U.S. DEPARTMENT OF INTERIOR 

U.S. GEOLOGICAL SURVEY

Revised grade and tonnage model of carbonatite deposits

by 

Donald A. Singer1

Open-File Report 98-235

This report is preliminary and has not been reviewed for conformity with 

U.S. Geological Survey editorial standards or with the North American 

Stratigraphic Code. Any use of trade, firm, or product names is for 

descriptive purposes only and does not imply endorsement by the U.S. 

Government.

'U.S. Geological Survey, 345 Middlefield Rd, Menlo Park, CA 94025

1998
COMMENTS This model applies to the descriptive model of carbonatite 

deposits (No. 10) by Singer (1986a) and should replace the grade and 

tonnage model in that volume (Singer, 1986b). Data used in this model are 

presented in Table 1. In some cases, other estimates of grades or tonnages 

were available, but their quality was questionable and so they were not used 

here.

Figure 1 presents a plot of the tonnages of these deposits. Figures 2 and 3 

present plots of the niobium and rare-earth grades respectively. In each 

figure the cumulative proportion of deposits versus the tonnage or grade of 

the deposits is plotted. Individual symbols represent the deposits. In Figure 

4 tonnage is plotted against both niobium and rare-earth grades. This plot 

demonstrates the lack of correlations among these variables and the lack of 

any distinct groupings of these deposits. Locally these carbonatite 

complexes may contain economically interesting grades of uranium, 

thorium, titanium, iron, copper, vermiculite, zirconium or phosphorus; 

frequently, the :; . : ommodities are in different zones than the niobium 

or rare-earth-ricl: parts of the complex. In addition, adjacent deposits can be 

either niobium or rare-earth rich, such as at Catalao I and Catalao II.

References used for data sources

Adams, J.W., and Staatz, M.H., 1973, Rare-earth elements, in Brobst, D.A., 

and Pratt, W.P., eds., United States mineral resources: U.S. Geological 

Survey Professional Paper 820, p. 547-556.

Anhaeusser, C.R., and Maske, S., eds., 1986, Mineral deposits of southern 

Africa: Volumes I & II: The Geological Society of South Africa, 2376 p.

Drew, L.J., Qingrun, Meng, and Weijun, 1990, The Bayan Obo iron-rareearth-niobium deposits, Inner Mongolia, China: Lithos, v. 26, p. 43-65.
Heinrich, E.W., 1980, The geology of carbonatites: Reprinted. Rand 

McNally, Chicago, 585 p.

Hughes, F.E., ed., 1990, Geology of the mineral deposits of Australia-Papua 

New Guinea, Volumes I & II: Melbourne, The Australasian Institute of 

Mining and Metallurgy, 1828 p.

Jackson, W.D., and Christiansen, Grey, 1993, International Strategic 

Minerals Inventory summary report-Rare-earth oxides: U.S. Geological 

Survey Circular 930-N, 68p.

Kamitani, Masaharu, ed., 1986, Preliminary report of the resource 

assessment of rare metals: a proposal for a future project: Geological Survey 

of Japan, 169 p. (in Japanese )

Kogarko, L.N., Kononova, V.A., Orlova, M.P., and Woolley, A.R., 1995, 

Alkaline rocks and carbonatites of the world: Part Two: Former USSR: 

Chapman & Hall, London, 226 p.

Olsen, J.C., Shawe, D.R., Prey, L.C., Sharp, W.N., and Hewlett, D.F., 1954, 

Rare earth mineral deposits of the Mountain Pass district, San Bernardino 

County, California: U.S. Geological Survey Professional Paper 261, 75 p.

Schobbenhaus, Carlos, and Silva Coelho, Eduardo, eds., 1986, Principals 

depositos minerais do Brazil: Vol. II: Ferro e metais da industria do aco: 

Ministerio das Minas e Energia, Brazil, 501 p. (in Portuguese)

Singer, D.A., 1986a, Descriptive model of carbonatites, in Cox, D.P., and 

Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 

1693, p. 51.

Singer, D.A., 1986b, Grade and tonnage model of carbonatite deposits, in 

Cox, D.P., and Singer, D.A., eds., Mineral deposit models: U.S. Geological 

Survey Bulletin 1693, p. 52-53.

Singer, D.A., Mosier, D.L., and Menzie, W.D., 1993, Digital grade and 

tonnage data for 50 types of mineral deposits-Macintosh version: U. S. 

Geological Survey Open-File Report 93-280, 1 disk, 52 files.

Tuttle, O.F., and Gittins, J., eds., 1966, Carbonatites: New York, John 

Willey&Sons, 591 p.
Woolley, A.R., 1987, Alkaline rocks and carbonatites of the world: Part 1: 

North and South America: University of Texas Press, Austin, Texas, 216 p.

Table 1. Grades and tonnages of carbonatite deposits. 

(Tonnages in millions of metric tons, niobium, rare-earth, and phosphate grades in 

percent of X2O3. Zero indicates no grade reported. Location codes: BRZL Brazil, 

BURN Burnai, CINA China, CNON Canada British Colombia, CNON Canada Ontario, 

CNQU Canada Quebec, INDA India, KNYA Kenya, MLWI Malawi, MNGL Mongolia, 

NAME Namibia, NRWY Norway, SAFR South Africa, TNZN Tanzania, UGND 

Unganda, USCA United States California, USCO United States Colorado, ZIRE Zaire)

DEPOSIT

Amma Dongar

Araxa

Argo

Bayan Obo

Bingo

Catalao I

Catalao II

Dominion Gulf

Iron Hill

James Bay

Kangankunde

Lueshe

Manitou Island

Martison Lake

Mountain Pass

Mrima Hill

Mushgia Khudag

Nemogos (Lackner Lake)

Nemogosenda Lake

Oka

Ondurukurme

Panda Hill

Palabora

Pocos de Caldas

Salitre II

Sandkopsdrif

Seis Lagos

Serra Negra

Sove

St. Honore (Soquem)

Sukula

Tapira

LOCATION Tonnes/106 Nb2Os grade% RE2O5 grade % P2O5 %

INDA

BRZL

CNON

CINA

ZIRE

BRZL

BRZL

CNON

USCO

CNON

MALI

ZIRE

CNON

CNON

USCA

KNYA

MONO

CNON

CNON

CNQU

NAME

TNZN

SAFR

BRZL

BRZL

SAFR

BRZL

BRZL

NRWY

CNQU

UGND

BRZL

105

462

62.5

750

7.1

21

2

33

36.3

36.3

11

30

4.85

145

90

50.8

6.1

10

20

221

8

272

652

6

200

57

2890

60

55.3

16

118

166

0

2.48

0.52

0.1

2.86

0.98

2.18

0.39

0.25

0.52

0

0.35

0.756

0.35

0

0.67

0

0.23

0.47

0.23

0.3

0.3

0

0

2

0.15

2.81

1.5

0.23

0.69

0.25

1.18

3

0.033

0

4.1

0

1.02

0

0

0.01

0

0.62

0

0

0

5

0.59

1.37

0

0

0.1

3

0

0.15

3

0

1

0

0

0

0.0088

0

0.03

0

15

0

0

0

8.9

0

0

0

0

0

0

0

20

0

0

0

7

0

0

0

0

9

0

0

3.2

0

0

0

0

0

8.3
PROPORTION OF DEPOSITS

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o o

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o

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o

0

o

0

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1 . 1 . 
PROPORTION OF DEPOSITS

o>

Tl co' c

CO1 Jl

0)

CD

3.

3-

(Q

Q. 

0 

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*" 

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8^ o ^

0°

o

o 1

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o ^

o o

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co^- O O

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i . i . i , 
CARBONATITE DEPOSITS

5.5 

5.0 

4.5 

4.0h

Iu 3.5 

O 

DC UJ

c 3.0h

UJ 

Q

< Q. 25^.O

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2.0 

1.5 

1.0 

0.5h

0.

, , ,_____.-,, |,|,|,, , ...... .", , ..", , , , , , , , , , , , , 

0 NIOBIUM 

~ RARE-EA

-

: c

-

; o

-

; o

n = 32 

RTH OXIDE * "

5 0

o -

0

o

o ; 

$ 

* ° o 9 o I

° o 0000° ! o 9 » o

n An i ' i» t Am i nha » ' ' « ! L_ft_i 1 i 1 i »

.0 3.2 10 32 100 320 1,000 3,500

MILLION TONNES

Figure 4--Niobium and rare-earth grades versus tonnages of carbonatite deposits.