Monazite Placers In the 

Southeastern Atlantic States 

By jOHN B. IvfERTIE, JR. 

GEOLOGICAL SURVEY BULLETIN 1390 

A4 ountain streams need exploration) 

but the main placers are likely 

to be in the Coastal Plain 

UNITED STATES GOVERN~1ENT PRINTING OFFICE, WASHINGTON : 1975 
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary 

GEOLOGICAL SURVEY 

V. E. McKelvey, Director 

Library of Congress Cataloging in Publication Data 

Mertie, John Beaver, 1888-

Monazite placers in the southeastern Atlantic States. 

(Geological Survey Bulletin 1390) 

Bibliography: p. 

Supt. of Docs. no.: I 19.3.1390 

1. Monazite-Southern States. 2. Hydraulic mining. 

I. Title. II. Series: United States Geological Survey Bulletin 1390. 

QE75.B9 No. 1390 [TN948.M7) 557.3'08s 

[553'.4943'0975] 74-14705 

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

Washington, D. C. 20402 -Price 80 cents (paper cover) 

Stock Number 024-001-02603 
CONTENTS 

Page 

Common measures and their metric equivalents _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ IV 

Abstract _____________________________________ ----- 1 

Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2 

Purpose of present report _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2 

Other investigations _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 

Rare-earth minerals and uses ____________________________ - 4 

Sources of monazite _______________________________ - 4 

Rare earths _________________ _ ______ _______ _____ _ 5 

Alluvial monazite ___ _____ __ _ _____ _______ _______ ____ _ _ 7 

Piedmont province _______ _ _____ _ ___ ___ _______ ____ _ _ 7 

Coastal Plain province _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10 

General geology _______ _ ____ _ _____ _ _______ _ _____ 10 

Deposits of heavy minerals _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ _ _ _ _ _ _ _ 12 

Sources ___ ______ _ _____ ______ _ _______ _____ 12 

Prospecting _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 13 

Exploration under the present investigation _ _ _ _ _ _ _ _ _ _ _ _ _ 14 

Genetic interpretation _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 14 

Placer mining __ _____ _ ______ ___ __ _ _______ _ ____ _ 25 

South Carolina ____ _ _____ _ ___ __ _ __ _____ _____ _ 25 

Florida _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 27 

Conclusions________________________________________ 38 

References cited _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 38 

ILLUSTRATIONS 

FIGURE 1. Map showing configuration of the three monazite belts in the 

Southeastern Atlantic States in relation to the inner edge of the 

Page 

Coastal Plain ______ ____ ___________ _ _____ ___ 3 

2. Map showing distribution of monazite-bearing samples from the 

Coastal Plain of South Carolina _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 15 

3. Map showing distribution of monazite-bearing samples from the 

Coastal Plain of Georgia------------------------ 16 

4-9. Photographs: 

4. The Perry bucket dredge, operating in the valley floor of Horse 

Creek, Aiken County, S.C.------------------ 26 

5. Suction dredge of the National Lead Co., Duval County, Fla. 29 

6. Battery of Humphrey spirals at the plant of the National Lead 

Co., Duval County, Fla.-------------------- 29 

7. Concentrating plant of Humphrey spirals on a barge, at the 

southern plant of the E. I. duPont de Nemours and Co. in 

Clay County, Fla. ----------------------- 32 

8. Suction dredge of the E. I. duPont de Nemours and Co., at the 

southern plant, in Clay County, Fla. _ _ _ _ _ _ _ _ _ _ _ _ 33 

9. Aerial view of the dredge, separatory plant, and offices of the 

Florida Minerals Co., Indian River County, Fla. 36 

III 
IV CONTENTS 

TABLES 

Page 

TABLE 1. Locality and description of samples from the Coastal Plain, South 

Carolina and Georgia ----------------- _______ 17 

2. Accessory minerals from sedimentary rocks in eight counties, 

Coastal Plain of South Carolina ________________ __:_ 20 

3. Accessory minerals from sedimentary rocks in four counties, Coastal 

Plain of Georgia __ _ ___________ _____ ________ 22 

4. Comparative mean tenors of accessory minerals in crystalline rocks 

and Pleistocene terraces _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 24 

5. Sizes of minerals in concentrates from the northern ore body, 

. National Lead Co. placer, Duval County, Fla _ _ _ _ _ _ _ _ _ _ 30 

6. Sizes of monazite grains from the northern ore body, National Lead 

Co. placer, Duval County, Fla ------------------- 31 

7. Composition of minerals and ilmenite products from placer mines in 

Florida _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 34 

8. Sizes of heavy minerals in concentrates from Trail Ridge, Fla _ 34 

9. Sizes of monazite grains from Vero Beach, Fla. _ _ _ _ _ _ _ _ _ _ 37 

COMMON MEASURES AND THEIR METRIC EQUIVALENTS 

Common Measure Equivalent 

Inch ____________________________________ 2.54 centimetres. 

Foot _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 0.3048 metre. 

Yard ____________________________________ 0.9144 metre. 

Mile ----- _ ---------- ____________________ 1.6093 kilometres. 

Acre ____________________________________ 0.404Thectare. 

Cubic yard _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 0. 7646 cubic metre. 

Pound, avoirdupois ___________________________ 0.4536 kilogram. 

Ton, long _________________________________ 1.0160 metric tons. 

Ton, short------------------ _______________ 0.9072 metric ton. 
MONAZITE PLACERS IN THE 

SOUTHEASTERN ATLANTIC STATES 

By JOHN B. MERTlE, JR. 

ABSTRACT 

Placer mining for monazite in North Carolina and South Carolina in the periods 

1887-1911 and 1915-17 was done on small deposits in the headwaters of streams that 

drained monazite-bearing rocks. Exploration was undertaken in 1951-54 by the U.S. 

Geological Survey and U.S. Bureau of Mines with the objective of finding larger ore 

bodies of suitable grade farther downstream that would warrant large-scale mining, but 

such deposits have not been found. The explanation for the lack of deposits is that a high 

percentage of the alluvial monazite moves continuously downstream unless it can be held 

in the interstices of gravel beds. However, the alluvial sediments contain only sparse 

gravel deposits, because the weathering of most common crystalline rocks in the 

Southeastern States generally yields only sand, silt, and clay. Exploration is not yet complete, and workable deposits may still be found in valleys where quartzite, chert, 

crystalline limestone, or other durable rocks are present to produce the thick beds of 

gravel. 

That part of the Coastal Plain most likely to have received detrital monazite from the 

belts of monazite-bearing crystalline rocks in the Piedmont is shown to be in Virginia, 

North Carolina, South Carolina, Georgia, and Florida. The formations of the Coastal 

Plain range in age from Cretaceous to Holocene. Distinct Pleistocene terraces are present. 

The occurrence of monazite in the sedimentary formations of the Coastal Plain is considered, and tables are presented showing the results of panning sedimentary materials 

from the Pleistocene and some of the Tertiary beds in South Carolina and Georgia. 

Monazite is generally found in these formations, but the tenors are so low that workable 

deposits are unlikely. Reconcentration of such deposits by local streams that do not head 

in the Piedmont province may yield workable placers. A fluvial deposit in Aiken County, 

S. C., is cited and described as an example of this process. 

The Pleistocene terraces are distinguished from one another by their maximum 

altitudes above sea level. The deposits that form the terraces have well-defined upper 

limits marked by ancient shorelines, but have no recognizable lower limits. The terraces 

have been correlated with the several interglaciations of the Pleistocene Epoch, and it is 

shown that the conditions of weathering, erosion, transportation, and deposition of these 

sediments were more favorable for the accumulation of heavy minerals during the interglaciations than in Holocene time. Therefore, the largest volume of heavy minerals will 

be found in the terrace deposits, rather than along the present beaches. 

Monazite is generally distributed in all the littoral deposits of Florida, but the content 

is too low to produce monazite placers. Placers of ilmenite, rutile, and zircon, however, 

are mined, and at two of the four operating plants, monazite is produced as byproduct. 

These deposits of heavy minerals, and the methods used in mining them, are briefly 

described. 

1 
2 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

INTRODUCTION 

PURPOSE OF PRESENT REPORT 

A reconnaissance for monazite, an ore of the rare earths and thorium, 

was made in North Carolina, South Carolina, and Georgia during 1945-

57 (fig. 1). This work consisted mostly of examining and sampling 

granite saprolites to determine the tenor and character of their 

accessory minerals. In part, the reconnaissance included an examination of areas where fluvial monazite placers were once mined and the 

areas where such placers might possibly exist. The investigation of the 

fluvial placers was begun in the Piedmont of North Carolina in 1945 

and was extended to South Carolina in 1948 (Mertie, 1953). In 1951, the 

study of the fluvial monazite deposits in the western Piedmont of North 

and South Carolina mainly, but also partly in Georgia and Virginia, 

became a separate project undertaken jointly by the U.S. Geological 

Survey and the U.S. Bureau of Mines. Reports on this work have been 

published (Griffith and Overstreet, 1953a, 1953b, 1953c; Griffith and 

Theobald, 1953; Hansen and Cuppels, 1954, 1955; Hansen and White, 

1954; Hansen and Caldwell, 1955; Hansen and Theobald, 1955; 

Overstreet and others, 1956; Overstreet and others, 1959; Caldwell, 

1962; Cuppels, 1962; Theobald, 1962; White, 1962, Overstreet, 1967; 

Williams, 1964, 1967; Overstreet and others, 1968; Overstreet and 

others, 1971; Cuppels and White, 1973; Caldwell and White, 1973). 

The formations in the Coastal Plain of South Carolina and Georgia 

were sampled for detrital monazite by me, in 1948. The investigation of 

such deposits later became a separate project conducted by Dryden 

(1958). 

I made annual visits, each of a week's duration, to Florida in 1944 and 

1945, and during every year from 1948 to 1957 inclusive, to review the 

placer mining in that State. Several minerals, including monazite, are 

recovered in Florida by placer mining operations for ilmenite on the 

present and the elevated beaches. Increasing industrial demand for 

titanium assures that placer deposits in Florida and other Southeastern 

Atlantic States will continue to be an important source of ilmenite for 

many years. Most of the criteria applicable to the exploration for ilmenite in the Coastal Plain also apply to monazite. 

Offshore placer deposits, which have recently attracted interest for 

monazite, ilmenite, and other heavy detrital minerals (Pepper, 1958; 

Tanner and others, 1961; Pilkey, 1963; and Emery, 1965), were not 

studied in this field investigation. 

The present report deals with the economic phases of my investigations, during 1945-57, of monazite in crystalline rocks and placer 

deposits in the Southeastern Atlantic States. 
EXPLANATION 

0 100 200 MILES 

0 100 200 KILOMETRES 

INTRODUCTION 

Pamlico 

Sound 

3 

FIGURE 1. -Configuration of the three monazite belts in the Southeastern Atlantic 

States in relation to the inner edge of the Coastal Plain. Base from U.S. Geological 

Survey (1970, p. 285). 

OTHER INVESTIGATIONS 

The existence of monazite in the Southeastern States has been known 

since 1849 when its presence in the gold placers of Rutherford County, 

N.C., was noted by Shepard (1849, p. 275; 1852, p. 109). The literature 

on monazite in this region is extensive. It was reviewed recently by 

Overstreet (1967); hence, the older reports will not be summarized here. 

Material published after that review, however, has been cited where appropriate in the present text. 
4 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

Reports up to about 1920 dealt largely with the distribution of 

monazite in North and South Carolina, the discovery of new deposits, 

then-current developments in the mining of monazite, and production 

data. The only deposits of monazite that had economic value were 

placers, and most of the work centered on these. Since 1925, papers 

relating to minerals containing the rare earths and thorium have 

appeared annually in the "Minerals Yearbook" and related 

publications by the U.S. Bureau of Mines. These do not deal 

specifically with the monazite of the Southeastern States, but discuss 

instead the world production and resources of monazite and the uses of 

the rare earths and thorium. A bibliography of the industrial uses of the 

rare earths was given by Lamb (1956, p. 743). 

The placer deposits in Florida are also the subject of a considerable 

literature first appearing when sporadic recovery of monazite was made 

in 1916 and 1917 at the earliest ilmenite mines on the Atlantic coast of 

the State (Liddell, 1917, p. 153) and continuing through the growth of 

mining on land and the development of offshore exploration for marine 

hard minerals (Martens, 1928, Tyler, 1934, Lamcke, 1940; Casperson, 

1948; Jones, 1949; Rove, 1952; Carpenter and others, 1953; Calver, 1957; 

Mertie, 1957; Trumbull and others, 1958; Giese and others, 1964). 

RARE-EARTH MINERALS AND USES 

More than 200 minerals are known that contain the rare earths and 

thorium. Monazite and bastnaesite, however, are the principal sources 

of the rare earths, and monazite has been the principal source of 

thorium. Small amounts of xenotime, the yttrian analog of 

monazite, occur with monazite in the Southeastern States, and may be 

recovered in mining. In this paper the term "monazite" commonly 

means both monazite and xenotime. 

Monazite was in demand in earlier years mainly for its content of 

thorium, which was used in the manufacture of Welsbach gas mantles, 

but beginning in the early part of this century, the rare earths in 

monazite became progressively more important. A potentially much 

larger increase in the demand for thorium is found in its use as a fuel in 

the high-temperature gas reactor power stations now being built in the 

United States. 

SOURCES OF MONAZITE 

Alluvial deposits of heavy minerals that include monazite are known 

in Brazil, India, Ceylon [Sri Lanka], Burma, Korea, Taiwan, Indonesia, 

Malaysia, Australia, Egypt [U.A.R.], Nigeria, The Congo (Leopoldville), Uganda, Kenya, Mozambique, Madagascar [Malagasy 

Republic], Canada, Argentina, and other foreign countries (Overstreet, 

1967). The principal producers of detrital monazite are India and 
RARE-EARTH MINERALS AND USES 5 

Brazil, but small outputs are coming from Australia, Ceylon [Sri 

Lanka], Malaysia, Indonesia, Egypt [U.A.R.], and Korea, mainly as a 

byproduct from the mining of other heavy minerals. A high-grade lode 

of monazite, however, was discovered in South West Africa in 1949, and 

was the principal producer of this mineral during 1952-59 and 1962-63. 

Monazite has hitherto been the principal source of thorium, but a 

new source of this metal has been developed in the Blind River uranium 

field, in the Elliot Lake area, Ontario, Canada. The lodes worked in this 

district consist of an ancient conglomerate containing ores of brannerite 

and uraninite, which are reported by Davidson (1957, p. 670) to contain 

about 0.11 percent U30s and 0.03 percent Th02 and are said by 

Williams (1969) to contain 0.05 percent Th02. The thorium at first was 

not saved, but in 1959 the Rio Tinto-Dow Co. built a plant near the 

Algom Uranium Mines to extract Th02 from the waste fluids that result 

in the recovery of uranium. 

In the United States, small fluvial placers of monazite were mined in 

North and South Carolina during 1887-1911, and, sporadically from 

1915-17. The richer and more extensive deposits of Brazil and India, 

that were discovered in 1905 and 1909, respectively, finally rendered the 

American mining unprofitable. Most of the mining in the Carolinas was 

done by many operators working on a small scale, but some was done by 

four larger companies, including one of British and one of German 

origin. The character and extent of this work, the volume of the production, and the nature of the monazite that was recovered have been 

reported (Mertie, 1953). The Carolina deposits were not exhausted and, 

under conditions of a world emergency, could be worked again if 

necessary. 

Alluvial monazite is widely distributed in Idaho, and monazite 

placers have been worked near Cascade, in Valley County. 

Monazite-bearing gold placers also occur at many localities in the Boise 

basin and northward within the area of the Idaho batholith. A small 

output has come from these sources in Idaho. A small production of 

monazite results as a byproduct in the mining of heavy minerals placers 

in the Southeastern Atlantic States, mainly from the littoral sands of 

Florida. A small volume of monazite, together with some xenotime, was 

also produced from a fluvial placer in Aiken County, S.C. Most of the 

monazite used in the United States, however, is imported. 

RARE EARTHS 

The name "rare earths" was given during the 18th century to some 

highly refractory and basic oxides, at the time considered to be 

elements, that were found during chemical studies of unusual 

pegmatite minerals. In time the true identity of these perplexing oxides 

was resolved and a host of new "rare-earth" elements was discovered 

(Weeks, 1956, p. 695-727). 
6 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

In modern usage, the rare earths include the 15 elements from 

lanthanum (atomic number 57) to lutetium (atomic number 71) which 

are calied the lanthanide group, together with yttrium (atomic number 

39). All or nearly all these elements, except promethium (atomic 

number 61), can expectably be found together in nature, although some 

may be much more abundant than others. Minerals containing these 

elements commonly are characterized by particular suites of the rare 

earths that are dominated by either cerium or yttrium and consist of 

the following elements: 

Cerium subgroup: 

Lanthanum (La) 

Cerium (Ce) 

Praseodymium (Pr) 

Neodymium (Nd) 

Samarium (Sm) 

Europium (Eu) 

Yttrium subgroup: 

Yttrium (Y) 

Gadolinium (Gd) 

Terbium (Tb) 

Dysprosium (Dy) 

Holmium (Ho) 

Erbium (Er) 

Thulium (Tm) 

Ytterbium (Yb) 

Lutetium (Lu) 

Monazite, a phosphate of the rare earths and for .many years their 

most important ore mineral, contains largely cerium subgroup elements 

but may also contain appreciable yttrium and some of its subgroup 

lanthanides as well. The other important ore mineral, bastnaesite, a 

rare-earth fluocarbonate, is almost exclusively a cerium subgroup 

mineral. Minerals that contain primarily yttrium subgroup rare earths 

are not as common but are represented by the phosphate xenotime 

which is a commercial source of yttrium. 

Monazite, in addition to rare earths, commonly contains both 

thorium and uranium. The Th02 content of the mineral may range 

from 0 to 31.5 percent (Overstreet, 1967, p. 1); but these extremes are 

rare, and from analyses of commercial concentrates, it appears that 

most monazite will contain from 3.5 to 9.0 percent Th02 (Parker and 

Baroch, 1971, p. 67). The uranium content of monazite is generally 

below 1 percent U30s. 

The tenor of Th02 in the monazite of the Southeastern States is well 
ALLUVIAL MONAZITE 7 

known. Fifty-three samples of alluvial monazite from the Piedmont of 

the Carolinas and Georgia were analyzed for their tenors in thoria by 

Frank C. Grimaldi and coworkers of the U.S. Geological Survey (Mertie, 1953). Thirty-six of these samples came from North Carolina, with 

22 from Cleveland County, 9 from Rutherford County, 3 from Burke 

County, 1 from McDowell County, and 1 from Alexander County. Sixteen samples came from South Carolina, comprising 11 from Cherokee 

County, 1 from Spartanburg County, and 4 from Greenville County. 

One sample came from Spalding County, Ga. The maximum, 

minimum, and mean tenors in thoria were found to be 7.8, 2.5, and 5.67 

percents, respectively. Subsequently, 126 similar analyses of monazite 

from bedrock in Cleveland and Rutherford Counties, N.C. (Overstreet 

and others, 1963, table 4) were made by K. J. Murata and H. J. Rose, 

.Jr., of the U.S. Geological Survey. The maximum, minimum, and mean 

tenors of thoria in the monazite from bedrock were found to be 11.2, 2.1, 

and 5.5 percents, respectively. The results of these 179 analyses agree 

remarkably well and tend to show a fairly uniform mean tenor in thoria. 

The tenors of U30s in 53 samples of alluvial monazite from the 

Southeastern States were also determined by Frank C. Grimaldi and 

coworkers (Mertie, 1953). The maximum, minimum, and mean tenor~ 

were found to be 0.98, 0.18, and 0.38 percents, respectively. Later, 10 

samples of monazite from saprolitic bedrock in the Shelby quadrangle, 

North Carolina, collected by W. C. Overstreet, were analyzed for U308 

by.Carmen Johnson and Blanche Ingram of the U.S. Geological Survey. 

The maximum, minimum, and mean tenors were found to be 1.48, 0.06, 

and 0.54 percents (Overstreet and others, 1963, table 5). These results 

are in general agreement. Subsequently, tenors in U30s as high as 2.34 

percent have been reported for monazite from North Carolina 

(Overstreet and others, 1970). 

ALLUVIAL MONAZITE 

PIEDMONT PROVINCE 

Fluvial monazite is· present in all the valleys of the Piedmont 

province that drain the monazite belts (Mertie, 1953, pl. 1), but is most 

plentiful in their extreme headwaters. Downstream, the fluvial deposits 

contain progressively less monazite and in the larger trunk valleys, this 

mineral is found only in traces. 

The monazite placers that were mined in the Southeastern States in 

the years 1887-1911 and 1915-17, were located in the headwaters of 

streams that drained monazite-bearing rocks. The sites of these placers 

were in the widest parts of the monazite belt in the western Piedmont 

where the host rocks have a high content of monazite. Such placers were 

commonly formed within a period of a few years, as indicated by the 

fact that headwater stretches of many streams were mined repeatedly 

over a period of 20 years. 
8 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

Monazite has a density of 4.6 to 5.4 and therefore is concentrated to 

some degree in the lower levels of alluvium, but most of it continues to 

move downstream with the other fluvial materials. If the alluvium contains beds of gravel, then the monazite can be held in the interstices. 

The source rocks of monazite, however, weather in the southern regions 

into sand, silt, and clay, and thus yield little or no broken bedrock that 

will produce gravel. Even where broken granitic or gneissic bedrock is 

present in the headwaters of streams, it is weathered and vulnerable to 

disintegration; therefore, it does not withstand fluvial transportation 

and is not abundant farther downstream. Consequently, unless the 

monazite-bearing bedrock and associated feldspathic country rock contain a large volume of vein quartz, or unless other rocks such as chert or 

quartzite that are immune to weathering occur in the drainage basins, 

extensive beds of monzite-bearing gravel will not be formed. In addition, the overall tenor of monazite in downstream placers will be 

diminished by the influx of fluvial materials from tributary valleys that 

do not contain monazite. 

Headwater placers do not have sufficient volume of sediment to be 

workable on a large scale, so the commercial placers must be sought 

downstream. Unfortunately, the grade of the downstream deposits is 

too low, and, as yet, monazite placers that can be worked on a large 

scale have not been discovered in the Piedmont province. Minerals of 

higher density than monazite, such as cassiterite (d= 6.8-7.1) and 

wolframite (d= 7.1-7.5), move less readily downstream, and where they 

are from bedrock sources of equal tenor are more likely to produce 

workable placers. 

I panned many of these small placers in North and South Carolina 

(Mertie, 1953, p. 10). In 52 samples I determined that the tenors of the 

workable gravel and sand ranged from 4.2 to 85.6 pounds of monazite to 

the cubic yard, with a mean value of 18 pounds per cubic yard. Few of 

the deposits were worked to depths in excess of 3-4 feet, and the widths 

were those of the narrow valley floors. During the period 1900-06 many 

men were engaged in the mining of these small deposits, mainly in 

groups of one to three men (Mertie, 1953, p. 6). The monazite was 

recovered by sluicing, and to judge from some old equipment seen in 

South Carolina, a single 12-foot sluice box, about 20 inches wide and 

without riffles, was set at a grade of about 1-2 inches in 12 feet. Above 

the upper end of the box a 3-foot-long piece of sheet iron perforated with 3

/R-inch holes acted as a grizzly. Gravel and sand were shoveled onto 

this iron plate, and after being washed, the coarse gravel was removed 

by shovels and pitchforks. Fine gravel, sand, silt, and clay passed 

through the holes; most of the finer alluvial material, including some of 

the monazite, was washed out of the box. Monazite recovery must have 

been exceedingly low. Sluice water came from behind a small dam that 

was made upstream from the ground to be worked. The work progressed 
ALLUVIAL MONAZITE 9 

upstream, and as one block of ground was exhausted, a new dam was 

built. 

A few deposits were worked farther downstream by larger operators, 

but the limits of these deposits were set by diminishing tenors. As 

terraces are present along most of the streams in this region, monazite 

placers may also exist in them. Few such deposits were worked owing to 

difficulty of reaching them with sluice water. 

The concentrates consisted chiefly of ilmenite, monazite, magnetite, 

and small amounts of other minerals such as garnet and zircon. Only 

the few larger operators had electromagnets used to separate the monazite from the other minerals; therefore, the small operators would sell 

their concentrates to these large operators. The sales price was determined by the amount of monazite recovered from the concentrates 

and ranged from 20 to 80 percent of the market price for pure monazite, 

which then was about 15 cents a pound. A high-grade monazite product 

could not be obtained simply by magnetically separating ilmenite and 

other magnetic minerals from monazite. A higher grade product could 

be obtained, however, by increasing the magnetic field, but some of the 

monazite was then separated with the ilmenite fraction. Such losses 

were common, as I verified by checking the ilmenite tailings at the old 

refining plant of the German-American Monazite Co. on the 

headwaters of Sandy Run Creek, northeast of Ellenboro, Rutherford 

County, N.C. Xenotime appears not to have been recognized, and 

doubtless most of it was lost with the ilmenite fraction. 

Exploratory work was begun in 1951 by the U.S. Geological Survey 

and the U.S. Bureau of Mines. The primary objective was the location 

of monazite placers within the western Piedmont monazite belt (fig. 1) 

in North Carolina, South Carolina, and Georgia that could be worked at 

a profit by modern mining methods (Overstreet and others, 1968). Such 

methods are costly and entail the purchase, installation, and eventual 

amortization of expensive mining and separatory equipment. Deposits 

must be of suitable grade and large enough to insure adequate financial 

return over a period of 15-20 years. The geologic conditions that prevail 

in this region are generally unfavorable for the formation of monazite 

placers of the required volume and grade, although placers of low grade 

and large volume and of higher grade and smaller volume have been 

found. 

The economic results of this exploratory work apply only to the 

alluvial deposits of the western Piedmont monazite belt of North and 

South Carolina and parts of Georgia. The parts of this belt that extend 

into Virginia and Alabama, the eastern Piedmont monazite belt, and 

the mountain monazite belt (fig. 1) have not been thoroughly explored. 

Some of these deposits were investigated where mining had formerly 

been done, and some areas were studied where the tenor of monazite in 

bedrock was most favorable. The existence of placers depends not so 

much upon the tenors of source rocks as upon the conditions of alluvial 
10 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

accumulation and concentration. High-grade gold placers, such as 

those in the Klondike district, Canada, have formed in regions where no 

gold lodes of any consequence have ever been found. Similarly, small, 

low-grade, monazite-bearing placers in parts of the western Piedmont, 

eastern Piedmont,· and mountain monazite belts are not necessarily indicative of the absence of placers in other parts of the same belts. If lowgrade sources of monazite occur in an area where resistant rocks, such 

as vein quartz, quartzite, chert, or massive limestone are prevalent, 

monazite placers could develop in gravels derived therefrom. One such 

possible area is south-southwest of Front Royal, Warren County, Va. 

There gravels are produced from the Beekmantown, Conococheague, 

and Elbrook Limestones in the tributaries of the South Fork Shenandoah River that head in an area of monazite-bearing Pedlar Formation 

(Bloomer and Werner, 1955). 

COASTAL PLAIN PROVINCE 

GENERAL GEOLOGY 

The Coastal Plain lies along the Atlantic coast of the United States 

from Long Island, N.Y., south to Florida and west along the Gulf of 

Mexico to Texas. It extends northward in the Mississippi embayment 

to southern Illinois. The part of the Coastal Plain that is most likely to 

have received monazite from the three monazite belts (fig. 1) is in 

Virginia, North Carolina, South Carolina, Georgia, and Florida. 

Monazite has been identified in the Cretaceous sedimentary rocks and 

in four of the seven Tertiary formations of the Coastal Plain in South 

Carolina (Overstreet, 1967, p. 252-255), and I have found it in 

sediments on eight Pleistocene terraces in the State. From oldest to 

youngest, the terraces are: the Hazlehurst, Coharie, Sunderland, 

Okefenokee, Wicomico, Penholoway, Talbot, and Pamlico. Monazite is 

present in the Cretaceous and Tertiary sedimentary formations in the 

western part of the Coastal Plain in Georgia (Overstreet, 1967, p. 

136-138), and I found the mineral in sediments on the Penholoway, 

Talbot, and Pamlico terraces. Commercial deposits of heavy minerals 

that include monazite have been mined in s·outh Carolina and are being mined in Florida and Georgia. 

The principal rivers, which drain the three monazite belts, are the, 

Roanoke in Virginia, the Pee Dee in North Carolina, the Santee and 

Savannah in South Carolina, and the Altamaha and Flint in Georgia. 

All generally drain southeastward except the Flint River which drains 

genera,lly southward. Accessory minerals of the crystalline rocks of the 

Piedmont and Blue Ridge provinces occur in all the streams that drain 

these areas. Some of the accessory minerals remain in the fluvial 

deposits, but most of them migrate downstream and eventually become 

a part of the Coastal Plain littoral deposits at or near strandlines that 
ALLUVIAL MONAZITE 11 

existed at the time of their formation. Heavy minerals were concentrated locally when many of these littoral deposits were subsequently 

modified by the action of winds, waves, and coastwise currents. Alluvial 

deposits at or near the present and older strandlines are the principal 

commercial sources of heavy minerals. 

The formations of the Coastal Plain range from Cretaceous to 

Holocene in age. The Tuscaloosa Formation, of Late Cretaceous age, is 

the basal formation in Alabama, Georgia, and the Carolinas, overlapping the crystalline rocks of the Piedmont province. The younger 

deposits include formations of Paleocene, Eocene, Oligocene, Miocene, 

Pliocene, and Pleistocene ages that have different names in different 

States. Nine Pleistocene terraces in the Atlantic Coastal Plain have 

been identified by Cooke (1945, p. 17, 248; 1954, p. 200-204). The 

alluvial deposits of these terrraces are distinguished from one another 

by their maximum altitudes above sea level (base levels of ancient 

shorelines). Named from highest (oldest) to lowest (youngest), these 

terraces and their maximum altitudes, in feet, are the Hazlehurst, 270; 

Coharie, 215; Sunderland, 170; Okefenokee, 145; Wicomico, 100; 

Penholoway, 70; Talbot, 42; Pamlico, 25; and Silver Bluff, 6. 

Although the deposits forming the terraces have well-defined upper 

surfaces, their lower limits are less clearly defined and may vary considerably in altitude. Thus, the base of a higher terrace locally may be 

lower than the base of the next younger terrace. For example, a sand or 

mineral horizon lying between the upper base levels of the Coharie and 

Sunderland terraces and at or close to the surface would be of Coharie 

age. If a stratum was located at some depth below the surface, but 

within the limits of the same base levels, it might be either Coharie or 

older in age, including possibly Tertiary or Cretaceous. 

Single terraces and groups of terraces have been correlated by Cooke 

(1945, p. 17, 248) with the several interglaciations of the Pleistocene 

Epoch. These correlations have a bearing upon the magnitude and 

tenor of the mineral-bearing littoral deposits. The more readily accessible sands of the Pleistocene terraces probably were deposited in the interglaciations, when base levels were relatively high; and these sands 

covered the deposits of the preceeding glaciations, when base levels 

were lower. Added to such oscillations of the strandline, a general uplift 

of the land bordering the Atlantic Ocean has been in progress since 

Cretaceous time. All the interglaciations are believed to be much longer 

than the time that has elapsed since the last major retreat of the 

glaciers. The climates of the interglaciations were probably milder than 

those of the glaciations or that of post-Wisconsin time. Thus, the conditions of weathering, erosion, transportation, and deposition of 

sediments are inferred to have been more favorable for the accumulation of heavy minerals during the interglaciations than in Holocene 

time. The largest volume of heavy minerals will therefore be found in 
12 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

the terrace deposits, rather than along the present beaches. The history 

of placer mining in Florida bears out this interpretation. Small deposits 

of heavy minerals have been found and worked on the present beaches, 

but large ore deposits, aggregating tens of millions of tons, have been 

located only on the terraces. 

The larger deposits of heavy minerals thus may be related to 

strandlines that existed in the interglaciations, but I would not infer 

that they are necessarily marine deposits. The general scarcity or 

absence of marine fossils in the placers contradicts an interpretation of 

marine origin. Some of these deposits may have been formed along 

oceanic or estuarine beaches, but most of them probably accumulated 

as outwash fluvial deposits from streams that debouched onto a wide 

lowland bordering the ocean. Many have clearly been modified by 

eolian action. 

DEPOSITS OF HEAVY MINERALS 

SOURCES 

All the formations of the Coastal Plain probably received varying 

amounts of heavy minerals from the crystalline rocks at the time of 

their deposition. In addition, each formation of the Coastal Plain, except the Holocene sands, has been partly eroded to form younger 

deposits, which constitute additional potential sources of heavy 

minerals. In particular, the Tuscaloosa Formation is recognized as a 

significant proximate source. However, the older formations have been 

covered to a great extent by younger formations, so they are not readily 

accessible. Large areas of Pleistocene and Holocene alluvium are more 

accessible; and such materials, mainly sands, constitute all the local 

concentrations of heavy minerals that approach or attain a commercial 

grade. 

Monazite makes up only a minor part of the heavy minerals in the 

Cretaceous and Tertiary formations of the Coastal Plain, but it is 

recognizable nearly everywhere in sands in the basins of rivers that 

drain the monazite belts. Although the present courses of such rivers 

are different from the courses of ancestral streams during the 

Cretaceous and Tertiary Periods, the areas lying along or closely adjacent to the present or ancestral courses of these rivers are the best sites 

to prospect for monazite. The ancient courses can be inferred from 

geomorphic and stratigraphic features in the Coastal Plain. 

Few clues are available to help locate the exact sites of deposits of 

heavy minerals, even when the best general areas are known. Neither 

the regional topography nor the results of surficial prospecting are 

reliable indices. In some areas the presence of dunes may be a guide by 

indicating where mineral-bearing sands may have been modified or 

further concentrated by eolian action. In addition to the general lack of 
ALLUVIAL MONAZITE 13 

clues, another handicap is that most of the commercial grade deposits 

found so far, other than those on the present beaches, lie at some distance below the surface of the ground. Although surficial prospecting is 

not a reliable tool, I have found that the panning of surficial sediments 

can give a clue to buried deposits, and that the low tenors of monazite 

above such deposits tend to be somewhat higher than the tenors of 

monazite elsewhere in the general area. A commercial grade deposit in 

Georgia was located by this method; and several sites in South 

Carolina, identified by panning surficial sediment, appear to be worthy 

of underground exploration. In general, deposits of heavy minerals in 

the Coastal Plain, except the smaller concentrations on the present 

beaches, are best discovered and appraised by systematic drilling. 

PROSPECTING 

Deposits of heavy minerals are being or have been sought in the 

Carolinas, Georgia, and Florida by State geological surveys and by 

private companies, including E. I. duPont de Nemours and Co., and the 

National Lead Co. The results of the private exploration have not yet 

been published, but considerable drilling was done in North Carolina 

north of Albemarle Sound in Chowan, Perquimans, Pasquotank, and 

Camden Counties; some drilling was undertaken between Albemarle 

Sound and Pamlico Sound; and some was done in Beaufort and 

Pamlico Counties, west of Pamlico Sound. These deposits appear to be 

a part of the Pamlico terrace. The tenors in heavy minerals are thought 

to be less than commercially acceptable grade. It is not known whether 

the heavy minerals contain monazite. 

In South Carolina prospecting for heavy minerals has been done by 

the State Development Board (McCauley, 1960) and by private companies. The monazite-bearing fluvial deposit on Horse Creek in Aiken 

County, S.C., has been mined. The present oceanic beaches of South 

Carolina, from the North Carolina line to the Georgia line, were 

prospected during 1958 by Neiheisel (1958a; 1958b; 1959). He noted 

that the Pee Dee and Santee Rivers are the principal present carriers of 

heavy minerals. 

Prospecting for heavy minerals is being done in Georgia, partly by 

the Geological Survey of Georgia (Neiheisel, 1962; Smith and others, 

1967), but mainly by private companies, particularly those mining 

placers in Florida. The panning I did (Mertie, 1953, p. 15) in 1948 in 

Brantley County, Ga., revealed surficial tenors near Hoboken of nearly 

1 percent of heavy minerals exemplified by samples 48-Mt-95 and 

48-Mt-96. Higher grade sands may lie below the surface, and this area 

may be the northward extension of the paystreak at Trail Ridge, Bradford County, Fla. Subsequently, a large block of ground in Charlton 

County, south of this area, was prospected and acquired by E. I. duPont 

de Nemours and Co. 
14 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

St. Simons Island in Glynn County, Ga., and Cumberland Island in 

Camden County, Ga., are known to have been prospected for heavy 

minerals, and some of the islands between them likely have been 

prospected. Cumberland Island has been extensively prospected by two 

or more large companies on behalf of the owners of this island. Owing to 

the settlement of several estates, the ownership of this island has been 

in litigation for several years, but recently the mineral deposits are 

reported to have been acquired by a large paint company. The deposits 

of heavy minerals on Cumberland Island are said to lie at the center of 

the island, trending nearly north, at a maximum altitude of about 40 

feet, thus corresponding closely to the shoreline of the Talbot terrace. 

Prospecting has also been done on the mainland in the vicinity of 

Darien in Mcintosh County, Ga. 

EXPLORATION UNDER THE PRESENT INVESTIGATION 

Some of the terrace d~posits of the Coastal Plain of South Carolina 

and Georgia were sampled by panning surface material in October 1948. 

The exploratory work was done along the northeast and southwest sides 

of the Santee River valley in South Carolina for distances up to 80 miles 

from the coast. Thirty-nine samples were taken from Pleistocene 

terraces, and four from Eocene formations. The samples taken in 

Georgia were collected in the vicinity of the Altamaha and Savannah 

Rivers, whose headwaters drain one or more of the monazite belts (fig. 

1). The samples from Glynn and Brantley Counties came from the 

valley of the Little Satilla River, not far south of the Altamaha River, 

and those from Camden and Charlton Counties came from the valley of 

the Satilla River. The localities are shown in figures 2 and 3 of this 

report and in an earlier report (Mertie, 1953, pl. 1, fig. 2), and the 

localities and character of the deposits are described in table 1. 

Mineralogical determinations are shown in tables 2 and 3, where the 

samples are arranged primarily in the order of increasing age of source 

material. 

C. W. Cooke, U.S. Geological Survey, accompanied me on the trip 

when these samples were taken and he identified the different terraces 

and formations that are listed. The mineralogical work on these 56 

samples was done by Eleanor Thompson and Judith Weiss Frondel, 

U.S. Geological Survey. 

GENETIC INTERPRETATION 

Mineralogically the samples shown in tables 2 and 3 are similar, 

though the proportions of the several accessory minerals. may differ considerably. The mean tenors of the five principal heavy minerals in the 

Pleistocene terraces and the monazite-bearing crystalline rocks of the 

monazite belts (fig. 1) are given in table 4. 
EXPLANATION 

.s1 

Sample locality 

0 10 20 MILES 

0 10 20 KILOMETRES 

Frf:URE 2. -Distribution of monazite-bearing samples from the Coastal Plain of South Carolina. Sample localities are those of 

monazite-bearing concentrates of series 48-Mt-46 to 48-Mt-88 panned from sedimentary formations of the Atlantic Coastal 

Plain; descriptions given in table 1. 

§ 

~ 

~ 

~ 

0 

z 

> N 

...... 

1-:3 

t;r:j 

....... 

01 
16 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

0 

I 

0 

I 

10 

10 

I I 

20 MILES 

I 

20 Kl LOMETRES 

FIGURE 3. -Distribution of monazite-bearing samples from the Coastal Plain of Georgia. 

Sample localities are those of monazite-bearing concentrates of series 48-Mt-89 to 

48-Mt-101 panned from sedimentary formations of the Atlantic Coastal Plain; descriptions given in table 1. 
ALLUVIAL MONAZITE 17 

TABLE 1.- Locality and description of samples from the Coastal Plain of South Carolina 

and Georgia 

Sample 

(figs. 2, 3) Locality and description 

Berkeley County, S.C. 

48-Mt- 68_ _ _ _ Ravenels quadrangle. North side of U.S. Highway 78, about 1.0.5 miles 1\'. .55° W. of Otranto. 

Altitude 30 ft, Talbot terrace. Semiconsolidated brown sand, in a section 4 ft thick. 69_ _ _ _ Summerville quadrangle. Northeast side of State Highway 31, about O.Sfi mile N. 80° W. of Wassamassaw Church, on west side of Wassamassaw Swamp. Altitude, 50-60 ft. Penholoway terrace. Clavev sand, mottled in tones of red, yellow, and white, in a section 4 ft thick. 80_ _ _ _ Honey Hill qu-adrangle. Southeast side of State Highway 179, about 1 1 , miles southeast of Honey 

Hill, and just southeast of the Honey Hill fire tower. Altitude 2.5 ft. shoreline of Pamlico terrace. Light-yellow unconsolidated sand in a section :3 ft thick. SL _ _ _ Honey Hill quadrangle. West side of State Highway 179. about 0.6 mile southeast of Honey Hill. and 0.83 mile northwest of Honey Hill fire tower. Altitude about -10ft. dune on Talbot terrace. White sand, stained irregularly yeilow, in a section 6 ft thick. 82_ _ _ _ .Jamestown quadrangle. East side of State Highway 179, about 1.7 miles southeast of .Jamestown, 

and about 100 ft northwest of junction with Pipkin Road. Altitude 36 ft. Talbot terrace. Brown sandy clay, in a section 3 ft thick. 83_ _ _ _ Jamestown 'quadrangle. Northwest side of State Highway 511, about 1' 2 miles southwest of 

Jamestown, and just southwest of Tiger Corner Road. Altitude 40--15 ft. Talbot terrace (may be Black Mingo Formation). Consolidated red clay containing mica, but no large grains of quartz, from a section 6 ft thick. 84_ _ _ _ Cordesville quadrangle, in Francis Marion National Forest. East side U.S. Highway 511, about 15J, 

miles southwest of Jamestown. Altitude about 35ft, Talbot terrace. Red to orange clay, in a sec- tion 10 ft thick. 86_ _ _ _ Summerville quadrangle. West side of State Highway 64, about 7'" miles northeast of Summerville. 

and 1 ' mile north of Poplar Branch. Altitude 70 ft. Penholoway terrace, bar or dune on Penholoway spit. Light-yellow unconsolidated sand 3 ft thick, underlain by yellow clayey sand. Sample from the light-yellow unconsolidated sand. SL _ _ _ Bonneau quadrangle. ~orth side of a secondary road leading from U.S. Highway .52 west to the Santee-Cooper hydroelectric power plant, and 0.7 mile from U.S. Highway 52. Altitude 50 ft. Black Mingo Formation. Section 8ft thick, overlain by 4ft of sand of the Penholoway Formation. Black Mingo Formation, from which sample was taken, is a yellow-brown to orange consolidated coarse sandstone and grit, mottled with white spots and stringers. 

88_ _ _ _ Bonneau quadrangle. Northeast side of U.S. Highway 52. about 4 miles northwest of St. Stephens, 

where a secondary road leads off to west; and about 4 miles southwest of Santee River. Altitude 77 ft, dune near Penholoway shoreline, possibly atop Wicomico terrace. White unconsolidated sand 6 ft thick, underlain by yellow clayey sand. Sample from white sand. 

Calhoun County, S. C. 

48-Mt- .54____ St. Matthews quadrangle. West side of U.S. Highway 21, about 11 , miles south of St. Matthews. Altitude about 220ft. McBean Formation of middle Eocene age, containing marine fossils. Road- cut 15 ft high. Sample from upper 5 ft of coarse-grained quartzose grit on west side of road. 55____ St. Matthews quadrangle. Same locality as No. 54. Sample from lower 5 ft of coarse-grained quart- zose grit on west side of road. 56____ Elloree quadrangle. Southwest side of State Highway 47, about 1.2 miles west-northwest of junction with Belleville Road. Altitude about 230ft. dune behind Coharie terrace. Unconsolidated vellow sand, with darker irregular-shaped masses in 8-ft roadcut. Sample from lower 6 ft of section. 5L _ _ _ Elloree quadrangle. East side of State Highway 47, about :3·1 , miles S. 23° E. of Lone Star. Altitude 

170 ft. Sunderland terrace. A 4-ft section of reddish-brown consolidated sandstone. about two- thirds quartz grains and one-third clay. 

Charleston County, S. C. 

48-Mt- 85_ _ _ _ Awendaw quadrangle. North side of U.S. Highway 17, about :3 miles east of Awendaw, at Buck Hall 

fire tower. Altitude 20 ft, offshore bar on Pamlico terrace. White to yellow unconsolidated sand, 

dug from pit 4 ft deep. 

Clarendon County, S. C. 

48-Mt- 70_ _ _ _ Summerton quadrangle. Southeast side of U.S. Highway 1.5, about 2.50 yds northeast of Lake Marion (Santee River dam) and 100 yds southeast of highway. Altitude about 100 ft. either Wicomico terace or dune on Penholoway terrace. Clavev cream-colored unconsolidated verv fine sand, with disseminated specks of iron ores. Sample taken from upper-± ft of a bluff where ·material was ex- cavated for causeway across the lake. 

Dorchester County, S. C. 

48-Mt- 62_ _ _ _ St. George quadrangle. Utsey Bluff. on northeast bank of Edisto River, about 5 miles S. 45° W. of 

Reevesville, and 0.7 mile southeast of Beulah Church. Altitude 87-95 ft. Wicomico terrace. Partlv consolidated gritty sandstone. Commencing at the surface, 8 ft ot' the blutT was sampled. · 63_ _ _ _ Ridgeville quadrangle. North side of U.S. Highway 78, about 2 1 ' miles east. by north of Dorchester, and 30 yds west of Four Hole Swamp. Altitude 70ft, Penholoway terace. Section: Cooper Marl, overlain by 3ft of carbonaceous sand, 2 1 c ft of very carbonaceous sand, 15ft of vellow sand. of which the-lower 12 ft was sampled. · · 

64_ _ _ _ Ridgeville quadrangle. Same locality as No. 63. Sample taken of 2' ,.ft bed of carbonasceous sand. 65_ _ _ _ Ridgeville quadrangle. Southwest side of C.S. Highway 78, about 27 s miles S. 87° E. of Ridgeville, 

on northwest side of Ashley River. Altitude about 40ft. either Talbot terrace or dune on Pamlico terrace. Sample taken from clayey material that forms the upper 4 ft of an 8-ft section. 
18 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

TABLE 1. - Locality and description of samples from the Coastal Plain of South Carolina 

- and Georgia - Continued 

Sample 

(figs. 2, 3) Locality and Description 

Dorchester County, S. C. - Continued 

48-Mt- 66_ _ _ _ Ridgeville quadrangle. Same locality as No. 65. Sample from semiconsolidated sand that forms the lower 4 ft of an 8-ft section. 67_ _ _ _ Ridgeville quadrangle. Noflheast side of U.S. Highway 78, about 3.3 miles S. 72° E. of Ridgeville, on southeast side of Ashley River. Altitude about 40ft, Talbot terrace. Clayey material from a section 4ft thick. 

48-Mt-7L __ _ 

72 ___ _ 

73 ___ _ 

74_---

75 __ --

76 ___ _ 

48-Mt-46 ___ _ 

47_---

48 ___ _ 

49 __ -- 50 ___ _ 

51_ __ _ 

52__--

53 ___ _ 

58 ___ _ 

59_---

60 ___ _ 

61_ __ _ 

Georgetown County, S.C. 

Georgetown North quadrangle. Southeast side of a secondary road, about 1.62 miles N. 35° W. from bend in U.S. Highway 521, west of Georgetown; also 100 yds southwest of junction of secondary road with Johnson Road. Altitude 25ft, Pamlico terrace. Fine yellow sand from a 4-ft section in pit excavated for road material. Georgetown North quadrangle. South bank of Black River, about 8 miles N. 13° W. of Georgetown, and 700ft west of pumping station. Altitude about 18ft, Pamlico terrace. Yellowish-brown sandy 

clay from a 4-ft section. Rhems quadrangle. East side of Browns Ferry Road, about 1.3 miles southeast of Browns Ferry. Altitude 25-30 ft, Talbot terrace. Yellow sand from a section 61

/2 ft thick. Rhems quadrangle. Southwest side of Browns Ferry Road, about 0.35 mile west-northwest of Browns Ferry. Altitude about 20ft, dune on shoreline of Pamlico terrace. Fine yellow sand in roadcut, of which 4 ft was sampled. Rhems quadrangle. Northeast side of Browns Ferry Road, about 0.1 mile southeast of road junction at Red Hill. Altitude 20-30 ft, Black Mingo Formation. Brownish-red to dark-red, well- consolidated sandstone and grit that disintegrate when panned. Sample from section 12 ft thick. Olin quadrangle. Northeast side of U.S. Highway 521, about 1.63 miles northwest of Oak Grove, and 0.2 mile northwest of junction with Bethel Road. Altitude 28 ft, Talbot terrace. Mottled red and orange clayey sand at top, and less clayey sand at base, of a section 4 ft thick. 

Orangeburg County, S.C. 

Orangeburg quadrangle. Northwest side South Carolina Highway 33, about a quarter of a mile northeast of Snake Swamp. Altitude 185ft, Coharie terrace. Section of 7ft, of which sample was of lower 3 ft. Fine-grained mottled white to reddish-brown clayey sand. Orangeburg quadrangle. Same locality as No. 46. Sample of upper 4 ft of section. Reddish-brown limonitic sand, more clayey than No. 46. Orangeburg quadrangle. Northwest side State Highway 33, about 1

/s mile southwest of Snake Swamp. Altitude 170ft, Coharie terrace. Section 6ft thick of quartzose grit with pebbles up to half an inch in size, exposed in an old excavation. Material mottled from light tan to brown to red. Orangeburg quadrangle. Same general locality as No. 48, but from an 8-ft section 40 ft to the north. Orangeburg quadrangle. Secondary road leading northwest from State Highway 33, about 0.2 mile southeast of Cooper Swamp; and 8.86 miles S. 54° W. of center of Orangeburg. Altitude 230ft, Hazlehurst terrace. Sample from lower 3 ft of sandy material, in a section 6 ft thick. Orangeburg quadrangle. North side of Bennecker Bridge Road, and 7.1 miles S. 62° W. of center of Orangeburg. Altitude 250 ft, Hazlehurst terace. Mottled white to brown to red pebbly sand, with quartz pebbles up to half an inch in size. Sample from lower _3 ft of two cuts. 

Orangeburg quadrangle. South side of State Highway 36, about 0.45 mile west of Cooper Swamp; and 10.8 miles S. 20° W. of center of Orangeburg. Altitude 155ft, Sunderland terrace. Sample from 3-ft cut of quartzose grit, with grains of quartz from very small size to "Is inch. Orangeburg quadrangle. North side of State Highway 36, about 0.1 mile west of North Fork of Edisto River, and 9.65 miles S. ll'l2 o W. of the center of Orangeburg. Altitude about 150ft, Sunderland terrace. Reddish-brown to yellowish-brown clayey sand, from the lower 6 ft of a 9-ft section. Eutawville quadrangle. North side of State Highway 6, about 7

/s mile west of junction of State Highway 6 with U.S. Highway 15. Altitude 120 ft, Okefenokee terrace. Brown unconsolidated to little-consolidated sand, from a section 4 ft thick. Eutawville quadrangle. South side of State Highway 45, about half a mile west of Eutaw Springs, and 75 yds east of junction of State Highways 45 and 6. Altitude 100 ft, Wicomico terrace. Yellowish-brown unconsolidated sand from a section 6ft thick. Eutawville quadrangle. South side of State Highway 45, about 21

14 miles west of Eutawville. Altitude 140 ft, dune on Wicomico terrace. Yellow sand from a section 2 ft-thick. Bowman quadrangle. North side of State Highway 4, about 1

14 mile west of Four Hole Swamp. Altitude 140ft, Okefenokee terrace. Coherent reddish sandstone, with shite mottling, from an old excavation, in a section 4 ft thick. 

Williamsburg County, S.C. 

48-Mt- 77_ _ _ _ Andrews quadrangle. Northeast side of U.S. Highway 521, about 0.6 mile N. 10° E. of West Andrews. Altitude 35 ft, Talbot terrace. Sample from a section 6 ft thick, consisting of 4 ft of yellow clay overlain by 2 ft of leached white sand. 78_ _ _ _ Indiantown quadrangle. Northeast side of U.S. Highway 521, about 4.8 miles west of Warsaw, and 200 yds east of Spring Gully Church. Altitude 40ft, Talbot terrace. Section of 3ft of yellowish- brown clayey sandstone, overlain by 3 ft of dune sand. Sample from lower 3 ft of section. 79_ __ _ Indiantown quadrangle. Northeast side of U.S. Highway 521, about 6.85 miles N. 77° W. of Warsaw, and 0.4 mile southeast of Spring Gully. Altitude 40 feet, Talbot terrace, close to Talbot shoreline. Reddish-brown slightly sandy clay, from a section 4ft thick. 
ALLUVIAL MONAZITE 19 

TABLE 1. -Locality and description of samples from the Coastal Plain of South Carolina 

and Georgia - Continued 

Sample 

(figs. 2, 3) Locality and description 

Brantley County, Ga. 

48-Mt- 9L _ _ _ Nahunta quadrangle. North side of U.S. Highway 84, about 1'/2 miles east of Waynesville. Altitude about 60 feet, outside bar on Penholoway terrace. Light- to dark-yellow consolidated sand, in sec- tion 5 ft thick. 92_ _ _ _ Nahunta quadrangle. North side of U.S. Highway 84, at crest of hill about ',2 mile west of Satilla River. Altitude about 70ft. bar or beach on Penholoway terrace. White sand in section 7ft thick, in pit on north side road. 93_ _ _ _ Nahunta quadrangle. North side of U.S. Highway 84, about 0.7 mile east of Lulaton, and 5.6 miles west of railroad crossing in Nahunta. Altitude about 80ft, Hawthorn Formation (Miocene age), overlain by 3ft of sand of the Penholoway Formation. Sample of a 7-ft section of the Hawthorn Formation. 94_ _ _ _ Winokur quadrangle. South side of U.S. Highway 84, about 1.2 miles east of Hoboken fire tower. Altitude about 70ft, Penholoway shoreline on east side of Trail Ridge. Fairly coarse carbonaceous sand with grains of uniform size, and no clay, from a dug section 5 ft thick. 95_ _ _ _ Winokur quadrangle. South side of U.S. Highway 84, about 0.5 mile east of Hoboken fire tower. Altitude about 100 ft, shoreline of Wicomico terrace, on east side of Trail Ridge. Coarse car- bonaceous sand from section 4 ft thick. 96_ _ _ _ Winokur quadrangle. North side of U.S. Highway 84, about 200 yds east of Hoboken fire tower. Altitude about 140ft, shoreline of Okefenokee terrace, on east side of Trail Ridge. Sample of sec- tion 8 ft thick. Upper 4 ft consists of unconsolidated gray carbonaceous sand; lower 4 ft is con- solidated brown sandstone. 

Camden County, Ga. 

48-Mt- 97_ _ _ _ Boulogne quadrangle. South side of Whiteoak-Folkston unpaved road, about 11,4 miles west- southwest of Jerusalem. Altitude about 45 ft, east side of an abrupt rise at about the level of the Talbot terrace. Hard-packed white sand at base, overlain by carbonaceous sand, and by 12 in. of windblown sand, in section 6 ft thick. 98_ _ _ _ Boulogne quadrangle. North side of Whiteoak-Folkston unpaved road, about 1% miles west- southwest of Jerusalem. Altitude about 65 ft, Penholoway terrace. Light-yellow sand overlain by 12 in. of windblown sand in dug section of 6 ft. 

48-Mt- 99 ___ _ 

100 ___ _ 

101_ __ _ 

Charlton County Ga. 

Boulogne quadrangle. West side of Burnt Fork-Folkston unpaved road, about 3.4 miles S. 71 o W. from Burnt Fork (crossing of Satilla River). Altitude 60ft, Penholoway terrace. Section of 5 ft of white sand that rests on Hawthorn Formation. 

Folkston quadrangle. West side of U.S. Highway 1, on west side of Atlantic Coast Line Railroad, and 3.3 miles N. 38° W. of Uptonville. Altitude about 100ft, Wicomico terace, along east side of Trail Ridge. Gray sand from upper 6 ft of cut. Folkston quadrangle. East side of U.S. Highway 1, at entrance to side road leading to Sand Hill Church, and 61 4 miles N. 29° W. ofUptonvil!e. Altitude about 145ft, Okefenokee terrace. Dug sec- tion 4 ft thick of yellow sand, overlain by a thin veneer of windblown sand. 

Glynn County, Ga. 

48-Mt- 89_ _ _ _ Bladen quadrangle. North side of U.S. Highway 84, about 2.3 miles east of College Creek, and 2.7 miles east of junction with State Highway 99. Altitude not exactly known, probably a bar on Pamlico terrace. Gray sand in roadcut 41.'2 ft high. 90 ____ Nahunta quadrangle. North side of U.S. Highway 84, about 2.6 miles east of Waynesvile, and 2.8 miles west of crossing of Seaboard Railroad. Altitude about 21 ft, Pamlico terrace near Pamlico shoreline. Roadcut 3 1

/2 ft high, of which upper half is light-gray carbonaceous sand; lower half is clayey yellow sand. 

The tenors of total heavy minerals in the Pleistocene terraces of 

South Carolina range from 0.68 to 0.017 weight percent, with a mean 

value of 0.14 percent. This is about twice as great as the mean tenor for 

the monazite-bearing crystalline rocks, but is almost exactly that of all 

the granitic rocks that I sampled in the Southeastern States. On the 

other hand, the tenors of accessory minerals in the sampled Pleistocene 

terraces of Georgia range from 0.96 to 0.078 weight percent, with a mean 

value of 0.36 percent, which is 2 Vz times greater than in South Carolina. 
20 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

TABLE 2. -Accessory minerals from sedimentary rocks 

[Tr., trace; ___ , absent. Mineralogy by 

Heavy minerals in bedrock Heavy minerals in 

Field No. (weight percent) concentrates (weight percent) 

(figs.2, 3) Geologic 

setting Total Monazite Ilmenite Leucoxene 

Terraces of Pleistocene age 

48-Mt-71 ------ Pamlico 0.184 0.0018 68 

72 ------ ___ do ------ .123 .0025 73 2 

74 ------ ___ do ------ .114 .0023 74 

80 ------ ___ do ------ .337 .0034 58 

85 ------ ___ do ------ .442 27 Tr. 

65 ------ Talbot .047 . 0023 60 Tr . 

66 ------ ___ do ------ .069 .0014 62 Tr. 

67 ------ ___ do ------ .038 .0004 68 

68 ------ ___ do ------ .123 .0061 50 3 

73 ------ ___ do ------ .146 .0015 64 

76 ------ ___ do ------ .024 .0002 40 2 

77 ------ ___ do ------ .040 .0004 65 3 

78 ------ ___ do ------ .109 .0022 66 2 

79 ------ ___ do ------ .034 .0010 56 

81 ------ ___ do ------ .620 62 3 

82 ------ ___ do ------ .034 50 

83 ------ ___ do ------ .026 .0005 71 1 

84 ------ ___ do ------ .050 .0015 67 Tr. 

63 ------ Penholoway .137 .0027 64 3 

64 ------ ___ do ------ .056 45 Tr. 

69 ------ ___ do ------ .106 .0021 67 Tr. 

86 ------ ___ do ------ .075 .0022 61 

88 ------ Wicomico .676 .0135 71 

59 ------ ___ do ------ .049 .0020 39 

60 ------ ___ do ------ .024 .0005 29 

62 ------ ___ do ------ .189 .0057 47 Tr. 

70 ------ ___ do ------ .236 .0330 30 

58 ------ Okefenokee .017 31 

61 ------ ___ do ------ .131 .0013 47 Tr. 

52 ------ Sunderland .071 .0037 73 

53 ------ ___ do ------ .028 .0014 37 

57 ------ ___ do ------ .078 .0031 54 

46 ------ Coharie .042 .0004 35 3 

47 ------ ___ do ------ .039 .0027 25 3 

48 ------ ___ do ------ .166 .0066 30 3 

49 ------ ___ do ------ .562 .0169 14 15 

56 ------ ___ do ------ .311 .0093 46 

50 ------ Hazlehurst .085 .0059 47 

51 ------ ___ do ------ .024 .0005 42 

Mean 0.145 0.0036 52 

Tertiary formations 

48-Mt-54 ------ McBean 0.019 0.0017 39 

55 ------ ___ do ------ .033 .0026 58 

75 ------ Black Mingo .276 .0028 56 Tr. 

87 ------ ___ do ------ .081 .0016 70 

Mean ---- 0.102 0.0022 56 
ALLUVIAL MONAZITE 21 

in eight counties. Coastal Plain of South Carolina 

Eleanor Thompson and Judith Weiss FrondE'!] 

Heavy minPrals in concentrates (weight percent) 

MonazitE' Epidote Garnet Staurolite Zircon Rutile Quartz and others 

Terraces of Pleistocene age - Continued 

1 Tr. 6 21 4 Tr. 

2 4 11 4 4 

2 Tr. 2 19 3 Tr. 

1 10 Tr. 2 25 3 1 

Tr. 14 1 4 Tr. 54 

5 1 3 21 3 7 

2 1 2 17 6 10 

1 2 18 4 7 

5 Tr. 35 5 2 

1 Tr. 2 28 5 Tr. 

1 Tr. 14 2 41 

1 2 5 11 5 8 

2 2 2 16 6 4 

3 4 1 25 3 8 

8 6 11 6 4 

5 1 22 5 17 

2 4 1 14 2 5 

3 Tr. 16 3 11 

2 4 16 6 5 

Tr. 4 7 24 8 12 

2 4 15 3 9 

3 1 30 5 Tr. 

2 3 1 11 3 9 

4 Tr. 17 9 31 

2 3 43 10 13 

3 1 5 16 7 21 

14 6 Tr. Tr. 6 1 43 

Tr. 2 5 34 12 16 

1 2 6 7 7 30 

5 2 Tr. 14 2 4 

5 1 3 26 9 19 

4 Tr. 13 3 26 

1 3 2 6 3 47 

7 3 3 26 9 24 

4 7 5 10 7 34 

3 4 3 6 6 49 

3 Tr. 2 41 7 1 

7 Tr. 6 3 37 

2 8 7 10 31 

3 2 3 18 5 16 

Tertiary formations- Continued 

9 Tr. 8 4 40 

8 Tr. 15 5 14 

1 3 2 20 3 15 

2 1 24 3 Tr. 

5 1 1 16 4 17 
22 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

Field No. (figs. 2, 3) 

48-Mt-89 _______ 

90-------

97-------

91 -------

92-------

94-------

98-------

99-------

95-------

100-------

96-------

101 -------

Mean ----

48-Mt-93 _______ 

TABLE 3. -Accessory minerals from sedimentary rocks 

Heavy minerals in bedrock (weight percent) 

Geologic 

setting Total 

[Tr., trace; ___ , absent. Mineralogy by 

Monazite 

Heavy minerals in concentrates (weight percent) 

Ilmenite Leucoxene 

Terraces of Pleistocene age 

Pamlico 0.244 0.0146 47 ___ do ------ .091 47 

Talbot .247 .0025 50 

Penholoway .125 .0012 63 ___ do ------ .078 .0039 49 ___ do ------ .205 39 ___ do ------ .201 .0020 47 2 ___ do ------ .312 51 3 

Wicomico . 928 31 Tr . ___ do ------ . 547 42 Tr . Okefenokee .958 43 ___ do ------ . 340 39 Tr . 

----------- 0.356 0.0020 46 

Miocene sedimentary rock 

Hawthorn 0.077 0.0062 67 

Formation 

Too few samples of the Tertiary formations were taken to warrant any 

dependable conclusions, but the tenor of total accessory minerals 

appears to be lower. The tenor of accessory minerals in the Upper 

Cretaceous Tuscaloosa Formation, where it overlaps the crystalline 

rocks, is probably greater than in any of the Tertiary formations. 

Magnetite is absent in all these Coastal Plain formations. Ilmenite is 

everywhere present, but is twice as plentiful in the Pleistocene terraces 

sampled in Georgia than in those sampled in South Carolina, thus 

partly accounting for the greater volume of accessory minerals in 

Georgia. Small amounts of leucoxene are recorded in both sets of 

samples, thus indicating losses in the total amounts of ilmenite. Much 

of the ilmenite may have been altered to leucoxene after the hostsediments were deposited, and thus the leucoxene may be mainly a 

product of alteration by ground water. 

The monazite, zircon, and rutile contents are likewise two to five 

times greater in the samples from Georgia than in those from South 

Carolina. This might be interpreted to mean that the heavy mineral 

content of the Pleistocene terraces increases southwestward from the 

Carolinas; alternatively, the areas in Georgia might be more favorably 

situated for the accumulation of heavy minerals than those in South 

Carolina. Much surficial and underground exploration, as well as a 

better knowledge of the terraces and of their formation, will be required 

to settle this and related questions. 

Insufficient data are at hand to determine whether the content of 
ALLUVIAL MONAZITE 23 

in four counties, Coastal Plain of Georgia 

Eleanor Thompson and .Judith Weiss Fronde!] 

Heavy minerals in concentrates (weight percent) - Continued 

Monazite Epidote Garnet Staurolite Zircon Rutile Quartz and others 

Terraces of Pleistocene age - Continued 

6 2 38 7 Tr. 

Tr. 4 40 8 1 

1 4 38 5 2 

1 2 27 7 Tr. 

5 2 38 6 Tr. 

Tr. 5 4 28 6 18 

1 Tr. 2 27 9 12 

Tr. 5 2 27 8 4 

Tr. 1 3 24 4 37 

4 4 29 7 14 

2 4 27 4 20 

2 Tr. 1 50 7 1 

1 2 3 33 6 9 

Miocene sedimentary rock- Continued 

8 Tr. 2 18 5 Tr. 

accessory minerals increases or decreases with age in the Pleistocene 

terraces. High-grade samples occur in the interval20-230 feet above sea 

level in the Pamlico, Talbot, Wicomico, and Coharie terraces, and so 

workable deposits are likely to be found in terraces within this range of 

altitudes. High contents of heavy minerals were noted in terraces at 

similar altitudes during prospecting and mining in Florida. 

Part of the concentration of the accessory minerals is due to the 

destruction and elimination by chemical and mechanical means of certain essential minerals of the granitic rocks in the Piedmont. Feldspars, 

the most vulnerable of such minerals, constitute about 60 percent of 

most granitic rocks. These and other vulnerable minerals may comprise 

75 percent of the country rock, and their elimination could cause a fourfold increase in the accessory minerals. On the other hand, the partial 

destruction of iron ores as a result of erosional processes will cause a 

decrease in the accessory mineral content, and processes of mechanical 

concentration associated with fluvial transport and winnowing have upgraded the relative abundances of the heavy minerals. The accessory 

minerals of the crystalline rocks have been concentrated from 10- to 25-

fold in the sedimentary rocks of the Coastal Plain. 

Magnetite is not found in accessory minerals of the Coastal Plain, 

although it is common in the crystalline rocks. If this mineral had survived chemical alteration, erosion, and fluvial transportation, the total 

iron ores in the Coastal Plain formations would have been much 

greater, and in the Pleistocene terraces of Georgia the mean tenor of 
24 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

TABLE 4. - Comparative mean tenors, in weight percent, of accessory minerals in 

crystalline rocks and Pleistocene terraces 

Accessory minerals 

Total accessory minerals _ Magnetite _________ _ 

Ilmenite-----------

Monazite ---------- Zircon ___________ _ 

Rutile ------------

Crystalline rocks 

0.072 

.017 

.029 

.0047 

.0022 

.0008 

Pleistocene terraces 

South Carolina Georgia 

0.14 

Absent 

.073 

.0036 

.022 

.0070 

0.36 

Absent 

.15 

.0020 

.11 

.022 

iron ores might have been 0.25 percent rather than 0.15 percent. The 

potential concentration of iron ores, from hardrock to the sands of the 

Coastal Plain, is on the order of 1:5. 

The tenor of monazite in the Pleistocene terraces is less than in the 

monazite-bearing crystalline rocks of the monazite belts (fig.1). This 

apparent anomaly results from the Pleistocene sands being derived 

from crystalline rocks, both within and without the monazite belts. 

Considerable concentration of monazite is indicated by the tenor of 

monazite in the terraces approaching that in the crystalline rocks, even 

though the monazite-free rocks greatly exceed in volume those that contain monazite. Zircon and rutile, the most durable of the accessory 

minerals, show maximum concentrations, respectively, of 1:50 and 

1:27. 

These data have a bearing upon the origin of the Coastal Plain formations. The concentration of accessory minerals, though striking, is 

much less than might be expected of beach deposits; and clearly the 

mean tenor of accessory minerals in the samples from Georgia is only a 

tenth of that in the commercial deposits of Florida. Beach deposits have 

been formed continuously since the Late Cretaceous; yet most of the 

deposits now exposed are not marine deposits. Judging by the concentration of accessory minerals on the beaches of the inland waterways of 

the Coastal Plain, such as Indian River, Fla., the deposits are not 

dominantly estuarine. Therefore, the beach deposits must be buried, 

and the visible formations must be interpreted as outwash or deltaic 

deposits that were subjected to repeated fluvial concentration by 

wandering and migrating rivers and streams. The formation of these 

deposits and the concentration of their heavy minerals, however, had to 

be of such a nature as to winnow most of the clay, inasmuch as these 

deposits, though locally clayey, are mainly sands. This inference 

suggests that the deposits now visible may have originated in the 

headwater stretches of deltaic areas, rather than farther downstream 

close to the ocean. 
ALLUVIAL MONAZITE 25 

PLACER MINING 

Placer mining in the Coastal Plain is mainly for ilmenite; monazite is 

a small, local byproduct. At one site in South Carolina, however, 

monazite was the main mineral produced. This was the Horse Creek 

deposit in Aiken County. 

SOUTH CAROLINA 

A fluvial placer of heavy minerals was discovered during the summer 

of 1951 by Owen H. Perry in the lower valley of Horse Creek in Aiken 

County, S.C. A similar placer of lower grade exists in the valley of 

Hollow (Holley) Creek, southeast of Horse Creek (Overstreet, 1967, p. 

259-260). Horse Creek heads in Edgefield County and flows i.n a general 

southwesterly direction to join the Savannah River at a point southwest 

of Aiken. A part of the placer on Horse Creek was drilled by the U.S. 

Bureau of Mines in the winter of 1951-52 (Kline and others, 1954). 

Thereafter, Perry transported to Horse Creek and reassembled there a 

6-foot bucket dredge which he had used from 1939 to 1944 for gold and 

sapphire mining on Eldorado Bar, Missouri River, northwest of Canyon 

Ferry, Mont. This dredge, as it appeared in April1956 in the valley floor 

of Horse Creek, is pictured in figure 4. This property and equipment 

were controlled at first by Perry, with the financial backing of the 

Callahan Lead and Zinc Co. Later, ownership passed to the Crane Co., 

and still later the property came to be owned by the Vitro Corporation 

of America, and the French Pechiney organization. This property, 

though otherwise named at the outset of mining, came finally to be 

known as the Heavy Minerals Co. Dredging began about a mile from 

the Savannah River, on the northwest side of the Southern Railway, 

and was extended upstream. Later the dredge was moved southeast of 

the railroad tracks. Mining began in the spring of 1955 (Lenhart, 1956) 

and was terminated early in 1959. 

This deposit is both underlain and surrounded by the Tuscaloosa 

Formation of Late Cretaceous age. This formation directly overlaps the 

crystalline rocks of the Piedmont province, and along its old shoreline 

the Tuscaloosa might be expected to have a higher tenor in heavy 

minerals than other formations of the Coastal Plain lying between the 

Fall Line and the ocean. At favored localities, the Tuscaloosa Formation may even contain workable deposits of heavy minerals, though 

none as yet has been found. The alluvial placers on Horse and Hollow 

(Holley) Creeks were formed by the reconcentration of heavy minerals 

from high-grade parts of the Tuscaloosa Formation. Such alluvial 

deposits are unlikely to form in large stream valleys that head far west 

or northwest of the Fall Line, inasmuch as the volume of barren 

alluvium would be too great to form a wor~able placer. Small streams 
26 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

FIGURE 4. - The Perry bucket dredge, operating in the valley floor of Horse Creek, Aiken 

County, S.C. 

that head within the Tuscaloosa Formation, or at no great distance 

above the Fall Line, are the best sites for prospecting. I found monazite 

and other heavy minerals in 1951 on a small branch of Sweetwater 

Creek, about 3 miles east of Thomson, McDuffie County, Ga. The tenor 

of the gravels in monazite at this locality, as gaged by panning, was estimated to be about half a pound to the cubic yard. Northwest of this 

locality, monazite was found in the Tuscaloosa Formation at four sites 

along a road that leads east-northeast from Thomson. As these 

localities are along the divide between Sweetwater Creek and Sills 

Branch of Germany Creek, the monazite was close to its bedrock source. 

A somewhat similar occurrence of monazite was also found in 1951 on 

Rocky Creek, about 5 miles west-northwest of Lexington, Lexington 

County, S.C., but the bedrock source of this deposit was not so clearly 

established. 

Thus, possible workable placers can be found by panning, both in the 

Tuscaloosa Formation and in some of the small streams that drain 

southeastward from it. Another example, reported by Henry S. Johnson, Jr. (oral commun., 1958), is where the Strategic Minerals Corp. 

located a deposit near McTier Creek, a south-flowing tributary of the 

South Fork of the Edisto River, in the northern part of Aiken County, 

S.C. There 1-3 feet of sand and gravel at the base of the Tuscaloosa Formation, where it overlaps a thoroughly weathered granite, contains 

about 1 percent heavy minerals that yield as much as 33 percent 

monazite. To a depth of 60 feet, this deposit covers an area of several 
ALLUVIAL MONAZITE 27 

hundred acres. The underlying granite has not been panned, but the 

coarseness of the grains of monazite in the sand and gravel suggests that 

this granite is the bedrock source. If this is so, then this locality is part 

of the eastern Piedmont monazite belt (fig. 1). 

The paystreak on Horse Creek was originally reported to extend from 

the Savannah River upstream for 7-8 miles, but the subsequent mining 

impugns this estimate. The width of the paystreak, where the dredge 

started, was reported to be about 1,800 feet, but its width at the upper 

end of the minable ground was said to narrow to 800 feet or less. The 

alluvium, at the initial site of mining, was about 20 feet thick and consisted of silt, sand, and gravel. At the base of the section a stratum of 

fine quartz gravel about 4 feet thick rests upon a bedrock of the 

Tuscaloosa Formation. This gravel was sold for use as concrete 

aggregate. 

The Horse Creek deposit probably could not have been mined 

without its significant content of gravel. The heavy mineral content is 

believed to be 1-2 percent or, more likely, 1-1.5 percent. The proportions of minerals recovered from the jigs are estimated to be 23 percent 

ilmenite, 19 percent zircon, 15 percent rutile, 8 percent monazite and 

xenotime, 7 percent staurolite, and 28 percent quartz and other 

minerals. The ratio of xenotime to monazite has been variously 

reported from 1:12 to 1:32, but the most probable value is between 1:15 

and 1:20. From these data, monazite and xenotime might be inferred to 

have constituted about 12 percent of the salable minerals. 

FLORIDA 

Monazite is present in nearly all samples of heavy minerals recovered 

in panning or mining the placer deposits of Florida, but the grade is exceedingly low. Nevertheless, in large-scale mining operations where 

10,000-25,000 tons of sand is processed daily, a significant production 

can be attained. Placer mining of heavy minerals has so far been confined to alluvial deposits along or close to the eastern coast of Florida, 

and monazite occurs in such ores in amounts ranging from 0. 7 to 0.01 

percent of the concentrates. The workable deposits have minimum 

tenors of 3-4 percent in heavy minerals, and so the tenor of monazite in 

the workable alluvium has the general magnitude of 0.03-0.0003 percent. Despite this low tenor, at two of the three properties where ilmenite, rutile, and zircon were being mined in 1957, a small byproduct 

of monzite was recovered. At the third plant, the tenor of monazite in 

the concentrates is considered to be too low to warrant its recovery. 

The principal placer mining plants of Florida where ilmenite, rutile, 

and zircon were being recovered in 1957 had the following ownerships. 

The National Lead Co. owned a plant operated by the Humphreys Gold 

Corp. in Duval County, about 2% miles S. 80° E. of Arlington. The E. 
28 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

I. duPont de Nemours and Co. owned and operated two plants, one in 

Clay County about 5 miles east of Starke, and the other about 7 miles to 

the north in Bradford County, about three-fourths mile north-northeast 

of Lawtey. The Hobart Brothers Welding Co. have a plant in Indian 

River County, mear Wabasso. Other deposits of heavy minerals have 

been mined, of which the most important was that of the Riz Mineral 

Co. in Indian River County, about half a mile south of Vero Beach. 

Small discontinuous deposits of heavy minerals were also worked during World War I in St. Johns County from Mineral City (Ponte Vedra) 

southward for 17 miles, and in Duval County, north of Mineral City. 

Similar deposits were mined from 1939 to 1943 for 28 miles along the 

west shore of Indian River, in Brevard and Indian River Counties. Littoral deposits were mined in 1952-53 along the Atlantic beach in 

Brevard County, 8-10 miles south of l\1elbourne. Monazite was identified in all these ores, and it was recovered from some of them (Calver, 

1957' p. 15-21). 

The principal part of the deposit o~ned by the National Lead Co. lies 

north of Atlantic Boulevard, a highway that connects South Jacksonville with the Atlantic beaches; but an extension of this ore body that 

was being worked in 1957 lies south of the boulevard. The northern, or 

principal, deposit of mineral-bearing sand had a general subelliptic 

shape, with maximum dimensions of 1 by 4 miles, trending N. 35° E.; 

but the actual area of 900 acres mined from 1943 to 1956 was indefinite 

in size and shape, depending upon the grade. When mining began, the 

tenor of heavy minerals to a minimum depth of 12 feet was about 8 percent; but with greater depth the average tenor decreased to about 4 percent. Before mining is finished the grade may decrease to 3 percent, 

which is regarded as the lower limit of profitable mining for sands of 

this mineralogical character. Since mining began in 1943, 3,000-10,000 

tons of sand has been processed daily; the larger figure was the capacity 

in 1957. 

Mining was started with a dragline excavator, but this was soon 

replaced by a suction dredge. The heavy minerals are concentrated by a 

large battery of Humphrey spirals that produce a concentrate consisting of 95 percent heavy minerals. A kiln-dried product then goes to 

electrostatic separators where ilmenite and rutile are recovered; ilmenite is separated from rutile in other electromagnetic machines. The 

reject from the first battery of electrostatic separators goes to another 

battery of Humphrey spirals, where zircon and monzite are separated 

from most of the minerals of lower density. Monazite is magnetically 

separated from zircon. The process is much more complex than this 

brief sketch indicates, as middlings have to be rerun repeatedly in the 

spirals, the electrostatic separators, and the electromagnetic 

separators. The suction dredge and a part of the Humphrey spirals are 

illustrated in figures 5 and 6. 
ALLUVIAL MONAZITE 29 

FIGURE 5. - Suction dredge of the National Lead Co., Duval County, Fla. 

FIGURE 6. - Battery of Humphrey spirals at the plant of the National Lead Co., Duval 

County, Fla. 
30 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

Another ore body owned by the National Lead Co., known as the 

Skinner tract, which had not been worked as of 1957, lies about 21/2 

miles south of the principal ore body. It has a length of about 3 miles, a 

width of about half a mile, and a workable thickness of 8-10 feet. The 

mineral-bearing sand, however, does not begin at the surface, but instead lies beneath 20-30 feet of low-grade sand. The workable stratum 

has a tenor of 4-5 percent heavy minerals. 

The altitude of the northern or principal ore body ranges from 40 to 65 

feet and averages 54 feet. The sands that were mined up to 1957 extend 

from the surface to a depth of 20-30 feet; hence, by reason of altitude, 

the ore body appears to belong in the Penholoway .terrace. But the ore 

sands show evidence of eolian action, and therefore possibly a part of 

this deposit is a dune that lies atop the Talbot terrace. The altitude of 

the top of the ore sand at the Skiriner tract ranges from 25 to 35 feet; 

therefore, this deposit is probably a part of the Talbot terrace, which is 

covered by dnne sand. 

The principal ore minerals in the northern ore body are ilmenite, 

rutile, and zircon, which occur in a variable mean ratio of 4:1:1.5, 

respectively; but the concentrates also include staurolite, kyanite, 

sillimanite, tourmaline, monazite, garnet, epidote, and other minerals. 

The recovery of the principal ore minerals is at least 85 percent. 

Monazite makes up about 0.7 percent of the concentrates, or about 

0.025 percent of the workable sand. Monazite is produced as a small but 

significant byproduct. Xenotime has not been reported, but this 

mineral may be rejected with others that are more electromagnetic than 

monazite, such as staurolite, epidote, and garnet. A small amount of 

xenotime may remain in the monazite product, because a weak double 

absorption band in the blue-green that characterizes samarium was 

noted when this product was examined with the hand spectroscope. 

The sizes of the minerals in the concentrates recovered at this plant, 

as reported by the owners, are listed' in table 5. 

The sizes of the grains of monazite, as determined by me, are shown 

in ·table 6. 

TABLE 5. - Sizes of minerals in concentrates from the northern ore body, National Lead 

Co. placer, Duval County, Fla. , 

Grain size 

Tyler standard mesh 

+ 40 - 40 to+ 60 - 60 to+ 80 - 80 to+ 100 

-100 to+ 120 

-120 to+ 140 

-140 to+ 160 

-160 to +200 

-200 

Material Millimetres 

+0.38 __ Quartz and organic matter 

-0.38 to +0.22 _____ do _______________ _ 

-0.22 to +0.17 __ Quartz and heavy minerals ____ _ -0.17 to+0.15 _____ do _______________ _ -0.15 to+0.12 _____ do _______________ _ -0.12 to +0.11 _____ do _______________ _ 

-0.11 to +0.096 _ Mainly heavy minerals ______ _ -0.096to+0.074 ____ do _______________ _ -0.074 __________ do _______________ _ 

Percent 

0.1 

1.3 

37.7 

41.1 

14.6 

1.6 

1.8 

1.2 

0.6 
ALLUVIAL MONAZITE 31 

TABLE 6. - Sizes of monazite grains from the northern ore body, National Lead Co. 

placer, Duval County, Fla. 

Tyler standarJ mesh 

-100 to+ 140 

-140 to +200 

-200 to +250 

-250 to +325 

-325 

Grain size 

Millimetres 

-0.15 to +0.11 __________ _ -0.11 to +0.074 __________ _ 

-0.074 to +0.061 __________ _ -0.061 to +0.043 __________ _ 

-0.043 - - - - - - - - - - - - - - - -

Percent 

4.5 

72.0 

15.0 

7.0 

1.5 

The two plants operated in 1957 by the E. I. duPont de.Nemours and 

Co. are located on Trail Ridge, which extends from east~central Florida 

northward into southeastern Georgia. Mining began at the southern 

plant in 1949 and at the northern plant in 1955. The mining methods at 

these two plants are generally similar to those employed by the 

National Lead Co., with the exception of changes required by local conditions. Much of the ore sand, for example, is so well indurated that it 

has to be blasted, and thereafter comminuted by a "root hog" underwater macerator, which also cuts up buried stumps. A second 

difference is that the ore minerals are cov~red by a carbonaceous 

coating, which changes their densities and electrical properties. At the 

outset a scrubbing operation to remove this coating was made a part of 

the flow sheet, but this was later abandoned, partly on account of the 

extra expense, and partly because it tended to comminute brittle ore 

minerals, such as ilmenite. The carbonaceous layer is ·now removed, 

though not so completely, by leaching it with a caustic compound. A 

third difference in mining practice at the southern duPont plant is that 

the entire assembly of Humphrey spirals is housed on a barge (figs. 7, 

8). 

In 1957 each of these two plants was producing far more total heavy 

minerals than all other plants in Florida. Monazite, however, was not 

recovered. 

The paystreak at Trail · Ridge has a width ranging from 0.5 to 1.5 

miles. The ore, which begins at a depth of 5-10 feet below the surface of 

the ground, exte'nds downward 10-65 feet and has an average thickness 

of about 35 feet. The U.S. Bureau of Mines (Spencer, 1948) traced this 

ore body' by drilling from a point 2 miles north of Highland in Clay 

County to the vicinity of Blue Pond Lake on the Camp Blanding 

Military Res'ervation, a distance of 19 miles. The mineralogical analysis 

of 1,622 samples taken from 243 drill holes showed an average grade of 

3.9 percent heavy minerals. These results agreed closely with those obtained by the E. I. duPont de Nemours and Co. The actual recovery of 

heavy minerals is reported to be about 75 percent of this average grade. 

The paystreak has not yet been completely outlined. The U.S. 

Bureau of Mines in 1948 carried out another scout drilling program 
32 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

FIGURE 7. -Concentrating plant of Humphrey spirals on a barge, at the southern plant of 

the E. I. duPont de Nemours and Co. in Clay County, Fla. 

beginning in Clay County and extending south-southeastward to the 

vicinity of Lake Okeechobee, but they were unsuccessful in locating a 

continuation of the paystreak. Although its northernmost limit is unknown, the Trail Ridge paystreak has been found in Florida and in 

Georgia east of the Okefenokee Swamp. The Trail Ridge deposit occurs 

at altitudes of 165-200 feet, and therefore appears to lie dominantly 

within the Coharie terrace, though some part of these ore sands may 

come from the underlying Hazlehurst terrace. 

The thickness of the sands at the southern plant was measured in 

three wells drilled for water. These wells passed through 300 feet of 

sands, and 500 feet of limestone, presumably the Ocala Limestone. The 

hydrostatic head of the water in these wells is 140-170 feet below the 

surface. 

The ore minerals recovered at the two duPont plants are somewhat 

different in character and tenors from those at the plant of the National 

Lead Co. The principal minerals are ilmenite, leucoxene, rutile, zircon, 

and staurolite, which occur in mean ratios of about 12:2.5:1:5:7, respectively. The concentrates also contain sillimanite, kyanite, tourmaline, 

monazite, corundum, and traces of spinel, andalusite, garnet, and 

epidote. The four principal commercial products are ilmenite, a mixture of leucoxene and rutile, zircon, and staurolite. Leucoxene, which is 
AL,LUVIAL MONAZITE 33 

FIGURE 8. - Suction dredge of the E. I. duPont de Nemours and Co., at the southern 

plant in Clay County, Fla. 

derived from ilmenite, has a magnetic susceptibility similar to that of 

rutile and thus cannot be separated from it. The mixture of these two 

minerals is called the ilmenite residue. The ratio of ilmenite to leucoxene is variable, ranging from 3:1 to 6:1, with a probable mean of about 

5:1. Staurolite is recovered as an impure separate and is sold to a subsidiary of the Lehigh Portland Cement Co. at Bunnell, Fla., where it is 

used with Ocala Limestone in the manufacture of cement. This 

separate consists of about 75-80 percent staurolite, 10 percent tourmaline, and the remainder is mainly sillimanite, kyanite, and quartz. 

The tenor of monazite at Trail Ridge is reported to be only about 0.03 

percent of the concentrates, or 0.001 percent of the ore sand. Its 

recovery would yield only a very small quantity. 

The ilmenite and leucoxene found in Florida have both mineralogical 

and geological interest. Commercial partial analyses of ilmenite from 

the plants of the National Lead Co. and the E. I. duPont de Nemours 

and Co., together with the theoretical compositions of ilmenite and 

arizonite, are given in table 7. 

The chemical analyses indicate that the composition of this commercial ilmenite differs greatly from that of theoretical ilmenite. The high 

tenors in TiOz have induced some of the operators in Florida to refer to 

their ilmenitic product as arizonite, but X-ray diffraction analyses give 
34 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

TABLE 7. - Composition, in percent, of minerals and ilmenite products from placer 

mines in Florida 

Oxides 

FeO ____________ _ 

Fe203 ___________ _ Ti02 ____________ _ 

Total ________ _ 

Theoretical composition 

Ilmenite 

47.35 

52.65 

100.00 

Arizonite 

39.98 

60.02 

100.00 

Commercial ilmenite 

National Lead Co. duPont Co. 

4.5 

25.0 

64.0 

93.5 

4.61 

26.40 

61.50 

92.51 

an ilmenite pattern. The high content of Ti02 suggests the presence of 

rutile, and the. term '.'EJ.rizonite" is no longer accepted as a mineral 

species; arizonite is. defined as a doubtful mineral (Fleischer, 1971, p. 

5). 

The FeO, Fe203, and Ti02 contents of ilmenite in the duPont and 

National Lead placers are not substantially different (table 7), yet a 

considerable part of the ilmenite at duPont's Trail Ridge placer has 

been completely altered to leucoxene. At Trail Ridge, leucoxene is most 

plentiful in the upper horizons of the ore body and ilmenite and leucoxene are reported by the operators to occuf. as distinct minerals, without 

any intermediate products. Local conditions are probably responsible 

for the occurrence of leucoxene here. Leucoxene may have formed as a 

result of chemical alteration by ground water of detrital ilmenite after 

the ilmenite was deposited. The fallacy of this interpretation is that 

products intermediate . between ilmenite and leucoxene should form, 

and these products are absent. Ilmenite at Trail Ridge could also be of 

two mineralogical types, one of which was readily altered to leucoxene, 

whereas the other was more resistant but ··was enriched in Fe203. 

The ore sand atTrail Ridge is coarser and less well sorted than the 

sand at the plant of the National Lead Co., but the ore minerals are 

finer grained; as shown in table 8. Monazite has not been separated 

from these concentrates, and so the range in grain size· has not been 

determined. All the monazite grains noted are smaller than 140 mesh, 

that is, less than 0.11 mm in size. 

The placer on the west .side of U.S. Highway 1, about 7V2 miles northTABLE 8. -Sizes of heavy minerals in concentrates from Trdil Ridge, Fla. 

[Data from E. I. duPont de Nemours and Co.) 

Tyler standard mesh 

+ 60 ~ 

- 60to+ 80 - 80to +100 

-100to +140 

-140 

Grain size 

Millimetres 

+0.22 ----------- --~--- -0.22to +0.17 ___________ _ 

-0.17to +0.15 ___________ :... -0.15to +0.11 ___ .::... ___ . .::.. ____ , 

-0.11 -----------------

Percent 

14 

22 

27 

28 

' 9 
ALLUVIAL MONAZITE 35 

northwest of Vero Beach and just south of the city limits of Wabasso, 

has had a checkered history of mining. Prior to 1945, it was prospected 

independently by George A. Pritchard and Floyd Snow, but at that 

time it appeared to be too low grade for profitable mining. In 1954, 

however, the Florida Ore Processing Co., operating under lease by the 

Hobart Brothers Welding Co., began work on this deposit. In 1955, the 

Florida Minerals Co. was organized as a subsidiary of the Hobart 

Brothers Welding Co., and since that time has operated this property. 

In the initial stages of this operation, a suction dredge was used, but in 

1957 this was replaced by a 2-foot bucket dredge built by Hobart 

Brothers. This dredge was equipped with a concentrating plant consisting of a large number of linearly alined Cannon pinched sluices. The 

sand, which consists of 50 percent heavy minerals, is transported from 

the sluices by pipe to the main separatory plant, where the final concentration is completed on 14 Deister tables. The process in which the kilndried product is separated is similar to the separation of the concentrates at the National Lead Co. plant, except that two additional concentrating tables are used instead of spirals to separate zircon and 

monazite from other minerals of lower density. The plant of the Hobart 

Brothers Welding Co. is shown in figure 9. 

The ore body, as originally mined, extended from the surface of the 

ground downward for about 20 feet, below which is a well-consolidated 

sand or hardpan 2-4 feet thick. The bucket dredge was designed to dig 

through the hardpan down to approximately sea level. This ore body 

had not been completely prospected in 1957, and so its length, width, 

and tenor were not accurately known. In 1956, the grade of heavy 

minerals was stated by the company to be 1 1

/z -2 percent. The principal 

minerals recovered are ilmenite, rutile, and zircon; these comprise 65 

percent of the heavy minerals, and occur in a mean ratio of 2.5:1:1, 

respectively. Monazite is said to constitute about 0.2 percent of the concentrates, and it is recovered as a small byproduct. 

The Hobart ore deposit is situated on a low, elongate ridge that extends as a marked topographic feature from the mouth of Sebastian 

Creek south-southeastward for 11 miles, passing west of Sebastian, 

Wabasso, and Winter Beach. This ridge is not continuous but is interrupted by a number of saddles. Its maximum height is west of 

Wabasso, where it attains an altitude of 52 feet; the other crests range 

in altitude from 35 to 45 feet. At the site of mining the altitude is about 

40 feet, and the ore body appears to be part of the Talbot terrace. 

A small ore body about half a mile south of Vero Beach was worked 

by the Riz Mineral Co., under the direction of George A. Pritchard, for 

several years after September 1943. This deposit had a workable length 

of about 1,500 feet, a minimum width of 200 feet, and a depth of from 10 

to 12 feet. Below the ore body was a consolidated sand or hardpan. A 

dragline excavator was used in mining. The longitudinal and lateral ex-
36 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

FIGURE 9. - Aerial view of the dredge, separatory plant, and offices of the Florida 

Minerals Co., looking east-northeast across U.S. Highway 1, Indian River County, Fla. 

Photography by Photocraft Commercial Studios, courtesy of Hobart Brothers Welding 

Co., 1957. 

tent of the deposit were limited by the tenor in heavy minerals, which in 

the workable ground had a mean value of 5 percent. 

The commercial minerals were ilmenite, rutile, and zircon, which occurred in a mean ratio of 2.5:1:1. Other minerals were staurolite, 

kyanite, tourmaline, epidote, garnet, monazite, spinel, and xenotime. 

This is the only reported occurrence of xenotime in the commercial 

operations of Florida. Monazite constituted 0.2 percent of the concentrates and, in the later stages of this operation, was saved as a small 

byproduct. 

The sizes of the heavy minerals recovered at Vero Beach are not 

known, but a sample of the monazite was determined by me to have a 

range in grain sizes as shown in table 9. This monazite is finer grained 

than that at the plant of the National Lead Co. in Duval County. 

The ore body occurs on a low elongate ridge at an altitude of 20-25 

feet and is therefore considered to be a part of the Pamlico terrace. 

Prospecting for heavy minerals was in progress during 1957 at a 

number of localities in Florida. The monazite content has been 

recorded at two of these localities. One of these sites is Amelia Island, 

along the northeast coast of Florida, at the mouth of St. Marys River, in 
ALLUVIAL MONAZITE 

TABLE 9.- Sizes of monazite grains from Vera Beach, Fla. 

Grain size 

Tyler standard mesh Millimetres 

-140to +200 -0.11 to +0.074 __________ _ 

-200to +250 -0.074 to +0.061 __________ _ 

-250to +325 -0.061 to +0.043 __________ _ 

-325 -0.043 ----------------

Percent 

46.0 

35.0 

16.0 

3.0 

37 

Nassau County. This island has been extensively prospected by several 

companies, and one company was preparing in 1957 to install a bucket 

dredge and separatory plant; but the decline in the metals markets, 

which began in August of that year, caused this project to be placed in 

abeyance. The mineral-bearing sand appears to lie mainly in the 

southern half of the island. The tenor in heavy minerals is reported to 

be about 3 percent, and monazite occurs in about the same tenor as at 

the property of the National lead Co. At the center of the island the 

paystreak trends about north and has an altitude of about 25 feet. Orebearing sands occur discontinuously eastward and westward to sea 

level. Hence, the mineral-bearing sands appear to lie within the 

Pamlico and Silver Bluff terraces. Talbot Island, in Duval County, and 

Anastasia Island, St. Johns County, have been prospected by other 

companies, but the results of the exploration are not known. 

A large block of ground, about 5,000 acres acquired by the National 

Lead Co. in Duval County, north of Highland and east of Macclenny, 

appears to be the northern extension of the Trail Ridge paystreak. Also, 

the Bear Creek Mining Co. had been prospecting in Putnam and Clay 

Counties, Fla., but the results are unknown. 

Considerable prospection has been done along the Gulf Coast of 

Florida. Prior to 1943, Stephen H. Rogers, of Tampa, acquired an option from the State of Florida to lease the sand deposits along the north 

shore of Santa Rosa Sound and along three bays east and northeast of 

Pensacola. These beach deposits, which were sampled by W. C. Hudson 

(1943, p. 13-15, 17-18), U.S. Bureau of Mines, were found to contain 

only a small volume of heavy minerals. Monazite was not reported from 

these deposits but could have been easily overlooked. 

In 1954, 1955, and 1956, the Heavy Minerals Co., a subsidiary of the 

Crane Co., prospected the beach sands of the Gulf Coast of Florida, 

from 15 to 50 miles west of Panama City; but they did most of their 

work in Walton County between Phillips Inlet and Santa Rosa Sound. 

Workable deposits may occur behind a barrier dune that follows the 

coastline. The company claims that several large blocks of workable 

ground in this area have widths of 200-600 feet, and depths of 15-30 feet 

from the foot of the dunes to the outer edge of the beach. 

The tenor in heavy minerals is reported to be about 3.5 percent. The 
38 MONAZITE PLACERS, SOUTHEASTERN ATLANTIC STATES 

principal ore minerals are ilmenite, rutile, and zircon, which compose 

about 62 percent of the concentrates and occur in the mean ratio of 

3.2:1:1, respectively. The concentrates also contain staurolite, kyanite, 

sillimanite, and monazite. The tenor in monazite according to one 

determination made by the company, was 0.16 percent .of the concentrates. Little or no prospecting appears to have been done on the higher 

ground inland from the Gulf of Mexico. 

Concentrations of heavy minerals have been reported at several sites 

along the west coast of Florida. One of these is at a prominent spit on 

the west side of Venice, where limestone is overlain by 6-8 feet of sand. 

The lower 1-2 feet of sand is coarse pieces of comminuted shells. Above 

this, the sand is quartzose and the heavy minerals are concentrated in 

black carbonaceous layers. One of these beds, about 8 inches thick, was 

panned by me and was found to contain ilmenite, rutile, zircon, 

staurolite, and other minerals. Among the latter was a very small, but 

definitely recognizable, amont of monazite. 

CONCLUSIONS 

Exploration for fluviatile monazite placers in the Piedmont province 

of the Southeastern Atlantic States in the 1950's failed to disclose 

deposits that might be mined except under conditions of emergency demand for thorium and the rare earths. However, streams with thick sequences of gravel, such as might be found in the Blue Ridge, have not 

been investigated. They may contain workable monazite placers. 

A fluviatile placer workable for monazite plus ilmenite, rutile, 

staurolite, and gravel has been mined at Horse Creek near Aiken, S.C. 

The source of the monazite is reworked sediments of Cretaceous and 

Tertiary age and monazite-bearing old granitic rocks at the Fall Line. 

Similar deposits are certainly present in similar geologic situations 

along the Fall Line in South Carolina and Georgia. 

Placers associated with Pleistocene terrace deposits in the Coastal 

Plain of North Carolina, South Carolina, Georgia, and Florida have 

been shown to have small amounts of monazite associated with dominant ilmenite and other titanium minerals. Exploration for these 

deposits requires careful attention to geomorphic features because the 

surface expression of buried deposits is weak. A continuing industrial 

demand for the ores of titanium assures the continuing exploration for 

these deposits. 

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t:I U.S. GOVERNMENT PRINTING OFFICE: 1975-677-308/31