCr"^""

* ut ^j,1 *-^^-^

~-=~-=^^

HI

ErEB-EE-E

 , * a * - *fc

~ ~ T=LJfjp~-^^ _

"i~~r,f\)

^fnS x " .- . r;^X

.../.../..

^ v^ » ^ g"1^' /

'i*;« Bv« /

r x T. /

^t^//'

L Jt: Jt jr. ^

L^jgr-... -^ __T**yT- ^^^ ^"^

:LJr^r^l sT

- -i

raf j-l A; 1

, ./.. ....f .. ;.' * ^_

2

24

14

31

14

10

11

5

19

15

4

22

12

41

45 

5

35

2

1 

20

7

10

2

2

2

2

3

3

2

5

12

2

25

14

3

1

1 

6

1

2

14 

0

0

0

Dinwoody formation 

Mudstone: calcareous, soft, pale-yellow, thin-bedded

PHOSPHORIA FORMATION

1 Member E 

Sandstone: hard, pale, yellowish-orange, thick-bedded

Chert: hard, light-gray, thick-bedded chert interbedded with medium-hard, pale 

yellowish-orange, thick-bedded chert

Sandstone and chert: medium-hard, light-gray, thick-bedded sandstone containing 

some interbeds of hard, light-gray chert

Sandstone and chert: medium-hard, brownish-gray, thick-bedded sandstone 

interbedded with hard, light-gray, thick-bedded chert

Sandstone: medium-hard, yellowish-brown, thick-bedded sandstone interbedded 

with hard, brownish-gray sandstone

Chert: medium-hard, dusky yellowish-orange, to medium-brown, thick-bedded

Mudstone: medium-hard, light-gray to yellowish-brown, thick-bedded

.Sandstone: hard, light-gray to yellowish-brown, thick-bedded; lowermost 0.75 

foot phosphatic

Member D 

Mudstone: phosphatic, soft, brownish-black, thin-bedded

Mudstone: soft, brownish-black to black, fissile

Phosphate rock: oolitic, soft, dark-brown, thin-bedded

Phosphate rock and mudstone: oolitic, medium-hard, brownish-gray, phosphaterock, interbedded With medium-hard, brownish-gray mudstone

Member C 

Sandstone: soft, duaky yellowish-orange, thick-bedded

Sandstone and chert: medium-hard, light brownish-gray, massive sandstone 

interbedded with hard, yello*ri»h-gray, massive chert

Dolomite: sandy, medium-hard, medium- to light-gray, contains lenses and 

nodules of chert

Sandstone: soft, dusky yellow, thin-bedded; contains many lenses and nodules 

of chert

Chert: hard, medium-gray to yellowish-brown, thick-bedded; contains some 

interbeds of mudstone and sandstone

, Member B

Mudstone: medium-hard, medium yellowish-brown, thin-bedded; contains several 

small lenses of oolitic phosphate rock

Phosphate rock and mudstone: soft, brownish-gray, oolitic phosphate rock 

interbedded with soft, pale yellowish-brown mudstone

Mudstoae: medium-hard, medium yellowish-brown, thin-bedded

Member A 

Mudstone: dolomitic, soft, light-gray, thin-bedded

Dolomite: medium-hard, pale yellowish-orange, thin-bedded; contains some 

interbedded cherty mndstone

Quadrant formation 

Sandstone: medium-hard, light-gray, thin-bedded

Figure 2. Generalized section of the Phosphoria formation at Sheep Creek (lot no. 1234).

3
It is a pleasure to acknowledge the fine 

cooperation extended to the field parties by the local 

residents, property owners, and operating companies 

who furnished information and services and gave access 

to property. These include principally R. B. Shelledy, 

R. J. Armstrong, and J. J. McKay, of the Montana 

Phosphate Products Co., and William Anderson and 

the Martin brothers who developed the Melrose and 

Canyon Creek properties.

STRATIGRAPHY OF THE PHOSPHORIA 

FORMATION IN MONTANA

The Phosphoria formation in southwestern 

Montana consists in general of five members, two 

phosphatic shale members and three hard members 

(fig. 2). The lower two hard members are dominated 

by limestone, the top member by chert and sandstone 

or quartzite. Most of the members can be identified 

over a large part of the area of outcrop, although 

correlation toward the east and northeast is difficult. 

The formation ranges in thickness from less than 

100 feet to more than 800 feet.

The lowermost, or A, member is thickest 

toward the west and southwest with a maximum thickness of nearly 350 feet and consists of limestone or 

dolomite, sandstone, mudstone, and chert. It overlies the Quadrant formation of Pennsylvanian age and 

is probably equivalent to the upper member of the 

Wells formation of southeastern Idaho and adjacent 

Wyoming and Utah (McKelvey, 1949).

The lower phosphatic shale member, or B, 

is about 50 feet thick near the southwest corner of the 

state but thins markedly to the north and east, where

in some areas it cannot be recognized. It contains a 

rich bed of minable phosphate in the Centennial Range.

The middle, or C, member consists of as much 

as 200 feet of limestone with some chert and sandstone. 

The upper phosphatic shale, or D, jnember is rather 

similar to and much more uniform and^ widespread 

than the B member, though minable phosphate is 

present only toward the north end of the area (plate 1), 

where the full thickness of the phosphatic zone may 

consist of a single 3- to 5-foot bed of high-grade 

phosphate rock.

The uppermost, or E, member is the most 

widespread and uniform, averaging about 100 feet in 

thickness and consisting chiefly of siliceous rocks 

siltstone, chert, and quartzitic sandstone. It is 

overlain by the Dinwoody formation of Triassic age 

in the greater part of the area and by the Ellis group 

of Jurassic age toward the north and northeast.

STRATIGRAPHIC SECTIONS

Analytical data and abstracts of stratigraphic 

sections measured at 20 localities follow. Their 

locations as well as those of other sections previously 

reported (Swanson and others, 1953) and sections to 

be reported later are shown on figure 1.

The semiquantitative spectrographic analyses 

are based upon comparisons with a standard plate 

representing known quantities of the elements tested 

for and made at the same exposure. Greater 

sensitivities for many elements can be obtained by 

additional exposures. The standard sensitivities for 

the elements noted in this report are as follows:

Element

A-LSbAsBaBeBiB 

CdCaCrCoCuGaGeAuFePbLiPercent

0.005 

.05

 .1 

.08 

.001 

.002 

.001 

.1 

.01 

.02 

.01 

.001 

.05 

.01 

.01 

.005

Element Percent

MgMnMoNiNbP 

Pt31- 

AgNaSrTaSnTiW 

V 

ZnZr0 .001

.004

.004

.01

.01

.8

.01

.002

.001

.05

.1

.0

.01

.002

.1

.01

.05

.003

REFERENCES

Clabaugh, P. S., 1946, Permian phosphate deposits

of Montana, Idaho, Wyoming, and Utah: U. S. Geol.

Survey, Strategic Minerals Inv. Preliminary Map 3-198. 

McKelvey, V..E., 1949, Geological studies of the

western phosphate field: Am. Inst. Min. Met. Eng.

Mining Trans., v. 184, p. 270-279.

McKelvey, V. E., Davidson, D. F., O'Malley, 

F. W., and Smith, L. E., 1953, Stratigraphic 

sections of the Phosphoria formation in Idaho, 

1947-48, part 1: U. S. Geol. .Survey Circ. 208.

Swanson, R. W., Lowell, W. R., Cressman,

E. R., and Bostwick, D. A., 1953, Stratigraphic 

sections of the Phosphoria formation in Montana, 

1947-48: U. S. Geol. Survey Circ. 209.
ANDERSON MINE, MONTANA. LOT NO. 1287.

D member of Phosphoria formation sampled at 4,800 level of Anderson mine of Montana Phosphate P

3, T. ION., R. 10W.( Powell County, Montana, on southwest flank of Garrison anticline, samples 308-313

of north heading and sample 314, locality B, from 150 feet south of crosscut. Beds strike about N. 30° W., 

measured and sampled by M. R. Klepper in October 1948. Samples analyzed by U. S. Bureau of Mines Labo

Bed

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

C

t

Locality A, 4,800 level, 100 feet south of north heading 

E member of Phosphoria formation basal beds only

E-2 

E-l

Quartzite 

Conglomerate

-- 1.0 

0.5 --

D member of Phosphoria formation

D-8

D-7

D-6

D-5

D-4

B-3

D-2

D-l

Clay

Phosphate rock, argillaceous

Phosphate rock

Phosphate rock

Phosphate rock

Phosphate rock

Phosphate rock

Clay

__

MR K- 3 13

MRK-312

MRK-311

MR K- 3 10

MRK-309

MRK-308

--

0.02

0.75

0.7

0.5

0.9

1.0

0.9

0.15

__

27.8

37.5

36.4

32.5

36.6

31.1

__

25.6

4.5

7.3

15.1

5.9

14.7

--

C member of Phosphoria formation top beds only

C-2 

C-l

C onglome rate 

Sandstone

1.0 

2.0

Locality B, 4,800 level, 150 feet south of crosscut 

E member of Phosphoria formation not measured

E-l 1 Chert -- 

* Cumulative data incomplete due to missing information.

** Note incompleteness of cumulative data.
Bed

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

D member of Phosphoria formation

D-l Phosphate rock 

Composite sample representing beds D-2 to

MR K- 3 14 

D-7 of locality

4.3 

A.

32.8 12.8

C member of Phosphoria formation top beds only

C-4 

C-3 

C-2 

C-l

Quartzite 

Conglomerate 

Clay 

Sandstone and chert

0.3 

0.9 

0.2 

2.0 __
GRAVELEY MINE, MONTANA. LOT NO. 1286.

D member of Phosphoria formation sampled in Graveley Mine of Montana Phosphate Products Compan

Powell County, Montana, on northeast side of Luke-Graveley syncline; samples 297-299, locality A, from 4,9

locality B, from 5,101 west heading. Beds strike about N. 70° W. and dip 50° S. Section measured and samp

September 1948. Samples analyzed by U. S. Bureau of Mines Laboratory, Albany, Oregon.

Bed

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cu

th

Locality A, 4,906 stope 

E member of Phosphoria formation not measured

E-l Chert

-- -- 

D member of Phosphoria formation

D-5

D-4

D-3

D-2

D-l

Clay

Phosphate rock

Phosphate rock

Phosphate rock

Clay

MRK-299

MR K- 29 8

MRK-297

--

0.05

1.3

1.0

1.25

0.1

__

35.0

37.5

37.4

--

-.

10.2

8.4

4.6

--

C member of Phosphoria formation not measured

C-l Quartzite -- -- 

Locality B, 5,101 west heading 

E member of Phosphoria formation-not measured

B-l Chert

' -- -- ~

D member of Phosphoria formation

D-5

D-4

D-3

D-2

D-l

Clay

Phosphate rock

Phosphate rock

Phosphate rock

Clay

__

MRK-303

MRK 302

MRK-301

0.05

1.2

1.0

0.8

0.05

__

36.8

37.5

34.4

__

6.2

3.9

4. 1

* Cumulative data incomplete due to missing information.

** Note incompleteness of cumulative data.
Bed

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cum

thi

(

C member of Phosphoria formation top beds only

C-3 

C-2

C-l

Conglomerate 

Sandstone 

Quartzite

MRK-300 1.0 

1.5

5.4 81.2 
CANYON CREEK NO. 1. MONTANA. LOT NO. 1237.

D member of Phosphoria formation sampled in hand trench near Canyon Creek, SE? sec. 12, T. 2 S., R. 10 W

on west limb of an overturned anticline. Beds strike N. 60" W. and dip 50* SW. Section measured by M. R. Klepper 

September 1948. Samples analyzed for P?Oc an<* acid insoluble by U. S. Bureau of Mines Laboratory, Albany, Oreg

Trace Elements Section Laboratory, U. S. Geological Survey, Washington, D. C.

Bed 

no. Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses (percent)

P2°5 A12°3 Fe203

Loss on 

ignition

Aci

insolu

E member of Phosphoria formation basal bed only

E-l Chert MRK-270 1.0 7.2 -- -- -- 77

D member of Phosphoria formation base not exposed

D-5

D-4

D-3

D-2

D-l

Phosphate rock

Mudstone, calcareous, and phosphate rock

Phosphate rock

Mudstone and phosphate rock

Mudstone, phosphatic

MRK-269

MRK-268

MRK-267

MRK-266

MRK-265

1.0

1.4

1.8

1.0

6.0

34.7

10. 1

34.6

16.3

19.6

1.3

9.7

2.6

8.5

7.9

2.57

8.74

2.40

5.38

2.34

1.64

6.72

3.60

7.74

7.06

7

47

6

39

38
CANYON CREEK NO. 2, MONTANA. LOT NO. 1238.

D member of Phosphoria formation sampled in hand trench near Canyon Creek, E^SEi sec. 6, T. 2 S., R. 9 

on overturned east limb of an anticline. Beds strike N. 5-10* W. and dip 70* W. Section measured by M. R. Kleppe

September 1948. Samples analyzed for P^O- and acid insoluble by U. S. Bureau of Mines Laboratory, Albany, Oreg

by Trace Elements Section Laboratory, UT S. Geological Survey, Washington, D. C.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses (percent)

P2°5 A12°3 Fe2°3

Loss on 

ignition

Ac

insol

E member of Phosphoria formation basal bed only

E-l Quartzite and conglomerate

-- -- -- -- -

D member of Phosphoria formation base not exposed

D-4 

D-3 

D-2 

D-1

Mudstone 

Phosphate rock and mudstone 

Phosphate rock and mudstone 

Phosphate rock

MRK-273 

MRK-272 

MRK-271

0.2 

3.0 

3.8 

3.0

19.1 

19.1 

30.8 1.1 0.90 7.08

43

35

7

* Cumulative data incomplete due to missing information.

** Note incompleteness of cumulative data.
MELROSE ADIT NO. 2, MONTANA. LOT NO. 1239.

D member of Phosphoria formation sampled in an adit of the Anderson Phosphate Mines, Incorporated, of Bu

Property, in NWi sec. 5, T. 2 S., R. 9 W., Silverbow County, Montana, on the normal limb of a northwest-trending 

through D-ll sampled at heading of a south*-southeast drift approximately 1,400 feet from portal; beds D-l through D

Beds strike northwest and dip 45° SW. Section measured by M. R. Klepper and O. A. Payne and sampled by Payne in 

by U. S. Bureau of Mines Laboratory, Albany, Oregon.

Bed

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses (percent)

P2°5 A1203 Fe2°3 F

Loss on 

ignition

A

inso

E member of Phosphoria formation basal bed only

E- 1 Chert and conglomerate

-- -- --

D member of Phosphoria formation

D-ll

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Mudstone

Phosphate rock, argillaceous

Phosphate rock and calcareous

mudstone

Phosphate rock

Mudstone

Phosphate rock

Mudstone, calcareous

Phosphate rock

Mudstone and phosphate rock

Phosphate rock

Phosphate rock, argillaceous

MRK-293

MRK-292

MRK-291

MRK-290

MRK-289

MRK-288

MRK-287

MRK-286

MRK-285

MRK-284

0.2

1.25

0.6

0.85

1.4

1.9

0.4

0.6

1.2

0.9

3.0

__

23.9

27.5

33.3

3.8

36.4

4.4

31.2

26.2

35.2

23.8

__

2.2

6.3

1.9

13.0

1.1

10.4

3.2

4.9

1.8

5.9

__

2.6

2.5

1.4

5.6

1.1

10.0

2.0

2.1

1.3

2.5

__

2.14

2.75

3.05

0.71

3.28

2.40

2.78

2.3

3.16

2.1

__

1.5

2.8

1.8

4.3

1.6

6.2

2*2

2.7

2.2

4.6

3

1

1

6

3

1

2

2

* Cumulative data incomplete due to missing information.

** Note incompleteness of cumulative data.
SPEC TROGRAPHIC ANALYSES-MELROSE ADIT NO. 2, MONTANA. LOT NO. 1

Semi-quantitative analyses of samples of the D member of Phosphoria formation, Melrose adit no. 2, Mont

page for location of section, thickness and description of strata, and chemical analyses of samples), made by U. S

Albany, Oregon. In addition to the elements listed in the table below, Sb, As, Ba, Be, Bi, Cd, Co, Cb, Ga, Ge, 

Sn, and W were looked for in all samples but were not detected.

Explanation of symbols

A = more than 10 percent E 

B « 5-10 percent F 

C = 1-5 percent G 

D = 0.1-1 percent

0.01-0.1 percent 

0.001-0.01 percent 

less than 0.001 percent

Bed 

no.

D-ll

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Sample 

no.

MRK-294

MRK-293

MRK-292

MRK-291

MRK-290

MRK-289

MRK-288

MRK-287

MBK-286

MRK-285

MRK-284

Al

B

C

B

C

B

C

B

B

B

C

B

B

E

F

F

F

E

F

F

F

F

F

F

Ca

C

A

A

A

B

A

A

A

A

A

A

Cr

D

E

E

E

E

E

D

E

E

E

D

Cu

F

G

G

G

G

G

G

G

G

G

G

Fe

A

C

C

C

A

C

A

C

C

C

C

Mg

C

C

C

C

C

D

A

C

C

D

C

Mn

E

E

E

E

E

E

E

F

F

F

F

Mo

F

F

F

F

F

F

E

F

F

F

F

Ni

E

E

E

E

E

E

D

E

E

E

E

Si

A

B

B

A

A

C

A

A

A

C

A

Ag

G

G

G

G

G

G

G

F

F

G

G

Na

E

E

E

E

E

E

E

E

E

E

E
MELROSE ADIT NO. 1, MONTANA. LOT NO. 1240.

D member of Phosphoria formation sampled in southwest crosscut 269 feet from portal of the Anderson Ph

Montana, known as the Melrose Property, NWi sec. 5, T. 2 S., R. 9 W., Silver Bow County, Montana, on normal 

strike northwest and dip 45* SW. Section measured by M. R.Klepper and O. A. Payne and sampled by Payne in Se

P2Og and acid insoluble by U. S. Bureau of Mines Laboratory, Albany, Oregon, and for other constituents by Trac

UrS; Geological Survey, Washington, D. C.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses (percent)

P2°5 A1203 Fe2°3

Loss on 

ignition

A

ins

E member of Phosphoria formation basal bed only

E- 1 Chert

-- -- -- -- -- 

D member of Phosphoria formation

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Conglomerate and phosphate rock

Mudstone

Phosphate roek

Mudstone

Phosphate rock, argillaceous

Mudstone

Phosphate rock

Phosphate rock

Phosphate rock

MRK-283

MRK-282

MRK-281

__

MRK-280

MRK-279

MRK-278

MRK-277

MRK-276

0.5

0.2

1.6

0.15

0.8

1.2

2.1

1.0

3.9

27.4

5.4

29.1

--

24. 1

1. 1

28.4

27.6

32.0

1.6

9.5

2.7

--

5.4

13.00

1.5

4.9

1.4

2.09

7.05

2.37

--

2.96

6.29

1.55

2.51

1.39

2.04

4.26

2. 16

--

2.56

4.68

1.68

3.50

2.70

Base of D-2 is a gougy fault zone of several strands cutting dark mudstone and phosphate rock.

Phosphate rock, argillaceous MRK-275 9.0 15.8 -- -- --

C member of Phosphoria formation top bed only

C- 1 Dolomite and chert

-- -- -- -- -- 

* Cumulative data incomplete due to missing information. Computations start from zero after interrupti

** Note incompleteness of cumulative data.
SOUTH GREENSTONE GULCH, MONTANA. LOT NO. 1250.

D member of Phosphoria formation sampled in south bulldozer trench at Greenstone Gulch, SE£ sec

Beaverh*ad County, Montana. Beds strike N. 10* W. and dip 50* NE. The stratigraphic sequence of the un

of a large number of faults, some of the beds may be omitted or repeated. Section measured and sampled b

E. R. Cressman in August 1948. Samples analyzed by U. S. Bureau of Mines Laboratory, Albany, Oregon.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

C

E member of Phosphoria formation basal bed only

E- 1 Quartz ite ERC-446 2.2? 0.4 92.2 

D member of Phosphoria formation

D-37

D-36

D-35

D-34

D-33

D-32

D-31

D-30

D-29

D-28

D-27

D-26

D-25

D-24

D-23

D-22

D-21

D-20

D-19

D-18

D-17

D-16

D-15

D-14

D-13

D-12

Mudstone

Mud stone

Mudstone

Mudstone

Mudstone, calcareous

Mudstone, calcareous, phosphatic

Mudstone, phosphatic

Phosphate rock

Mudstone, phosphatic

Mudstone

Mudstone, phosphatic

Mudstone, calcareous

Mudstone, calcareous

Limestone, argillaceous

Mudstone, calcareous , and phosphatic

mud stone

Mudstone and phosphate rock

Mudstone and phosphate rock

Mudstone

Phosphate rock

Phosphate rock and mudstone

Phosphate rock, argillaceous

Phosphate rock and mudstone, cherty

Mudstone, calcareous, and calcareous

phosphate rock

Limestone

Phosphate rock and mudstone

Mudstone, phosphatic

ERC-445

RLP-444

RLP-443

RLP-442

RLP-441

RLP-440

ERC-439

ERC-260

ERC-259

ERC-258

ERC-257

ERC-256

ERC-255

ERC-254

ERC-253

RLP-252

RLP-251

RLP-250

RLP-249

RLP-248

RLP-247

RLP-246

RLP-245

RLP-244

RLP-243

RLP-242

3.6

3.2

2.5

5.0

1.4

2.0

1.4

0.9

0.9

1.3

2.2

4.1

2.1

1.1

1.6

1.0

0.8?

1.4

0.7

1.05

1.1

1.6

0.7

1.3

2.0

1.0

3.7

1.1

0.9

1.1

6.2

9.2

9.8

24.4

15.4

3.6

9.8

3.3

1.9

6.5

5.3

17.2

10.2

5.9

29.4

21.4

21.6

12.3

15.2

2.5

24.6

14.9

51.9

72.9

76.4

77.5

58.6

50.5

53.4

17.8

46.0

72.2

54.7

59.8

45.1

38.4

53.2

35.8

57.8

69.0

14.3

32.0

30.2

52.7

25.8

5.5

26.2

44.8
Bed 

no.

D-ll

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Rock description

Limestone

Phosphate rock and mudstone, cherty

Mudstone, phosphatic, calcareous

Limestone, argillaceous, phosphatic

Mudstone, phosphatic

Mudstone, calcareous

Mudstone, phosphatic

Limestone, argillaceous, phosphatic

Phosphate rock, argillaceous

Phosphate rock and mudstone, cherty

Chert, phosphatic

Sample 

no.

RLP-241

RLP-240

RLP-239

ERC-238

ERC-237

ERC-236

ERG-235

ERC-234

RLP-233

RLP-Z32

RLP-231

Thickness 

(feet)

1.0

0.8

1.3

0.95

2.8

2.6

3.1

1.3

1.4

0.9

2.0

Chemical analyses 

(percent)

P2°5

1.2

18.5

11.7

11.7

15.7

5.5

11.3

9.5

20. 1

13.7

13.4

Acid 

insoluble

17.5

39.1

46.3

31.0

41.7

58.6

52.0

36.1

25.5

58.9

60.3

Cu

th

4

4

4

5

5

5

5

5

6

6

6

C member of Phosphoria formation top bed only

C- 1 Mudstone, calcareous RLP-230 1.0 1.5 67.9 
KELLEY GULCH, MONTANA. LOT NO. 1249.

A, B, D, and part of E members of Phosphoria formation sampled in bulldozer trenches and C memb

Kelley Gulch, sec. 2, T. 6 S., R. 11 W., Beaverhead County, Montana. A dacitic? sill 2. 7 feet thick occurs 

member. Beds strike N. 25° E. and dip 45° NW. Section measured by R. L. Parker and D. A. Bostwick and 

J. E. Joyce, Bostwick, J. A. Kelleher, and E. T. Ruppel in August 1948. Samples analyzed by U. S. Bureau o

Oregon.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cu

th

Dinwoody formation not exposed

E member of Phosphoria formation top contact approximately located

E- 9

E- 8

E- 7

E- 6

E- 5

E- 4

E- 3

E- 2

__

E- 1

Chert

Chert

Chert

Chert

Chert, sandy?

Mudstone

Chert

Chert

Dacitic? dike

Chert

__

--

--

--

DAB-229

DAB -2 28

DAB-227

DAB- 226

DAB- 225

23.0

25.0

25.0

25.0

29.0

4.5

2.6

7.4

(2.7)

2. 1

__

--

--

--

--

0.3

1.2

1.4

0.5

1.8

__

--

--

--

--

85.7

91.4

90. 7

85.9

89.9

D member of Phosphoria formation

D-38

D-37

D-36

D-35

D-34

D-33

D-32

D-31

D-30

D-29

D-28

D-27

D-26

Chert; fos. col. no. 48-KPM-51 1

Phosphate rock, cherty and mudstone

DAB- 224

RLP-223

Fault zone; includes gougy streaks and crushed phosphate.

Fault gouge and breccia

Mudstone

Phosphate rock, cherty

Mudstone and phosphate rock

Mudstone

Mudstone

Mudstone

Mudstone

Mudstone

Mudstone

Mudstone

RLP-222

RLP-221

RLP-220

RLP-219

RLP-218

DAB-217

DAB- 2 16

DAB-215

DAB-214

DAB-213

DAB-212

3.4

0.9

3.0

1.3

1. 1

0.8

1.3

7.0

5.0

5.0

5.0

5.0

5.0

5.6

21.9

2.1

4.4

22.9

6.3

2.3

1.8

0.7

0.7

0.7

0.6

1.3

69.3

36.4

74.2

76.5

34.6

62.5

72.7

82.9

86.2

89.3

90.0

89.3

88. 5
D-25

D-24

D-23

D-22

D-21

D-20

D-19

D-18

D-17

D-16

D-15

D-14

D-13

D-12

D-ll

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Mudstone

Mudstone

Mudstone and phosphate rock

Mudstone, calcareous

Dolomite, phosphatic

Phosphate rock

Limestone

Phosphate rock and dolomite

Limestone

Mudstone, phosphatic, calcareous

Phosphate rock, argillaceous; fos. col.

no. 48-KPM-50

Mudstone, phosphatic

Phosphate rock, argillaceous

Phosphate rock, argillaceous

Mudstone, phosphatic

Mudstone, phosphatic

Mudstone

Mudstone, phosphatic

Limestone, argillaceous

Mudstone

Mudstone, cherty

Mudstone, phosphatic

Mudstone, phosphatic

Mudstone, cherty

Mudstone, phosphatic, cherty

DAB-211

DAB- 210

DAB- 209

DAB- 208

DAB-207

DAB- 206

DAB- 205

DAB- 204

DAB- 203

DAB- 202

DAB- 201

DAB- 200

RLP-199

RLP-198

RLP-197

RLP-196

RLP-195

RLP-194

RLP-193

RLP-192

RLP-191

RLP-190

RLP-189

RLP-188

DAB- 187

5.0

5.0

2.2

3.6

2.8

0.6

1.1

0.7

1.3

0.9

0.9

0.9

0.7

1.7

1.2

1.5

0.6

2.4

1.7

0.9

3.0

1.7

1.4

2.7

1.4

0.9

2.3

9.8

4.5

11.0

24.3

6.7

9.7

2.6

11.9

22.5

8.9

19.4

18.0

16.6

9.5

5.2

10.4

1.8

7.2

6.4

13.2

9.3

7.2

13.8

87.5

83. 1

58.0

65.5

6.8

9.3

11.6

19.2

6. 1

39.2

30.5

62.5

36.5

38.8

42.9

57.8

70.6

50.0

20.7

58.8

62.9

49.9

59.6

61.8

52.7

4

5

5

5

6

6

6

6

6

6

6

6

6

7

7

7

7

7

7

7

8

8

8

8

8

C member of Phosphoria formation

C- 2

C- 1

Chert and quartzite, calcareous

Dolomite, cherty

__ 37.2

24.0

__

--

__

--

3

6

B member of Phosphoria formation

B- 4

B- 3

B- 2

B- 1

A- 9

A- 8

A- 7

A- 6

A- 5

A- 4

Chert and sandstone

Phosphate rock, cherty

Chert, phosphatic and phosphate rock

Quartzite and chert

DAB- 186

RLP-185

RLP-184

RLP-183

1.0

1.0

0.8

3.7

2.9

27.9

22.4

2.4

82.3

21.9

31.9

85.7

A member of Phosphoria formation

Mudstone

Mudstone, calcareous

Sandstone

Sandstone, calcareous

Mudstone, calcareous and sandstone

Mudstone

DAB- 182

DAB- 181

DAB- 180

DAB- 179

RLP-178

RLP-177

4.2-

10.6

3. 1

3.3

17.5

17.7

1.0

0.6

0.3

0. 1

0.1

0. 1

87.5

73.4

79.5

76.1

73.6

72.6

»U TT O /"«

1

1

2

3

5
Bed 

no.

A- 3 

A- 2 

A1

Rock description

Mudstone, calcareous, sandy 

Sandstone, cherty? 

Mudstone and sandstone

Sample 

no.

RLP-176 

DAB- 175 

DAB- 174

Thickness 

(feet)

23.7 

6.3 

19. 1

Chemical analyses 

(percent)

P2°5

0.3 

0.3 

0.2

Acid 

insoluble

75.6 

94.9 

85.6

Cu

th

Quadrant formation

Cq-1 Sandstone, quartzitic DAB -173 5.0 0.3 97.2 
CAVE CREEK, MONTANA. LOT NO. 1257.

D member of Phosphoria formation sampled in bulldozer trench on south side of Cave Creek, NW^NWi se

County, Montana, about 2,000 feet west of axis of northeastward-plunging Cave Creek syncline. Beds strike N. 2

by E. T. Ruppel and sampled by J. A. Kelleher in August 1948. Samples analyzed for P^O- and acid insoluble by 

Albany, Oregon, and for other constituents by Trace Elements Section Laboratory, U. s. Geological Survey, Was

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses (percent)

P2°5 A1203 Fe2°3

Loss on 

ignitionin

Dinwoody formation not exposed

E member of Phosphoria formation top approximately located

E- 8

E- 7

E- 6

E- 5

E- 4

E- 3

E- 2

E- 1

Chert and quartzite

Chert and quartzite

Chert and quartzite

Chert and quartzite

Chert and quartzite

Chert

Chert

Chert

._

--

--

--

--

__

--

ETR-620

11.0

16.0

11.0

20.0

22.0

28.0

32.5

3.5

__

--

--

--

__

--

3.1

__

--

__

--

--

__

--

--

--

--

__

--

--

__

--

--

--

-~

_.

--

D member of Phosphoria formation base not exposed

_.

D-31

D-30

D-29

D-28

D-27

D-26

D-25

D-24

D-23

D-22 

D-21

D-20

D-19

D-18

D-17

Rhyolite?

Phosphate rock

Phosphate rock, argillaceous

Flow breccia?

Mudstone, phosphatic

Mudstone

Mudstone

Mudstone, phosphatic

Rhyolite sill?

Mudstone

Phosphate rock

Mudstone, phosphatic

Phosphate rock, argillaceous 

Mudstonej fos. col. no. 48-KPM-561

Phosphate rock, argillaceous

Mudstone, phosphatic

Phosphate rock, argillaceous

Phosphate rock

ETR-619

ETR-618

ETR-617

ETR-616

ETR-615

ETR-614

ETR-613

ETR-612

ETR-611

ETR-610

ETR-609

ETR-608

ETR-607 

ETR-606

ETR-605

ETR-604

ETR-603

ETR-602

(5.25)

1.6

1.8

(1.2)

1.4

1.1

3.0

1.9

(Z.3)

4.6

0.8

0.5

0.5 

0.8

0.8

1.1

0.9

0.75

0.9

30.4

29.4

3.7

9.7

1.4

5.6

8.5

1.8

0.5

32.85

15.85

22.1 

6.7

23.6

14.4

24.6

30.7

__

--

1.6

--

1.8

__

_-

--

--

__

--

--

--

__

--

--

__

--

1.24

--

1.00

__

_-

--

__

 

--

__

--

--

_.

--

2.26

--

2.18

__

--

--

--

__

--

--

--

__

--

--

Fossil collection made by K. P. McLaughlin, Paleontology and Stratigraphy Branch, U. S. Geological S
Bed 

no.

D-16

D-15

D-14

D-13

D-1Z

D-ll

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Rock description

Phosphate rock and phosphatic mudstone

Mudstone, phosphatic

Mudstone, phosphatic

Mudstone, calcareous; fos. col. no.

48-KPM-55

Phosphate rock, argillaceous

Mudstone, phosphatic, fos. col. no.

48-KPM-54

Phosphate rock, argillaceous

Mudstone, phosphatic; fos. col. no.

48-KPM-53

Mudstone, phosphatic

Phosphate rock, argillaceous and

mudstone; fos. col. no. 48-KPM-52

Mudstone, phosphatic

Mudstone

Mudstone, phosphatic, calcareous

Mudstone

Phosphate rock, argillaceous

Phosphate rock, sandy

Sample 

no.

ETR-601

ETR-600

ETR-599

ETR-598

ETR-597

ETR-596

ETR-595

ETR-594

ETR-593

ETR-592

ETR-591

ETR-590

ETR-589

ETR-588

ETR-587

ETR-586

Thickness 

(feet)

0.6

0.7

0.75

0.6

0.4

0.8

0.15

0.4

0.9

1.7

0.55

1.6

1.3

0.7?

0.3

Chemical analyses (percent)

P2°5

21.1

11.8

9.4

2.0

24.5

10.5

18.7

14.7

14.9

18.4

13.8

4.4

13.6

6.4

29.4

20.2

A12°3

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

Fe2°3

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

__

Loss on 

ignition

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

A

ins

4

4

5

6

4

6

2

4

Stratagraphic interval of 116 feet between D-1 and approximate top of Quadrant formation includes few ex
CEDAR CREEK. MONTANA. LOT NO. 1256.

D member of Phosphoria formation sampled in bulldozer trench near Cedar Creek, sec. 26, T. 9 S., 

Montana, on eastern limb of a syncline. Beds strike north and dip 61° W. Section measured by E. T. Ruppe

in August 1948. Samples analyzed by U. S. Bureau of Mines Laboratory, Albany, Oregon.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cu

th

E member of Phosphoria formation basal bed only

E- 1 Chert ETR-585 5.0 2.3 78.5 

D member of Phosphoria formation base not exposed

D-43

D-42

D-41

D-40

D-39

D-38

D-37

D-36

D-35

D-34

D-33

D-32

D-31

D-30

D-29

D-28

D-27

D-26

D-25

D-24

D-23

D-22

D-21

D-20

D-19

D-18

Mudstone

Mudstone

Phosphate rock, cherty, calcareous

Limestone, phosphatic, argillaceous

Mudstone

Mudstone, calcareous, phosphatic

Mudstone

Mudstone and calcareous phosphate rock

Mudstone, calcareous and phosphate rock

Limestone

Mudstone, calcareous

Phosphate rock, calcareous

Phosphate rock, calcareous

Mudstone

Phosphate rock, argillaceous

Phosphate rock; fos. col. no. 48-KPM-48

Phosphate rock, argillaceous

Mudstone

Phosphate rock, argillaceous

Phosphate rock, argillaceous

Phosphate rock, argillaceous

Limestone, argillaceous

Mudstone, calcareous, phosphatic

Mudstone, phosphatic

Phosphate rock and calcareous mudstone;

fos. col. no. 48-»KPM-47

Phosphate rock, argillaceous

ETR-584

ETR-583

ETR-582

ETR-581

ETR-580

ETR-579

ETR-578

ETR-577

ETR-576

ETR-575

ETR-574

ETR-573

ETB-572

ETR-571

ETR-570

ETR-569

ETR-568

ETR-567

ETR-566

ETR-565

ETR-564

ETR-563

ETR-562

ETR-561

ETR-560

ETR-559

11.5

10.0

0.8

0.3

1.5

0.3

3.0

1.0

0.7

1.2

1.2

1.0

0.8

0.9

0.15

0.7?

0.3

0.7

0.1

0.3

0.4

0.5

0.5

0.4

0.5

0.6

1.0

1.1

15.4

H.4

4.6

9.2

2.0

9.6

6.3

1.8

7.6

17.4

21.0

1.4

18.9

32.6

23.5

5.7

20.9

17.5

22.1

3.5

9.8

8.9

24.8

22.8

74.0

82.3

34.2

22.7

62.6

42.2

77.6

51.0

42.8

48.3

12.7

19.6

2.6

72.0

33.5

25.0

26.8

64.7

33.0

35.8

24.3

39.1

41.4

58.3

20.3

27.0

Fossil collection made by K. P. McLaughlin, Paleontology and Stratigraphy Branch* U. S. Geologi
Bed

no.

D-17

D-16

D-15

D-14

D-13

D-12

D-ll

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Rock description

Phosphate rock, argillaceous, and

calcareous mudstone

Mudstone, phosphatic

Mudstone, calcareous

Phosphate rock, calcareous; fos. col.

no. 48-KPM-46

Mudstone, phosphatic

Mudstone, phosphatic

Phosphate rock and limestone

Phosphate rock, calcareous

Mudstone, phosphatic

Phosphate rock, argillaceous

Phosphate rock, argillaceous

Mudstone, calcareous

Mudstone

Mudstone, calcareous

Phosphate rock and mudstone

Mudstone, phosphatic

Phosphate rock, sandy; fos. col.

no. 48-KPM-44

Sample 

no.

ETR-558

ETR-557

ETR-556

ETR-555

ETR-554

ETR-553

ETR-552

ETR-551

ETR-550

ETR-549

ETR-548

ETR-547

ETR-546

ETR-545

ETR-544

ETR-543

ETR-542

Thickness 

(feet)

0.9

0.25

0.9

0.3

0.3

0.6

0.9

0.4 '

0.25

0.33

0.2

0.6

0.5

0.6

1.1

0.35

3.0

Chemical analyses 

(percent)

P2°5

20.3

10.1

2.9

25.1

9.9

12.4

16.8

20.8

14.1

19.7

21.5

6.6

1.7

6.7

16.5

8.2

26.3

Acid 

insoluble

26.6

55.0

58.9

17.6

56.1

52.1

3.8

17.7

46.5

30.2

30.6

49.8

79.4

62.0

40.3

51.1

28.6

C

Stratigraphic interval of 286 feet between D-1 and approximate base of C member, includes few ex

and limestone or dolomite.

Stratigraphic interval of 123 feet between approximate base of C member and approximate top of Q

formation, strata concealed.
SAWTOOTH PEAK, MONTANA. LOT NO. 1241.

C and E members and part of A member of Phosphoria formation measured in natural exposures, and 

from hand trenches on Sawtooth Peak, NE^SWi sec. 10, T. 12 S., R. 5 W., Beaverhead County, Montana, on o

Snowcrest anticline. Beds at top of section strike N. 5° W. and dip 75' W. Beds at base of section strike N. 4

Section measured by F. S. Honkala and O. A. Payne and sampled by Payne in August 1948. Samples analyzed b

Laboratory, Albany, Oregon.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cum

thi

(

Dinwoody formation

Trd-2 

Trd-1

Not described; fos. col. no. 48-KPM-77 1 

Muds tone, quartz itic 5.0 

E member of Phosphoria formation

E-15

E-14

E-13

E-12

E-II

E-10

E- 9

E- 8

1- 7

E- 6

E- 5

E- 4

E- 3

E- 2

E- 1

Quartzite

Sandstone

Quartzite

Quartzite

Sandstone

Sandstone

Sandstone

Quartzite

Quartzite

Quartzite

Sandstone, quartz itic

Quartzite

Sandstone, quartzitic

Sandstone, quartzitic

Conglomerate and quartzite

_-

--

__

--

--

--

--

 

2.4

4.3

5.0

5.0

2.8

5.0

5.0

3.4

5.0

5.0

5.0

3.8

5.0

5.0

5.0

__

--

--

--

__

»_

« *»

--

--

--

--

__

--

__

--

--

--

 -

D member of Phosphoria formation

D-14

D-13

D-12

D-ll

D-10

D- 9

Phosphate rock and quartzite

Phosphate rock and mudstone

Mudstone

Phosphate rock and mudstone

Mudstone, phosphatic, calcareous

Mudstone and phosphate rock, argillaceous,

calcareous

PSH-438

PSH-437

FSH-436

FSH-435

FSH-434

FSH-433

3.5

2.8

4.6

2.5

5.0

5.0

7.4

14.7

4.7

20.9

7.9

16.3

77.7

51.7

63.1

27.5

50.7

33.8

Fossil collection made by K. P. McLaughlin, Paleontology and Stratigraphy Branch, U. S. Geologica

16.3 feet above base of formation.
D8

D7

D6

D5

D4

D3

D2

D1

Phosphate rock and mudstone

Limestone; fos. col. no. 48-KPM-76

Mudstone

Mudstone

Mudstone

Mudstone

Mudstone

Mudstone

FSH-432

FSH-431

FSH-430

FSH-429

FSH-428

FSH-427

FSH-426

FSH-425

2.3

2.9

3.2

5.0

5.0

5.0

5.0

5.0

16.9

6.9

0.2

0.3

0.4

0.3

0.4

0.2

35.4

18.7

85.7

84.9

83.7

87.3

83.3

86.3

C member of Phosphoria formation

C-60

C-59

C-58

C-57

C-56

C-55

C-54

C-53

C-52

C-51

C-50

C-49

C-48

C-47

C-46

C-45

C-44

C-43

C-42

C-41

C-40

C-39

C-38

C-37

C-36

C-35

Chert

Sandstone

Sandstone

Sandstone

Sandstone

Sandstone, quartzitic

Quartzite

Chert and mudstone

Conglomerate, cherty

Chert

Covered interval, float strongly suggests

limestone

Limestone

Limestone

Limestone

Limestone

Limestone

Limestone

Limestone

Limestone; fos. col." no. 48-KPM-75

Limestone

Limestone

Limestone

Limestone and dolomite

Chert

Dolomite

Dolomite

Dolomite

__

--

FSH-424

__

__

-_

--

--

--

__

__

--

_ 

_-

2.3

4.3

5.0

2.0

1.8

3.3

3.2

2.7

0.6

4.0

11.0

5.0

5.0

5.0

5.0

2.5

5.0

2.6

5.0

5.0

5.0

5.0

5.0

1.1

3.5

5.0

5.0

__

-_

--

3.6

__

--

,._

-.

--_

--

--

-_

--

_ _

86.7

 _

--

 .

--

__

_, _

__

1

1
C-34

C-33

C-32

C-31

C-30

C-29

C-28

C-27

C-26

C-25

C-24

C-23

C-22

C-21

C-20

C-19

C-18

C-17

C-16

C-15

C-14

C-13

C-12

C-ll

C-10

C- 9

C- 8

C- 7

C- 6

C- 5

C- 4

C- 3

C- 2

C- 1

Dolomite

Limestone; fos. col. no. 48-KPM-74

Limestone and chert

Limestone and chert

Limestdne and chert

Limestone

Limestone

Limestone

Limestone

Limestone

Limestone

Limestone, sandy

Limestone, sandy

Limestone, dolomitic, sandy?

Chert

Sandstone, calcareous

Chert, sandy, calcareous

Chert, sandy

Chert* sandy

Chert, sandy

Chert, sandy

Chert* sandy

Chert, sandy

Chert, sandy

Chert, sandy

Chert

Chert

Sandstone and chert

Chert

Chert

Chert

Chert

Chert

Chert, argillaceous

_

..

--

_-

- 

-~

__

--

--

--

__

--

« 

«

--

--

--

__

--

--

__

--

__

1.6

4.2

5.0

5.0

5.0

3.0

5.0

5.0

5.0

5.0

5.0

5.0

3.4

3.7

3.5

1.4

1.8

4.4

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

4.8

4.0

3.8

5.0

5.0

5.0

5.0

5.0

...

--

__

--

__

__

--

--

--

--

_.

-«

--

- 

_-

.-

--

--

--

__

--

--

__

--

..

 « 

--

--

--

__

--

--

--

 _

--

-w

--

B member of Phosphoria formation

B- 6

B- 5

B- 4

B- 3

B- 2

B- 1

Mudstone and phosphate rock

Mudstone and phosphate rock

Mudstone

Phosphate rock

Limestone, phosphatic, sandy; fos. col.

no. 48-KPM-73

Phosphate rock, sandy; fos. col. no.

48-KPM-72

FSH-423

FSH-422

FSH-421

FSH-420

FSH-419

FSH-418

3.1

3.6

2.8

2.7

1.2

2.8

4.0

5.2

7.0

27.6

10.2

23.5

80.8

73.6

60.1

12.7

24.0

30.3
Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

C

A member of Phosphoria formation base not exposed

A-16

A-15

A-14

A-13

A- 12

A-ll

A- 10

A- 9

A- 8

A- 7

A- 6

A- 5

A- 4

A- 3

A- 2

A- 1

Chert

Dolomite, argillaceous; fos. col.

no. 4S-KPM-71

Mudstone and sandstone, calcareous

Sandstone, calcareous, argillaceous

Sandstone, calcareous, argillaceous

Sandstone, calcareous

Sandstone, calcareous

Sandstone, calcareous

Sandstone, calcareous

Sandstone, calcareous, argillaceous

Dolomite, argillaceous

Dolomite, argillaceous

Dolomite, sandy

Dolomite, sandy

Dolomite, sandy

Dolomite, sandy

__

__

__

--

--

--

--

__

--

--

1.8

4.2

4.6

2.6

5.0

5.0

5.0

5.0

5.0

3.7

5.0

5.0

5.0

5.0

5.0

5.0

__

__

--

--

__

--

~

-_

-_

__

--

--

__

--
UPPER FRENCH CREEK, MONTANA. LOT NO. 1248.

D member of Phosphoria formation sampled in bulldozer trench near Upper French Creek, SW^ sec. 

Beaverhead County, Montana. Beds strike N. 15° E. and dip 55° W. The stratigraphic sequence and thickne

questionable due to thrust faulting exposed in the trench and to the fragmented and weathered condition of the 

by D. A. Bostwick and R. L. Parker and sampled by R. L. Konizeski and J. E. Joyce in August 1948. Sample

of Mines Laboratory, Albany, Oregon.

Bed

no. Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

C

th

D member of Phosphoria formation top not exposed

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Phosphate rock, argillaceous

Mudstone, phosphatic

Phosphate rock and mudstone

Phosphate rock and mudstone, cherty

Mudstone

Mudstone

Mudstone

Mudstone

Mudstone, calcareous

Mudstone, calcareous

RLP-172

RLP-171

RLP-170

RLP-169

RLP-168

RLP-167

DAB- 166

DAB- 165

DAB -164

DAB -163

Probable fault; units below may be part of a fault zone.

1.0

1.3

1.0

1.7

0.7

1.6

0.9

2.9

1.8

1.6

20.4

11.3

19. 1

16.0

0.9

2.0

2.8

2.7

3.6

4.3

35.7

51.0

37.2

43. 1

66.6

79.6

66.6

72.5

71.0

72.6

C member? of Phosphoria formation top and base not exposed

C- 5

C- 4

C- 3

C- 2

C- 1

Quartz ite and chert

Quartzite and chert

Quartz ite and chert

Chert

Sandstone and chert

Thrust fault

DAB- 162

DAB- 161

DAB- 160

DAB -159

DAB- 1 58

?

?

1.5?

2.2

2.0

1.6

1.5

2.3

0.5

0.3

85.8

85.3

81.2

93.1

94.9

Quadrant formation not measured

Cq-1 Quartzite -- -- -- -- 
WADHAM SPRINGS, MONTANA. LOT NOS. 1246 and 1247.

Phosphoria formation sampled in bulldozer trenches near Wadham Springs on southeast limb of anticl

lot no. 1246, . . -- -- --

6, sampled in north trench. SE?SW$ sec. 22; and lower part of formation, lot no. 1247, in south tr

T. 13 S.. R. 7 W,, Beaverhead County. Montana. Beds strike N. 30° E. and dip 70-80° SE. Section measure

E. R. Cressman, and L. A. Thomas and sampled by Bostwick, Cressman, Thomas, and W. H. Wilson in Aug

by U. S. Bureau of Mines Laboratory, Albany. Oregon.

Bad 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cu

th

Dinwoody formation

1-d- i Mudstone ERC-157 .. 1.3 83.1 

E member of Phosphoria formation, lot no. 1247

E-12

E-ll

E-10

B- 9

E- 8

8- 7

B- 6

E- 5

E- 4

E- 3

E- 2

E- 1

Mudstone and chert

Siltstone and sandstone

Mudstone, chert, and sandstone

Mudstone and chert

Sandstone and chert

Mudstone and chert

Chert

Mudstone and chert

Mudstone and chert; fps.

eol. no. 48-KPM-69 1

Mudstone and chert

Mudstone and chert; foe. col. no.

48-KPM-69

Chert, phosphatic

ERC-156

ERC-155

DAB- 154

DAB- 153

DAB- 152

ERC-151

ERC-150

ERC-149

DAB- 148

DAB- 147

DAB- 146

ERC-145

3.6

5.8

9.4

11.2

2.1

14.5

8.1

12.3

9.3

18.0

14.8

0.8

1.4

1.3

1.4

1.4

1.3

1.4

1.7

1.1

1.4

1.0

1.1

16.9

78.5

78.2

88. 1

89.1

86.3

89.7

90.5

89.9

92.0

92,5

93.1

53.2

E- 2

E- 1

Mudstone and chert; foe. col. no.

48-KPM-69

Chert, phosphatic

DAB- 146

ERC-145

14.8

0.8

1.1

16.9

93.1

53.2

D member of Phosphoria formation, lot no. 1247

D-23

D-22

D-21

D-20

D-19

D-18

D-17

D-16

D-15

D-14

D-13

D-12

Mudstone, phosphatic

Phosphate rock, argillaceous

Phosphate rock, argillaceous

Mudstone. phosphatic

Mudstone; fos. col. no. 48-KPM-68

Mudstone and phosphate rock

Mudstone

Mudstone and phosphate rock

Mudstone

Mudstone. phosphatic

Phosphate rock, argillaceous

Mudstone, phosphatic

ERC-144

ERC-143

DAB- 142

DAB- 141

DAB- 140

ERC-139

ERC-138

ERC-137

DAB- 136

DAB- 135

DAB- 134

DAB- 133

1.5

2.05

0.5

0.8

3.3

3.5

1.2

0.7

1.8

1.5

0.6

1.0

17.0

28.5

21.6

9.9

3.9

14.2

3.6

10.5

4.4

11.4

17.9

9.7

51.2

20.2

31.7

59.6

75.9

48.0

72.9

52.0

71.3

53.3

44.3

55.8
D-ll

D-10

D- 9

D- 8

D- 7

D- 6

D- 5

D- 4

D- 3

D- 2

D- 1

Mudstone and phosphate rock

Mudstone

Mudstone

Mudstone, phosphatic

Mudstone

Mudstone and phosphate rock

Mudstone

Mudstone, phosphatic

Phosphate rock, argillaceous

Mudstone and phosphate rock

Mudstone and phosphate rock

DAB- 132

DAB- 131

ERG -130

ERG -129

ERG -128

ERG -127

ERG -126

ERG -125

DAB- 124

DAB- 123

DAB- 122

0.8

1.0

1.9

1. 1

1.2

3.7

0.8

2.3

0.8

3.6

2.3

14.3

6.2

6.4

8.5

6.3

17.1

5.3

14.3

16.2

9.7

7.2

46.1

66.0

65.8

52.5

63.0

40.3

75.7

45. 1

41.3

59.0

61.7

29 feet below D-l not exposed though trenched by bulldozer and hand to depth of 24 feet. Interval pr

C member of Phosphoria formation, lot nos. 1246 and 1247

C-18

C-17

C-16

C-15

C-14

C-13

C-12

C-ll

C-10

C- 9

C- 8

C- 7

C- 6

C- 5

C- 4

C- 3

C- 2

C- 1

Lot no. 1247

Limestone; fos. col. no. 48-KPM-67

Limestone; fos. col. no. 48-KPM-66

Limestone; fos. col. no. 48-KPM-65

Limestone; fos. col. no. 48-KPM-64

Mudstone, calcareous

Mudstone, calcareous

Mudstone, calcareous

Limestone

Limestone; fos. col. no. 48-KPM-63

Limestone; fos. col. no. 48-KPM-62

Limestone

Limestone

Limestone

Limestone, argillaceous

Sandstone, calcareous

Chert

Lot no. 1246

Chert, sandstone and mudstone

Mudstone and chert

ERG- 121

DAB- 120

DAB- 119

DAB-118

ERG-117

ERG -116

ERG- 115

DAB- 114

DAB- 113

DAB- 112

DAB-111

DAB- 110

DAB- 109

DAB- 108

DAB- 107

DAB- 106

LAT-105

DAB- 104

21.8

22.5

15.0

18.4

17.7

20.3

12.2

2.6

19.8

13.3

14.9

13.6

7.3

8.2

1.2

14.8

17.7

13.6

0.7

1.2

0.8

0.6

0.6

0.4

0.7

0.3

0.3

0.3

0.3

0.2

0.2

0.3

1.3

0.2

0.7

0.65

11.3

16.5

11.3

16.0

53.3

73.4

57.0

18.9

6.8

5.8

12.6

12.5

5.9

21.3

56.5

87.7

93.9

93.3

B member of Phosphoria formation, lot no. 1246

B- 8

--

Mudstone; fos. col. nos. 48-KPM-61 and

48-KPM-60

Mudstone. phosphatic

DAB- 103

LAT-264

LAT-264 represents upper 1.3 feet of DAB- 103.

13.2

(1.3)

2.2

10.7

87.2

70.0

1 Fossil collection by K. P. McLaughlin, Paleontology and Stratigraphy Branch, U. S. Geological Sur
Bed 

no.

B- 7

B- 6

B- 5

B- 4

B- 3

B- 2

B- 1

Rock description

Chert and mudstone

Mudstone and chert

Mudstone, cherty

Phosphate rock, sandy

Mudstone; fos. col. no. 48-KPM-59

Phosphate rock, argillaceous

Phosphate rock, argillaceous

Sample 

no.

DAB- 102

ERG-101

ERG -100

ERG- 99

LAT- 98

LAT-263

LAT-262

Thickness 

(feet)

4.6

5.7

14.3

0.9

8.2

0.8

4.3

Chemical analyses 

(percent)

P2°5

0.35

0.60

0.3

26.1

4.6

26.3

23.2

Acid 

insoluble

95.3

93.3

94.0

29.5

74.0

22.4

23.6

Cu

th

A member of Phosphoria formation, lot no. 1246

A-15

A- 14

A-13

A-12

A-ll

A-10

A- 9

A- 8

A- 7

A- 6

A- 5

A- 4

A- 3

A- 2

A- 1

Mudstone, calcareous

Mudstone and limestone

Limestone

Mudstone, calcareous

Limestone

Mudstone, calcareous

Limestone; fos. col. no. 48-KPM-58

Mudstone, calcareous

Mudstone, calcareous

Mudstone, calcareous

Mudstone, calcareous, cherty

Mudstone and limestone

Mudstone and chert; fos. col. no. 48-KPM-57

Limestone

Mudstone, calcareous and sandstone

LAT- 96

ERG- 95

ERG- 94

ERC- 93

DAB- 92

DAB- 91

DAB- 90

LAT- 89

LAT- 88

LAT- 87

ERC- 86

ERC- 85

ERC- 84

DAB- 83

DAB- 82

6.8

3.8

2.0

3.2

3.3

1.9

5.4

12.7

12.7

11.6

9.4

8. 1

11.6

18.2

12.4

0.6

0.6

0.2

0.4

0.2

0.25

0.3

0.1

0. 1

0.25

0.4

0.4

0.3

0.2

0.5

76.0

51.6

6.5

67.6

10.2

70.1

6.7

50.0

57.0

66.6

72.8

32.4

56.6

4.6

85.5

Quadrant formation

Cq -1 1 Sandstone DAB- 81 18.0 0.2 97.6
CENTENNIAL RANGE TRENCH NO. 4, MONTANA. LOT NO. 1251.

B member of Phosphoria formation sampled in hand trench at Centennial Range locality no. 4 along south si

Ei corner sec. 6, T. 15 S., R. 1 W., Beaverhead County, Montana, on southward-dipping hornocline. Beds strike 

measured by F. S. Honkala and sampled by O. A. Payne in August 1948. Samples analyzed for P^Oc. F» and acid i

Laboratory, Albany, Oregon, and for other constituents by Trace Elements Section Laboratory, u. S. Geological S

Bed

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses (percent)

P2°5 A1203 Fe203 F

Loss on 

ignition

A

in

C member of Phosphoria formation not measured

B member of Phosphoria formation

B-l Phosphate rock FSR-261 6.2 31.3 0.97 0.81 3.16 3.90 

A member of Phosphoria formation not measured
ODELL CREEK, MONTANA. LOT NO. 1252.

Upper part of Phosphoria formation sampled and lower part of Dinwoody formation measured in hand 

Creek, SEj sec. 1, T. 15 S., R. 2 W., Beaverhead County, Montana, on southward-dipping homocline. Beds 

Section measured by F. S. Honkala and O. A. Payne and sampled by Payne and J. A. Kelleher in 1948. Sampl

of Mines Laboratory, Albany, Oregon.

Bed 

no.

Bock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cu

th

Lower part of Dinwoody formation

Trd-30

Trd-29

Trd-28

Tfrd-27

Tfrd-26

I'd- 25

Tfrd-24

Trd- 23

Trd-22

I'd- 21

Tfrd-20

Trd- 19

I'd- 18

I'd- 1 7

Tfrd-16

I'd- 15

Trd- 14

TM-13

1x1-12

Thi-11

Trd- 10

Trd- 9

Trd- 8

Trd- 7

Trd- 6

Trd- 5

Trd- 4

Trd- 3

Trd- 2

Trd- 1

Limestone

Limestone

Mudstone

Limestone

Limestone and dolomite

Limestone

Mudstone, calcareous

Limestone and calcareous mudstone

Dolomite

Dolomite and calcareous mudstone

Dolomite

Dolomite

Dolomite

Dolomite and calcareous mudstone

Dolomite

Limestone

Dolomite and limestone

Mudstone and dolomite

Dolomite and mudstone

Dolomite

Dolomite

Dolomite

Dolomite and mudstone

Dolomite

Dolomite

Dolomite and mudstone

Mudstone, calcareous

Mudstone

Mudstone

Mudstone, calcareous and dolomite

__

--

--

__

__

--

--

__

__

.

__

--

__

FSH-417

2. 1

2.8

2.6

2.9

3.6

5.0

4.9

2.7

4.5

5.0

3.3

5.0

2.2

2.3

3.3

1.8

3.4

3.2

0.5

1.3

2.0

1.7

3.0

1.4

3. 1

1.6

2.1

0.3

2.2

2.4

_ 

--

--

--

__

--

--

--

--

_ _

--

__

--

--

__

--

--

__

--

--

_ _

--

-_

--

0.6

__

--

--

__

--

--

--

--

 _

-.

__

--

-_

--

--

__

--

--

--

__

-_

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CENTENNIAL RANGE TRENCH NO. 1, MONTANA. LOT NO. 1253.

D, E, and part of C members of Phosphor!a formation sampled in hand trench at Centennial Range loc

range, NW corner sec. 33, T. 14 S., R. 1 W., Beaverhead County, Montana, on southward-dipping homocline. 

20° S. Section measured by F. S. Honkala and O. A. Payne and sampled by J. A. Kelleher in July 1948. Samp

of Mines Laboratory, Albany, Oregon.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent)

P2°5

Acid 

insoluble

Cum

thi

(

Dinwoody formation

Ttd-1 Mudstone OAP-496 0.7 0.8 79.7

E member of Phosphoria formation

E-21

£-20

E-19

E-18

E-17

E-16

E-15

E-14

E-13

E-12

E-ll

E-10

B- 9

E- 8

E- 7

E- 6

E- 5

E- 4

E- 3

E- 2

E- 1

Mudstone, calcareous

Mudstone, calcareous

Mudatone, calcareous

Mudstone, calcareous

Chert

Chert

Chert

Chert

Chert

Chert

Chert

Chert

Chert

Chert

Dolomite and calcareous mudstone

Chert

Chert

Chert, calcareous and mudstone

Mudstone and limestone

Mudstone and chert

Mudstone, calcareous and chert

OAP-495

OAP-494

OAP-493

OAP-492

OAP-491

OAP-490

GAP- 489

OAP-488

OAP-487

FSH -486

FSH -485

FSH -484

FSH -483

FSH -482

FSH -481

FSH -480

FSH -479

FSH -478

FSH -477

FSH -476

FSH -4 75

2.8

2.5

3.4

2.0

1.5

3.5

4.1

3.2

2.9

5.0

5.0

5.0

5.0

5.0

3.2

4.3

5.0

5.0

3.5

5.0

5.0

1.3

1.4

1.3

1.3

1.0

0.3

0.5

0.7

0.5

0.6

0.6

0.5

0.5

0.5

0.3

0.5

0.6

0.5

0.5

0.6

0.8

58.8

75.7

74.6

75.0

77.7

95.3

83.3

90.2

93.5

93.3

88.0

86.7

86.7

85.2

50.7

84.3

82.3

77.0

76.2

81.7

77.3

2

2

3

3

4

4

5

5

6

6

7

7

D member of Phosphoria formation

D-12

D-ll 

D-10

D- 9

Mudstone

Mudstone 

Mudstone

Mudstone

OAP-474

OAP-473 

OAP-472

OAP-471

3.3

2.2 

1.2

4.6

1.0

0.9 

1.5

0.6

76.0

77.5 

74.7

69.0

Beds D-9 through D-12 are slumped and thicknesses may not be correct.
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35
CENTENNIAL RANGE TRENCHES NOS. 2 AND 3, IDAHO. LOT NOS. 1254 AND 

Phosphoria formation sampled in Centennial Range hand trenches nos. 2 and 3. Upper part of forma

in trench no. 2, NWi sec. 12, T. 14 N., R. 40 E.; lower part of formation, lot no. 1254, sampled in trench n

R. 41 E., Clark County, Idaho, at crest of range on southward-dipping homocline. Beds at trench no. 2 stri

and beds at trench no. 3 strike N. 70* W. and dip 22* S. Section measured by F. S. Honkala and O. A. Payne 

awl R. L. Konizeski in July 1948. Samples analyzed by U, S. Bureau of Mines Laboratory, Albany, Oregon.

Bed 

no.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent]

P2°5

Acid 

insoluble

Cu

th

Dinwoody formation

l-d-2 

1-d-l

Mudstone, calcareous, sandy 

Mudstone and limestone FSH-540

0.5 

0.8 0.65 77.5

E member of Phosphoria formation, lot no. 1255

E-12

E-ll

B-10

E- 9

E- 8

E- 7

E- 6

E- 5

E- 4

E- 3

E- 2

E- 1

Mudstone* sandy

Mudstone

Mudstone, sandy, calcareous

Mudstone and chert

Chert

Chart, argillaceous

Chert, argillaceous

Chert, argillaceous

Chert, argillaceous

Chert and mudstone

Mudstone

Mudstone

FSH-539

FSH-538

FSH-537

FSH-536

FSH-535

FSH-534

FSH-533

FSH-532

FSH-531

FSH -530

FSH-529

FSH -528

5.0

5.0

5.0

0.9

0.6

2.2

1.3

3.8

2.7

4.0

1.8

1.7

1.0

1.1

1.2

1.3

0.4

0.4

0.4

0.6

0.6

0.6

0.65

0.80

81. 1

81.5

74.4

89.0

93.0

92.5

87.4

89.5

90.2

90.1

81.6

82.4

D member of Phosphoria formation, lot no. 1255

D-12

D-ll

D-10

D- 9

D- E

D- 7

D- 6

D- 5

D- 4

D- 3

Mudstone

Mudstone

Mudstone

OAP-527

GAP -536

OAP-525

0.9

1.6

3.0

0.8

1.0

1.05

86.5

81.5

80.7

Possible fault at top of D-9 indicated by gouge and breccia zone. No displacement apparent.

Mudstone

Mudstone

Mudstone, calcareous

Phosphate rock

Mudstone

Mudstone, calcareous and phosphate rock

Phosphate rock

OAP-524

GAP- 523

OAP-522

OAP-521

OAP-520

OAP-519

OAP-518

3.2

2.2

5.0

1.5

0.7

1.4

0.7

1.6

1.1

1.7

31.4

5.4

9.65

34.5

80.3

77.1

70.6

10.0

66.0

52.3

4.3
D- 2 

D- 1

Mudstone 

Phosphate rock, argillaceous

GAP- 51 7 

GAP- 5 16

1.7 

0.9

2.8 

19.8

74.4 

35.2

C member of Phosphor!a formation, lot nos. 1255 and 1254

C-10 

C- 9 

C- 8 

C- T 

C- 6

C- 5 

C- 4 

C- S 

G- 2

C- 1

Lot no. 1255

Sandstone 

Sandstone 

Sandstone, calcareous 

Sandstone 

Sandstone

Sandstone 

Sandstone 

Sandstone; phosphatic

Sandstone) calcareous

FSH-515 

FSH-514 

FSH-513 

FSH-512 

FSH-511

FSH-510 

FSH -509 

FSH-508 

FSH -507

1.6 

3.0 

2.6 

5.0 

5.0

2.1 

5.0 

1.1 

4.3

3.2 

1.7 

1.3 

1.7 

2.8

5.0 

3.7 

12.8 

7.5

87.1 

92.9 

76.2 

85.7 

85.3

80.2 

77.0 

52.6 

45.2

There is probably a gap of 10 feet or more between the lowest bed of lot no. 1255 and the highest bed 

Lot no. 1254

Chert OAP-541 1.0 0.4 93.2 

B member of Phosphoria formation, lot no. 1254

B- 2 

B- 1

Phosphate rock, argillaceous 

Phosphate rock

GAP- 506. 

GAP- 505 *

1.7 

4.6

22.8 

32.4

34.1 

8.4

A member of Phosphoria formation, lot no. 1254

A- 7 

A- 6 

A- 5 

A- 4

A- 3

A- 2 

A- 1

Limestone and conglomerate 

Limestone, argillaceous 

Limestone, sandy , and calcareous sandstone 

Sandstone, calcareous 

Limestone, sandy, and calcareous sandstone

Sandstone, calcareous 

Conglomerate, calcareous

GAP- 504 

GAP- 503 

FSH -502 

FSH-501 

FSH -500

FSH -499 

FSH -498

2.7 

4.8 

5.0 

5.0 

4.6

5.0 

2.1

2.7 

1.5 

0.1 

0.1 

0.4

0.0 

0.2

35.2 

47.2 

60.3 

68.6 

68.7

64.5 

56.0

Quadrant formation

Cq-1 Sandstone, calcareous FSH -497 4.4 0,3 61.0 

. Cumulative data incomplete due to missing information. 

See additional analyses at end of table.
Additional analyses of sample OAP-505

Bed 

no,

B-l

Sample 

no.

OAP-505

P2°5

33.93

Ni

0.005

VZ°5

0.03

CrZ°3

0.07

F

3.63

Co

0.000

Si02

4.83

Zn

0.012

Ti02

0.008

Cu

0.001

CaO

49.84

Pb

0.002

MgO

0.11

Ag

0.00004

. Analyses made by the U. S. Geological Survey, Geochemistry and Petrology Branch. 

Co_ and S reported present.
LUKE MINE, MONTANA. LOT NO. 1285.

D member of Phosphoria formation sampled in Luke Mine of Montana Phosphate Products Company, s

Powell County, Montana, on southwest side of Luke-Graveley syncline; samples 304-305, locality A, from so

samples 306-307, locality B, from northwest heading, 5,300 level. Beds strike about N. 40° W. and dip 45° N

sampled by M. R. Klepper in September 1948. Samples analyzed by U. S. Bureau of Mines Laboratory, Alban

Bed 

so.

Rock description

Sample 

no.

Thickness 

(feet)

Chemical analyses 

(percent}

P2°5

Acid 

insoluble

Cu

th

Locality A, 5,300 level, southeast heading 

E member of Phosphpria formation basal bed only

E-l Quartzite, cherty 4.0 --

D member of Phosphoria formation

t>-4 

D-3 

D-2 

D-l

Clay 

Phosphate rock 

Phosphate rock 

Cloy

MRK-305 

MR K- 3 04

0.02 

1.6 

1.6 

0.1

34.0 

35.5

9.3 

5.8

C member of Phosphoria formation top beds only

C-2 

C-l

Quartcite 

Quartette

~ 2.0 

4.0

--

Locality B, 5,300 level, northwest heading 

E member of Phosphoria formation basal bed only

E-l Quartzite -- 1.5 ~ --

D member of Phosphoria formation

D-2 

D-l

Phosphate rock 

Phosphate rock

MRK-307 

MR K- 3 06

1.6 

1.6

33.1 

36.7

9.8

4.1

C member of Phosphoria formation top beds only

C-3 

C-2 

C-l

Quartzite 

Conglomerate 

Chert __

0.3 

0.5 

2.0 __

 - 

** Note incompleteness of cumulative data.