Geology and Monazite 

Content of the Goodrich 

Quartzite, Palmer Area 

Marquette County

3

j Michigan

GEOLOGICAL SURVEY BULLETIN 1030-F

This report concerns work done on behalf 

of the U. S. Atomic Energy Commission 

and is published with the permission of 

the Commission

Geology and Monazite 

Content of the Goodrich 

Quartzite, Palmer Area 

Marquette County 

Michigan

By R. C. VICKERS

CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

GEOLOGICAL SURVEY BULLETIN 1030-F

This report concerns work done on behalf 

of the U. S. Atomic Energy Commission 

and is published with the permission of 

the Commission

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1956
UNITED STATES DEPARTMENT OF THE INTERIOR 

Fred A. Seaton, Secretary

GEOLOGICAL SURVEY 

Thomas 6. Nolan, Director

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

Washington 25, D. C. - Price 50 cents (paper cover)
CONTENTS

	Pas:* 

Abstract_________________________________________________ 171

Introduction. _________________________________________________ 171

Location, accessibility, and history________________________ 172

Acknowledgments. ____________________________________________ 172

Geology_________________________________________ 173

General features_______________________________________ 173

Rock units______________________________________________ 175

Palmer gneiss_____________________________________________ 175

Ajibik quartzite.__________________________________________ 175

Siamo slate_______________________________________________ 176

Negaunee iron-formation._________________________________ 176

Goodrich quartzite______________________________________ 176

Dike rocks_______________________________ 177

Structure.. ___________________________________ 177

Occurrences of monazite____________________________________________ 179

Mineralogy-________________________________________________ 179

Determination of the monazite content of samples of Goodrich

quartzite.__________________________________________________ 181

Distribution-__________________________________ 182

Results of sampling of outcrops____________________________ 182

Results of gamma-ray logging of drill holes ___________________ 183

Results of analyses of core____________________-___________ 184

Occurrences of monazite in the Goodrich quartzite outside the Palmer

area_________________________________________________ 184

Conclusions--_____________________________________________________ 185

Literature cited-__________________________________________________ 185

ILLUSTRATIONS

PLATE 9. Geologic map of the Palmer area, Marquette County, Mich_ _ In pocket 

10. Geologic cross section through part of sec. 29, T. 47 N., R. 26 

W., Marquette County, showing gamma-ray logs of drill 

holes in Goodrich quartzite-_________________________ In pocket

Page 

FIGURE 42. Index map showing the location of the Palmer area.________ 173

43. Sketch of a photomicrograph (X 28) of Goodrich quartzite-_ 179

44. Graph showing relationship between equivalent uranium and 

monazite content of samples of Goodrich quartzite from 

the Palmer area_________________________-________ _ 181

TABLES

Page

TABLE 1. Chemical and spectrographic analyses of monazite concentrates from the Goodrich quartzite, Palmer area________ 180

2. X-ray powder diffraction data of monazite from the Goodrich

quartzite, Palmer area_______________________________ 180

m

CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

GEOLOGY AND MONAZITE CONTENT OF THE GOODRICH 

QUARTZITE, PALMER AREA, MARQUETTE COUNTY,

MICHIGAN

By R. C, VICKERS

ABSTRACT

The Palmer area, which is on the south limb of the Marquette synclinorium, 

consists of a downfaulted block of Precambrian sedimentary rocks about 4 miles 

long and three-quarters of a mile wide. The block is composed mainly of middle 

Huronian Ajibik quartzite and Negaunee iron-formation and upper Huronian 

Goodrich quartzite. Monazite occurs in the Goodrich quartzite as rounded 

detrital grains concentrated mainly in the matrix of quartz pebble conglomerate 

which is interbedded with coarse-grained quartzite.

Correlation of gamma-ray logs of drill holes which penetrate an apparent thickness of 1,100 feet of Goodrich quartzite and enter the underlying Negaunee ironformation shows that most of the monazite occurs more than 300 feet above the 

base of the Goodrich quartzite. Drill-core specimens contain as much as 54 

pounds of monazite per ton of rock. Outcrops of Goodrich quartzite, which are 

practically restricted to the lower 200 feet of the formation, contain an average 

of 2.9 pounds of monazite per ton. Samples from locally derived erratics contain 

as much as 110 pounds of monazite per ton.

Laboratory work indicates that more than 85 percent of the monazite is recoverable by gravity methods after grinding and sizing.

INTRODUCTION

Abnormal radioactivity in specimens of Goodrich quartzite on rock 

dumps at the Old Volunteer and Old Maitland mines near Palmer, 

Marquette County, Mich., was detected in 1951 by Robert Reed, 

geologist working for L. P. Barrett, U. S. Atomic Energy Commission 

contractor. Analyses of the rock indicated that most of the radioactivity was caused by thorium. The locality was brought to the 

attention of the writer during an examination of radioactive materials 

in northern Michigan in August 1952, and subsequent chemical and 

spectrographic analyses of the samples indicated that the Goodrich 

quartzite contains locally as much as 0.37 percent thoria and O.X 

percent each of Ce, La, Nd, Y, and Zr. Additional information 

concerning the radioactive material was obtained during 2 days 

of fieldwork in the Palmer area in November 1952 and in subsequent 

laboratory study.

171
172 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

Preliminary laboratory work indicated that most of the radioactivity is caused by detrital grains of thorium-bearing monazite in 

the matrix of pebble conglomerate of the Goodrich quartzite and 

that about 85 percent of the monazite is recoverable by gravity concentration after grinding and sizing.

To obtain further information concerning the geology of the Goodrich quartzite and the tonnage and grade of monazite-bearing rock 

that might be present in the Palmer area, 1 month was spent during 

the 1953 field season in mapping the Goodrich quartzite, sampling 

outcrops of the Goodrich, and gamma-ray logging three drill holes 

that penetrated the Goodrich. An examination was also made of 

many outcrops of Goodrich quartzite outside the Palmer area.

This report presents the results of the fieldwork together with the 

results of laboratory study. The work was done by the U. S. Geological 

Survey on behalf of the Division of Raw Materials of the U. S. Atomic 

Energy Commission.

LOCATION, ACCESSIBILITY, AND HISTORY

The Palmer area, whose location is shown in figure 42, is about 3 

miles south of Negaunee on Michigan Route M-35, Marquette 

County, Mich.; it includes parts of sees. 27, 28, 29, 30, 31, 32, 33, and 

34, T. 47 N., R. 26 W. The area is served by a branch of the Chicago 

and North Western Railway.

The Palmer area, part of the Marquette iron district, has been a 

source of iron ore since the 187.0's. About 17 million tons has been 

shipped from the area, of which about 25 percent has been produced 

from underground mines. The workings of several of the mines 

penetrated part of the Goodrich quartzite but are inaccessible at 

present.

ACKNOWLEDGMENTS

The writer wishes to acknowledge the cooperation and interest of 

personnel of the Cleveland-Cliffs Iron Co., who made available the 

results of recent diamond drilling in the Palmer area and reopened a 

diamond-drill hole so that it could be gamma-ray logged. E. R. 

Randolph, geologist of the Cleveland-Cliffs Iron Co., assisted in the 

gamma-ray logging.

J. H. Eric assisted the writer in the fieldwork during August 1953, 

and L. P. Barrett, of the U. S. Atomic Energy Commission, supplied 

special information on the Marquette and Gwinn districts.

Equipment of the Department of Geology and of the Department 

of Mining and Metallurgy of the University of Wisconsin was used 

for the preparation and study of samples.
MONAZITE IN GOODRICH QTJARTZITE, PALMER AREA, MICHIGAN 173

MARQUETTE

10 20 Miles

FIGURE 42. Index map showing the location of the Palmer area, Marquette County, Micb.

GEOLOGY 

GENERAL FEATURES

The Palmer area is on the south limb of the Marquette trough, a 

westward-plunging synclinorium about 40 miles long and from 1 to 6 

miles wide, that is composed of Huronian rocks locally intruded by 

dikes and sills of diorite and minor amounts of granite. The position
174 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

cd

h

Precambrian

Upper Cambrian sandstone

Killarney granite . . ,. .

AfMnlr* TnTTM1filV**fi Stratigraphic position doubtful ACUUC imrusives

Keweenawan Basic intrusives

a>

1 

o

rchean type

<;

Huronian

Upper

Middle

Lower

Laurentian granite

Keewatin

Upper slates

 , . , . Bijiki iron-for- Michxgamme slate mation member

Lower slates

Clarksburg volcanics 

Greenwood iron-formation 

Goodrich quartzite

Negaunee iron-formation 

Siamo slate 

Ajibik quartzite

We we slate 

Kona dolomite

Mesnard quartzite

Granite, syenite, peridotite 

Palmer gneiss

Kitchi schist and Mona schist

of the Palmer area in relation to the Marquette trough is shown in 

figure 42. The stratigraphy of the Marquette trough as given by 

Leith, Lund, and Leith (1935, opposite p. 10) is shown above.

The Palmer area consists of a downfaulted block of Huronian sedimentary rocks, about 4 miles long and three-quarters of a mile wide, 

which is separated from the main part of the Marquette synclinorium 

by an eastward-trending fault. All known outcrops of Goodrich, 

quartzite are shown on the geologic map of the Palmer area (pi. 9),. 

whereas outcrops of other formations are shown only to indicate theposition of the Goodrich contacts and the general geology of the 

adjacent area.
MONAZITE IN GOODRICH QUARTZITE, PALMER AREA, MICHIGAN 175

BOCK UNITS

According to Van Hise and Leith (1911) the sequence of Precambrian rocks in the Palmer area is as follows:

Approximate 

Series Formation thickness (feet)

Upper Huronian____ Goodrich quartzite__ _______ 850

Middle Huronian___ Negaunee iron-formation-...--- 1,000

Ajibik quartzite--___--____-_- 150

Archean___________ Palmer gneiss_-----__----_ .__ _ _

Other interpretations of the geology in the Palmer area have been 

proposed more recently. The Palmer gneiss is believed by Lamey 

(1935, p. 1137-1161) to consist mainly of metamorphosed lower and 

middle Huronian rocks. Furthermore, according to Tyler and Twenhofel (1952, p. 118-128), the Negaunee iron-formation and Goodrich 

quartzite of Van Hise and Leith in the Palmer area are correlated with 

the Goose Lake iron-formation member of the Siamo slate and the 

Siamo slate, respectively.

The correlation of the quartzite that overlies the iron-formation in 

the Palmer area with the Goodrich quartzite of the Marquette range 

proper, as proposed by Van Hise and Leith, is accepted by the writer 

because of the lithologic similarity of the quartzite mapped as Goodrich in the Palmer area to known Goodrich quartzite in outcrops about 

5 miles to the northwest near the center of the Marquette trough; 

the presence of monazite both in the quartzite in the Palmer area and 

in outcrops of known Goodrich quartzite; and the absence of abnormal 

radioactivity in the Siamo slate (see table 1) in the Marquette trough.

PAUMER GNEISS

The highly metamorphosed rocks along the southern boundary of 

Huronian rocks in the mapped area were -assigned to the preHuronian Palmer gneiss by Van Hise and Leith (1911, p. 255-256). 

This interpretation is followed in the present report, but some of these 

rocks may represent metamorphosed lower or middle Huronian sedimentary rocks in accordance with the interpretation of Lamey (1935).

These rocks are granite, granite gneiss, diorite, amphibolite, chlorite 

schist, sericite schist, dolomite, and quartzite.

AJIBIK: QUARTZITE

The recognition of the Ajibik quartzite is difficult, because it grades 

from a massive, dense, white or reddish quartzite with scattered beds 

of conglomerate to a highly sericitized and granitized quartzose rock. 

Some of the rocks mapped as Ajibik quartzite may consist in part of 

lower Huronian Mesnard quartzite which has a similar lithologic 

character. The Ajibik quartzite is probably about 300 feet thick in

383411 56 2
176 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

the eastern part of^the mapped area and thins to about 50 feet in the 

western part.

SIAMO SLATE

The Siamo slate was not recognized in the Palmer area by Van 

Hise and Leith (1911). However, several outcrops of interbedded 

coarse-grained quartzite and sericitic slate occur in the SW% sec. 28 

and NW% sec. 30 (pi. 9), and these have been designated on the map 

as Siamo slate. These beds dip about 60° to the northeast, overlie 

the Ajibik quartzite, and underlie the Negaunee iron-formation.

NEGAUNEE IRON-FORMATION

The Negaunee iron-formation overlies the Ajibik quartzite in most 

of the Palmer area and consists of alternating laminae of red jasper 

and specular hematite or of interbedded gray chert and fine-grained 

hematite, possibly specular. Interbedded with the chert and hematite 

are many beds of coarse quartzite. At the Moore mine (S% sec. 28) 

many lenses and beds of coarse quartzite ard conglomerate, some of 

which contain cobbles as large as several inches in diameter, are 

associated with the iron-formation. Some of the lenses have been 

interpreted by Tyler and Twenhofel (1952, p. 123) as filled channels 

that were cut in the iron-formation, but H. L. James (1954, written 

communication) believes that they are hi infolded masses.

The true thickness of the Negaunee iron-formation in the Palmer 

area is probably about 800 feet. However, the thickness is not 

uniform and in places much, if not all, of the Negaunee iron-formation 

may be absent because of faulting. Thinning of the iron-formation on the flanks of the major folds has also probably occurred. 

Other geologists have interpreted the thinning and local absence of 

the iron-formation in the Palmer area as caused by pre-Goodrich 

erosion.

GOODRICH QUARTZTTE

^ In the Palmer area the Goodrich quartzite is composed of a locally 

developed basal cobble or boulder conglomerate which grades upward 

into interbedded coarse-grained quartzite and pebble conglomerate. 

Locally the lithologic character of the basal conglomerate varies and 

is dependent upon the character of the subjacent formation. At the 

Isabella mine (SWK sec. 29) the lower part of the Goodrich is composed almost entirely of cobbles and boulders of granite and schist 

derived from the early Precambrian to the south and also abundant 

jaspilite derived from the underlying Negaunee iron-formation. 

Locally, as at the Old Volunteer mine (on section line between sees. 30 

and 31), the basal part of the Goodrich contained enough specular 

hematite fragments to constitute ore. The local abundance of ironformation fragments in the lower part of the Goodrich indicates that
MONAZITE IN GOODRICH QTJARTZITE, PALMER AREA, MICHIGAN 177

erosion of the underlying iron-formation was taking place during 

Goodrich time. Because of the difference in competence between the 

two formations, as evidenced by the complex folding in the iron-formation as contrasted with the gentle folding in the quartzite, the contact 

is commonly faulted, and the Goodrich seems to rest with angular 

unconformity on the underlying Negaunee iron-formation.

Except for the local development of boulder and cobble conglomerate near the base of the formation, the Goodrich quartzite consists 

almost entirely of alternating beds of coarse quartzite and pebble 

conglomerate. The thickness of the observed pebble conglomerate 

beds ranges from about 2 inches to 2 feet. The pebble conglomerate 

beds are separated by beds of coarse sand, which range from 1 foot to 

10 feet or more in thickness. These lithologic relationships are based 

on outcrops of only the lower 200 feet of the Goodrich. The lower 

part of the Goodrich is fairly well exposed in the Palmer area, but only 

one exposure is known which is definitely more than 200 feet from the 

base. Because monazite is most abundant in beds of pebble conglomerate and because gamma-ray logs show an increase in monazite content in the middle and upper parts of the formation, the percentage 

of pebble beds probably increases similarly in those parts of the 

formation.

The maximum thickness of Goodrich quartzite penetrated by diamond drilling in the Palmer area is about 1,100 feet. The true 

stratigraphic thickness of the formation is not known because no 

sediments younger than the Goodrich quartzite were penetrated in 

the diamond drilling, and no information is available on the amount 

of folding that might be present.

DIKE ROCKS

An eastward-trending metadiabase (H. L. James, 1954, written 

communication) dike occurs in the NK sec. 31 and the S% sec. 29. 

The total thickness of the dike is not shown in any of the several outcrops but the writer believes it ranges from 50 to 100 feet. An outcrop of sheared metadiabase (?) in the SW% sec. 28 is along the strike 

of the metadiabase dike and is probably a sheared and altered portion 

of the dike. Others (Tyler and Twenhofel, 1952, p. 123-124) have 

interpreted this outcrop as being pyroclastic material in the ironformation.

Hotchkiss 1 has reported a northward-trending dike about 30 feet 

wide in the underground workings of the Old Volunteer mine.

STRUCTURE

The interpretation of the structure of the Palmer area is complicated 

by the lack of good exposures. The main structural features are the

1 Hotchklss, W. O., 1903, Some changes in the geologyoftheareaaboutPalmer,Mich.:UnpublishedBachelor of Science thesis in flies of Univ. Wis. Library, Madison, Wis.
178 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

major eastward-trending Palmer fault, which separates the Palmer 

area from the main part of the Marquette synclinorium, and several 

other faults of smaller displacement. The general dip of the rocks 

in the Palmer area is northward, but locally in the Negaunee ironformation the rocks are tightly folded ard highly contorted.

The Palmer fault, originally described by Hotchkiss, 2 has a vertical 

displacement of probably 1,000 to 3,000 feet, and its position on the 

surface has been inferred chiefly on the basis of topography (pi. 9). 

A fault-line scarp is formed by steep south-facing hills composed of 

lower(?) and middle Huronian quartzites, in contrast to the relatively flat valley to the south which is underlain by the more easily 

eroded upper Huronian Goodrich quartzite.

According to Hotchkiss, 3 the Volunteer fault is known mainly from 

diamond drilling at the Old Volunteer mine; it probably extends eastward as evidenced by the brecciation in quartzite along the north 

side of the hill of Ajibik quartzite in the NK^W% sec. 28.

The fault in the S% sec. 28 and trending southeast through the N% 

sec. 34 is inferred to explain the northwestward-trending hill composed of Ajibik quartzite in the SW^ sec. 28. This quartzite has been 

designated as Goodrich quartzite by other writers (Van Hise and 

Leith, 1911, pi. 17), but it is believed by the writer to be Ajibik, as it 

exhibits no abnormal radioactivity and is a hard dense white to reddish fine-grained pure quartzite and lithologically is very similar to 

known Ajibik quartzite in outcrops north of the Palmer fault.

The structural relationships at the Old Maitland mine (WK sec. 30) 

are not known. Abundant pieces of Goodrich quartzite occur on the 

dump near the shaft, but the nearest outcrop of Goodrich is about 

2,000 feet east of the shaft. Geologic information in the area of the 

Old Maitland mine is scanty, but there probably is a downfolded or 

downfaulted segment of Goodrich quartzite in the vicinity of the 

shaft.

The absence of the iron-formation between the Ajibik quartzite and 

the Goodrich quartzite in the SE% sec. 30 is probably due to faulting. 

Slickensided surfaces in Ajibik quartzite near the center of sec. 30, 

where the road crosses the railroad, strike N. 55° W. and dip vertically. The thinning of the iron-formation in the NK sec. 31 may be 

due to flowage of material from the more steeply dipping flanks of 

the major folds.

The occurrence of Goodrich quartzite near the east side of the New 

Richmond pit (sec. 27) is probably due to a small downfolded or downfaulted block of quartzite into the iron-formation.

2 Hotchkiss, W. O., 1903, op. cit., p. 35-42. 

* Idem, p. 28-35.
MONAZITE IN GOODRICH QUARTZITE, PALMER AREA, MICHIGAN 179

OCCURRENCES OP MONAZITE 

MINERALOGY

The monazite occurs as rounded to subrounded detrital grains in 

the matrix of quartz pebble conglomerate. The brownish-red to 

honey-colored monazite grains are generally 0.10 to 0.20 mm in diameter. The identification of the monazite was confirmed by the writer 

by X-ray powder diffraction photographs. Locally the monazite 

grains make up more than 50 percent of the matrix in the conglomerate, and several lenses of monazite grains as much as 2 mm 

thick were noted in thin sections. A sketch of a photomicrograph of 

a concentration of monazite in the quartzite is shown in figure 43.

FIGURE 43. Sketch of a photomicrograph (X 28) of Goodrich quartzite showing quartz (<?), interstitial 

monazite (m), and altered feldspar (/). Stippled areas (s) are mainly sericite, chlorite, hematite, rutile, and 

magnetite.

Results of chemical and spectrographic analyses of a relatively pure 

sample of monazite are shown in table 1. X-ray powder diffraction 

data are shown in table 2.

The sample of monazite (about 92 percent pure) was extracted from 

a composite chip sample of several glacial boulders and selected mine 

dump samples. The sample is probably representative of the monazite in the Palmer area. The monazite was concentrated by gravity 

separation on a Wilfley table after grinding and sizing, and then 

further purified with a Frantz isodynamic separator and separated
180 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

magnetically into two fractions to find out if the difference in magnetic 

susceptibility was related to a difference in chemical composition.

Heavy minerals other than monazite in the Goodrich are mainly 

hematite, magnetite, ilmenite, and rutile.

TABLE 1. Chemical and spectrographic analyses of monazite concentrates from the 

Goodrich quartzite, Palmer area, Marquette County, Mich.

MMMc> MMMd

Chemical analyses 2

P205 ---- - -

Rare-earth oxides (total) _ _ _ _ 

ThO2 _ _--__--_--__-__

SiO__ - _-_-_ _-___ 

Fe2O3 3 --_- __________

A12O3 8.._. ._._____.___. _ .

Ti02 8 _--__ 

U_ --_-_.

PbO 8_ -____ ___ _______

Total ________________

19.4

47.9 

7.6

6.9

5-10

5-10

1-5

0.18

1-5

94-112

19.3

46.0

7.4

5.7

5-10

5-10

1-5

0.17

1-5

91-109

Spectrographic analyses *

Percent range: 

More than 10__ _ __ _

5-10__ _______ _ ____

1-5 ____ ______________

.5-1 ___________ 

.1-.5. ________ _ ____

.05-.l____-____________

.01-.05________________

.005-.01 _______________

.001-005 ______________

.0005-.001 _______ __

.0001-.0005. ___________

Ce

P, Si, La, Th

Fe, Al, Nd, Pr, Pb

Ti

Dy, Mg, Gd, Er, Y

Sm, Zr, Sr, Ca, Ni, Tm

Yb Ho, Co, V

B, Mn, Sc, Eu, Cu, Lu

Ba

Cr

Ag, Be

Ce

P, Si, La, Th

Pb, Fe, Al, Nd, Pr

Ti

Dv Gd Y Er Ms

Sm, Zr, Sr, Ca, Ni, Tm

Yb, Ho, Co, V

B, Mn, Sc, Eu, Cu

Lu, Ba

Cr

Ag, Be

i Sample MMMc slightly more magnetic than sample MMMd. Specific gravity 4.63 (Herman balance 

determination of several grains).

* By Harry Leyine, U. S. Geological Survey.

* Spectropraphic analyses.

* By Katherine E. Valentine, U. S. Geological Survey.

TABLE 2. X-ray powder diffraction data of monazite from the Goodrich quartzite, 

Palmer area, Marquette County, Mich.

[X-ray data by R. C. Vickers. Spacing obtained with a diffractometer calibrated with a silicon standard. 

Copper radiation, nickel filter, speed H° per min]

Intensity 

estimated

1

2

4.17. 6

2

4

8

10

1

d(A)

2.442.

1.963.

Intensity 

estimated

.__ 6

.__ 2

... 3

... 3

.__ 6

.__ 3

	2

.__ 4

NOTE. The above d-values agree very closely with those calculated by Pabst (1961, p. 63) from unit cell 

 dimensions determined by Parrish (1939, p. 651-652) for a thorium-free monazite.
MONAZITE IN GOODRICH QUARTZITE, PALMER AREA, MICHIGAN 181

DETERMINATION OF THE MONAZITE CONTENT OF SAMPLES OF 

GOODRICH QUARTZITE

The monazite content of all samples of Goodrich quartzite listed in 

this report was determined by comparing the beta-gamma activity 

of the sample with prepared standards. The standards were prepared 

by separating relatively pure monazite obtained from a composite 

sample of several glacial boulders and mine dump samples of Goodrich 

quartzite and then re-mixing various proportions of the monazite 

with the crushed rock from which the monazite had been separated. 

A graph was then plotted to show the relation of the monazite content 

of the standards to their equivalent uranium content (fig. 44).

The ordinate intercept at 0.002 percent eTJ represents the background radiation of the quartzite and may be due in part to small 

amounts of monazite that could not be recovered in the separation.

This method of monazite determination was used because a study 

of alpha-sensitive stripping film on thin sections of the quartzite 

indicated that almost all radioactivity of the quartzite was due to

0.05

IUJ

o 

a:

£0.04

Z

r URANIUM, 

o b CM

EQUIVALENl 

o b

f\>

0.01 

0.00

/

/

/

^

r

/

I/

'

Standard 

known

/

/

®

/

/

sample containing 

amount of monazite

10 20 30 40 50 6

MONAZITE CONTENT, IN POUNDS PER TON

FIGURE 44. Graph showing relationship between equivalent uranium and monazite content of samples 

of Goodrich quartzite from the Palmer area, Marquette County, Mich.
182 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

monazite. The accuracy of the method was checked by determining 

the monazite content of a sample by three methods. The methods 

and results are tabulated below.

Monazite 

pounds 

Method per ton

Grain count of heavy liquid fraction (plus 2.96 specific gravity)_________ 36. 6

Gravity (Wilfley table) and magnetic concentrate (Frantz isodynamic

separator)______________________________________________________ 34. 9

Equivalent uranium content (from graph)____________________________ 34. 0

In using the radioactivity of the samples to determine their monazite content, it is assumed that the radioactivity of the monazite (due 

mainly to its thorium content) in the individual samples tested is 

about the same as the average radioactivity of the monazite in the 

composite sample that was used to prepare the standards, and that 

the ratio of other radioactive minerals to monazite is very low.

DISTRIBUTION

The stratigraphic position and lateral extent of the monazitebearing beds are known from (1) samples of outcrops which are mainly 

restricted to the lower 200 feet of the formation, (2) gamma-ray logs 

of three diamond-drill holes that penetrate an apparent thickness of 

1,100 feet of the Goodrich quartzite, and (3) analyses of several diamond-drill core samples.

RESULTS OF SAMPLING OF OUTCROPS

In most outcrops examined, the monazite was concentrated in 

narrow beds of pebble conglomerate from 2 inches to 2 feet thick and 

separated by beds of coarse-grained quartzite from 1 foot to 10 

feet or more thick. Samples from the coarse sand beds contained as 

much as 6 pounds of monazite per ton, whereas samples from the pebble conglomerate beds contained as much as 23 pounds of monazite 

per ton.

Eighteen chip-channel samples were taken across the beds in most 

of the outcrops which represent only the lower part of the Goodrich 

quartzite. The total of the individual stratigraphic thicknesses 

sampled was about 65 feet. However, some of the samples from 

different outcrops may represent the same stratigraphic position in 

the Goodrich, and therefore the actual stratigraphic thickness sampled 

may be considerably less. Two of the samples taken from the lower 

part of the Goodrich contained 11.5 and 17 pounds of monazite per 

ton in beds 0.5 and 0.2 foot thick, respectively. The remainder of 

the outcrop samples contained less than 6 pounds of monazite per 

ton. The weighted average monazite content of all samples taken 

from the lower 200 feet of the Goodrich was 2.9 pounds per ton.

A sample of pebble conglomerate from the only quartzite outcrop 

that is known to be more than 300 feet from the base of the formation
MONAZITE IN GOODRICH QUARTZITE, PALMER AREA, MICHIGAN 183

contained 23 pounds of monazite per ton. This outcrop is about 500 

feet east of DDH-4, near the center of sec. 29 (pi. 9). The full thickness of the pebble conglomerate bed was not exposed, and, because of 

weathering, the attitude of the beds could not be determined. A 

scintillation-counter survey of the outcrop containing the pebble 

conglomerate indicated an average monazite content of about 6 

pounds per ton.

Because of the relatively high monazite content found in many 

glacial boulders (as much as 110 pounds per ton) and from mine dump 

samples (as much as 50 pounds per ton), it was apparent that the 

higher grade monazite-bearing beds were not observed in outcrops.

RESULTS OF GAMMA-RAY LOGGING OF DRILL, HOLES

Three diamond-drill holes that penetrated the Goodrich quartzite 

were logged with a portable gamma-ray logging instrument consisting 

of a 1- by 12-inch Geiger-Miiller tube in a waterproof probe, 700 

feet of cable, and a portable survey meter. The meter deflection 

was recorded by the operator at 2-foot intervals and at all inflection 

points.

Two of the holes (DDH-3 and DDH-4) were drilled during the 

past 4 years by the Cleveland-Cliffs Iron Co. The third hole (DDH101) was drilled during the early 1900's and was recently reopened 

by the Cleveland-Cliffs Iron Co. The results of the gamma-ray 

logging are shown in plate 10. DDH-5, also drilled many years 

ago, was logged but showed no anomalous radioactivity. This hole 

is just north of the Palmer fault and is probably in the middle Huronian 

Siamo slate. The water level in all the holes was within a few feet of 

the surface.

Because the logging reel was equipped with only about 700 feet of 

cable, the lower part of the Goodrich quartzite could be logged in 

only one drill hole (DDH-3); the gamma-ray log indicates that most 

of the radioactivity occurs more than 300 feet from the base of the 

formation. The sharp peaks of the gamma-ray logs are interpreted 

as being caused by relatively thin beds of monazite-bearing pebble 

conglomerate that contain from 20 to 160 pounds of monazite per ton. 

These monazite-rich layers are separated by beds of coarse quartzite 

which range from a few inches to a few feet in thickness.

The fairly close correlation between the gamma-ray logs suggests 

that the zones composed of more closely spaced monazite-bearing 

beds are persistent laterally for several hundred feet in a north-south 

direction. The persistence of the zones east and west of the cross 

section can only be inferred.

Accurate calibration of the gamma-ray logs in terms of actual 

monazite content is not possible because of the many variable factors 

involved and because of the lack of enough analyzed core for standardizing the instrument. The approximate monazite content can be
184 CONTRIBUTIONS TO THE GEOLOGY OF URANIUM

estimated, however, by comparing the results of channel sampling of 

the lower part of the Goodrich with the values obtained on the gammaray log of DDH-3. If the average gamma-ray log value for the lower 

200 feet of the Goodrich quartzite in DDH-3 is about 0.12 thousand 

counts per minute (background 0.05 thousand counts per minute), 

representing 2.9 pounds per ton, then a gamma count of 0.4 thousand 

per minute may indicate a monazite content of as much as 10 pounds 

per ton.

RESULTS OF ANALYSES OF CORE

Specimens of core representing about 3 percent of the total core 

from diamond-drill holes DDH-3 and DDH-4 were scanned with a 

scintillation counter, and several 3-inch lengths of the core were found 

to be abnormally radioactive.

The specimens were analyzed with the following results:

Field no.

MM-113-52.. __ _____ _

MM-97-53.. __________________

MM-98-53.... _______ _ __ .

MM-99-53 ___ ____ ________

MM-10Q-53 ___ _ __ _______

MM-101-53._._ _ _ __ _

MM-102-53.. .__ _ ________

Hole no.

DDH-4

DDH-4

DDH-4

DDH-4

DDH-4

DDH-3

DDH-3

Footage '

36-52

523-532

362-385

567-585

585-611

30-36

59-71

eU2

0 049

014

006

013

021

007

Oil

Monazite 

(pounds per 

ton)3

54

14

4

13

22

6

10

1 Footage is the drilled interval from which a single specimen of core was saved and does not represent 

footage of entire sample. Actual length of core samples was about 3 inches for each sample.

2 Analyses by S. P. Furman, U. S. Geol. Survey, Denver, Colo. 

s Based on ell/monazite ratios of standard samples. (See p. 181.)

The location and monazite content of the samples are shown on the 

cross section, plate 10.

Because only a small percentage of core was available for study from 

the drill holes, the analyses of the core are of little value for quantitative appraisal. It is noteworthy that, although specimens of core from 

the lower 300 feet of the Goodrich quartzite from DDH-3 and DDH-^4 

were scanned with a scintillation counter, no abnormal radioactivity 

was detected.

OCCURRENCES OF MONAZITE IN THE GOODRICH QUARTZITE 

OUTSIDE THE PALMER AREA

A brief examination with a scintillation counter was made of the 

Goodrich quartzite outside the Palmer area to determine the extent 

of the monazite-bearing beds. Outcrops of Goodrich quartzite were 

examined in several places in the Marquette trough including the 

Goodrich mine on the south side of the Marquette trough, the Blueberry mine on the north side, the Humbolt and Michigamme mines 

toward the west end, and in the city of Ishpeming in the east-central 

part of the Marquette trough. Only slight abnormal radioactivity
MONAZITE IN GOODRICH QUARTZITE, PALMER AREA, MICHIGAN 185

was detected in the Goodrich at these localities. The highest radioactivity (0.05 mr/hr, background 0.02 mr/hr) was detected in an outcrop of Goodrich quartzite in the NK sec. 20, T. 47 N., R. 27 W. A few 

grains of monazite were identified in thin sections from this outcrop, 

which is about 5 miles N. 75° W. of Palmer and is the closest occurrence 

of Goodrich quartzite in the Marquette trough to the Goodrich in the 

Palmer area.

In the Gwinn district, which is an outlier of upper Huronian rock 

about 12 miles southeast of Palmer, quartzite probably correlative 

with the Goodrich was found by L. P. Barrett to exhibit local abnormal radioactivity. The author re-examined the area briefly and 

found several local concentrations of monazite in a coarse arkosic 

quartzite that overlies and grades downward into a granite porphyry. 

Samples from this locality (SW% sec. 19, T. 45 N., R. 25 W.) contained 

as much as 9 pounds of monazite per ton. A scintillation-counter 

survey of the outcrops indicated that the monazite concentrations 

were of a very local extent.

CONCLUSIONS

The study of the occurrence of monazite in the Goodrich quartzite 

in the Palmer area, Marquette County, Mich., shows that monazite is 

concentrated in beds of pebble conglomerate from a few inches to a 

few feet thick. Sampling of outcrops, which are mainly restricted 

to the lower 200 feet of the quartzite, indicates an average monazite 

content of only about 2.9 pounds per ton, but correlation of gamma-ray 

logs of diamond-drill holes that penetrate 1,100 feet 9f the Goodrich 

indicates that most of the radioactivity probably occurs more than 

300 feet above the base of the formation. Individual beds of pebble 

conglomerate in glacial erratics contain as much as 110 pounds of 

monazite per ton.

The large tonnages of monazite-bearing quartzite suggest that 

this area should be considered as a potential low-grade monazite

source.

LITERATURE CITED

Lamey, C. A., 1935, The Palmer gneiss: Geol. Soc. America Bull., v. 46, p. 1137-

1162. 

Leith, C. K., Lund, R. J., and Leith, Andrew, 1935, Pre-Cambrian rocks of the

Lake Superior region: U. S. Geol. Survey Prof. Paper 184. 

Pabst, Adolf, 1951, Huttonite, a new monoch'nic thorium silicate: Am. Mineralogist,

v. 36, p. 60-65. 

Parrish, William, 1939, Unit cell and space group of monazite (La, Ce, Y) P0*t

Am. Mineralogist, v. 24, p. 651-652. 

Tyler, S. A., and Twenhofel, W. H., 1952, Sedimentation and stratigraphy of

the Huronian of Upper Michigan: Am. Jour. Sci., v. 250, p. 1-27,118-151. 

Van Hise, C. R., and Leith, C. K., 1911, The geology of the Lake Superior

region: U. S. Geol. Survey Mon. 52.

o