GEOLOGICAL SURVEY CIRCULAR 237

MONAZITE DEPOSITS 

OF THE

SOUTHEASTERN 

ATLANTIC STATES
UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

GEOLOGICAL SURVEY CIRCULAR 237

MONAZITE DEPOSITS OF THE SOUTHEASTERN 

ATLANTIC STATES

By John B. Mertie, Jr.

Washington, D. C., 1953

Free on application to the Geological Survey, Washington 25, D. C.
MONAZITE DEPOSITS OF THE SOUTHEASTERN ATLANTIC STATES

By John B. Mertie, Jr.

CONTENTS

Page

Abstract.................................. . 1

Introduction................................ 2

Geography and geology...................... 2

General features. ..................... 2

Special features ...................... 3

Economic geology.......................... 5

Properties of monazite................ 5

Occurrence and production ............. 5

Southeastern placers .................. 7

Piedmont province ............... 7

Distribution ................ 7

Valuation.................. 7

Content of thorium

and uranium.............. 11

Page

Economic geology--Continued

Southeastern placers Continued

Coastal Plain.................. 12

Fluviatile placers......... 13

Beach placers............ 13

Bedrock sources...................... 15

Monazite belts ................. 15

Outlying localities .............. 26

Petrographic character

of rocks..................... 27

Heavy minerals in bedrock...... 27

Origin of monazite belts.'........ 29

References cited........................... 30

ILLUSTRATIONS

Page

Plate 1. Monazite belts of the southeastern Atlantic states................................ Inside back cover

Figure 1. Monazite placers of North and South Carolina ................................................ 4

2. Samples and mines in Coastal Plain of southeastern Georgia and northeastern Florida............. 14

ABSTRACT

Monazite, a phosphate of the rare earths, is the 

principal mineral from which the cerium earths and 

thorium are obtained. Fluviatile monazite placers were 

mined in the Piedmont province of North and South 

Carolina from 1887 to 1911, and again intermittently 

from 1915 to 1917; but the principal sources in recent 

years have been the beach placers of India and Brazil. 

In 1946, an embargo was placed on the exportation of 

Indian monazite, and the Brazilian production has not 

increased materially to replace this loss. Accordingly 

monazite in recent years has become a scarce commodity.

The principal domestic sources from which monazite 

may be recovered commercially are in Idaho and in 

the Piedmont province of the southeastern States. Some 

monazite is now being produced in Idaho, and a small 

output is being recovered as a byproduct of heavy mineral mining in Florida. The southeastern placers were 

not exhausted by the earlier mining and new deposits 

have been discovered; but production from this region 

awaits adequate exploration.

The country rock of the southeastern Piedmont 

province is a complex assemblage of metamorphic 

and igneous rocks. The monazite occurs in two belts.

A western belt has been traced from east-central 

Virginia for 600 miles southwestward into Alabama; 

and an eastern belt has been traced from the vicinity 

of Fredericksburg, Va., south-southwestward for 

200 miles into North Carolina. Monazite-bearing rocks 

near. Rion, S. C., appear to indicate a southwestward 

continuation of the eastern belt.

The western, or principal belt, includes the 

placers that were formerly mined in North and 

South Carolina. These placers were sampled, and 

the monazite was separated from the best of the samples, 

for mineralogical and chemical analysis. The tabulated results show a mean tenor, in the headwater 

placers of highest grade, of 8. 4 pounds of monazite 

to the cubic yard. Farther downstream where mining 

must be done to obtain larger yardages, the tenor will . 

be much lower. The mean contents of ThOg and U3O 8 

in the placer monazite are shown to be respectively 

about 5. 7 and 0. 4 percents.

The western monazite belt was explored northeastward and southwestward from the sites of earlier 

mining by sampling the weathered bedrock; and the 

eastern monazite belt was discovered and sampled by 

the same technique. The principal source-rocks are 

certain types of granitic intrusives, granitized and 

pegmatitized country rock, and certain granitic gneisses
of the Carolina gneiss. Some of the associated pegmatites 

also contain high percentages of monazite. Most of 

the monazite-bearing granitic intrusives are quartz 

monzonite or closely related rocks. The mean tenor 

of monazite in bedrock is about 0. 006 percent. No 

search has yet been made for workable placers in these 

belts beyond the original sites of mining.

Monazite derived from bedrock sources in the 

piedmont has been found in small quantities in all of 

the Coastal Plain formations, but the tenor is too low 

to warrant mining for this mineral alone. At favored 

localities, however, commercial deposits of heavy 

minerals may be found, similar to those now being 

mined in Florida, that may yield monazite as a byproduct. Small fluviatile deposits of heavy minerals, 

including monazite, that were r'econcentrated from 

detrital deposits of Cretaceous age, have recently been 

found in Georgia and South Carolina, along the inner 

margin of the Coastal Plain.

The monazite belts are conceived to be the sites 

of early pre-Cambrian valleys, wherein detrital monazite derived from an earlier pre-Cambrian granite, 

was distributed. These ancient fluviatile deposits were 

later reconstituted into gneisses of Carolina age, and 

parts of the latter were remelted to form monazitebearing granitic intrusives. Some of the monazitebearing granites may also have originated by the 

remelting of earlier pre-Cambrian intrusives. The 

distribution of iron ores in the monazite-bearing rocks 

appears to accord with this hypothesis.

INTRODUCTION

Monazite is the principal mineral from which the 

rare earths and thorium are obtained, but it also contains small amounts of uranium and numerous other 

elements. Years ago monazite was mined mainly for 

its content of thorium, which was used in the manufacture of Welsbach gas mantles; but in recent years 

it has been sought chiefly for the contained rare earths, 

which are becoming progressively important in industrial applications. A part of the thorium present in 

monazite is still used commercially, but a large part 

of it is being stockpiled in unused tailings. Thorium 

has great potential importance in the future production 

of nuclear power. The uranium contained in monazite 

is available as a valuable byproduct.

Monazite placers were mined commercially in 

North and South Carolina from 1887 to 1911, and again 

on a smaller scale from 1915 to 1917; but, other deposits were discovered in Brazil in 1905, and in India 

in 1909, and competition with these foreign sources 

proved unprofitable. In 1946, an embargo was imposed 

on the exportation of Indian monazite, and the Brazilian 

output has not increased materially to compensate for 

this loss. Accordingly monazite, which a few years 

ago sold for 3 cents a pound or less, is quoted nominally, 

as of October, 1952, at 16-| to 19 cents a pound, depending upon the content of total rare earths plus ThO,. 

The placers of the Carolinas, however, were not 

exhausted by the earlier mining; and the partially worked 

and unworked placers, together with others that were 

unknown during the era of mining, now constitute one 

of the principal reserves of this mineral in the United 

States.

The importance of monazite, both for its rare 

earths and for the contained thorium and uranium, was 

recognized by the Geological Survey during World 

War II. Most of the sites in Idaho, where monazite was 

known to exist, were visited by the writer in 1944; and 

the placers of North and South Carolina were examined 

and sampled in 1945. The latter work, however, soon 

led to a study of the bedrock sources of monazite, and 

ultimately to a general study of all the granitic rocks 

of the southeastern States. The Shelby, N. C., quadrangle, in the heart of the monazite placer district, 

was selected for detailed geologic mapping; and 

Robert G. Yates and William C. Over street, beginning 

in 1948, and Wallace R. Griffitts, starting in 1949, 

carried this work to completion in 1951. Meanwhile 

the writer continued his study of the granitic rocks, 

with special reference to the bedrock sources of 

monazite; and the present paper outlines the results 

of this work in the five states of Virginia, North Carolina, 

South Carolina, Georgia, and Alabama. Collateral 

investigations relating to the occurrence of monazite 

in the formations of the Coastal Plain have also been 

made.

GEOGRAPHY AND GEOLOGY 

General features

The Piedmont province in northern Virginia has 

a width of about 40 miles, increasing southwestward 

to a maximum width of 125 miles in North Carolina, 

and decreasing thereafter as the crystalline rocks of 

South Carolina, Georgia, and Alabama are overlapped 

progressively by the sediments of the Coastal Plain. 

The maximum width of the Coastal Plain is about 

225 miles in Georgia, decreasing northeastward and 

westward. The altitude of the Piedmont province, 

excepting isolated hills or groups of hills, ranges 

from 1, 200 feet at the southeastern flank of the 

Blue Ridge to 400 feet at the northwestern limit of 

the Coastal Plain. Numerous large streams that head 

in or northwest of the Blue Ridge flow southeastward 

and southward, draining both the Piedmont and the 

Coastal Plain. Most of these rivers and their tributaries are shown in plate 1.

The general geology of the crystalline rocks of 

the southeastern Piedmont province is imperfectly 

known, as little detailed geologic mapping has yet been 

done, and even the reconnaissance surveys are incomplete. Geologic maps of Virginia, Georgia, and Alabama, 

on a scale of 1:500,000, were published respectively 

in 1928, 1939, and 1926, but no comparable maps of the 

crystalline rocks are available for North and South 

Carolina. The country rock of the Piedmont comprises 

a complex assemblage of metamorphic and igneous 

rocks, together with some unmetamorphosed or little - 

metamorphosed sedimentary rocks. The metamorphic 

rocks include mica and hornblende gneisses, amphibolite, 

and schists of several kinds; the igneous rocks include 

granitic and dioritic rocks, pegmatites, rhyolitic rocks 

with associated pyroclastics, gabbro, diabase, and 

ultrabasic rocks. Many of the igneous rocks are 

partially sheared, gneissoid, or recrystallized.

The general distribution of the igneous and 

metamorphic rocks is fairly well shown on the State 

geologic maps, but t*he limits of these rocks are only
approximately given. The Carolina and Roan gneisses, 

a complex assemblage of metamorphic rocks, constitute the country rock over a large part of the southeastern Piedmont province. The Carolina gneiss includes granitic gneisses of sedimentary origin, some 

gneisses of eruptive origin, and a variety of schistose 

rocks. The Roan gneiss includes all the metamorphosed 

basic and ultrabasic rocks. These two groups of rocks 

are too generalized for satisfactory geologic mapping, 

and locally have been subdivided into several series 

and formations; but these smaller units have not 

generally been adequately defined, so that their limits, 

ages, and correlation are more speculative than factual.

The terms "granite" and "granitic intrusive" "are 

used in this paper in a generic sense to include all 

intrusive igneous rocks with a granitic texture and 

composition. These terms therefore include granite, 

monzogranite, quartz monzonite, granodiorite, quartz 

diorite, and their quartz-free equivalents. Gneisses 

having the same range in composition are called 

"granitic gneiss, " regardless of their origin. The 

terms "granitic rock" and "granitic saprolite" are 

used where the character of the material, commonly 

saprolite, is not clear; but it is also used, when 

convenient, to describe a group of intrusive and 

metamorphic rocks having a granitic composition, as 

above defined. Some of the granites and granitic 

gneisses shown on the geologic maps of Virginia, 

Georgia, and Alabama have been given formational 

names; and similarly the Carolina gneiss has locally 

been subdivided into smaller units. These formational 

names are used in the following pages merely as convenient descriptive designations, to refer observations 

or collections to published maps. They are not necessarily used to imply ages or correlations that may be 

inferred from such maps.

Plate 1 and figure 1, which accompany this report, are not to be construed as geologic maps. They 

show merely the positions of the two monazite belts, 

and the localities within and without the belts where 

sampling has been done. The rocks within the monazite 

belts are heterogeneous. Some are monazite-bearing 

but many, and probably most, are not. It is believed 

that many of the localities are isolated, and it is 

reasonably sure that some gaps of considerable length 

exist, along which monazite-bearing rocks do not exist. 

Nevertheless the localities where monazite has been 

found have a linear collocation that warrants their 

collective designation as belts.

The boundary between the crystalline rocks 

and the formations of the Coastal Plain is shown 

on plate 1 as it is drawn on the geologic maps 

of Virginia, North and South Carolina, Georgia, 

and Alabama; but at many places the formations 

of Cretaceous and younger age extend much farther 

inland than mapped. The pre-Pleistocene stratigraphic column varies from state to state, but 

the subdivisions of the Pleistocene are fairly well 

standardized. Eight Pleistocene formations have 

been recognized, which named from oldest to 

youngest are the Brandywine, Coharie, Sunderland, 

Okefenokee, Wicomico, Penholoway, Talbot, and 

Pamlico. All the formations of the Coastal Plain 

have been found to contain small amounts of 

monazite, derived obviously from bedrock sources 

within the monazite belts.

Special features

Geologic study and mapping of the crystalline rocks 

in the southeastern Piedmont has all the difficulties that 

prevail in other regions where such rocks occur. But 

geologic work is further complicated by deep residual 

weathering, so that few outcrops of unaltered bedrock 

are present. The country, in fact, is mantled by a 

considerable thickness of decomposed, earthy but 

untransported bedrock, known as saprolite. The 

principal characteristic of saprolite is that the feldspars 

are completely or nearly completely altered to clayey 

products, though the original structure of the rock may 

still be visible. The essential characteristics of the 

crystalline rocks are thus obscured or rendered indeterminate, making it impossible to determine their 

true petrographic character. Chemical data are 

similarly vitiated.

Saprolite, however, has some remarkable advantages in the study and mapping of granitic rocks. 

It can readily be cut along any desired plane, thus 

making it possible to measure structural features in 

the most advantageous sections. But its principal 

asset is that it may be picked, shoveled, and panned, 

with the acquisition of representative samples of the 

contained heavy minerals, most of which are resistant 

to weathering. These suites of heavy minerals serve 

two principal purposes. Their total and relative 

percentages in the granitic rocks are commonly more 

distinctive than the character and amounts of the feldspars, so that they afford an effective substitute for 

the latter in the local correlation of such rocks. The 

heavy minerals are also useful because they are the 

sources of most of the radioactivity of the rocks; and 

some of them, notably zircon and monazite, are most 

useful in the determination, by radiometric and spectrographic measurements, of the absolute and relative 

ages of the granitic rocks.

Saprolite, because it can readily be panned, is 

also a great asset in evaluating rocks for heavy minerals of economic value, such as monazite. The 

investigation of the occurrence of monazite in the 

southeastern states was done by the use of a gold pan,, 

and could not otherwise have been accomplished. 

Panning also gives approximately the total percentage 

lof the feldspars in granitic rocks, as the clay representing the feldspars is removed by washing, leaving 

a residue of nonfeldspathic minerals to be panned, 

whose volume may readily be estimated. If only the 

plagioclase feldspar is completely altered to clay, 

and the potash feldspar is unaltered, the percentage 

of the former may similarly be estimated. The 

technique of panning saprolite was stressed by 

Orville A. Derby in Brazil before 1890, and for many 

years thereafter, but geologists are not yet generally 

aware of its potentialities.

References are made in the following pages to 

what are described by the writer as "pavements. " 

A pavement is the upper surface of a dome-shaped 

mass of crystalline rock, commonly of granitic character, from which erosion has partially removed the 

overlying mantle of saprolite, producing a level or 

nearly level hardrock floor. If the erosion has been 

more extensive, a large volume of the crystalline 

rock may be bared, creating a prominent bedrock dome. 

An outstanding example of a large pavement is the outcrop of granite on which is located the quarry at Mt. Airy,
83° 82°

Lincolntbh

Hendersonville.a

EXPLANATION

Sample locality in 

alluvium,eluvium,and

soil in Piedmont 

(Monazite-bearing

oAnderdon

Greenvyooa

34?

10

By John B. Mertie, Jr. 8I ° 

50 Miles

Figure 1. Monazite placers of North and South Carolina.

4
Sorry County, N. C. A prominent bedrock dome 

produced by extensive removal of the saprolite is 

exemplified by Stone Mountain, about 14 miles eastnortheast of Atlanta, Ga. Practically all granite 

quarries in the southeastern states are located on 

pavements or domes.

The boundary between saprolite and the underlying hardrock is at some places transitional, at 

others very abrupt, and appears to represent either 

a variable or sharp lower limit of the zone of weathering. 

This boundary is now exposed at the surface at many 

places, thus leading to the interpretation that most of 

the saprolite in this region was formed in an earlier 

physiographic cycle, and probably under climatic 

conditions different from those which prevail at the 

present time. The saprolite is therefore regarded as 

a relic of an earlier zone of weathering that is now 

being bared to erosion.

Outcrops of saprolite are much more plentiful 

than outcrops of hardrock, and rarely is it possible 

to find saprolite in such a relation to hardrock, that 

the two are unmistakably equivalent. Quarries are 

the best sites for this purpose, because they are 

located on pavements, above which may be uneroded 

remnants of saprolite. Collections made at such favored 

localities, from both saprolite and hardrock, serve 

to determine the stability of rock-forming minerals 

under the influence of the climatic conditions that 

produced the saprolite.

ECONOMIC GEOLOGY 

Properties of monazite

Monazite is essentially an ortho-phosphate of 

the rare earths, with the formula RPO4, where R 

represents mainly lanthanum, cerium, praseodymium, 

neodymium, and samarium, though smaller quantities 

of the terbium and yttrium earths may also be present. 

Gadolinium, one of the terbium earths, is particularly 

prevalent in monazite, commonly constituting 1 percent 

or more of the rare earths present. Xenotime may 

likewise be represented by the same general formula, 

where R represents mainly the yttrium earths. Silicon 

is a common constituent of monazite, ranging in content from 1 to 10 percent, and proxying for phosphorous; 

at least a dozen other nonradioactive elements in small 

quantities have been identified.

Monazite contains commonly from 2 to 10 percent 

of thorium, and much smaller amounts of uranium. 

These two super-rare earths proxy for the cerium 

earths. Owing mainly to its content of thorium, monazite 

is a highly radioactive mineral, though this property 

is accentuated by the contained uranium, to a minor 

degree by the contained samarium, and by lutetium, 

if present. The radiogenic elements resulting from the 

decomposition of thorium, uranium, and samarium are 

necessarily present.

Both monazite and xenotime are electromagnetic, 

but xenotime is more strongly magnetic than monazite, 

approaching the magnetism of ilmenite. All the elements 

of the rare earths have high paramagnetism, and 

gadolinium is known to be ferromagnetic at room 

temperature. The atomic susceptibilities of these 

elements, however, are no criteria for predicting

the magnetic properties of the rare earth minerals, 

but they do serve to explain that the high magnetic 

susceptibilities of monazite and xenotime, approaching 

ferromagnetism, are inherent properties of these minerals, and are not caused by ferromagnetic inclusions.

Monazite is distinctly brittle with a hardness of 

about 5, and a specific gravity of about 5.1. The small 

grains found in granitic rocks are honey-yellow to 

greenish-yellow and resinous, but the larger crystals 

found in pegmatites are more commonly reddish brown 

and opaque. This mineral is highly resistant to 

alteration by weathering, for which reason the grains 

found on ocean beaches do not differ materially, except 

for size and shape, from those recovered directly 

from saprolite. Monazite is a poor electrical conductor, 

and this property is utilized in its commercial separation 

from ilmenite and rutile, which are good conductors.

Monazite, if it contains neodymium, can invariably 

be identified in the field by examining it in reflected 

sunlight with a hand spectroscope. A broad absorption 

band will be seen in the yellow, centering at 578 millimicrons, and a faint and narrow absorption band may 

also be seen in the green, centering at 521 millimicrons. This test will work on concentrates in which 

the percentage of monazite is as low as 5 percent. The 

absorption band in the yellow can also be seen in 

diffused daylight, and almost equally well by the use 

of an ordinary Mazda light. Lower concentrations of 

monazite can be rendered amenable to this test by 

the removal of minerals that are more magnetic than 

monazite. The sample may be further concentrated 

by spreading in on a piece of paper, which is gently 

tapped on one edge. By either or both of these methods, 

monazite may be recognized with the hand spectroscope 

in samples containing only a small fraction of 1 percent.

The writer has discovered that xenotime can 

similarly be determined in the field by recognition 

of one or two absorption bands in the green, centering 

at 521 and 539 millimicrons, caused by the presence 

respectively of erbium and holmium. No absorption 

band shows in the yellow. This test is much more 

effective if a hand spectroscope with an iris diaphragm, 

is used, so that the absorption may be viewed through 

a small aperture. The test is made possible by the 

fact that xenotime may be separated from a mixture of 

xenotime and monazite by the use of an Alnico magnet 

of the proper power.

Occurrence and production

Small percentages of monazite are common in 

certain granitic rocks, including pegmatites, and 

concentrations occur in derived detrital deposits; and 

this mineral has been described from many localities 

throughout the world. Deposits of heavy minerals that 

include monazite are known in India, Burma, Ceylon, 

Netherland Indies, Malaya, Korea, Formosa, Australia, 

Tasmania, Nigeria, French West Africa, Uganda, 

Kenya, Nyasaland, Egypt, Madagascar, Norway, 

Brazil,and other countries. These, except for the 

monazite of Norway, are detrital deposits that contain ilmenite, leucoxene, magnetite, zircon, monazite, 

xenotime, rutile, garnet, staurolite,and other heavy 

and semi-heavy minerals, in widely varying proportions. Monazite, therefore, is only one of the 

minerals recovered from such placers. The principal
commercial sources in recent years have been the beach 

placers of India and Brazil.

Monazite has been reported at many localities in 

the, United States. It is known to occur in many of the 

eastern states from New England to Florida; in the 

Black Hills; in Arkansas and Texas; and in a number of 

the Cordilleran states, notably in Idaho. The principal 

commercial sources of monazite in this country are in 

Idaho and in the southeastern states. The deposits of 

the southeastern states are not being mined at present, 

although a small byproduct output is coming from the 

mining of heavy minerals in Florida. Monazite was 

not saved in the earlier gold placer mining operations 

in Idaho, but significant quantities are known in the 

Boise basin, the Warren-Burgdorf district, the Dixie 

district, the Florence district, and others. Old tailings 

will have to be reworked to recover the monazite lost 

in this earlier mining, but some monazite is now being 

recovered in present gold-mining operations. Recently, 

moreover, three dredges have started to operate near 

Cascade, Idaho, mining monazite placers that contain 

little or no gold.

The principal commercial sources of monazite, 

since 1910, have been the .province of Travancore, in 

India, and Brazil. The production in India has come 

mainly from monazite-bearing littoral sands, that

occur intermittently from Cape Comorin northwestward 

for more than 100 miles to Trikunnapuzha, though 

deposits of lower grade are found east of Cape Comorin 

in the Tinnevelly district and also near Walthair in 

Vizagapatam. The primary sources are granitic rocks 

that occur inland, though a secondary source is the 

Warkalay formation, of late Tertiary age. The 

monazite deposits of Brazil occur intermittently along 

the Atlantic beaches of Bahia, Espirito Santo, 

Rio de Janeiro, and Sao Paulo, though monazite also 

has been found in the Barreiras (Tertiary) formation, 

on elevated beaches, and along the bars of streams 

close to the ocean. The Brazilian placers have been 

concentrated from monazite-bearing granitic rocks, 

mainly gneisses, that crop out along and close to 

the beaches, and from the alluvial sources mentioned. 

A small production has come from Ceylon, Netherland 

Indies, Australia, and elsewhere.

The production of monazite from India and 

Brazil is no longer being reported, and Brazil has 

limited its annual exports to 3, 000 tons. The production of monazite in the United States, Brazil, and 

India, so far as known to the writer, is given in the 

following tabulation. The data on Brazil, from 1911 

to 1929, have been taken from Houk's figures (Houk, 

1943, pp. 11-12). The 1 other data have been taken 

from published reports and official information.

Monazite production in United States, Brazil and India 

(Short tons)

Year

188?

1893

1894

1895

1896

1897

1898

1899

1900

1901

1902

1903

1904

1905

1906

1907

1908

1909

1910

1911

1912

1913

1914

1915

1916

1917

1918

1919

1920

1921

u. s.

10

65

273

786

15

22

125

175

454

374

401

431

373

676

423

274

211

271

50

19

18

19

11

Brazil

 

 

___

3,307

192

249

2,149

2,932

1,633

l,8li

1,328

3,636

5,357

4,891

4,797

4,891

5,473

7,121

5,994

4,064

3,746

1,584

661

484

1,252

551

161

1,270

366

India

..__

 _

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

932

1,271

1,382

1,328

1,241 1,447 2,173

2,371

2,266

1,838

1,411

Year

1922

1923

1924

1925

1926

1927

1928

1929

1930

1931

1932

1933

1934

1935

1936

1937

1938

1939

1940

1941

1942

1943

1944

1945

1946

1947

1948

1949

Total

U. S.

___

 

 _

 

 

 _

 

 

 

 

 

 

 

 

 

 

 

 _

 

 

_ 

 

 _

 

 

 

 

5,476

Brazil

127

 

22

221

224

112

99

17

331

449

460

356

53

198

941

1,576

1,709

3

1,135

1,378

1,930

2,205

'2,381

85,827

India

140

276

697

72

314

115

202

16

101

732

156

1,130

4,277

2,943

3,451

5,848

4,480

(Average

2,258

Not reported

80,708

1 Exports.
Southeastern placers 

Piedmont province

Distribution. Certain granitic intrusives and 

granitic gneisses that occur in the Piedmont province 

of Virginia, North Carolina, South Carolina, Georgia, 

and Alabama are the principal bedrock sources of 

monazite in the southeastern states, but other rocks 

into which granitic material has been introduced are 

also important hardrock sources. Certain monazitebearing schists are also known, in which the monazite 

may be either detrital or secondary. The principal 

monazite placers so far developed lie in an area 

between Shelby, Rutherfordton, and Morganton, N. C., 

that extends southwestward through Spartanburg, and 

Greenville, S. C. This area is'shown in figure 1. 

Monazite in bedrock, however, is now known to occur 

in two belts that cross five states, as shown in plate 1. 

A little monazite also has been found west of the Blue 

Ridge, and in isolated localities outside the two principal 

belts. No placer exploration has yet been done in 

these extended fields, but it is possible that new 

fluviatile placers will later be found in the Piedmont 

province.

The monazite deposits of the southeastern states 

were not seriously depleted by the earlier mining, 

because only the stream placers in the extreme headwater stretches of the valleys were worked, and many 

of these by extremely crude methods. There remain 

the deposits in or close to the stream channels in the 

lower valleys, the deposits of the valley floors, other 

deposits that were known but had not been developed 

by 1911, and still others that were not known at that 

time. Since the era of mining, the monazite-bearing 

gravels in the headwater stretches of streams have 

been rejuvenated, because the soil nearby is permeated 

with monazite, and every torrential rain delivers a 

large quantity of this mineral to the stream channels.

Some of the placer concentrates have been found 

to contain significant quantities of xenotime. Thus" a

sample from Grassy Creek, in the Shelby quadrangle, 

contains about 8 percent of xenotime; and smaller 

amounts were detected in other placer samples. 

In the earlier placer mining operations in North 

and South Carolina, all separatory work was done 

with an electromagnet; and owing to its magnetic 

susceptibility, xenotime was probably separated 

and discarded with the ilmenite. In present operations, where a high tension separator first removes the ilmenite and rutile, some xenotime 

will doubtless be recovered with the monazite. 

The net effect is commercially negligible, being 

merely to increase slightly the percentage of 

yttrium earths at the expense of the cerium earths.

Valuation. The placers, at the sites of earlier 

mining, were sampled by the writer in 1945. Placers 

of any kind can be sampled accurately only by open 

cutting, by sinking shafts with or without drifting, 

or by drilling with casing. A favored method 

in Alaska utilizes a Keystone drill, or some 

modification thereof, and 6-inch casing. The 

writer, working alone, was unable to use any 

of these methods, but panned instead the gravel 

riffles in those headwater stream channels, where 

mining had formerly been done. Such work 

necessarily could not give the true tenors of the 

placers, but gave instead a set of approximate 

values, that differ from the true tenors according 

to local conditions. The results served, nevertheless, to compare the tenors of different streams, 

and to obtain samples of adequate size for mineralogical and chemical analysis.

Samples of this kind were taken at 104 localities, 

mainly from stream gravels, but also from eluvium 

and soils. The total volume handled by panning was 

about 3.2 cubic yards, or roughly the same number of 

tons. About half of these samples, mainly those of 

highest tenor, were selected for measurement of the 

contained monazite, and chemical analysis of the 

same. The localities of these selected samples are 

given below.

Localities of monazite placer samples 

North Carolina

45 Mt 110. Hickory Creek, at the old L. U. Campbell mine, which was also the site of mining for the British 

Monazite Co., about- 2^ miles northeast of Shelby, Cleveland County, N. C.

45 Mt 117. Head of Little Hickory Creek, on ground of W. M. Spake, about 2-3/4 miles N. 75° E. of Shelby, 

Cleveland County, N. C.

45 Mt 124. East fork of Knob Creek, about 7/8 mile N. 30° W. of Tuluca, Cleveland County, N. C.

45 Mt 126. West fork of Knob Creek, about 1-3/4 miles N. 69° W. of Tuluca, Cleveland County, N. C.

45 Mt 128. Branch of Crooked Run, about li miles S. 15° E. of Casar, Cleveland County, N. C.

45 Mt 141. Fork of Brushy Creek, about 4 miles S. 37° W. of Double Shoals, Cleveland County, N. C.

45 Mt 154. Fork of Brushy Creek, about 2^ miles S. 57° W. of Double Shoals, Cleveland County, N. C.

45 Mt 154-a Branch of Buffalo Creek, about 1 mile N. 30° E. of Fallston, Cleveland County, N. C.

45 Mt 155-a Long Branch, a west tributary of Buffalo Creek, about 1-3/4 miles §. 13° E. of Fallston, Cleveland 

County, N. C.
Localities of monazite placer samples Continued

North Carolina--Continued 

45 Mt 157. West branch of Buffalo Creek, about li miles S. 47° E. of Fallston, Cleveland County, N. C.

45 Mt 160. West branch of Little Knob Creek, about 3 miles N. 85° E. of Eakers Corners, Cleveland County, 

N. C.

45 Mt 162. Headwater fork of Sandy Run Creek, about 1-1/8 miles N. 12° W. of Hopewell, Rutherford, N. C. 

Site of mining by old German-American Monazite Co.

45 Mt 163. Old Louisa Smart property, on Webb Creek, about 2^ miles S. 68° E. of Bostic, Rutherford County, 

N. C.

45 Mt 164. Same general site as 45 Mt 163, but from a small south-flowing branch of Webb Creek, about 

2-5/8 miles S. 75° E. of Bostic, Rutherford County, N. C.

45 Mt 165. Monazite Branch, about 2-3/8 miles N. 74° E. of Ellenboro, Rutherford County, N. C.

45 Mt 169. Southwest branch of Duncans Creek, about 1-7/8 miles N. 5° E. of Hollis, Rutherford County, N. C.

45 Mt 171. Southwest branch of Duncans Creek, about 2^ miles north of Hollis, Rutherford County, N. C.

45 Mt 172. East branch of Second Broad River, about 2-3/4 miles S. 37° W. of Ellenboro, Rutherford County, 

N. C.

45 Mt 175. Henderson Branch of Hollands Creek, about 2| miles N. 63° E. of Rutherfordton, Rutherford County, 

N. C.

45 Mt 178. Chunk Creek, a south branch of Hollands Creek, about 2-3/8 miles N. 75° E. of Rutherfordton, 

Rutherford County, N. C.

45 Mt 184. West branch of Sandy Run Creek, about 1-3/8 miles N. 22° W. of Mooresboro, Cleveland County, 

N. C.

45 Mt 185. Same general locality as 45 Mt 184, but from a small tributary.

45 Mt 186. West branch of Sandy Run Creek, about 7/8 mile S. 43° W. of Mooresboro, Cleveland County, N. C.

45 Mt 189. South branch of Silver Creek, about 2i miles S. 10° E. of Glen Alpine, Burke County, N. C.

45 Mt 192. Grassy Creek, about 3/4 mile S. 50° E. of Polkville, Cleveland County, N. C.

45 Mt 193. Rock Creek, about 7/8 mile N. 80° E. of Pleasant Grove, Burke County, N. C.

45 Mt 209. West branch of Buffalo Creek, about 2i miles N. 6° E. of Fallston, Cleveland County, N. C.

45 Mt 213. Head of Maple Creek, about 1 mile south of Belwood, Cleveland County, N. C.

45 Mt 215. Alexander Creek, tributary of Muddy Creek, about 2-3/8 miles N. 29° W. of Dysortsville, 

McDowell County, N. C.

45 Mt 221. Camp Creek, about 1 mile S. 47° E. of Ramsey, Burke County, N. C.

45 Mt 229. Beaverdam Creek, about 2 miles east of Boiling Springs, Cleveland County, N. C.

45 Mt 230. Bald Knob Creek, about 1-3/8 miles S. 73° E. of Casar, Cleveland County, N. C.

45 Mt 233. Branch of Knob Creek, about 1-3/8 miles S. 65° W. of Belwood, Cleveland County, N. C.

45 Mt 234. Wellman Branch of Knob Creek, about 2 miles S. 61° W. of Belwood, Cleveland County, N. C.

45 Mt 235. Original site sf Millholland Mill, on Third Creek, about 2-5/8 miles S. 30° E. of Hiddenite, 

Alexander County, N. C.

45 Mt 244. East branch of Crooked Run Creek, about 3i miles N. 25° W. of Lawndale, Cleveland County, N. C.
Localities of monazite placer samples Continued

South Carolina 

45 Mt 29. Little Cherokee Creek, about 3-? miles north of Gaffney, Cherokee County, S. C.

45 Mt 36. The old Swofford mine, on Pole Bridge Branch of Cherokee Creek, about 0. 8 mile S. 25° W. of 

Grassy Pond, Cherokee County, S. C.

45 Mt 38. The old Lemmon mine, on a small branch of Cherokee Creek (flowing N. 15° E.) about 2 miles 

S. 35° W. of Grassy Pond, Cherokee County, S. C.

45 Mt 40. The old Jonas Blanton mine, on N. Fork of Beaverdam (Irene) Creek, about 4 miles N. 68° W. of 

Gaffney, Cherokee County, S. C.

45 Mt 50. Floyd Branch of Island Creek, about ! § miles south of Cowpens Battleground Monument, Cherokee 

County, S. C.

45 Mt 55. Cudds Creek, about 1-3/4 miles N. 83° W. of Cowpens Battleground Monument, Cherokee County, 

S. C.

45 Mt 59. Bill Martin Creek, about 1 mile S. 35° E. of Cowpens Battleground Monument, Cherokee County, 

S. C.

45 Mt 60. Joe Welchel Creek, a southeast-flowing tributary of the N. Fork of Beaverdam Creek, adjoining 

the old Jonas Blanton mine, Cherokee County, S. C.

45 Mt 65. Cherokee Creek, about 2 miles north of Gaffney, Cherokee County, S. C.

45 Mt 66. Double Branch (Melon) Creek, about 3 miles S. 30° E. of Chesnee, Spartanburg County, S. C.

45 Mt 73. South branch of Macedonia Creek, about 5 miles N. 51° W.i of Thicketty, Cherokee County, S. C.

45 Mt 74. Little Thicketty Creek, about 4-3/4 miles N. 69° W. of Thicketty, Cherokee County, S. C.

45 Mt 81. South-flowing branch on the old Waldrop farm, about 3-3/4 miles S. 69° E. of Piedmont, Greenville 

County, S. C.

45 Mt 98. Branch of Gillard Creek, about 1 mile N. 17° E. of Mauldin, Greenville, S. C.

45 Mt 101. South-flowing branch of Reedy Creek, on the old Charles Brooks farm, about 7/8 mile south of 

Mauldin, Greenville County, S. C.

45 Mt 105. Small north-flowing branch, about 4-3/8 miles N. 78° E. of Piedmont, Greenville, S. C.

Georgia 

49 Mt 18. Small stream, about 7 miles S. 87° W. of Griffin, Spalding County, Ga.

The following tabulation gives the results work most of the larger cobbles were thrown out

of this sampling, which was done with a 16-inch and replaced by finer material, for which reason

gold pan. About 130 heaped pans are considered only 80 pans were taken as the equivalent of a

to be equivalent to a cubic yard, but in this cubic yard.
Sample 

no.

45 Mt 29

45 Mt 36

45 Mt 38

45 Mt 40

45 Mt 50

45 Mt 55

45 Mt 59

45 Mt 60

45 Mt 65

45 Mt 66

45 Mt 73

45 Mt 74

45 Mt 8l

45 Mt 98

45 Mt 101

45 Mt 105

45 Mt 110

45 Mt 117

45 Mt 124

45 Mt 126

o 45 Mt 128

45 Mt 141

45 Mt 154

45 Mt 154 -a

45 Mt 155-a

45 Mt 157

45 Mt 160

Number 

of pans675331134321246384885255543

Heavies 

(grams)

350.1

274.2

240.9

120.9

135.6

120.8

109-7

127.4

94.3

69.2

276.0

74.1

257.6

248.6

271.8

1455-4

236.6

196.8

277.6

395.9

249.2

548.0

424.5

248.0

89.4

84.2

158.2

Monazite 

percent

30

26

41

17

39

37

23

48

34

43

30

30

38

35

47

49

58

45

50

56

37

22

2433'

58

60

84

Heavies1

10.3

6.9

8.5

7.1

8.0

21.3

19-3

7-5

4.2

4.1

24.3

13.1

22.7

11.0

8.0

85.6

5-2

8.7

6.1

8.7

8.8

48.3

15.0

8.7

3.1

3-7

9.3

Monazite1

3-1

1.8

3-5

1.2

3-1

7-9

6.4

3.6

1.4

1.7

7.3

3-9

8.6

3.8

3-8

41.9

3.0

3-9

3.1

4.9

3.3

10.6

3.6

2.9

1.8

2.2

7-8

Sample 

no.

45 Mt 162

45 Mt 163

45 Mt 164

45 Mt 165

45 Mt 169

45 Mt 171

45 Mt 172

45 Mt 175

45 Mt 178

45 Mt 184

45 Mt 185

45 Mt 186

45 Mt 189

45 Mt 192

45 Mt 193

45 Mt 209

45 Mt 213

45 Mt 215

45 Mt 221

45 Mt 229

45 Mt 230

45 Mt 233

45 Mt 234

45 Mt 235

45 Mt 244

Mean

Number 

of pans5314332543233843233121134

Heavies 

( grams )

1251.3

239.1

195-9

423.0

187.2

150.4

84.4

575.6

918.5

17^.5

207.1

136.3

144.3

661.7

370.2

168.8

855.7

485.0

289.2

103-0

175.7

189.7

205-3

352.4

359.9
The mean content of these samples is 8.4 pounds 

of monazite to the cubic yard, but the tenors 

range upward to five times this value. The 

nominal price of monazite, as of October 1952, 

was 19 cents a pound for a product containing 

65 percent of rare earths and ThOa. Analyses 

of 19 of the preceding samples, made in the 

chemical laboratory of the U. S. Geological Survey, show an average tenor of 68.87 percent in 

the rare earths plus ThOg. These figures suggest the presence of some high-grade placers, 

but it should be emphasized that these samples 

were taken in headwater stretches of the streams 

where no great volume of alluvial material is 

available. In order to obtain yardage, mining 

must be carried on farther downstream where 

the valleys open out to alluvial floors of some 

width. Necessarily the tenors will decrease 

downstream, owing partly to the addition of 

alluvium from tributaries that carry little or no 

monazite, and partly to other factors. One 

unfavorable condition results from the specific 

gravity of monazite, together with the omnipresence 

of saprolite. Monazite is only one-third as dense 

as ordinary placer gold, and therefore does not 

gravitate toward bedrock to the same degree as 

gold. Instead it tends to migrate downstream, 

unless retained by beds of gravel; but gravel, in 

a region characterized by saprolite, is replaced 

in large measure by sand and silt. William C. 

Overstreet, in drilling the fluviatile deposits within 

the western monazite belt, has found that such 

conditions are generally prevalent, resulting in the 

production of placers of lower grade than might 

be expected from headwater panning. A large 

movement of monazite downstream is further 

corroborated by its presence in all the formations 

of the Coastal Plain, many miles from the bedrock sources. It is improbable, however, that 

placer mining is at all possible in -the valleys of 

master streams like the Broad and Saluda Rivers, 

except as a byproduct in the recovery of other 

products, such as sand and gravel; and in the 

Coastal Plain, monazite is more likely to be recovered as a byproduct of heavy mineral mining.

Other factors must be considered in placer 

mining downstream from these headwater stretches. 

The lack of a marked concentration of monazite 

near bedrock, and the presence of much overlying 

sand and silt with a low tenor, will require the 

processing of all the overburden above the basal 

gravels, if a high recovery is to be obtained. 

But this requirement is opposed, in a farming 

country where the land is privately owned, by 

laws which forbid the discharge downstream of 

a large volume of fine sediments, and may require the replacement of soil after mining is 

ended.

Another deterrent to the domestic mining 

of monazite is the uncertainty regarding its future 

value. The present high price results from an 

artificial scarcity, caused by the removal of

Indian monazite from the market, and by a 

limited Brazilian output. _ These conditions could 

change suddenly. Moreover, if a large volume 

of rare earth minerals should be produced from 

the southeastern States,- from Idaho, or from 

other domestic or foreign sources, competition 

would quickly lower the market price. Mining 

men who understand these conditions are understandably cautious in attempting to mine domestic 

monazite on a large scale.

Extensive placer mining in the southeastern 

States will have to be preceded by exploration, 

either by private concerns or by governmental 

agencies; and such work, preferably by drilling, 

-should also give heed to other heavy and semiheavy minerals contained in the placers. Starting 

in November 1951, the Geological Survey began 

to block out fluviatile deposits in the western monazite belt that should be drilled; and the Bureau 

of Mines has already started such drilling. In 

the mining of fluviatile monazite placers in the 

Piedmont province, ilmenite, rutile, and zircon 

should constitute saleable byproducts. Garnet, 

kyanite, sillimanite, staurolite, and other semiheavy minerals might also be of interest if they 

could be economically separated from one another.

The situation regarding placer monazite 

mining in the southeastern States may be summarized as follows. At present only the highgrade deposits, lying in or not far downstream 

from the headwater stretches of the streams, 

offer quick and profitable returns. Such mining 

will require many plants, consisting probably of 

small power shovels and mobile concentrating 

equipment. Deposits of larger volume may be 

discovered by the underground exploration now in 

progress. A vast volume of monazite, however, 

is present, if one considers the total content of 

the fluviatile deposits, the saprolites, and the 

formations of the Coastal Plain. In a period 

of future emergency, when the,motive of profit 

might temporarily be inoperative, the monazite 

of the southeastern States could be invaluable.

Content of thorium and uranium. The thorium 

contained in monazite was formerly used in the 

manufacture of Welsbach gas mantles, but it now 

is used in limited quantities for other purposes. 

Its potential use in the future is as a substitute 

for uranium in the production of nuclear power. 

Thus TJ233 can be produced from Thzsz by means 

of a breeder reaction exactly analogous to that 

being used to produce Pu239 from u238 ; and 

U233 , in its susceptibility to nuclear fission, is 

intermediate between U23 ° and Pu2 39. The 

content of uranium in monazite, though small, 

is also significant.

The monazite from 53 samples of placer 

concentrates was analyzed for the contents of

and U3 O8. Acknowledgment for this work

11
is gratefully made to John C. Rabbitt, Chief of the Trace 

Elements Laboratory of the Geological Survey; and to 

Frank C. Grimaldi and his co-workers, who did the

analytical work. The results are shown in the 

following tabulation:

Content, in percent, of Th0 2 and U3 O 8 in placer monazite

Sample no.

45 Mt 29

45 Mt J>6

45 Mt 38

45 Mt 40

45 Mt 50

45 Mt 55

45 Mt 59

45 Mt 60

45 Mt 65

45 Mt 66

45 Mt 75

45 Mt 74

45 'Mt 81

45 Mt 98

45 Mt 101

45 Mt 105

45 Mt 110

45 Mt 117

45 Mt 124

45 Mt 126

45 Mt 128

45 Mt 141

45 Mt 154

45 Mt 154 -a

45 Mt 155-a

45 Mt 157

45 Mt 160

Th02

4.90

6.45

6.21

5-91

4.95

4.84

4.91

6.44

5.87

5-47

6.76

6.59

5.08

5.56

5.05

4.85

7.72

5-77

6.80

7-00

6.45

4.62

5-06

6.34

6.13

7.38

7.84

U3 0 8

0.45

.23

.22

.22

.55

.58

.58

.24

.49

.36

.18

.19

.24

 55

.47

 32

.33

-98

 39

.29

.32

.55

.53

.45

.38

.31

.35

UsO^ 

Th02

0.092

.036

.035

.037

.111

.120

.118

.037

.083

.066

.027

.029

.047

.099

.093

.066

.043

.170

.057

.041

.050

.119

.105

.071

.062

.024

.045

Sample no.

45 Mt 162

45 Mt 163

45 Mt 164

45 Mt 165

45 Mt 169

45 Mt 171

45 Mt 172

45 Mt 175

45 Mt 178

45 Mt 184

45 Mt 185

45 Mt 186

45 Mt 189

45 Mt 192

45 Mt 193

45 Mt 209

45 Mt 213

45 Mt 215

45 Mt 221

45 Mt 229

45 Mt 230

45 Mt 233

45 Mt 234

45 Mt 235

45 Mt 244

49 Mt 18

Mean

Th02

4.58

5.76

4.47

5-80

5.28

5.02

4.74

5-49

5-27

5-52

5.86

5-58

2.48

5.31

4.94

6.46

7.22

3-60

6.20

5-08

5.66

5.08

7-06

5-19

7-54

4.42

5.67

U3 08

0.33

.40

 34

.28

.33

.28

.64

.25

.22

 31

.28

.33

.28

.49

 58

.41

.28

.27

.45

.54

 36

.40

.34

.36

.37

.26

 38

U3 08 

Th0 2

0.072

.069

.076

.048

.062

.056

.135

.046

.042

.056

.048

.059

.113

.092

.117

.063

.039

.075

.073

.106

.064

.079

.048

.069

.049

.059-

.070

The contents of thorium and uranium are 

not so related that a high content of thorium 

necessarily implies a high content of uranium.

This is shown in the following tabulation, where 

the analyses are arranged in seven groups, according to their contents of ThO 2 .

Number of samples

7 

3 

8 

10 

12 

9 J 5

Range in Th0 2

7.84-7.00 

6-99-6.50 

6.49-6.00 

5.99-5.50 

5.49-5.00 

4.99-4.50 

4.49_2.48

Range in U3°9 

Th0 2

0.039-0.049 

.027- .057 

.035- .073 

.037- .170 

.042- .106 

.072- .135 

.043- .113

Mean value of u?° 8

Th0 2

0.044 

.038 

.053 

.073 

.072 

.106 

.073

1 Includes one sample from saprolite not given in preceding tabulation.

This arrangement indicates that the largest content of UaOe in the southeastern monazite is to be expected in samples that contain from 4^ to 5 percent 

Th0 2 , and that the tenor in uranium decreases in both 

directions from this optimum value. This relationship appears not to be the result of any particular geographic distribution or localization, as the samples were 

taken from all parts of the placer mining area of North 

and South Carolina.

Coastal Plain

Monazite, unlike gold, is transported for long 

distances from its bedrock sources, and therefore

it occurs also in small quantities in all of the 

formations of the Coastal Plain. These deposits, 

in turn, may function as secondary or proximate 

bedrock sources, from which other placers may 

be concentrated. In addition to monazite, however, 

many other heavy and semiheavy minerals are 

present in the Coastal Plain deposits derived from 

all the crystalline rocks of the Piedmont. In 

general, neither the monazite nor the other heavy 

minerals occur in sufficient quantities in this 

environment to constitute workable deposits, but 

under favorable conditions they may be reconcentrated to produce fluviatile and littoral placers 

of heavy 'minerals.

12
Fluviatile placers. Streams that head in the 

monazite belts of the Piedmont may contain commercial 

deposits of monazite in their headwaters and possibly 

for moderate distances downstream. Still farther 

downstream, however, the monazite-bearing alluvium 

becomes mixed with a large volume of detrital materials from other streams that do not head in monazitebearing bedrock. Therefore the valley floors of master 

streams, such as the Broad and Saluda Rivers, are 

unlikely to contain workable deposits either of monazite or of other heavy minerals; and downstream from 

the Piedmont, within the Coastal Plain, the presence 

of such placers may be regarded as highly improbable. 

This generalization, however, recognizes the possibility that monazite and other heavy minerals may 

be recovered from the valleys of master streams, 

either within the Piedmont or the Coastal Plain, as 

a byproduct of other mining operations, such as the 

recovery of sand and gravel.

Fluviatile placers of heavy minerals, however, 

may occur in streams that head within the Coastal 

Plain, where the source-rocks are the various formations of the Coastal Plain. Such smaller streams are 

generally too sluggish to be favorable sites for the 

concentration of heavy minerals, except close to the 

Piedmont, where the stream gradients are higher. At 

such sites the streams are small, even if they head 

back a short distance in the Piedmont. It follows, 

therefore, that fluviatile placers of heavy minerals 

in the Coastal Plain are most likely to occur in the 

valleys of small streams that head either within this 

province or at no great distance back in the piedmont. 

Such placers, moreover, will probably be localized 

near the inner margin of the Coastal Plain, and most 

of them are likely to be of small volume, though unusual physiographic conditions may result in the 

development of larger placers. It also follows, because the formations of the Coastal Plain are the 

proximate sources of the heavy minerals, that any 

such deposits will be heavy mineral placers, rather 

than placers that might be worked for their content 

of monazite alone.

Two such placers of low grade were discovered 

by the writer in the spring of 1951. One of these occurs 

on a small branch of Sweetwater Creek, about 3 miles 

east of Thomson, McDuffie County, Ga. The tenor at 

this site, as gaged by panning on the riffles, is about 

li pounds of monazite to the cubic yard. The sourcerock was found to be the Tuscaloosa formation, of 

Late Cretaceous age, which in this vicinity contains 

a very small percentage of monazite. The second 

deposit was discovered on Rocky Creek, about 5 miles 

west-northwest of Lexington, Lexington County, S. C. 

The tenor of this deposit is only about -| pound of monazite to the cubic yard. Rocky Creek is a small tributary of Saluda River that heads and flows in the Coastal 

Plain. Some granite has been bared to erosion in its 

drainage basin, but this was found not to be monazitebearing. Therefore the source of the monazite is 

believed to be the basal formations of the Coastal Plain.

Neither of these deposits has any commercial 

significance, but they show that fluviatile placers can 

exist within the Coastal Plain; and it is possible under 

favorable physiographic conditions that placers of 

higher grade and larger volume may exist in this 

environment. Similar placers were in fact found later

in the summer of 1951, near Aiken, Aiken County, S. C., 

about midway between the two deposits mentioned above. 

The valleys of Horse and Holley Creeks, in this vicinity, were drilled by the U. S. Bureau of Mines between 

December 1951 and March 1952.

Beach placers. The occurrence of beach placers 

of heavy minerals is closely related to the geologic 

history of the Coastal Plain, and particularly to the 

depositional history of the Pleistocene formations. An 

adequate discussion of these topics would far exceed 

the bounds of this paper, and the best that can be done 

is to present a few terse statements of the guiding principles.

Most of the sediments of the Pleistocene formations are believed by the writer to be of deltaic and 

estuarine origin, particularly those in the vicinity of 

the large rivers that drain the Piedmont province; and 

it is further believed that these deposits were not generally reworked by the sea, although obviously strand 

lines existed throughout the Pleistocene. Oscillations 

of the shorelines during the Pleistocene were produced 

unquestionably by the storage and release of ice in 

successive glacial and interglacial stages; and if changes 

in the strandline had been produced by this process alone, 

the deposits of the Coastal Plain would largely have been 

reworked by waves and shore currents. But concurrently, 

throughout the Pleistocene, a general lowering of the 

base level of erosion was superposed on these glacial 

oscillations, such that the sediments of each stage were 

deposited generally farther offshore than those of the 

preceding stage, and new terrigenous sediments were 

deposited above those that had been reworked by the sea. 

Thus the wave-worked beaches were buried by later 

deltaic deposits, which owing to epeirogenic uplift were 

not generally reached by the sea, and therefore remained 

in their primitive condition. This regimen was less 

effective in southeastern Georgia and Florida, owing 

to the absence of large rivers that would produce the 

deltaic sediments; and therefore in this part of the 

eastern Coastal Plain a greater percentage of the sediments at or near the surface show signs of littoral reconcentration.

A larger volume of heavy minerals was transported 

from the Piedmont to the Coastal Plain during the interglacial stages of the Pleistocene than during the glacial 

stages, owing to warmer, and possibly more humid, 

climates and more active weathering and erosion. More 

over each of the interglacial stages was much longer 

than post-Wisconsin time. The upper limits of the 

Pleistocene formations, at the altitudes heretofore 

mentioned represent the uppermost base levels that 

prevailed at each of the interglacial stages, so that the 

surficial sediments now exposed are mainly of deltaic 

or estuarine origin, whereas the marine sediments of 

both the interglacial and glacial stages are' either buried 

by terrigenous deposits or are actually offshore beyond 

the present strand line. The net result of these conditions 

is that any marine terrace deposits that may be found are 

much more likely to be the sites of commercial deposits 

of heavy minerals than are the Recent sediments.

These conclusions were reached partly from 

theoretical considerations and ipartly as a result of 

panning 56 samples from the Coastal Plain. The localities at which these samples were taken are in southeastern South Carolina and in southeastern Georgia,

13
.82°

-- -

Sample from Coastal 

Plafn formations 

(No monazite)

Sample from Coastal

Plain formations 

/Y (Monazite-bearing)

30°

82° By John B. Mertie, Jr.

25 Miles

Figure 2. Samples and mines in coastal plain of southeastern Georgia and northeastern Florida.

14
and are shown in plate 1 and figure 2. Southeastern 

South Carolina was selected as one site of exploration 

because of its proximity to the Santee River, whose 

headwater tributaries drain the most important part 

of the western monazite belt. Southeastern Georgia 

was selected as the other site because of its proximity 

to Florida, where deposits of heavy minerals are now 

being mined.

The net results of these theoretical conclusions 

and actual exploration follow. Heavy mineral concentrations were nowhere found, at the sites charted, that 

attain the minimum commercial grade, which is between 3 and 4 percent of the sand. But the concentration in southeastern Georgia is greater than in 

southeastern South Carolina; and at a few places along 

the eastern margin of the Okefenokee Swamp, the concentration of several feet of sediments at the surface 

was found to attain one percent. As the commercial 

deposits of Florida lie mainly below the surface, a 

concentration of one percent at the surface is significant, 

and suggests that the region just east of the Okefenokee 

Swamp is worth prospecting.

The amount of monazite found in the formations 

of the Coastal Plain of South Carolina and Georgia 

ranged from less than 1 to 9 percent of the heavies, 

but as the heavies in general constitute only 0.01 to 

0. 1 percent of the sediments, it follows that no placers 

are present in which monazite is of primary importance. 

Monazite, however, may be recovered as a byproduct 

in the mining of heavy mineral placers, if it occurs 

in amounts sufficiently large to be saved. Thus, two 

large plants in Florida are now engaged in the mining 

of the ilmenite, leucoxene, rutile, zircon,and staurolite. 

One of these plants, owned by the National Lead Co. 

.and operating east of Jacksonville in the Penholoway 

terrace, is working sand that contains about 5 percent 

of heavies, whereas the tenor of the sand in monazite 

is only about 0.03 percent. This low percentage of 

monazite nevertheless makes possible in a large scale 

operation the production of a small but significant output of this mineral. The other plant, owned by E. I. 

du Pont de Nemours & Co. and operating in the Sunder land 

and Coharie terraces southeast of Starke, produces no

monazite because the tenor of the sand in this mineral 

is a mere trace.

Bedrock sources 

Monazite belts

The monazite placers of the Piedmont, up to 

1948, were known to extend for about 100 miles in 

North and South Carolina, with a general northeasterly 

trend. This stretch, now called the western monazite 

belt, was subsequently traced by the writer northeastward into Virginia, and across that State for 170 miles. 

Southwestward, it was traced through North and South 

Carolina, Georgia, and Alabama for 430 miles, to a 

point where it finally is overlapped by the southern 

Coastal Plain. Hence the total length of the western 

monazite belt is now known to be about 600 miles. 

In 1949, however, monazite was discovered by the 

writer in bedrock about 15 miles northeast of Raleigh, 

N. C., and thence was traced for 200 miles northnortheastward to the vicinity of Fredericksburg, Va. 

These occurrences were designated as the eastern 

monazite belt. Recently the writer discovered monazite in bedrock about 20 miles north of Columbia, S. C., 

at a site that may constitute a southwestern continuation 

of the eastern monazite belt. These two belts, shown 

in plate 1, appear to join each other at an angle of 

about 45 degrees, in the vicinity of Manakin, Goochland 

County, Va.

The study of the southeastern granitic rocks, including those that contain monazite, has required a 

great deal of panning. A total of 516 samples of saprolite, aggregating about 45, 200 pounds, have been collected and processed by the writer, of which 175 samples, weighing about 18, 400 pounds, were found to 

contain monazite. The localities where these samples 

were collected are charted on plate 1, but owing to the 

small scale of this map, the symbols greatly exaggerate 

the size of the sites. To compensate for this shortcoming, the actual localities of the monazite-bearing 

samples, with which this paper is primarily concerned, 

are given herewith.

Localities of monazite-bearing saprolite and hardrock 

Virginia

50 Mt 172 Saprolite of granitic gneiss from north side of Route 103, 0. 9 mile by road west of Route 663 (entering 

103 from south), and 7. 4 miles S. 54° W. of Stuart, Patrick County, Va.

50 Mt 178 Saprolite of granitic gneiss from southeast side of Route 57, just southwest of junction of 57 with 

Route 647 from south, and about ^ mile southwest of Mountain Valley, Henry County, Va.

50 Mt 179 Saprolite of aplitic granite from northwest side of Route 57, just southwest of junction of 57 with 

Route 647 from south, and about i mile southwest of Mountain Valley, Henry County, Va.

50 Mt 196 Granitic saprolite from east side of Route 663, about 1. 3 miles by road south of Route 103, and 

1. 6 miles by road north of Virginia-North Carolina line, in Patrick County, Va.

50 Mt 202 Granitic saprolite from southeast side of Route 626, about 4. 3 miles by road north-northeast of 

intersection of Routes 626 and 58, and 7. 3 miles N. 86° E. of Stuart, Patrick County, Va.

50 Mt 204 Saprolite of granitic dike in sheared gneiss, from east side of Route 626, about 5. 3 miles by road 

south-southeast of junction of Routes 626 and 687, and 10.1 miles N. 75° E. of Stuart, Patrick 

County, Va.

15
Localities of monazite-bearing saprolite and hardrock--Continued 

Virginia- -Continued

50 Mt 205 Saprolite of banded granitic gneiss from west side of Route 626, about 5.0 miles by road south-southeast 

of junction of Routes 626 and 687, and 10.3 miles N. 72 1/2° E. of Stuart, Patrick County, Va.

50 Mt 222 Granitic saprolite from northeast side of Route 38, about 150 yards northwest of junction of Routes 38 

and 153, and 7.4 miles S. 57° E. of Amelia, Amelia County, Va.

50 Mt 233 Saprolite of granitic gneiss from south side of Route 460, 0.8 mile east of the Nottoway-Dinwiddie 

County line, and 1. 4 miles S. 64° W. of Wilson, Dinwiddie County, Va.

50 Mt 234 Saprolite of granitic gneiss from east side of Route 46, about 200 yards north of Nottoway River, and 

6.1 miles S. 20° E. of Blackstone, Nottoway County, Va.

50 Mt 235 Saprolite of granitic gneiss from northwest side of US 1, 0.3 mile west-southwest of the MecklenburgBrunswick County line, and 6. 3 miles N. 60° E. of South Hill, Mecklenburg County, Va.

50 Mt 251 Saprolite of granitic gneiss, from east side, of Route 51, about 2. 4 miles by road north-northwest of 

Little River, and about 0. 4 mile north-northeast of Trinity Church, Hanover County, Va.

50 Mt 264 Saprolite of granitic gneiss, from north side of Route 606, and 0.1 mile by road east-southeast of 

Post Oak, Spotsylvania County, Va.

50 Mt 267 Saprolite of granitic gneiss, from south side of Route 3, about 5. 3 miles by road west of the intersection of Routes 3 and 1-A, and about 1. 3 miles by road west of Five Mile, Spotsylvania County, Va.

50 Mt 268 Saprolite of granitic gneiss, from south side of State Route 3, and about 7.0 miles by road west of the 

intersection of State Route 3 and US 1-A, Spotsylvania County, Va.

50 Mt 269 Saprolite of Petersburg granite(?), from northeast side of Route 33, about 3. 8 miles by road northwest of Chickahominy River, and about 0. 4 mile by road southeast of the intersection of Routes 33 

and 623, Hanover County, Va.

50 Mt 271 Saprolite of granitic gneiss, from east side of Route 621-623, and about 0.8 mile by road north of the 

intersection of this road with Route 6, Goochland County, Va.

50 Mt 272 Saprolite of granitic gneiss, from southwest side of Route 6, and about 1.0 mile by road west of the 

intersection of Route 621-623 with Route 6, Goochland County, Va.

52 Mt 57 Granitic saprolite from north side of Route 615, about 2. 5 miles by road west of the junction of Routes 615 

and 47, and 2.8 miles airline S. 78° W. of Madisonville, Charlotte County, Va.

52 Mt 61 Saprolite of granitic rock from northeast side of Route 26, about 3. 5 miles by road southeast of Red 

House, Charlotte County, Va.

52 Mt 73 Saprolite of granite gneiss from north side of Route 658, about 2.9 miles by road east-north east of the

junction of Routes 658 and 650; and 0.3 mile by road east of Buffalo Creek, Prince Edward County, Va.

52 Mt 74 Saprolite of cream-colored gneiss, from south side of Route 460, about 1. 7 miles by road west of the 

western junction of Routes 460 and 15, Prince Edward County, Va.

52 Mt 75 Saprolite of cream-colored gneiss, from east side of Route 45, just north of the city limits of Farmville, 

Cumberland County, Va.

52 Mt 84 Saprolite of granitic gneiss from northeast side of Route 640, and about 100 yards northwest of the

junction of Routes 640 and 670, and within sight of the schoolhouse at.Renan, Pittsylvania County, Va.

52 Mt 89 Saprolite of white granite gneiss, from north side of Route 13, about 0. 3 mile by road west of Macon, 

Powhatan County, Va.

52 Mt 91 Saprolite of white pegmatitic gneiss, from west side of Route 38, about 0. 4 mile by road north of 

Appomattox River, Powhatan County, Va.

52 Mt 97 Granitic saprolite from west side of Route 15, about 1.6 miles by road north-northwest of west junction 

of Routes 460 and 15, and 0. 3 mile south-southeast of Appomattox River, Prince Edward County, Va.

16
Localities of monazite-bearing saprolite and hardrock Continued 

North Carolina

45 Mt 112 Saprolite of pegmatized gneiss, from the bedrock excavation of the BritishMonazite Co., on east side 

of Hickory Creek, 2 1/2 miles N. 47° E. of Shelby, Cleveland County, N. C.

45 Mt 119 Saprolite of pegmatite dike, on north side of Route 74, about 5.6 miles east of Buffalo Creek, Cleveland 

County, N. C.

45 Mt 125 Saprolite of the gneissoid granite near Toluca, from east side of an unpaved road, and 1. 5 miles N. 11° 

W. of Toluca, Cleveland County, N. C.

45 Mt 136 Saprolite of the granite near Toluca, from east side of Route 18, and about 0.6 mile by road north of 

Fallston, Cleveland County, N. C.

45 Mt 137 Saprolite of the granite near Toluca, from east side of Lawndale-Casar road, and about 2. 4 miles by 

roadS. 35° E. of Casar, Cleveland County, N. C.

45 Mt 138 Granitic saprolite, from east side of Route 18, and about 2.8 miles by road north of Jacob Fork River, 

Burke County, N. C.

45 Mt 139 Granitic saprolite from east bank of small south-flowing branch of Brushy Creek, about 4 1/2 miles 

northwest of Shelby, Cleveland County, N. C:

45 Mt 152 Granitic saprolite from south side of unpaved road, about 2.1 miles by road east of Fallston, Cleveland 

County, N. C.

45 Mt 155 Saprolite of granitic bedrock in branch on farm of Cliff C. Blanton, about 5.3 miles N. 32° W. of 

Shelby, Cleveland County, N. C.

45 Mt 158 Saprolite of granitic material in schist, in bank of a short northeast-flowing branch of Buffalo Creek, 

about 1.7 miles S. 43° E. of Fallston, Cleveland County, N. C.

45 Mt 16.1 - Saprolite of gneissoid granite, in bank of small branch of Little Knob Creek, about 3.7 miles S. 40° E. 

of Casar, Cleveland County, N. C.

45 Mt 173 Granitic saprolite from north side of Route 74, under the Southern Railway bridge, and about 0. 8 mile 

by road east of Mooresboro, Cleveland County, N. C.

45 Mt 177 Granitic saprolite from east side of Route 221, about 1.0 mile by road north of Gilkey, Rutherford 

County, N. C.

45 Mt 179 Saprolite of granitized schist from west side of an unpaved road, about 1.3 miles northeast of Spindale, 

Rutherford County, N. C.

45 Mt 180 Saprolite of slightly granitized schist from west side of an unpaved road, about 1.3 miles northeast 

of Spindale, Rutherford County, N. C.

45 Mt 182 Granitic saprolite from south side of Route 74, in a soil erosion gulch, about 5.2 miles S. 88° W. of 

Shelby, Cleveland County, N. C.

45 Mt 194 Saprolite of granite of the type found near Toluca, from south side of an unpaved road, and 0.8 mile 

S. 80° W. of Pleasant Grove, Burke County, N. C.

45 Mt 210 Saprolite of granitized schist, from bank of a small tributary of Buffalo Creek, and 2.4 miles N. 6° E. 

of Fallston, Cleveland County, N. C.

45 Mt 218 Crushed building stone from the Winthrow quarry, about 1-1/2 miles west of Hollis, Rutherford County, 

N. C.

45 Mt 225 Saprolite of granitic gneiss, from north side of Route 64 and 70, just west of the Burke-McDowell 

County line, in McDowell County, N. C.

45 Mt 232 Saprolite from the granite near Toluca, from banks of a small branch of Knob Creek, and 3.4 miles 

N. 30° W. of Fallston, Cleveland County, N. C.

45 Mt 236 Excavated material from dump of Hiddenite mine, near Hiddenite, Alexander County, N. C.

17
Localities of monazite-bearing saprolite and hardrock Continued

North Carolina Continued 

45 Mt 243 Crushed granitic intrusive rock, from dump of Hiddenite mine, near Hiddenite, Alexander County, N.C.

45 Mt 245 Saprolite of granite of the type found near Toluca, from banks of a small branch of Crooked Run Creek; 

and 3. 5 miles N. 23° W. of Lawndale, Cleveland County, N. C.

45 Mt 251 Saprolite of pegmatite and country rock at the site where a 16-inch crystal of monazite was recovered

years ago (the Mars Hill pegmatite), about 2-3/4 miles S. 58° W., of Mars Hill, Madison County, N.C.

45 Mt 279 Saprolite of pegmatite, from a narrow gulch tributary to Hickory Creek from east, about 300 yards 

upstream from the site of an old dam built by the British Monazite Co., Cleveland County, N.C.

45 Mt 284 Granitic saprolite from northeast side of Spruce Pine-Bakersville road, about 4.2 miles by road

northwest of the bridge at Spruce Pine, and 3.4-miles N. 52° W. of Spruce Pine, Mitchell County, N.C.

45 Mt 285 Saprolite of coarse-grained pegmatitic granite, from an old quarry on the northeast side of the Spruce 

Pine-Bakersville road, about 1.7 miles by road northwest of the bridge at Spruce Pine, Mitchell 

County, N. C.

45 Mt 294 Saprolite of coarse-grained pegmatitic granite, from north side of Route 19-E, about 5.2 miles by 

road west of the bridge at Spruce Pine, Mitchell County, N. C.

45 Mt 296 Saprolite of the granite near Mt. Airy, from both sides of Route 89, about 3 miles by road west of 

Mt. Airy, Surry County, N. C.

47 Mt 57 Crushed Toluca quartz monzonite from Acre Rock, about 0.7 mileS. 45° W. of Toluca, Cleveland 

County, N. C.

47 Mt 71 Saprolite of. granite of the type found near Toluca, from west side of Route 18, .about 2. 5 miles by

road north-northwest of Jacob Fork River, and 3.1 miles N. 20° W. of Ramsey, Burke County, N.C.

47 Mt 73 Saprolite of gneissic granite of the type found near Toluca, from east side of an unpaved road; and 

0.8 mile N. 11° W. of Toluca, Cleveland County, N. C.

48 Mt 2 Saprolite of granitized gneiss from east bank of small south-flowing branch of Brushy Creek, about 

4 1/2 miles northwest of Shelby, Cleveland County, N. C. '

48 Mt 7 Saprolite of granitized schist or gneiss, from southeast bank of Webbs Creek, at site of old Louisa Smart 

monazite placers, where trail from house of T. W. Smart meets the creek. Also 2 1/2 miles 

S. 68° E. ofBostic, Rutherford County, N. C.

48 Mt 28 Saprolite of granitized gneiss, from west side of Polkville-Casar road (Route 10), and about 3.7 miles 

by road north of Bakers Corners, Cleveland County, N. C.

48 Mt 29 Saprolite of granite of the type found near Toluca, from west side of an unpaved road, about 0.7 mile 

S. 22° W. of Ramsey, Burke County, N. C.

48 Mt 43 Saprolite.of the granite found at Mt. Airy, from west side,of Route 601, and about 1 1/2 miles by 

road south of center of Mt. Airy, Surry County, N. C.

48 Mt 45 Saprolite of granitized country rock, from northeast side of Route 18, and 0.4 mile S. 38° E. of Ramsey, 

Burke County, N. C.

49 Mt 136 Saprolite of granitized gneiss, from soil erosion gulch on south side of a dirt road, and 2.7 miles 

N. 5° E. of Fallston, Cleveland County, N. C.

49 Mt 182 Granitic saprolite from west side of a paved road, and 1 1/4 miles S. 22° E. of Rolesville, Wake County, 

N. C.

50 Mt 192 Saprolite of banded granitic gneiss, from north side of Route 421, about 5.9 miles by road east of 

junction of Routes 421 and 115, Wilkes County, N. C.

50 Mt 274 Granitic saprolite from south side of a cut along Seaboard Airline Railroad, and 0. 5 mile east of 

Norlina, Warren C ounty, N. C.

50 Mt 275 Granitic saprolite from southwest side of Route 158, and 2.2 miles S. 38° E. of Norlina, Warren 

County, N. C.

18
Localities of monazite-bearing saprolite and hardrock Continued 

North Carolina Continued

50 Mt 276 Granitic saprolite from southwest side of Route 158, and 3.6 miles S. 38° E. of Norlina; also 0.9 mile 

by road northwest of the center of Warrenton, Warren County, N. C.

50 Mt 278 Granitic saprolite from west side of Route 58, about 8.0 miles by road S. 29° W. of the center of 

Warrenton, Warren County, N. C.

50 Mt 282 Granitic saprolite from north side of Route 64, and 1.2 miles by road west of the Neuse River, Wake 

County, N. C.

50 Mt 284 Granitic saprolite from south side of Route 64, and 0.8 mile by road east of the Neuse River, Wake 

County, N. C.

50 Mt 290 Granitic saprolite from south side of Route 56, and 2.6 miles S. 62° W. of Louisburg, Franklin County, 

N. C.

50 Mt 295 Granitic saprolite from north side of Route 56, and south side of cut along Seaboard Airline Railroad; 

also 1.2 miles S. 49° W. of Louisburg, Franklin County, N. C. (Trace of monazite)

50 Mt 296 Granitic saprolite from south side of Route 56, and 1 3/4 miles S. 60° W. of Louisburg,' Franklin 

County, N. C.

52 Mt 37 Saprolite of granitic rock, from west side of an unpaved road, and 1.1 miles airline S. 42° W. of 

Garner, Wake County, N. C.

52 Mt 76 Saprolite of granite at Mt. Airy, from north side of Route 103, about 1.0 mile by road east of Ararat

River, and 0.4 mile east of entrance to quarry of North Carolina Granite Corp., Surry County,- N. C.

52 Mt 77 Saprolite of peripheral phase of granite at Mt. Airy, from southwest side of Route 52, and about 0.9 mile 

by road northwest of the junction of Routes 52 and 104, Surry County, N. C.

52 Mt 79 Saprolite of granite at Mt. Airy, from north side of Route 89, and 1.7 miles by road west of Lovills 

Creek; also 2.3 miles by road west of the junction of Routes 89 and 52, in center of Mt. Airy, 

Surry County, N. C.

52 Mt 81 Saprolite of fine-grained white granite gneiss, from west side of Route 601, about 4.7 miles by road

south of Dobson, and 0.6 mile by road north of the junction of Routes 601 and 268, Surry County, N.C.

South Carolina

45 Mt 34 Granitic saprolite, in part pegmatitic, in stringer and pockets, from east side of an unpaved road

a short distance northeast of Route 150, and 3 1/4 miles N. 50° W. of Gaffney, Cherokee County, S.C.

45 Mt 37 Pegmatitic saprolite, a thin stringer in schist, from southwest bank of Pole Bridge Branch of Cherokee 

Creek, and 0.9 mile S. 25° W. of Grassy Pond, Cherokee County, S. C.

45 Mt 39 Saprolite of schist impregnated with granitic material, from small headwater tributary of Cherokee 

Creek, northeast of Route 11, and 3 3/4 miles N. 45° W. of Gaffney, Cherokee County, S. C.

45 Mt 52 Pegmatitic saprolite in lenses and pockets, from bank of Floyd Branch of Island Creek, about 1.0 mile 

south of Cowpens Battleground Monument, Cherokee County, S,C.

45 Mt 62 Saprolite of pegmatized schist, from west bank of Joe Welchel Creek, a tributary of Beaverdam Creek, 

and 2.0 miles west of Gaffney, Cherokee County, S. C.

45 Mt 67 Pegmatitic saprolite in bank of Double Branch Creek, about 4.0 miles S. 23° E. of Chesnee, 

Spartanburg County, S. C.

45 Mt 89 Saprolite of gneissoid granite in east bank of Rock Ford Creek, and 2.2 miles N. 57° E. of Moonville, 

Greenville County, S. C.

45 Mt 95 Saprolite of pegmatized gneiss, from south side of paved road leading east from Greenville airfield, 

and 1 3/4 miles S. 32° E. of Conestee, Greenville County, S. C.

45 Mt 96 Aplitic saprolite, from south side of paved road leading east from Greenville'airfield, and 1-3/4 miles 

S. 32° E. of Conestee, Greenville County, S. C.

19
Localities of monazite-bearing saprolite and hardrock Continued 

South C arolina- -C ontinued

49 Mt 45 Saprolite of granite of the type found near Toluca, N. C., from east side of Route 29, about 1.1 miles 

by road north of the Saluda River, Greenville County, S. C.

50 Mt 119 Saprolite of granitic gneiss from northwest side of Route 76, and 1.3 miles by road northeast of 

Honea Path, Anderson County, S. C.

50 Mt 120 Saprolite of granitic dike from southeast side of Route 76, and 2.0 miles by road northeast of 

Honea Path, Anderson County, S. C.

50 Mt 122 Saprolite of granitic gneiss from south side of Route 76, about 1/4 mile west of Reedy River, and 

3. 5 miles N. 81° E. of Princeton, Laurens County, S. C.

50 Mt 123 Saprolite of muscovite granite gneiss, from north side of Route 101, and 150 yards west of the city 

limits of Gray Court, Laur ens County, S. C.

50 Mt 124 Saprolite of coarse-grained granitic gneiss, from north side of Mauldin-Conestee road, and 0.7 mile 

N. 53° E. of Conestee, Greenville County, S. C.

50 Mt 126 Granitic saprolite from southeast side of the paved road that connects Simpsonville and Pelzer, and 

2.3 miles N. 39° W. of Woodville, Greenville County, S. C.

50 Mt 127 Granitic saprolite from northwest side of the paved road that connects Simpsonville and Pelzer, and 

2.6 miles N. 58° W. of Woodville, Greenville County, S. C.

50 Mt 145 Granitic saprolite from southeast side of Route 221, and 1.1 miles by road northeast of Pacolet River; 

also 0.3 mile by road southwest of Mayo, Spartanburg County, S. C.

50 Mt 149 Granitic saprolite from west side of Route 221, about 0. 4 mile northeast of the junction of Routes 221 

and 9-43, and just north of the city limits of Spartanburg, Spartanburg County, S. C.

50 Mt 160 Granitic saprolite from southeast side of Route 296, and 1.9 miles N. 67° E. of Reidville, Spartanburg 

County, S. C.

50 Mt 161 Saprolite of pegmatized gneiss, from northeast side of Route 49, and 3 3/4 miles S. 9° W. of 

Batesville, Greenville County, S. C.

50 Mt 163 Saprolite of granitic gneiss, from east side of a paved road, 3.5 miles S. 73° E. of Simpsonville,

Greenville County, S.C. (

51 Mt 105 Granitic saprolite from north side of Route S-20-19, leading from Route 29 to Rion, just west of the 

track of the Rockton-Rion R. R. Also 5. 5 miles S. 22° W. of Winnsboro, Fairfield County, S. C.

51 Mt 107 Saprolite of coarse-grained granite, from west side of Route 269, and 9. 5 miles S. 24° W. of Winnsboro, 

Fairfield, County, S. C.

51 Mt 109 Granitic saprolite from west side of Route 269, and 6.7 miles S. 24° W. of Winnsboro, Fairfield County, 

S. C.

51 Mt 110 Granitic saprolite at entrance to quarry of Rion Crush Stone Corp., 6.1 miles S. 27° W. of Winnsboro, 

Fairfield County, S. C.

51 Mt 140 Granitic saprolite behind shop at the Blair quarry, about 1/2 mile east-southeast of Elair station on the 

Southern Railway, Fairfield County, S. C.

Georgia

49 Mt 14 Saprolite of granite near Zetella, from north side of Route 16, and 1.3 miles east of Zetella, Spalding 

County, Ga.

49 Mt 15 Saprolite of granite near Zetella, from both sides of an unpaved road that leads south-southeast from 

Zetella, and 2.2 miles by road from Zetella, Spalding County, Ga.

49 Mt 35 Granitic saprolite from south side of unpaved road that connects Covington with Pace (the old CovingtonMcDonough road), and 3. 5 miles S. 71 1/2° W. of Covington, Newton County, Ga.

20
Localities of monazite-bearing saprolite and hardrock--Continued 

Georgia- - C ontinued

49 Mt 40 Saprolite of granitized schist, from north side of an unpaved road (the old Porterdale-McDonough 

road), and 10. 0 miles S. 665° W. of Covington, Newton County, Ga.

49 Mt 41 Saprolite of granitized gneiss, from north side of an unpaved road (the old Porterdale-McDonough 

road), and 9.0 miles S. 66° W. of Covington, Newton County, Ga.

49 Mt 42 Saprolite of granitized gneiss, from north side of an unpaved road (the old Porterdale-McDonough 

road), and 7. 8 miles S. 64° W. of Covington, Newton County, Ga.

49 Mt 43 Saprolite of granitized gneiss, from north side of an unpaved road (the old Porterdale-McDonough 

road), and 6. 5 miles S. 58° W. of Covington, Newton County, Ga.

49 Mt 46 Saprolite of granite similar to that near Zetella, from northwest side of US 29, and 0. 7 mile N. 20° E. 

of Athens, Clarke County, Ga.

50 Mt 50 Saprolite of massive granite, from north side of Route 16, about 3i miles west of Sharpsburg, 

Coweta County, Ga.

49 Mt 59 Granitic saprolite along south side of Route 18, and 3. 7 miles S. 68° E. of Greenville, Meriwether 

County, Ga.

50 Mt 15 Saprolite of a granite stringer in augen gneiss, from a point just east of an old shaft in pegmatite, 

which is 3. 5 miles N. 55° W. of Yatesville, and 2. 0 miles N. 25° W. of Tobler Mill, Upson 

County, Ga. (Sample donated by Georgia Geological Survey.)

50 Mt 17 Saprolite of banded granitic gneiss, from west side of Route 85, and 3. 4 miles S. 27° E. of Gay, 

Meriwether County, Ga.

50 Mt 33 Saprolite of Snelson granite, from west side of Route 18-41, and about 0. 5 mile by road north of 

Harris, Meriwether County, Ga.

50 Mt 36 Saprolite of granitic gneiss, from southwest side of Route 18, and 1. 8 miles by road S. 76° E. of 

Greenville, Meriwether County, Ga.

50 Mt 40 Sun-baked reddish-brown saprolite of Carolina gneiss, from north side of Route 18, and 0. 8 mile by 

road west of Woodbury, Meriwether County, Ga.

50 Mt 44 Saprolite of granitic gneiss, from northeast side of Route 27, and 1. 7 miles S. 55° E. of Franklin, 

Heard County, Ga.

50 Mt 45 Saprolite of granitic gneiss, from northeast side of Route 27, about \ mile southeast of Franklin, 

Heard County, Ga. This locality is on an unpaved (abandoned) road, in sight of Route 27.

50 Mt 52 Saprolite of granitic gneiss, from north side of Route 34, and 1. 7 miles by road east-northeast of 

Texas, Heard County, Ga.

50 Mt 70 Granitic saprolite from northwest side of Route 14, about 4.0 miles by road west-southwest of 

La Grange, and 1. 4 miles by road west-southwest of railroad crossing, Troup County, Ga. 

In 1951, this locality was obliterated by a grader that cut away this bank, but equivalent material 

crops out on southeast side of road.

50 Mt 75 Granitic saprolite from northwest side of Route 14, about 2 3/4 miles by road west-southwest of 

La Grange, and 0.15 mile by road west-southwest of railroad crossing, Troup County, Ga.

50 Mt 76 Granitic saprolite from northwest side of Route 14, about 75 yards west of the road that leads southwest of Gallaway Field, and 3.15 miles by road west-southwest of La Grange, Troup County, Ga.

50 Mt 80 Saprolite of granitic gneiss, from northwest side of Route 14, about 5.9 miles by road west-southwest of La Grange, and 3. 3 miles by road west-southwest of railroad crossing, Troup County, Ga.

50 Mt 106 Saprolite of coarse-grained crenulated white granite, from northwest side of an unpaved road, 

0. 2 mile northeast of Flat Creek, and 4.2 miles S. 32° E. of Clermont, Hall County, Ga.

50 Mt 107 Granitic saprolite along southeast side of an unpaved road, 0. 3 mile southwest of Flat Creek, and 

4. 5 miles S. 28° E. of Clermont, Hall County, Ga.

21
Localities of monazite-bearing saprolite and hardrock--Continued 

Georgia--Continued

50 Mt 108 Saprolite of pegmatitic stringer in schist, from north side of an unpaved road, 0.4 mile west of a 

north-south road, and 4.4 miles S. 3° E. of Clermont, Hall County, Ga.

50 Mt 114 Saprolite of granitic gneiss, from west side of US 29, about 200 yards south of Little Bluestone Creek, 

and 3.1 miles N. 21° E. of Danielsville, Madison County, Ga.

50 Mt 115 Saprolite of white residual (pegmatitic) clay, along east side of a small gulch tributary to Shoal Creek, 

south of Route 51, and 1. 0 mile S. 58° E. of Bowersville, Hart County, Ga.

50 Mt 116 Saprolite of granitic gneiss, on south side of Route 51, and 1.1 miles S. 67° E. of Bowersville, 

Hart County, Ga.

50 Mt 117 Saprolite of a mixture of pegmatite and schist, along east side of Shoal Creek, just north of Route 51, 

and 1. 2 miles S. 74° E. of Bowersville, Hart County, Ga.

50 Mt 139 Saprolite of granitic gneiss on north side of an unpaved road, 1. 0 mile by road east of Route 59, and 

6. 1 miles N. 17° E. of Bowersville, Hart County, Ga.

51 Mt 204 Saprolite of red granitic gneiss, from west side of Route 29, and 2. 7 miles N. 19° E. o.f the junction 

l of Routes 29 and 18, in West Point, Troup County, Ga.

51 Mt 205 Saprolite of Snelson granite, from southeast side of Route 18, and 0. 6 mile by road east-northeast

of the railroad station at Durand; also 1.1 miles by road south-southwest of Crowders, Meriwether 

County, Ga.

51 Mt 206 Saprolite of Snelson granite, from east side of Route 41, and 2. 6 miles N. 18° W. of center of 

Warm Springs, Meriwether County, Ga.

51 Mt 212 Saprolite of granitized gneiss, from north side of Route 238, about 0.1 mile east-southeast of

bridge across Chattahoochee River; and 8. 6 miles S. 76° W. of center of La Grange, Troup County, 

Ga.

51 Mt 216 Saprolite of a thin seam of very coarse grained biotite granite, from north side of Route 238, and 

7. 2 miles S. 69° W. of center of La Grange, Troup County, Ga.

51 Mt 217 Saprolite of granitized gneiss, from south side of Route 238, and 7.0 miles S. 67° W. of center of 

La Grange, Troup County, Ga.

51 Mt 218 Saprolite of granitized gneiss, from west side of Route 29, and 6.9 miles S. 54° W. of center of 

La Grange, Troup County, Ga.

52 Mt 154 Saprolite of granite from west side of Liberty (Parker Hunt Co.) quarry, about 11. 65 miles N. 49^° E. 

of Lexington, Oglethorpe County, Ga.

52 Mt 160 Saprolite of granite gneiss (interbanded with schist) from east side of Route 22, and 6. 6 miles by

road south of junction of Routes 72 and 22; also 7. 8 miles b*y road north of junction of Routes 78 and 

22; in Oglethorpe County, Ga.

52 Mt 163 Saprolite of granite from southeast side of Route 72, and 1 3/4 miles northeast of Carlton; also 

1.0 mile by road southwest of Broad River, Madison County, Ga.

52 Mt 164 Saprolite of coarse-grained (pegmatitic) gneiss, from east side of Route 77, about 3.2 miles by 

road south-southeast of center of Hartwell, Hart County, Ga.

52 Mt 165 Saprolite of granite from east side of Route 172, about 6.1 miles by road south-southwest of center 

of .Hartwell; also 0. 5 mile north-northeast of Coldwater Creek; in Hart County, Ga.

52 Mt 167 Saprolite of banded gneiss, from northwest side of Route 78-10,-about 3. 7 miles by road southwest 

of Walton-Oconee county line, Walton County, Ga.

52 Mt 169 Saprolite of granitic stringer in schist, from east side of Route 129, and about 0. 3 mile by road northnortheast of Barber Creek, Clarke County, Ga.

52 Mt 170 Saprolite of granite from east side of Route 129, about 0. 9 mile by road north-northeast of Barber 

Creek, in Princeton, Clarke County, Ga.

22
Localities of monazite-bearing saprolite and hardrock--Continued

Georgia Continued

52 Mt 172 Saprolite of gneiss with granitic stringers, from north side of Route 29-82, about 3/4 mile by road 

west of the railroad station at Colbert, Madison County, Ga.

52 Mt 173 Saprolite of coarse-grained granitic dike, from east side of a newly paved road, about 2. 5 miles by 

this road southwest of Dewy Rose, Elbert County, Ga.

52 Mt 174 Saprolite of a granitic dike, from northeast side of Route 17, about 3. 0 miles by road southeast of 

center of Royston, Hart County, Ga.

52 Mt 175 Saprolite of a coarse-grained pegmatite, from southeast side of Route 17, about 1. 9 miles' by road 

northeast of the Madison-Clarke County line, in Madison County, Ga.

Alabama

51 Mt 161 Saprolite of granitic gneiss, from north side of paved road that connects Foster with Penton; and 

1. 0 mile N. 70° E. of Foster, Chambers County, Ala.

51 Mt 165 Saprolite of Pinckneyville "granite, " from southwest side of the Route 241 bypass southwest of 

Alexander City; and 2.1 miles S. 31° E. of center of Alexander City, Tallapoosa County, Ala.

51 Mt 166 Saprolite of Pinckneyville "granite, " from south side of Route 241, and 0. 8 mile S. 40° E. of center 

of Kelleyton, Coosa County, Ala.

51 Mt 167 Saprolite of Pinckneyville "granite," from west side of Route 115, and 2. 7 miles S. 33° W. of center 

of Kelleyton, Coosa County, Ala.

51 Mt 171 Saprolite of strongly biotitic Pinckneyville "granite, " from west side of Route 9, and 4. 7 miles 

S. 31° W. of center of Kelleyton, Coosa County, Ala.

51 Mt 172 Saprolite of Pinckneyville "granite, " from east side of Route 9, and 2. 6 miles. N. 17° W. of Equality, 

Coosa County, Ala.

51 Mt 173 Saprolite of Pinckneyville "granite, " from northwest side of Route 22, and 4. 8 miles S. 53° W. of 

center of Alexander City, Coosa County, Ala.

51 Mt 175 Saprolite of gneissic Pinckneyville "granite, " from west side of Route 63, and 3. 3 miles S. 7° W. 

of center of Alexander City, Tallapoosa County, Ala.

51 Mt 184 Saprolite of Pinckneyville "granite," from west side of Route 11, and 6. 6 miles S. 8° W. of Rockford, 

Coosa County, Ala.

51 Mt 185 Saprolite of Pinckneyville "granite, " from north side of Route 22, and 5.1 miles S. 82° E. of Rockford, 

Coosa County, Ala.

51 Mt 190 Saprolite of Pinckneyville "granite," from west side of paved road that connects Alexander City with 

Hackneyville, Tallapoosa County, Ala.

51 Mt 192 Saprolite of Pinckneyville "granite," from southwest side of paved road that connects Alexander City 

with Hackneyville, and 3.1 miles N. 14° E. of center of Alexander City, Tallapoosa County, Ala.

51 Mt 201 Saprolite of granitic gneiss, from east side of the unpaved road that connects Hickory Flat with 

Finley, and 2. 7 miles N. 83° E. of Stroud, Chambers County, Ala.

51 Mt 220 Saprolite of granitic gneiss, from northeast side of a paved road that connects Five Points with 

Fredonia, and 2. 4 miles S. 55° E. of Five Points, Chambers County, Ala.

51 Mt 222 Saprolite of granitic gneiss from east side of an unpaved road that runs parallel and close to the 

Alabama-Georgia boundary line, and 4.2 miles N. 75° E. of Fredonia, Chambers County, Ala.

51 Mt 224 Saprolite of granitic gneiss, from east side of an unpaved road that connects Buffalo with Chapel Hill, 

and 1. 6 miles N. 21° W. of Buffalo, Chambers County, Ala.

51 Mt 225 Saprolite of gneissic granite, from east side of an unpaved road that connects Chapel Hill with

Albany, and 5. 2 miles N. 21° W. of Buffalo; also 1. 6 miles N. 5° W. of Chapel Hill, Chambers 

County, Ala.

23
The bedrock source of monazite was first recognized in 1948 in Cleveland County, N. C., in the 

heart of what is now called the western monazite belt. 

One of the areas in which a great deal of placer mining 

was done in earlier years includes the valleys of Knob 

Creek and its tributaries, which head in and around a 

prominent granitic hill called Carpenter Knob, that 

lies about 17i miles north of Shelby. About 2 miles 

south-southeast of Carpenter Knob is one of the pavements of granitic rocks earlier mentioned, known 

locally as Acre Rock. A small opening has been made 

at this site, and rough building stone has been quarried 

there for many years. Sampling of the placers in the 

vicinity of Carpenter Knob and Acre Rock led to the 

belief that the granitic rocks exposed at these two 

sites are the principal sources of the placer monazite 

in this vicinity. This conclusion "was fortified by the 

discovery of monazite in the soil adjacent to Acre Rock; 

but as the residual character of this soil was uncertain, 

it was necessary also to sample the unweathered bedrock. Accordingly two samples, aggregating 760 pounds, 

were crushed, rolled, and panned, and these likewise 

were found to contain monazite.

The monazite-bearing rocks are now known to 

consist mainly of granitic intrusives, older granitic 

gneisses of the Carolina gneiss, and country rock of 

various kinds into which granitic materials have been 

introduced. It is stated by William C. Overstreet, 

in an oral communication, that about one-fifth of the 

samples collected in the Shelby quadrangle comprise 

monazite-bearing schists, that have no proven granitic 

affinity. The granitic intrusives are generally massive 

rocks that .have not been rendered gneissoid by regional 

metamorphism, but locally have a primary foliation 

of magmatic origin. The monazite-bearing rocks of 

the Carolina gneiss are largely granitic gneisses, 

most of which are probably of sedimentary origin, 

and are therefore to be designated as paragneiss. 

Other granitic gneisses of the Carolina gneiss that 

are monazite-bearing are probably ancient intrusives, 

that properly may be called orthogneiss. Rocks into 

which granitic minerals of normal size have been 

introduced, either in seams or lamillae of discernible 

size, or in more intimate association, are said to be 

granitized; and where the introduced material comprises minerals of large size, the term pegmatitization 

is used. The monazite in the schists cited by Overstreet 

may either have been derived from detrital grains 

that were a part of the original sediments from which 

these rocks were formed, or it may be of secondary 

origin. In either case, such schists are proximate 

rather than original sources of monazite.

The gneiss adjacent to the Toluca quartz monzonite in the Shelby quadrangle was found by Yates 

and Overstreet 1 to be granitized close to the intrusive 

by thin- seams of granitic material which gave place 

farther from the contact to granitic lamellae, that 

still farther from the intrusive became megascopically 

indistinguishable from the gneiss itself. Dikelike 

processes of granitization and pegmatitization were 

found to be more prevalent in the biotite and sillimanite 

schists; but pegmatitic impregnation has been observed 

by the writer in both massive and schistose types of 

country rock. Granitization and pegmatitization are 

specially prevalent in the Shelby area, but also have

1 Yates, Robert G., and Overstreet, William 

quadrangle, North Carolina, in preparation.

C. Geology of the Shelby

been observed to constitute important processes in 

South Carolina, particularly in the area southeast of 

Greenville. At most places in the monazite belts, however, where monazite occurs in granitic gneisses, later 

granitic materials appear'not to have been introduced 

secondarily.

Granites, pegmatites, and granitic orthogneisses 

are thus the original bedrock sources of monazite; the 

monazite-bearing paragneisses and schists, in the 

absence of evidence to the contrary, are interpreted 

as metamorphosed detrital rocks that contained monazite at the time of their deposition. Such rocks and 

also those into which granitic material has been introduced may be called proximate bedrock sources of 

monazite. Ortho and paragneisses are difficult to 

differentiate, and in fact are generally indistinguishable 

in roadside exposures of saprolite; similarly the introduction of granitic material into the country rock is 

not strikingly self-evident. Most southern geologists 

believe, however, that the granitic gneisses of the 

Carolina gneiss are dominantly of sedimentary origin, 

and it therefore is probably true that most of the bedrock sources of monazite in the Carolina gneiss are 

proximate sources. The field evidence so far accumulated 

indicates that granitic intrusives and the granitic gneisses 

of the Carolina gneiss, regardless of origin, are the 

principal sources of the monazite; and that the ratio 

of original to proximate bedrock sources varies greatly 

from one area to another.

Some of the granitic rocks within the monazite 

belts that have received formational names, and others 

of unusual significance, will now be mentioned. General 

geologic maps of North and South Carolina have not 

been made, so that formational names for the igneous 

and metamorphic rocks have not been generally applied. 

The name Whiteside granite was applied originally by 

Keith (1907, p. 4) to the granite at Whiteside Mountain, 

Jackson County, N. C.; and later this name was used 

(Keith and Sterrett, 1931, p. 6) to designate certain 

granitic rocks east of the Blue Ridge, in the Kings Mountain, N. C., and Gaffney, S. C., quadrangles. The 

use of this formational name at a distance of more than 

100 miles from the type locality, across the regional 

strike, was unwarranted, and the correlation is now 

believed to be erroneous. A part of this so-called 

Whiteside granite, that lies within and adjacent to the 

Shelby quadrangle, North Carolina, was found by the 

writer to be monazite-bearing; and later the name 

Toluca quartz monzonite was applied by Griffitts and 

Overstreet (1952, pp. 777-789) to this monazite-bearing 

rock. This formational name, however, was defined 

only for a small area, so that it can not properly be 

applied to similar rocks to the northeast or southwest. 

The specialized designation of quartz monzonite also 

limits its areal extension; the name Toluca granite 

would have been better. Finally the Toluca quartz 

monzonite is defined as monazite-bearing; but judging 

by experience elsewhere in the Piedmont, the same 

rock will probably be found not to contain monazite 

outside the western monazite belt.

One of the larger bodies of monazite-bearing 

granite found in the western belt occupies an area 

surrounding Mt. Airy, Surry County, N. C. This is 

well exposed at the quarry of the North Carolina Granite 

Corp., originally a large pavement called The Rock, 

where quarrying has been in progress since 1889. The 

central part of this mass is characterized by exposures

24
along the highways of partly decomposed bedrock and 

of saprolite, that are monazite-bearing. The peripheral 

part of the intrusive, however, is somewhat finer 

grained, and crops out commonly as a clayey saprolite, 

which contains little or no monazite.

Between the Shelby and Mt. Airy districts, a 

few localities of monazite-bearing saprolite are shown 

on plate 1, but in general this stretch has been little 

explored. The monazite that has been known for many 

years at Hiddenite, Alexander County, occurs in pegmatite and in granitized country rock. The localities east 

of North Wilkesboro, Wilkes County, and south of 

Dobson, Surry County, are the sites of monazite-bearing 

granitic gneiss.

Northeast of Mt. Airy, N. C., in Virginia, is a 

formation described on the geologic map of Virginia 

as the Leatherwood granite (Pegau, 1932), which is crossed 

by the western monazite belt. Monazite has been found 

in'the vicinity of Pegau's Leatherwood granite, but not 

actually within the areas mapped as such. Owing to 

possible inaccuracies of charting on the geologic map, 

it can not be said with assurance that monazite is 

absent from the so-called Leatherwood granite, but 

certainly it is not present in most of this formation. 

The geologic map of Virginia also delineates three 

other formations of granitic rocks that lie athwart or 

close to the western monazite belt. These are the 

Shelton granite gneiss, an unnamed granite shown near 

Redhouse, in Charlotte County, and the Redoak granite 

(Laney, 1917). None of these has been found to contain 

monazite. Instead, the monazite of the western belt 

in Virginia has been found largely in gneissic horizons 

of the three mapped divisions of the Wissahickon. These 

are the schist, the granitized gneiss, and intrusives 

in the schist all of the Wissahickon formation. West 

of Farmville, in Prince Edward County, monazite was 

found in massive granite that is undifferentiated on the 

map, but may be regarded as a part of the intrusives 

in the schist of the Wissahickon.

Granitic saprolites containing monazite have 

been recognized at numerous localities in South Carolina, 

all of which are shown on plate 1. One granitic saprolite 

of a type high in ilmenite, is exposed in the northern 

suburbs of Spartanburg. Numerous monazite-bearing 

granitic intrusives and gneisses were sampled southeast of Greenville, in Greenville County, and others 

still farther southeast in Anderson and Laurens Counties. 

Some of those southeast of Greenville are pegmatized 

rocks that have a high tenor in monazite. The sizes 

and shapes of the host-rocks are not known. The 

localization of the western monazite belt across South 

Carolina is determined partly by the sites of monazite 

placers that were formerly mined in Cherokee and 

Greenville Counties, and partly by discoveries in bedrock. 

Three principal formations are shown on the 

geologic map of Georgia that constitute most of the 

granitic bedrock lying within the western monazite belt. 

These are: first, granite of the type of Lester's Stone 

Mountain (Lester, 1938); second, granite gneiss of 

the type of his Lithonia; and third, the old Carolina 

gneiss. The granite at Stone Mountain, east-northeast 

of Atlanta, is a muscovite granite that is not monazitebearing, and is characterized by an extraordinarily 

low content of heavy minerals, mainly zircon. At 

Zetella, Spalding County, Ga., however, is a mass

of granite, occupying an' area of about 90 square miles, 

that is correlated on the geologic map with the Stone 

Mountain type; and southwest of this is a smaller body 

of the same type. Both these masses are biotite granite, 

actually quartz monzonite, that are monazite-bearing 

and are characterized by heavy minerals that are largely 

ilmenite, although the tenor in monazite is not less 

than in most of the granitic rocks of North and South 

Carolina.

A body of granite with a major elongation of 

N. 35° E. extends for 40 miles through Elberton and 

Lexington, Ga. This, though correlated on the geologic map of Georgia with the granite at Stone Mountain, 

is a biotitic rock and includes the monumental stones 

of Elbert and Oglethorpe Counties. This monumental 

stone is not generally monazite-bearing, but along the 

northwestern edge of the intrusives, specifically at 

the Liberty quarry (sample 52 Mt 154), it was found 

to contain monazite. This site is along the southeastern margin of the western monazite belt. Thus 

is displayed a feature that has been observed at other 

places in the southeastern States; a rock, which is not 

ordinarily monazite-bearing, becomes so where it extends into the monazite belt.

The typical granite gneiss at Lithonia, De Kalb 

County, Georgia is likewise not monazite-bearing, but 

granitic rocks that are mapped as the Lithonia type 

have been found to be monazite-bearing at Athens and 

Princeton, in Clarke County, in the vicinity of Greenville, 

Meriwether County, and west of La Grange, Troup 

County. The rock near Athens is a biotite quartz monzonite, as are some of those near Greenville. In the 

area west of La Grange, is a complex assemblage of 

granitic rocks, that include a monazite-bearing intrusive 

characterized by a high content of ilmenite, like that 

near Zetella, and also monazite-bearing gneisses. 

These rocks will only be distinguished by detailed geologic mapping.

The Carolina gneiss of Georgia, though not 

generally monazite-bearing, has been found to contain 

monazite near Bowersville, Hartwell, and Royston, 

in Hart County; near Danielsville, Colbert, and at 

other places in Madison County; in Clarke, Oconee, 

and Walton Counties; southeast of Covington, in Newton 

County; west of Sharpsburg, in Coweta County; and at 

other localities. Further exploration is needed in the 

country between Athens and La Grange.

A detailed geologic map has been made by the 

U. S. Geological Survey (Hewett and Crickmay, 1937, 

pi. 1), of the Warm Springs quadrangle, lying in 

Meriwether, Harris,and Talbot Counties, Georgia, 

Four granitic formations are shown on this map, namely, 

the Snelson and Cunningham granites, the Woodland 

gneiss, and the undivided Carolina gneiss. Four samples taken of the Snelson granite prove it to be generally 

monazite-bearing; and one of these, collected just east 

of Durand, in Meriwether County, contains about 0.02 percent of monazite, which is as high as any found in 

North Carolina, excepting pegmatite or pegmatized 

schist. The Carolina gneiss, just west of Woodbury, 

in Meriwether County, was also found to be monazitebearing.

The Pinckneyville granite, the principal granitic 

rock of the crystalline rocks of Alabama, has been 

found to be weakly monazite-bearing, Farther east,

25
in Tallapoosa and Chambers Counties, the country 

rock that is shown on the geologic map of Alabama as 

Archean schist and gneiss has also been found to be 

monazite-bearing within a narrow belt. These occurrences are collinear with the similar belt west of La 

Grange, in Troup County, Ga.

The eastern monazite belt is shown in plate 1 

to extend from a point 6 miles south of Raleigh northnortheastward for 200 miles to a point a short distance 

west of Fredericksburg, Va. The original discovery 

of an eastern monazite belt was made about IT miles 

south-southeast of Rolesville, Wake County, where 

a granitic intrusive and its altered saprolite crop out 

close together. The few localities to the southwest are 

granitic gneisses. North-northeast of Rolesville, 

the eastern belt, though distinguishable, is nowhere 

strongly defined until it reaches the Norlina-Warrenton 

area, where a monazite-bearing granite is well developed.

South of Raleigh the eastern monazite belt appears 

to be overlapped by the formations of the Coastal Plain, 

but it may reappear farther to the southwest. Evidence 

tending to confirm this idea was recently obtained near 

Rion, Fair field County, S. C., where monazite was 

found to be present in granitic saprolite at the quarry 

of the Rion Crush Stone Corp., and elsewhere in that 

vicinity'. It was also found in granitic saprolite at 

the Blair quarry, near Blair station on the Southern 

Railway, in Fairfield County.

The monazite-bearing rocks of the eastern belt 

in Virginia are heterogeneous. The principal hostrock is the granitized Wissahickon gneiss in which 

monazite is fairly plentiful. Five samples from this 

source were taken in Dinwiddie, Nottoway, Mecklenburg, 

and Goochland Counties. Three samples were taken 

in Spotsylvania County from a gneissic granite that 

continues north-northeastward toward the District of 

Columbia. One sample was taken in Hanover County 

from rocks mapped as Baltimore gneiss; and another, 

likewise from Hanover County, was taken from rocks 

mapped as Petersburg granite, though this formation 

is known not to be generally monazite-bearing. Finally, 

one sample was taken at a site southeast of Amelia, 

in Amelia County, from a small body of granitic 

saprolite, resembling somewhat the saprolite of 

Laney's Redoak granite (Laney, 1917). The latter 

however, is not monazite-bearing, and its heavies 

include considerable epidote, whereas the monazitebearing granite southeast of Amelia contains no epidote.

Outlying localities

Monazite has been found at a number of localities 

that lie outside of the two monazite belts. Most of the 

granitic rocks at these sites are either pegmatite, or 

coarse-grained granitic rocks with a pegmatitic habit. 

A few monazite-bearing granites have been found, 

however, that do not fit into these categories.

Monazite has been known for years as a rare 

mineral in some of the pegmatites in the Spruce Pine 

district, of western North Carolina. Recently however, 

the writer has discovered that the coarse-grained granite 

of this area, though generally barren of monazite, contains some of this mineral at a few places. The largest 

amount of monazite was .found at a site along the northeast side of the Spruce Pine-Bakersville road, about

26

4.2 miles by road from Spruce Pine. A horse or 

slice of schist, bounded on both sides by granite, crops 

out here; and monazite is present in the granite on 

both sides of the schist. Some of this monazite is 

coarse-grained, the larger grains ranging upward to 

1/8 inch in size. At a few other sites, smaller amounts 

of monazite were recognized in the granite near Spruce 

Pine.

Another occurrence in this part of western 

North Carolina is a small dike of pegmatite about 

2 3/4 miles west-southwest of Mars Hill, in Madison 

County. A 16-inch crystal of monazite, which was 

recovered at this locality years ago, is now a part of 

the mineral collection of the University of South Carolina, 

at Columbia.

A third locality is at and near "The Glades, " 

in Hall County, Ga. This place was repeatedly mentioned in the older literature on monazite in the southeastern states, but various writers, quoting one another, 

gave no details. The writer recently visited this place, 

and found "The Glades" to be an abandoned town site, 

which was formerly the center of an old gold-placer 

mining camp. Monazite evidently was found in the 

concentrates recovered with the gold, but apparently 

was not mined, except possibly as a small by-product. 

Exploration revealed that some of the local bedrock 

is a coarse-grained monazite-bearing granite, not 

unlike the granite near Spruce Pine. The monazite 

is coarse-grained. In an oral communication, 

A. S. Furcron, assistant State Geologist of Georgia, 

reported monazite northeast of The Glades, in Habersham 

and Rabun Counties. This would suggest the presence 

in this part of Georgia of a narrow subsidiary belt of 

monazite-bearing rocks, about 30 miles northwest 

of the main western belt. Another locality in this 

general area where alluvial monazite has been found 

is near Gillsville, about 10 miles east of Gainesville, 

in Hall County.

A fourth locality is in Upson County, Ga., about 

halfway between Yatesville and The Rock. This also 

is an occurrence of monazite in pegmatite. A sample was furnished to the writer by Dr. Furcron.

Other localities have been found where the 

source-rock is not pegmatitic. One of these, lying 

northwest of the western monazite belt, is the site 

of a red saprolite derived from massive granite, about 

3i miles west of Sharpsburg, Cow eta County, Ga. 

Three other localities where monazite-bearing granites 

occur, have also been found in the general vicinity of 

Franklin, Heard County, Ga. Sporadic occurrences 

of monazite outside the two monazite belts are to be 

expected, particularly in pegmatite.

Doubt has been expressed by some geologists 

regarding the reality of the two principal monazite 

belts. The existence of monazite at 176 localities 

is admitted, but it is suggested that the other 340 sites, 

where monazite is proven to be absent, are insufficient 

to establish the localization of monazite shown in 

plate 1. Some knowledge of the geology of the southeastern Piedmont region, coupled with a critical 

examination of the localities where monazite is absent, 

will reveal that a large percentage of the granitic 

rocks of this region have already been sampled, though 

not at very close intervals. But many of these more 

prominent bodies of granite and granitic gneiss are
remarkably similar along their major elongations, 

both petrographically and with regard to their contained 

heavy minerals. Therefore 340 scattered localities 

have more significance than may be realized by the 

casual reader.

No claim to finality, however, can be made for 

conclusions that are based upon reconnaissance work, 

though it seems reasonably certain, from the work so 

far done, that monazite is not universally distributed 

in the southeastern Piedmont region. It has already 

been stated that most of the rocks within the monazite 

belts are not monazite-bearing; and that the two belts 

represent merely the limits within which most of the 

southeastern monazite is likely to be found. It should 

also be emphasized that parts of the monazite belts 

are imperfectly explored, even for the standard of 

reconnaissance work, and may be found to be wider 

than shown in plate 1. It is envisaged that detailed 

geologic mapping, if done with the aid of the gold pan, 

will reveal the presence of many thin and unconnected 

horizons of monazite-bearing rocks, .as well as isolated 

spots where such rocks occur, both within and without 

the two principal belts. Thus the three localities east 

of Anderson, S. C., may possibly constitute part of a 

narrow subsidiary belt that is not a part of the main 

western belt; and the same is true of the five localities 

shown between Athens and Elberton, Ga. Attention 

has already been called to the definitely outlying 

localities near Spruce Pine, N. C., the area extending 

northeastward from The Glades, Ga., and the FranklinTexas area, Ga. It is hoped that the reconnaissance 

work recorded in this paper will stimulate other geologists to familiarize themselves with the use of the 

gold pan, so that more detailed results can eventually 

be obtained.

Petrographic character of rocks

The monazite-bearing source rocks enumerated 

in the preceding pages have been described generically 

as granite, pegmatite, granite gneiss, or merely as 

granitic rocks; and only a few of them can be more 

accurately designated. The reason for this nomenclature 

is that petrographic names can be given only from a 

study of hardrock samples; and outcrops of hardrock 

are rare at critical localities. In order to correlate 

saprolite with hardrock, the two must be found either 

in contact, or so close together that no doubt can exist 

of their equivalence. Granite quarries are the best 

sites for this correlation, but only a few quarries have 

been developed in monazite-bearing granitic rocks, and 

even at such sites saprolite does not necessarily overlie 

the hardrock. It therefore is much easier to discover 

monazite-bearing saprolite than it is to identify its 

hardrock equivalent.

Most of the granitic rocks that contain monazite, 

excepting the pegmatites, are biotitic. The granites 

in the Shelby area, and at Mt. Airy, N. C., are known 

to be quartz monzonites. The granites near Zetella, 

Spaulding County, and at Athens, Clarke County, Ga., 

likewise are biotite-quartz monzonites. The Snelson 

granite, of the Warm Springs area, exposed" at an old 

quarry a short distance east of Harris, Meriwether 

County, Ga., is a gneissoid granite, which is classified 

as a biotite monzogranite. The monazite-bearing rocks 

of western Georgia and of Alabama have not yet been 

studied. In the eastern monazite belt, the granite near

27

Rolesville, Wake County, N. C. is likewise a biotite 

monzogranite. The granite at the quarry of the Rion 

Crush Stone Corp., in Fairfield County, S. C., is 

a biotite-quartz monzonite; and that .at the Blair quarry, 

in the same county, is likewise a biotite-quartz monzonite, veering toward a monzogranite. Thus it appears 

that most of the monazite-b earing granites, excepting 

the pegmatites, are either quartz monzonite, or other 

granitic rocks not far removed from the monzonitic 

family.

Few of the monazite-bearing granite gneisses 

have been found in contact with their saprolites, but 

generally they appear to conform in petrographic 

character with the less-gneissic granitic rocks. 

Evidence accrues that monazite is much more widely 

distributed in granite gneisses than in massive granitic 

intrusives.

The data so far obtained, together with that 

gleaned from the several publications of T. L. Watson 

(1902, 1906, 1910) on the granitic rocks of the southeastern States, indicate that most of these rocks, 

though of different ages and origins, will have similar 

petrographic designations. Petrography alone is 

evidently an inadequate means of geological mapping. 

Correlation of the granitic rocks by means of their 

heavy minerals will be of great value in mapping; but 

determinations of absolute and relative ages by radiometric, chemical, and spectrographic studies of the 

radiogenic elements in the heavy minerals will be much 

more effective.

Heavy' minerals in bedrock

Most of the samples of heavy minerals that have 

been recovered from the granitic rocks of the southeastern states were taken from saprolites, but some 

necessarily were obtained by panning powdered hardrock. About one-third of these samples, lying mainly 

within the two monazite belts, have been found to contain monazite. The mineralogic character of most 

of the heavies and semiheavies obtained from the monazite-bearing rocks has been determined in the Trace 

Elements Laboratory of the Geological Survey by 

counting, but this work is still too incomplete to present the results in tabular form. Samples of purified 

monazite have also been separated for future chemical 

and spectrographic work. Only the content of magnetite 

has yet been determined in those samples that contain 

no monazite.

The mineralogical results so far obtained lead 

to some tentative generalizations. Comparison of 

concentrates that have not been recomputed free of 

quartz and other rock-forming minerals, suggest the 

following conclusions. The average content of concentrates recovered from monazite-bearing rocks has 

been found to be 0. 068 percent; from the non-monazitebearing rocks, 0.18 percent; the difference is caused 

by the lower tenor of iron ores in the rocks containing 

monazite. The average percentage of magnetite in 

concentrates obtained from monazite-bearing rocks is 

13 percent; the average percentage in concentrates 

from rocks that contain no monazite is 37 percent. 

This difference is still more marked when the average 

percentage of magnetite in the rocks is computed, as 

the corresponding values for the monazite-bearing 

and non-monazite-bearing rocks are found to be
0. 017 and 0. 094 percent. The mean tenor in ilmenite 

has been determined only for the monazite-bearing rocks, 

and is found to be 26 percent of the concentrates, and 

0.025 percent of the rocks. Comparing these two values 

with the corresponding values for magnetite, namely, 

13 and 0. 017 percent, it is apparent that ilmenite is 

much more plentiful than magnetite in the monazitebearing concentrates ahd rocks. The relative plenitude 

of these two minerals in many concentrates is even 

more marked when it is stated that about one-third 

of the monazite-bearing rocks contain less than 0.01-percent ilmenite.

The percentages of the minerals comprising about 

two-thirds of the monazite-bearing concentrates have 

been determined, and recomputed .free of quartz and 

other minerals having a specific gravity less than 3. 0. 

The writer is well aware of the fallacy of averaging 

percentages to obtain mean tenors, but so many possible 

errors are present in the initial determinations of these 

minerals, that the work involved in the proper method 

seems hardly warranted.

The principal minerals of the concentrates are 

monazite, ilmenite, magnetite, zircon, rutile, and 

garnet, with smaller amounts of epidote, sillimanite, 

kyanite, sphene, hematite, and opaque black minerals. 

The content of monazite is calculated to range from a 

trace to 98 percent, with a mean value of 34 percent. 

The tenor in the host-rocks ranges from 0. 00005 to 

0. 02 percent, with a mean value of 0.006 percent, though 

the tenor in pegmatite and pegmatized country rock may 

attain 0.1 percent. No linear relationship exists between 

the mean tenors of the concentrates and of the rocks, 

as concentrates that are very high in monazite are likely 

to constitute only a very small percentage of the hostrock.

The total and relative amounts of iron ores present in the monazite-bearing granitic rocks permit a 

three-fold classification of these concentrates, which 

may or may not correlate with differences in the origin 

or ages of the host-rocks. The first type, which includes 44 percent of these concentrates, contains less 

than 20 percent of iron ores, almost entirely ilmenite; 

about one-fifth of these are entirely free of iron ores; 

and about three-fifths contain from a fraction of 1 percent to 10 percent of iron ores. The second type, which 

includes 37 percent of the concentrates, contains from 20 

to 99 percent iron ores, in all of which the content of 

ilmenite exceeds that of magnetite. About three-fifths 

of the concentrates of the second type contain no magnetite, and another fifth contains from a fraction of 

1 percent to 10 percent of magnetite. The remainder 

of the concentrates, constituting the third type, contain ilmenite and magnetite in varying proportions, but 

six-sevenths of these contain more magnetite than 

ilmenite. These three types of concentrates are therefore designated respectively as the low iron-ores type, 

the high-ilmenite type, and the high-magnetite type. 

This classification appears to apply both to the granitic 

intrusives and to the granitic gneisses that are monazite bearing.

Next to monazite and the iron ores, zircon is 

the most plentiful mineral of the concentrates. It 

occurs in about 80 percent of the monazite-bearing 

concentrates, ranging in tenor, where present, from 

a trace to 96 percent of the heavies. The mean tenor 

is about 13 percent. The percentage of zircon in the

28

rocks that contain no monazite has not yet been determined, so that no comparison can be made with the 

monazite-bearing rocks. The monazite-bearing granite 

gneiss of the Shelby quadrangle, however, was found to 

contain more zircon than the monazite-bearing granitic 

intrusives; and this fact was used in the field to differentiate between saprolites of gneiss and granite that 

were not otherwise distinguishable. This relationship 

may be only of local application.

Rutile has been identified in almost 40 percent 

of the monazite-bearing concentrates so far examined, 

ranging in tenor from a trace to as much as 63 percent 

of the heavies, with an average tenor, where present, 

of about 7 percent. The high maximum and the low 

mean contents show that rutile rarely constitutes any 

large part of the heavies. Garnet has been recognized 

in about 27 percent of the monazite-bearing concentrates, ranging in tenor from a trace to 98 percent 

of the heavies, with an average tenor, where present, 

of about 13 percent. Three samples of concentrates 

were obtained in which garnet constitutes more than 

70 percent of the heavies, yet-it is absent entirely in 

62 percent of the monazite-bearing concentrates. Comparison of the mean tenors of garnet and zircon show 

them to be about the same, but zircon is nearly three 

times as widely distributed as garnet.

Xenotime, the yttrian counterpart of monazite, 

has been identified in 10 percent of the monazitebearing concentrates, but may be present in a still 

larger proportion. One sample of concentrates, 

52 Mt 91, which was collected from a coarse-grained 

granitic gneiss in Powhatan County, Va., consists 

mainly of xenotime and ilmenite with no recognizable 

monazite. The xenotime constitutes about half of the 

heavies, and about 0. 003 percent of the rock. The 

next highest tenor found in xenotime was in sample 

52 Mt 164, of a pegmatitic gneiss, collected a short 

distance south-south east of Hartwell, Ga. About half 

of these concentrates consist of xenotime, the remainder 

being mainly monazite and zircon. No iron ores are 

present. A third sample worthy of mention is50Mt 120, 

collected northeast of Honea Path, S. C. The concentrates include 62 percent of monazite and 15 percent 

of xenotime. Three other of the samples so far 

examined contain more than 10 percent xenotime, but 

the mean tenor, where recognized to be present, is 

3 percent or less.

Epidote has been found in a very few of the monazite-bearing granitic rocks, but where present, it 

may constitute a high percentage of the concentrates. 

Two samples of concentrates in which epidote is 

plentiful come from the granite near Mt. Airy, Surry 

County, N. C., and from the granite near Blair, 

Fairfield County, S. C. It must be emphasized, however, that epidote is not universally present in the 

granite at Mt. Airy, as samples of concentrates have 

been obtained wherein this mineral is absent. Sillimanite has been identified in about 9 percent of the 

concentrates, mainly in those obtained from metamorphosed granitic rocks. Itst&verage tenor, where present, is about 7 percent of th* heavies.

The quartz monzonite at Acre Rock, Cleveland 

County, N. C., exemplifies that type of rock which 

yields concentrates low in iron ores. Its heavies are 

largely garnet, with relatively small amounts of zircon, rutile and monazite, and practically no iron ores.
A more typical example, because it contains little or 

no garnet, is a granite (49 Mt 45) from Greenville 

County, S. C., whose concentrates contain about 83 percent monazite, 16 'percent zircon, 1 percent ilmenite, 

and 0.2 percent xenotime. Many similar granites are 

known. Monazite-bearing granitic gneisses also fall 

in this class. Thus the concentrates of samples 50 Mt 172 

and 50 Mt 196 contain respectively 0. 7 and 4. 5 percent 

ilmenite, and 87 and 83 percent monazite. Also the 

granitized gneiss of the Wissahickon formation, 50Mt233, 

from Dinwiddie County, Va., yields concentrates that 

contain 0.1 percent ilmenite and 61 percent monazite.

The granitic intrusive south of Zetella, Spaulding 

County, Ga., exemplifies the second type of concentrates, as the heavies comprise about 94 percent 

ilmenite, no magnetite, and about 6 percent monazite. 

The volume of concentrates per pound of bedrock is 

very large, so that the tenor in monazite, though low 

in the concentrates, is about 0.017 percent of the bedrock. Another representative of this type is a granite 

in the northern suburbs of Spartanburg, Spartanburg 

County, S. C. The concentrates of this rock comprise 

86 percent ilmenite, no magnetite, 10. 7 percent monazite, 0. 7 percent rutile, and 2. 6 percent of opaque 

dark minerals. The tenor of monazite in bedrock is 

about 0.003 percent. This type of intrusive is also 

well represented in the eastern monazite belt. Thus 

the granitic rock near Norlina, Warren County, N. C., 

yields concentrates that contain about 89 percent 

ilmenite, no magnetite, about 11 percent monazite, 

and a little rutile. The volume of concentrates is fairly 

large, so that the percentage of monazite in the hostrock is about 0.005 percent. The granite near Rolesville, 

Wake County, N. C., however, yields concentrates 

that comprise about 77 percent ilmenite, 16 percent 

magnetite, 4 percent monazite, and about 3 percent 

zircon. The tenor of monazite in bedrock is about 

0.003 percent.

Some of the monazite-bearing granitic gneisses 

also belong to the type high in ilmenite. An example 

in the western belt is a part of the Carolina gneiss 

that crops out as saprolite just west of Woodbury, 

Meriwether County, Ga. The concentrates from this 

rock contains about 42 percent ilmenite, 2 percent 

magnetite, about 45 percent monazite, and about 11 percent zircon. The tenor of monazite in bedrock is about 

0.007 percent. An example from the eastern belt is 

a granitic gneiss (50 Mt 251) from Hanover County, Va., 

whose concentrates contain about 97 percent ilmenite, 

a trace of magnetite, 3 percent monazite, 1 percent 

garnet, and 61 percent zircon. The tenor of monazite 

in bedrock is 0.0015 percent.

Concentrates of the third type constitute only 

about one-fifth of all the samples. Two examples in 

the western belt are granite gneisses, samples 50 Mt 122 

and 50 Mt 123, from Laurens County, S. C. Two from 

the eastern belt are granites from the quarry of the 

Rion Crush Stone Corp., and the Blair quarry, both 

in Fairfield County, S. C.

Origin of monazite belts

The restriction of monazite largely to two belts 

warrants some consideration. The western belt extends southwestward from east-central Virginia to 

Alabama, for a distance of about 600 miles; the eastern

belt extends from the vicinity of Fredericksburg, Va., 

south-southwestward for 200 miles, but seems to reappear 175 miles farther along its trend, near Rion, S. C. 

These belts are not geological formations, as they include various kinds of crystalline rocks. Indeed most 

of the rocks within these belts are not monazite-bearing; 

the belts merely delimit the areas within which monazite-bearing rocks are likely to be found.

Monazite is restricted largely to granitic rocks, 

or to derivatives thereof. Under this general heading 

are included a variety of granitic intrusives, granitic 

gneisses of both sedimentary and intrusive origin, and 

granitized country rock. Granitic intrusives, including 

both massive granitic rocks and orthogneiss, are the 

original source-rocks. Granitic rocks of sedimentary 

origin, in which monazite was originally a detrital 

constituent, constitute a second major source. Geologists consider that most of the granitic gneisses of 

the southeastern Piedmont are paragneiss, but the 

ratio of paragneiss to orthogneiss has not been determined. A third source-rock comprises various types 

of country rock, into which monazite has been introduced secondarily. Certain monazite-bearing schists 

have also been mentioned, wherein the origin of the 

monazite has not been determined.

Monazite occurs in certain formations within 

the monazite belts, but not contiguously in the same 

formations outside the belts. It appears, moreover, 

that the monazite belts do not everywhere follow the 

strike of the country rocks, but more commonly cut 

across the strike. The junction of the western with 

the eastern monazite belt, as shown in plate 1, is 

ample evidence of this general condition. It follows 

from these two conditions that the belts, rather than 

the rocks or rock structure within the belts, are the 

really significant features.

Finally it has been shown that monazite occurs 

in three types of concentrates, called the low iron ore, 

the high ilmenite, and the high magnetite types. As 

these types are reasonably distinct, without continuous 

gradations from one to the others, it is surmised that 

they may have some significance in the origin of the 

host rocks.

These environments of monazite, apparently 

unrelated primarily to the petrology, structure, or 

geologic age of the various host-rocks, are hard to 

explain; but possibly a speculative hypothesis is 

warranted. Let it be assumed that certain monazitebearing granitic rocks were injected in this country, 

possibly about the time when the granites of the 

Laurentian series were elsewhere emplaced. Let it 

further be supposed that the original country rock that 

existed at the time of this intrusion was subsequently 

deeply eroded, baring some or all of the underlying 

granitic intrusives; and that all of these events occurred 

in early pre-Cambrian time. Later, certain of the 

rocks that are now described collectively as the Carolina 

gneiss originated as sedimentary formations; and these 

finally were metamorphosed to produce the paragneisses 

and schists that are now exposed in the Piedmont. Any 

of the original granitic intrusives that now remain, and 

are bared to erosion, would naturally have become 

orthogneisses.

These ancient sedimentary rocks were doubtless 

of various types, but if rivers existed then as now,

29
it appears reasonable that some part of these sediments 

may have been of fluviatile origin. Let it be assumed 

that at least two master valleys existed in the area that 

we now call the southeastern Piedmont region; and that the 

monazite released from the original intrusives of 

Laurentian age was distributed in the fluviatile deposits 

of these valleys. In order to be preserved, such fluviatile deposits were probably deeply buried, in one or 

more geosynclines, of the same or different ages; and 

these, together with many other sediments of diverse 

origin, were reconstituted to form what is now known 

as the Carolina gneiss. Later, perhaps much later, 

parts of the Carolina gneiss, including some of the 

original fluviatile deposits, were melted by heat and 

pressure, and were injected into their surrounding 

host-rock. Also some of the original granite of the 

Laurentian series may also have been remelted, and 

injected as another granite intrusive into the Carolina 

gneiss. And finally, remnants of the original Laurentian, 

now a granite gneiss, may have been bared to recent 

erosion, thus constituting the minor proportion of 

orthogneiss in the Carolina gneiss.

This composite hypothesis, unproven and at 

present improvable, would account for the presence of 

monazite in two well-defined belts that join each other. 

It would also explain the presence of monazite in diverse 

types of granitic intrusives, in orthogneisses, and in 

metamorphosed sedimentary rocks, such as paragneiss 

and certain schists. An alternative hypothesis, considered by the writer, is that the two monazite belts 

represent concentrations of heavy minerals along preGambrian beaches. But this hypothesis was rejected 

because beaches move inland and seaward during successive physiographic cycles, with the result that heavy 

minerals are likely to be distributed over a foreland 

of considerable width. The present distribution of 

monazite in all the formations of the southeastern Coastal 

Plain exemplifies this condition; the distribution of gold 

on the foreland north of Nome, Alaska is another example. 

Other explanations that have no relation to sedimentation, 

but instead deal entirely with igneous geology, are 

certainly possible; but none has occurred to the writer 

that conforms so well with the field evidence.

The iron ores in the early pre-Cambrian granites 

should have included both magnetite and ilmenite, as 

magnetite is much more prevalent than ilmenite in many 

of the granitic rocks outside the monazite belts. But 

ilmenite is known to have a much greater resistance to 

weathering than magnetite. The heavy minerals now 

being recovered in Florida, for example, contain about 

38 percent ilmenite and only 4 percent magnetite or 

less, although no such relationship exists between the 

iron ores in the rocks of the Piedmont. Therefore the 

paucity of magnetite in most of the monazite-bearing 

granitic rocks can be explained by supposing that most 

of it was oxidized during one or more stages of sedimentation earlier in the pre-Cambrian.

This explanation has two implications. First, 

it suggests that most of the monazite was at one time 

deposited in sedimentary rocks that were subsequently 

changed either by regional metamorphism to paragneiss, 

or by remelting to later granitic intrusives. Under 

such cpnditions the resulting metamorphic and igneous 

rocks would have much more ilmenite than magnetite. 

But the quantitative effects of this process remain to 

be demonstrated. Ilmenite, although much more resistant to weathering than magnetite, eventually succumbs

to oxidation. Thus the so-called ilmenite produce now 

being recovered at the plant east of Jacksonville, Fla., 

is reported to contain about 4. 5 percent FeO, 26. 5 percent Fe2O3,and 61. 5.percent TiOg, whereas ilmenite 

theoretically should contain no FegOs and a much lower 

content of TiOg.' This product may be arizonite. Similarly 

at the plant southeast of Starke, Fla., nearly 20 percent 

of the ilmenitic iron ores are really leucoxene, and 

the remainder similar to those above described. It 

therefore may not be stated how much ilmenite should 

occur in the paragneiss of the Carolina, or in its 

palingenetic derivatives; nor may the chemical character of the ilmenite be anticipated. These conditions 

will depend upon the nature and duration of the physiographic cycles, through which the iron ores have passed. 

Great variations may be expected in the paragneisses, 

but in general the tenor in magnetite should be relatively 

low.

A second implication is that certain other gneisses 

and granitic intrusives should occur within the monazite belts that are relatively high in magnetite. Such 

rocks would represent the original intrusive of Laurentian 

age, now converted to an orthogneiss, and remelted 

parts of this orthogneiss that would constitute a part 

of the monazite-bearing intrusive granitic rocks. The 

presence of rocks have already been mentioned, containing concentrates in which magnetite predominates 

over ilmenite. As might be expected, rocks yielding 

concentrates of this type are relatively uncommon. 

The nature of the iron ores, both in the granitic intrusives and in the granitic gneisses, therefore appear 

to be consonant with the hypothesis that has been outlined.

The foregoing considerations suggest a statistical 

approach to a study of the origin of granitic intrusives 

and gneisses in the southeastern Piedmont region. If 

such rocks have passed through one or more sedimentary 

stages in their evolution, this fact might well be reflected in the amounts and character of their iron ores, 

and particularly in the chemical composition of the 

contained ilmenite. It is impossible to predict the 

results that might result from this approach, but the 

method is worthy of investigation. The iron ores from 

more than 500 samples of granitic concentrates that 

have already been collected in the southeastern Piedmont 

province could constitute a beginning for such a research program.

REFERENCES CITED

Griffitts, W. R., and Overstreet, W. C., 1952, 

Granitic rocks of the western Carolina Piedmont: 

Am. Jour. Sci., vol. 250, no. 11, pp. 777-789.

Hewett, D. F., and Crickmay, G. - W., 1937, The 

warm springs of Georgia, their geologic relations 

and origin, a summary report: U. S. Geol. Survey 

Water Supply Paper 819, pi. 1.

Houk, L. G., 1943, Monazite sand: U. S. Bur. Mines 

Inf. Circ. 7233, pp. 11-12.

Keith, Arthur, 1907, The Pisgah quadrangle, North 

Carolina: U. S. Geol. Survey Atlas (folio 147), p. 4.

Keith, Arthur, and Sterrett, D. B., 1931, The Gaffney 

and Kings Mountain quadrangles, South Carolina and 

North Carolina: U. S. Geol. Survey Atlas (folio 222), 

p. 6.

30
Laney, F. B., 1917, The geology and ore de- Pegau, A. A., 1932, Pegmatite deposits of Virginia:

posits of the Virgilina district of Virginia and Virginia Geol. Survey Bull. 33, pp. 15, 29, pis. 2, 3.

North Carolina: Virginia Geol. Survey Bull. 14, Watson, T. L., 1902, A preliminary report on a part

pp. 35-36, map. of the granites and gneisses of Georgia: Geol. SurLester, J. G., 1938, The geology of the region around vey of Georgia Bull. ,9-A, 367 pp.

Stone Mountain, Ga. (abstract): Colorado Univ. Studies, _______, 1910, Granites of the southeastern Atlantic

vol. 26, no. 1. States: U. S. Geol. Survey Bull. 426, 282 pp.

_______, 1939, Garnet segregations in granite Watson, T. L., and Laney, F. B., 1906, The building

gneiss of De Kalb County, Ga.: Jour. Geology, vol. 47, and ornamental stones of North Carolina: North

no. 8. Carolina Geol. Survey Bull. 2, 283 pp.

IHT.-DUP. SEC., WASH., D.C. 1.0270

GEOLOGICAL SURVEY 

87°

CIRCULAR 237 PLATE 1 

77°

MONAZITE BELTS OF THE SOUTHEASTERN ATLANTIC STATES

Sample localities 

EXPLANATION

Saprolite and hardrock 

(IMo monazite)

Saprolite and hardrock 

(Monazite-bearing)

Alluvium,eluvium, and soil in Piedmont 

{IMo monazite)

Alluvium, eluvium, and soil in Piedmont 

(Monazite-bearing)

Coastal Plain formations 

(IMo monazite)

Coastal Plain formations 

(Monazite-bearing)

Fluviatile deposits in Coastal Plain 

I IMo monazite)

Fluviatile deposits in Coastal Plain 

(Monazite-bearing)

Approximate location of monazite belt