Tin Resources of the World 

By C. L. SAINSBURY 

GEOLOGICAL SURVEY BULLETIN "' 

IIi 

A description of the types of tin deposits 

and main tin-producing areas of the world. 

Reserves and resources are estimated to be 

sufficient /or 87 years 

1301 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1969 
UNITED STATES DEPARTMENT OF THE INTERIOR 

WALTER J. HICKEL, Secretary 

GEOLOGICAL SURVEY 

William T. Pecora, Director 

Library of Congress catalog-card No. GS 69-367 

For &ale by the Superintendent of Docu:m.ents, U.S. Govern:m.ent Printing Office 

Washington, D.C. 20402- Price 35 eenh (paper cover) 
CONTENTS 

Abstract---------------------------------------------------------- Introduction _____________________________________________________ _ 

VVorldreserves GeologY---------------------------------------------------------- ___________________________________________________ _ 

~orthAmerica---------------------------------------------------- lJnitedStates ________________________________________________ _ 

Alaska--------------------------------------------------- Conterminous lJnited States _______________________________ _ 

Canada------------------------------------------------------

~exico ______________________________________________________ _ 

South Bolivia America---------------------------------------------------- ______________________________________________________ _ 

Brazil Argentina---------------------------------------------------- _______________________________________________________ _ 

Europe----------------------------------------------------------- England _____________________________________________________ _ 

Portugal and Spain ___________________________________________ _ 

France-------------------------------------------------------

German Democratic Republic (East Germany) and Czechoslovakia __ Asia ____________________________________________________________ _ 

Indonesia ____________________________________________________ _ 

~alaysia ____________________________________________________ _ 

Thailand-----------------------------------------------------

Burma-------------------------------------------------------

Vietnam and Laos---------------------------------------------

Japan--------------------------------------------------------

Airica------------------------------------------------------------

~igeria------------------------------------------------------- Democratic Republic of the Congo _____________________________ _ 

Republic of South Airica_ -------- ___ -------------------- _ ------

South-VVest Africa---------------------------------------------

Southern Rhodesia--------------------------------------------

Rwanda, Burundi, Uganda, and Tanganyika (Tanzania) __________ -

Oceania Other areas in Africa------------------------------------------- _________________________________________________________ _ 

Australia-----------------------------------------------------

China ~ew Zealand-------------------------------------------------- ___________________________________________________________ _ 

u.s.s.R _________________________________________________________ _ References cited __________________________________________________ _ 

Index------------------------------------------------------------

III 

Pap 

1 

1 

2 

8 

10 

10 

11 

12 

13 

13 

14 

14 

17 

18 

19 

19 

21 

21 

22 

23 

23 

26 

28 

29 

30 

31 

31 

32 

33 

35 

36 

36 

37 

38 

38 

38 

44 

44 

44 

49 

53 
IV CONTENTS 

ILLUSTRATIONS 

Page 

FIGURE 1. Map showing major stanniferous regions of the world________ 4 

2. Map showing location of the main tin deposits of Bolivia_____ 15 

3. Chart showing zoning in the tin deposits of Cornwall, England_ 20 

4-6. Maps: 

4. Tin-bearing areas of Southeast Asia_________________ 24 

5. Tin-bearing areas of Australia______________________ 39 

6. Tin deposits in the Nanling and Coastal zones, China_ 45 

TABLES 

Page 

TABLE 1. Tin reserves of noncommunist countries, excluding the United 

States________________________________________________ 9 

2. Tin resources of the world, exclusive of the U.S.S.R. and China_ 9 

3. Estimated tin reserves and resources of the U.S.S.R. and China_ 10 

4. Reserves and resources of tin in the United States---------- 11 

5. Estimated tin reserves of Bolivia__________________________ 17 

6. Tin reserves of Brazil, by area____________________________ 19 

7. Tin reserves of Indonesia, 1965---------------------------- 25 

8. Tin reserves and known resources of Malaysia ____ ---------- 28 

9. Tin reserves of Thailand, 1965---------------------------- 29 

10. Estimated reserves of tin, Democratic Republic of the Congo, 

1965_________________________________________________ 35 
TIN RESOURCES OF THE WORLD 

By c. L. SAINSBURY 

ABSTRACT 

Lode deposits of tin, and commercial placers derived from them, almost invariably are associated with biotite or biotite-muscovite granite. Most lode 

deposits fall into one of two distinct types: (1) long, narrow belts of tin-bearing 

granites in a wider intrusive romplex, or (2) diffuse belts of tin-bearing granites 

in extensive areas of Precambrian rocks. The most productive placer deposits of 

the world (Southeast Asia) are associated with a stanniferous region of type 1. 

At many places, extensive areas have fluctuated between marine and continental 

conditions because of oscillations of sea level during the Pleistocene, am.d productive placers have resulted from a complex interplay of stream and marine erosion 

and concentration, such as those in Southeast Asia, Brazil, and Western Australia. 

As a result, many economically important placers lie seaward of present 

shorelines. 

Most tin is smelted from cassiterite ( Sn02) contained in placer concentrates, 

and many other valuable metal commodities are also recovered during the mining 

and concentration of tin. Lode deposit's yield valuable amounts of tantalum, 

niobium, tungsten, copper, lead, zinc, silver, arsenic, and antimony; in the future, 

others may yield beryllium. Placer deposits yield valuable amounts of niobium, 

tantalum, and rare-earth minerals. 

Tin reserves of the world, exclusive of the U.S.S.R. and China, at a price between $2,000 and $3,080 per long ton (2,240 pounds) of tin, are estimated to be 

at least 3,500,000 long tons in 1970 ; tin resources of lower grade are estimated to 

be at least 7,108,000 long tons. Reserves and resources of the U.S.S.R. and China 

together are estimated to be at least 2,130,000 and 4,260,000 long tons of tin, 

respectively. 

Thus, world reserves are ample to satisfy demand at a yearly rate of production 

of 180,000 long tons of tin for about 31 years; resources shoum sustain production 

at a rate of 200,000 long tons per year for an additional 56 years. 

INTRODUCTION 

'This report was prepared as a chapter on tin resources for inclusion in a U.S. Bureau of Mines Materials Survey on tin. Owing to a 

change in publication plans, however, the Materials Survey is not 

scheduled for publication in the near future. As this report presents 

data on reserves and resources of tin, data which change with time, 

the report is being presented now to retain the timeliness and applicability of the contained information. 

1 
2 T~ RESOURCES OF THE VVORLD 

Many of the ta;bles of reserve data are from a report by M. A.. 

Robertson ( 1965) , prepared under the auspices of the International 

Tin Council; without Robertson's permission to use the data, preparation of the report would have been infinitely more difficult. 

It is difficult to estimate the amount of tin that reasonably can be 

expected to be 1nined in the future. F'actual data must be supplemented 

by subjective interpretation of factors such as geologic similarity of 

very large areas, unforeseen economic conditions, state of knowledge 

of known stanniferous areas, and availability and objectivity of published data, especially for the Iron Curtain countries. Resource figures 

represent multiplications involving factors and figures that are changeable, and they must be evaluated with this in mind. For those who 

would consider the presented estimates of potential resources ,ag being 

unrealistically conservative, it is pointed out that the clarke (average 

crustal 3Jbundance) of tin probably exceeds 1 gram per metric ton. 

(See Borchert and Dybeck, 1959-60.) Thus, the earth, with a mass 

of about 5.976 X 1027 grams, should contain about 5.976 X 10111 

metric tons of tin. Very little of this tin, however, is concentrated in 

amounts suitable for mining. 

GEOLOGY 

Tin, a useful metal of commerce since the bronze age, has long been 

sought and mined. Consequently, several major mining areas have 

been studied in three dimensions. CompaJ:>ed with that of many metals, 

the geology of tin deposits is relatively well known; and even though 

new producing areas are being found, the geology o:f each new district falls within that predicted from past experience .as summarized 

in an early paper on the geology of tin deposits (Ferguson and Bateman, 1912). 

Associated metals.-Most tin of commerce is smelted from concentrates that contain a high proportion of tin in cassiterite, many other 

valu:tble metals are recovered during the mining and concentration 

of tin ores. Lode deposits yield valuable amounts of tantalum, niobium, tungsten, copper, lead, zinc, silver, arsenic, and antimony; in 

the :future, others may yield beryllium. Placer deposits yield notable 

amounts of niobium, tantalum, and rare-earth minerals. 

Lode tin deposits of importance almost invariably are ~associated 

with biotite or biotite-muscovite granite or, as in Bolivia, with shal-

-low-seated volcanic rocks such as quartz latite or dacite. The g~anites 

with associated tin deposits are generally referred to as tin granites. 

As a group, the tin deposits a,re probahly the best example o:f epigenetic magmatic ore deposits. Most of the ma,j or lode areas of the world 

fall into one of two distinct types : ( 1) long, narrow belts of tin -bearing 
· GEOLOGY 3 

granites in a wider intrusive complex (Southeast Asia), or (2) more 

diffuse belts of younger granites in extensive areas of Precambrian 

rocks (Nigeria). Most of the major linear belts lie near continental 

margins or along major orogenic belts inland in which granite magma 

was generated (fig. 1). Some can be correlated with tectonism along 

segments of extensive transcurrent faults, which are the continuation 

under the continents of major fractures affecting su!bcrustal rocks of 

the ocean basins (Siberia). Thus, most tin deposits are looalized along 

tectonic belts in which granite has been intruded; their ages range 

from Precambrian to Tertiary, but some workers (Pereira and Dixon, 

1965) hold that statistical studies show that tin deposits are more 

common in younger rocks. 

Lode tin deposits can be classified generally into six distinct types : 1 

1. Pegmatite deposits, 

2. Pneumatolytic-hydrothermal deposits, 

3. Subvolcanic or tin-silver deposits, 

4. Disseminated deposits, 

5. Contact-metamorphic deposits, and 

6. Fumerole deposits. 

Pegmatite deposits.-Tin-bearing pegmatites are generally associated with granitic rocks and contain cassiterite (Sn02 ) as well as 

other uncommon, valuable minerals such as columbite-tantalite, beryl, 

or spodumene. Most productive pegmatites are in areas o:f deep tropical 

weathering, which allows the economic exploitation of pegmatites 

which contain less than 0.4 percent tin. Some pegmatites are very 

large, contain cassiterite throughout, and constitute major reserves of 

tin-for example, the Manono pegmatite in the Democratic Republic 

of the Congo, which is 10 kilometers long and 100-400 meters wide. 

Pneumatolytie-hydrotherrnal deposits.-The bulk of the major lode 

tin deposits of the world (those of Bolivia excepted) are o:f this type.2 

Lodes are near or in biotite or two-mica granite and form replacement 

deposits or fissure fillings in diverse types of country rock. Owing to a 

regional zonation commonly displayed, deposits vary widely in 

mineralogy. In or near granite, lodes typically contain cassiterite in 

greisen (quartz-mica rock) or quartz-topaz-tourmaline rock that also 

contains wolframite and many base-metal sulfides. Farther from the 

granite, lodes may contain stannite (Cu2FeSrrS4 ), base-metal sulfides, 

and silver; in some places, the deposit may be valued principally for 

the silver content. Some individual deposits are very large, such as 

the Dalcoath lode in Cornwall, England, which produced 80,000 tons 

of tin (Dines, 1956). 

1 This classification cklsely follows that of Ahlfeld ( 1958). 2 This distinction of the Bolivian type of deposit from what may be called the Cornwall 

type may not be valid. The writer here is following most others, who consider them in 

separate categories. 
., NORTH{F- ·~A MERICA \ ~ x3 ;,.) 

~ 6 /~ ~~ X i4 10 x: J;J':p _;;--&-/ 

X X 

x'~-' x' 

1 

oo ')~, ~.,---- -*- [_ ,5 ;r-~,~ 

EXPLANATION 

_,_ Important stanniferous area 

X Area of minor importance or unossessed potential 

),6 x1 

x~f AMERICA 

'\) 

/r 

( 

oo 

ASIA 

·~3 

<:::::::, ((Jt,l c:;:) p 9~10 d 

OCEANIA 

~ 

~ 

i!l 

l1J 

0 

d 

~ 

("::1 

l,?!j 

l1J 

~ 

~ 

~ 0 

=:tl 

t'4 

!:=' 
Cl,:) 

~ 

~ 

I 

~ 

H'-

00 

I 

~ 

~ 

I 

~ 

FIGURE 1.-Major stanniferous regions of the world. 

NORTH AMERICA 

1. Seward Peninsula, Alaska 

2. Manley Hot Springs, Alaska 

3. Sullivan mine, British Columbia, 

Canada 

4. New Brunswick area, Canada 

5. Southern Appalachian area 

6. Black Hills area, South Dakota 

7. Franklin Mountains, Tex. 

8. Black Range district, New Mexico 

9. Climax mine, Colorado 

10. Gorman area, California 

SOUTH AMERICA 

1. Rio Grande do Norte-Para1ba, Brazil 

2. Northeast Ceara, Brazil 

3. Central Ceara, Brazil 

4. Eastern Minas Gerais, Brazil 

5. Rondonia-Tapajos, Brazil 

6. Tin belt, Bolivia 

7. lpameri, Goias, Brazil 

8. Encruzilhalda, Brazil 

9. Amapa area, Brazil 

EUROPE 

1. Cornwall, England 

2. Portugal and Spain 

3. Erzgebirge, German Democratic Republic (East Germanw) and 

Czechoslovakia 

4. France 

AFRICA 

1. El Karit area, Morocco 

2. lgla, Nuweibeh Abu, and Dabbab el 

Mueilha areas, Untited Arab Republic (Egypt) 

3. Djilouet area, Algerria 

4. 'l1amanra~sset area, Algeria 

5. Bir Oumgreine avea, Mauritania 

6. Iforas area, Mali 

7. Air district, Niger 

8. Ta walafa area, Sierra Leone 

9 . .los Plateau, Nigeria 

10. Ma:ruiema area, tin belt, Democratic 

Republic of the Congo 

11. Rwanda, Burundi, Uganda, and Tanganyika (Tanza:nia) 

12. ManonQ-Kitololo mines, Katanga, 

Democratic Republic of the Congo 

13. South-West Africa 

14. Southern Rhodesia and Nyasaland 

15. Rooiberg-Leeuwport area, Republic 

of South Africa 

16. Warmbad area, Republic of South 

Africa 

AUSTRALIA 

1. Herbe~rton-Cooktown area 

2. Croydon area 

3. Stanthorpe-Ballandean district 

4. New Englarul district 

5. Mount TaUenburg-Albury-Eldorado 

belt 

6. Barrier Range 

7. Southwest Western Australia 

8. Northwes't Western Australia 

9. Northwest Tasmania 

10. Northeast Tasmania 

ASIA 

1-14. Siberia, U.S.S.R. 

15. 

16. 

17. 

18. 

19. 

20. 

1. Altai Mountains 

2. Naryn, Kazaksrtan area 

3r. Kalba, East Kazakstan 

4. Transbaikal (Zabaykal'ye) 

area 

5. Yana-Adycha area 

6. Erge-Khaya-Deputatskiy region 

7. Ust'-Omchug, Batugychag area 

8. Bilibina area 

9. Kolyma area 

10. Galimyy area 

11. Krasnoarmeyskoye area 

12. Iul'tin area 

13. Khingansk area 

14. Lifudzin-Khrustal'Illyy area 

Honshu Island, Japan 

Kwangsi-Kwangtung-Hunan 

Provinees, China 

Kochiu area, China 

Coastal zone, China 

Hainan Island, China 

Malay Peninsula 

Q 

l2j 

g 

0 

~ 

Clt 
6 T~ RESOURCES OF THE VVORLD 

Subvoleania or tin-silver deposits.-This type is exemplified by the 

mineralogically complex and very rich deposits o£ Bolivia, where 

bonanza tin lodes also contain large amounts o£ silver. Deposition in 

a near-surface environment led to strong telescoping of the deposits 

and to mineralogical complexity, which creates a problem in therecovery of tin. Rare tin-bearing minerals, such as teallite (PbSnSz), 

herzenbergite (SnS), cylindrite (Pb3SI4Sb2S14), -and canfieldite 

(AgsSnS6), are common in these deposits. Individual mines in such 

deposits have produced enormous amounts of tin; one mine at Llallagua, Bolivia, produced over 500,000 tons (~lfeld, 1936). 

Disseminated deposits.-ln these deposits, cassiterite in small 

amounts is disseminated widely in altered granite, especially in border 

zones or parts changed by addition of tourmaline, topaz, or fluorite. 

Although only a few disseminated deposits are presently worked commerically, erosion of such lodes (particularly border zones of granites) 

has resulted in large and rich placer deposits (Southeast Asia and 

elsewhere) . 

Contact-metamorphic deposits.-Such deposits are relatively uncommon and generally consist of cassiterite or malayaite ( CaSnSi05) in 

tactites near granite (Cornwall). The minerals customarily associated 

are magnetite, garnet, pyroxene, fluorite, tourmaline, various sulfide 

minerals, and, in the Lost River area, Alaska, beryllium minerals 

(Sainsbury, 1964a). The grade is generally less than 0.5 percent tin, 

but large tonnages and potential byproduct recovery of base metals, 

beryllium, and fluorite may give added importance to such deposits 

when other tin supplies dwindle. 

Furmarole deposits.--This term was used by Ahlfeld (1958) to describe small but widespread deposits that fonn fracture fillings in 

Tertiary lavas. The fracture fillings contain cassiterite generally intergrown with specular hematite, and minute grains of cassiterite are 

distributed in kaolinized wallrock along veins. A few deposits are 

mined commercially, on a small scale. Placers derived from the erosion 

of such veins are mined in ~{exico, New Mexico, and Argentina. 

Worldwide, placer deposits are more productive and more cheaply 

mined than lode deposits ; they furnish, therefore, the bulk of commercial production. Cassiterite, the main tin mineral of commerce, is 

both heavy and chemically resistant; consequently, it fonns large 

placers or residual concentrations. Placers can be conveniently classed 

as residual, eluvial (slope), alluvial (stream), marine, and fossil 

placers. 

Residual placers form in place over a bedrock source of cassiterite 

by the chemical decay and removal of the rock minerals. At places such 

as Kitololo in the Democratic Republic of the Congo, residual placers 
GEOLOGY 7 

grade downward into weathered lodes and are mined either as placers 

or as open-pit lodes. In a truly residual placer, the enriched zone con-· 

tains not only heavy minerals such as cassiterite and columbite-tantalite but also chemically resistant light minerals such as bery 1. In 

Indonesia, residual placers commonly are cemented tightly by hydrous 

iron oxides, forming the "kaksa" of industry, which must be crushed 

to free the cassiterite. 

Eluvial placers are formed by the chemical decay of tin-bearing 

rocks and the gravity separation of cassiterite and other heavy resistates as the decayed mantle moves downslope under the influence of 

sheetwash, gravity, and, locally, frost action. Such placers grade 

imperceptibly into residual placers upslope, and often into alluvial 

(stream) placers downslope. Because of active gravity sorting, eluvial 

placers may be richer than residual placers; often, however, they contain coarse rubble, and, in cold regions (Alaska and Siberia), fragments of unoxidized deleterious constituents such as arsenopyrite. 

Alluvial placers, by far the largest and richest placers, furnish most 

comn1ercial tin. In 1964, almost 60 percent of the world's tin production 

came from alluvial placers in Southeast Asia (Shelton, 1965). Other 

major producing placer areas are in Nigeria and in the newly developed tin fields in the Territory of Rondonia Brazil (Brazil Div. Fomento Prod. Mineral, 1964). Alluvial placers occupy both modern and 

fossil stream beds, and the distribution of tin is dependent upon the 

location of the source areas and the hydraulics of running water. The 

best placers form near lodes in sections of streams where the velocity 

is sufficient to result in good gravity separation but not so swift that 

the channel is swept clean. A type of location proven especially favor:-

able for placer tin is a long stream that flows parallel to the margin 

of a tin-bearing granite. 

In Southeast Asia, stream placers formed sea ward of present shorelines when sea level was eustatically lowered periodically during the 

Pleistocene. These stream placers now lie beneath sea water; they are 

mined by seagoing dredges. In Rondonia, Brazil, some placers now lie 

in areas so low that sea water covered them during certain interglaci-:-

ations when sea level stood much higher than at present. Elsewhere in 

the world, as in Cornwall and Tasmania, both lode and placer deposits 

occur within areas which have fluctuated between land and sea bottom 

during Pleistocene climatic changes; placers in such areas may have 

characteristics of both marine and alluvial deposits. 

Owing to the long exposure to air and water and to good gravity 

separation, tin concentrates produced from alluvial placers are relatively free of deleterious constituents and may contain as much as 

70 percent tin; as such, they constitute prime smelter concentrates. 
8 T~ RESOURCES OF THE VVORLD 

Marine placers are for the most part beach placers or inundated 

beach placers. They form where a marine shoreline intersects or transgresses either a stream valley containing alluvial cassiterite or a bedrock source of tin. Although a true beach placer normally has a large 

length-to-width ratio, a placer of transgressive origin may consist of 

a sheet of heavy minerals buried beneath marine sediments (Australia). 

Placers of this type have yielded large amounts of cassiterite in Indonesia ( Bangka and Billiton Islands) and will continue to do so. 

Any or all of the preceding four types of placers may become fossil 

placers by burial beneath younger sediments or lava. Uplift and renewed erosion along disrupted drainages may expose such placers 

irregularly, and second-cycle alluvial placers may be generated (Nigeria). Depending in part on the age of a fossil placer, the gravels may 

be lithified to such an extent that they must be mined by lode-mining 

methods. In others, n1ajor postdepositional changes such as partial 

solution of cassiterite, may affect the value. 

WORLD RESERVES 

The International Tin Council assembled information on tin reserves 

and published a report by vV. A. Robertson (19'65) that gives detailed 

information on tin reserves of the world. The factual basis of the report 

was a questionnaire sent to all the leading noncommunist tin-producing 

countries, most of which responded with official projected reserve estiInates for the years 1965 and 1970, based upon three price levels adjusted to a common index. Table 1, used by permission from Robertson's report, shows the status of world reserves by major producing 

areas, and although small modifications of this table are shown later 

in the present report, especially for Brazil and Canada, no great change 

in the reserve estimates can be n1ade. The probable magnitude of submarginal and undiscovered resources,3 as estimated by the writer, are 

given in table 2. 

The reserves of China, Russia, and other Communist countries cannot be assessed from available data. Even the International Tin Coun~ 

cil does not attempt a tabular summary. For this report, the writer has 

assembled table 3, which cannot be considered more than an educated 

guess based upon the parameters stated later in this report. 

II The term "reserves," with only minor exceptions, refers to tin in deposits which are 

minable under present conditions a:t the price levels given. As used in this report, "resc>urces" refers to tin in deposits not currently minable because of diverse factors such as 

low price, low grad.e, land-use problems, and beneficiation problems. "Und,iscovered resources" refers to tin in deposits not yet discovered, but which are assumed to exist 

because of probable favorable geol:ogy in unexplored areas. 
WORLD RESERVES 9 

TABLE 1.-Tin reserves of noncommunist countries, excluding the United States 

[Estimated total reserves, in long tons, of tin-in-concentrates; from Robertson (1965, p. 90)) 

Year _________ ---- ____ ------- 1960 1965 1970 

Price, long ton tin ______________________ At $1,960 At $2,520 At $1,080 At $1,960 At $2,520 At $3,080 

( .£700) ( .£900) ( .£1,100) ( .£700) ( .£900) ( .£1,100) 

~y~~~i~~~ = = ==== === = ========= 

1 737,000 ------------ 514,000 514,000 ------------ 485,000 485,000 

Democratic Republic of the 

100, 000 44, 000 105, 000 110,000 32,000 48,000 86,000 

Congo 2 __________________ _ 203,000 15,000 158,000 190,000 3, 000 136, 000 155, ()()() Thailand 3 _________________ _ 1, 000,000 1, 089,000 _ ---- ____ _ I, 500,000 1, 010,000 ---------- 1, 402,000 Malaysia 600,000 (no price) 4 _________________ _ [1, 000, 000] 900, 000 (no price) Indonesia s _________________ _ 558, 000 650,000 (no price) 550,000 (no price) Australia ______ ------ ______ _ 4 7, 000 3, 000 68, 000 83, 000 2, 000 67, 000 81, 000 

United Kingdom __________ _ 47,000 ------------ 41,000 42,000 ------------ 18,000 37,000 

Others 6--------------------- 1 02, 000 30, 000 62, 000 65, 000 25, 000 56, 000 65, 000 

TotaL________________ 3, 800,000 (approximately 4,000,000) (approximately 3,500,000) 

1 1961. 

2 Democratic Republic of the Congo: $2,800 ( .£1,000) in 1965 and 1970. 3 Thailand: Excluding measured reserves of dredging companies. Measured reserves, excluding offshore 

deposits, are in the order of 40,D00--60,000 long tons of metallic tin (Robertson, 1965, p. 87). 4 Malaysia: 1963, 1,000,000 tons, reported reserves; 1965 and 1970, our estimates, allowing for production 

in intervening years. Reserves of 1,000,000 tons used for 1960 column. • Indonesia: 1970, our estimate, allowing for production in intervening years. e Others: No figures for Mexico or Korea for 1965 and 1970. Countries included are Canada, France, Japan, Korea, Portugal, Republic of South Africa, Tanganyika (Tanzania). No allowance is made for Burma, 

Brazil, Argentina, Spain, Rwanda, Laos, Northern and Southern Rhodesia, and other parts of Africa. 

Reserves in Burma were put at 300,000 tons of tin metal in 1952 according to the Paley Commission. [These 

figures do not include recent estimates of Brazilian reserves. If the reserves estimated in the present report are included (see section on "Brazil"), these figures, particularly for the 1970 date, would be larger by sev- eral hundred thousand long tons of tin metal.] 

TABLE 2.-Tin resources of the world, exclusive of the U.S.S.R. and China 

[As used in this report, "resources" refers to tin in deposits not cun-ently minable because of factors such as low price, low grade, and beneficiation problems. Estimates by C. L. Sainsbury] 

North America: 

United States ____________ _ Canada _________________ _ 11exico __________________ _ 

TotaL ______________ _ 

South America: Bolivia __________________ _ BraziL __________________ _ 

Argentina _______________ _ 

Total _______________ _ 

Europe: England _________________ _ 

Portugal and Spain _______ _ France __________________ _ 

German Democratic Republic (East Germany) and 

Czechoslovakia _________ _ 

Thousands 

of long tons 

43 

40 

5 

88 

1, 000 

1,074 

7 

2,081 

94 

150 

4 

50 

TotaL_______________ 298 

Asia: Indonesia _______________ _ 11alaysia ________________ _ Thailand ________________ _ Burma __________________ _ 

Vietnam and Laos ________ _ Japan ___________________ _ 

TotaL ______________ _ 

Africa: 

Nigeria _____________ -----

Democratic Republic of the Congo ________________ _ 

Republic of South Africa __ _ South-West Africa ________ _ Southern Rhodesia _______ _ 

Rwanda, Burundi, Uganda, 

and Tanganyika (Tan- zania) __________ -- ____ -

Other areas in Africa _____ _ 

Thousands 

of long tons 

540 

1, 000 

1, 120 

250 

75 

16 ----

3,001 

138 

1,000 

22 

100 

60 

20 

50 

TotaL_______________ 1, 390 

Oceania: 

Australia and New Zealand_ 250 

Grand totaL_________ 17,108 

1 This obviously cannot represent the total tin that will be available eventually to industry. As geologie knowledge increases, and as price rises, new sources of tin will become classifiable as resources. 
10 TIN RESOURCES OF THE WORLD 

The figures in tables 1, 2, and 3 show that world reserves of tin are 

ample to satisfy world needs at a projected consumption rate of 180,000 

tons per year for at least 31 years, and that resources are at least capable of sustaining production for another 56 years at a rate of 200,000 

tons per year. Furthermore, if a critical shortage develops over a long 

term, new sources should become available, such as tin from malayaite, 

a tin silicate. 

TABLE 3.-Estimated tin reserves and resources of the U.S.S.R. and China 

[In thousands of long tons; estimates by C. L. Sainsbury for this report] 

Measured plus indicated 

U.S.S.R---------------------------------- China____________________________________ 210 500 

Total______________________________ 710 

Inferred 

420 

1,000 

1,420 

Submarginal 

resources 

1, 260 

3,000 

1 4, 260 

1 This obviously cannot represent the total tin that will be available eventually to industry. As geologic knowledge increases, and as price rises, new sources of tin will become classifiable as resources. 

NORTH AMERICA 

UNITED STATES 

Since the date of the last comprehensive report on tin prepared by 

the Pennsylvania State University (Ridge, 1953), continued work by 

goven1ment and industry has increased the domestic reserves of tin 

by several hundred percent; nevertheless, the United States remains 

critically short of tin. Additional reserves were generated in the longknown tin district of the western Seward Peninsula, Alaska, principally at the Lost River lode mine, and at Cape Creek, where a deep 

alluvial deposit was found by a private company supported by a U.S. 

Government loan. 4 Additional diamond drilling at the Lost River 

mine by a large United States company has confirmed the existence of 

additional marginal resources. Recent geologic mapping by the U.S. 

Geological Survey resulted in the discovery of large deposits of bery Ilium in fluorite in the tin district (Sainsbury, 1963), and of additional 

tin-bearing veins at Black Mountain which have not been assessed. 

Elsewhere in the United States, more information was obtained on 

placer tin deposits at Tozimoran Creek, central Alaska, and at Gorman, Calif., where tin is presently being produced in small amounts, 

but no large expansion of reserves is reported, The tin reserves and 

resources of the United States are estimated in table 4. 

"This deposit is being mined (1968) and is proving to be richer than drilling had 

indicated. 
NORTH AMERICA 11 

TABLE 4.-Reserves and resources of tin in the United States 

[In long tons of tin metal] 

Lode deposits: 

Reserves ______________ -----_---------------·-- Resources _____________________ ------------- __ 

Total ___________________________________ _ 

Placer deposits: Reserves ____________________________________ _ Resources ___________________________________ _ 

Measured and 

indicated 

3,035 

2, 700 

5,735 

2,600 

Inferred 

3,000 1 36, 000 

39,000 

100 2 4, 100 

Total____________________________________ ~700 ~ 100 

================== 

Grand totaL______________________________ 8, 435 43, 100 

1 Includes 10,000 long tons of tin in pegmatites of the Appalachian tin district which contain about 0.025 

percent tin; this tin will be recovered only as a byproduct from the mining of other minerals, such as spodu- mene. 2 Includes inferred known resources of 1,400 long tons, and unknown resources estimated to equal all 

known and inferred reserves and resources. 

ALASKA 

The Alaskan tin deposits form a belt that extends eastward across 

central Alaska from the Bering Strait, but the only important known 

deposits are on the Seward Peninsula. The geology of the Seward 

Peninsula deposits was first described by ICnopf ( 1908). More recent 

information on the geology and on recent work at the Lost River mine 

was presented by Sainsbury ( 1964b) and by Lorain, Wells, Mehelich, 

Mulligan, Thorne, and Herdlick ( 1958). A comprehensive report on 

the lode area near Lost River gives up-to--date information on the 

structure and stratigraphy of the York Mountains (Sainsbury, 1969). 

The main lode deposit at Lost River consists of cassiterite and wolframite associated with numerous base-metal sulfides in quartz-topaz 

greisen. The main ore shoot lies along a greisenized rhyolite porphyry 

dike; the shoot is confined to a zone some [100 feet in vertical extent 

above a buried biotite granite. Smaller, submarginal deposits are 

known along several altered dikes and in a conelike mass of altered 

limestone, know as the Cupola area, above the buried granite. Other 

lode deposits on the western Seward Peninsula are much smaller, but 

are mineralogically similar. 

The known placer deposits are small; the largest one at Buck Creek 

on the Seward Peninsula yielded several hundred tons of tin between 

1940 and 1959. The deep placer at Cape Creek on the Seward Peninsula 

is currently (1968) being mined. Investigations of placer deposits by 

the U.S. Bureau of Mines (Mulligan, 1959a, b; Mulligan and Thorne, 

1959) have confirmed the absence of economic placers in the main 

streams near some other tin-bearing granites on the western Seward 

Peninsula. The absence of placers can be attributed to glacial scouring 
12 T~ RESOURCES OF THE VVORLD 

during a widespread glaciation of Wisconsin age that extended far 

beyond the limits previously assigned (Sainsbury, 1967). 

New information on tin placers at Manley Hot Springs and elsewhere in interior Alaska has been released (Wayland, 1961; Chapman and others, 1963). A large American company clUTently is 

investigating the tin belt of Alaska. 

CONTERMINOUS UNITED STATES 

Small amounts of tin have been produced from distinctly different 

types of deposits in several widely spaced areas : ( 1) the southern 

Appalachians; (2) Black Hills area, South Dakota; (3) New Mexico; 

( 4) Gorman area, California; and as a minor byproduct at the Climax 

mine, Colorado. 

The Appalachian tin deposits lie in a linear belt along the east flank 

of the mountains from central Alabama to west-central Virginia. 

Two main types of deposits are clearly recognized : quartz veins or 

quartz-pegmatite veins, and greisen veins. In the pegmatites, cassiterite occurs in small amounts associated with minor beryl and 

columbite-·tantalite, and much spodumene. Many of the greisens 

(quartz-mica or quartz-mica-topaz rock) occur as bands along the 

walls of quartz veins; in addition to cassiterite, the greisens contain 

sulfide minerals. Most of the deposits are small, and those that have 

yielded the few hundred tons of metallic tin produced to date contain from about 0.5 to about 1.5 percent tin. A few small placers are 

associated with outcropping lodes; some placers contain 12-75 pounds 

of tin per cubic yard. No systematic evaluation of the placers has 

been made. Some are of economic grade but may not be currently 

minable because of factors such as unavailability of water and problems of tailings disposal. 

Tin deposits of the Black Hills occur principally as cassiteritebearing pegmatites, some of which were mined on a small scale. Not 

all pegmatites contain tin; those that do may contain variable amounts 

of one or more of the following economically useful minerals: Columbite, beryl, spodumene, and albite. Most of the richer pegmatirtes contain less than 1 percent tin in the ore shoots. Reserves amount to less 

than a thousand tons of metallic tin. 

Small tin deposits confined to rhyolitic lavas of Tertiary age are 

widespread in New Mexico, especially in Catron and Sierra Counties. 

The tin lodes consist of cassiterite and specular hemrutite in small discontinuous veins that are bordered by kaolinized rock which contains 

fine-grained cassiterite. Where streams eroded lode deposits, small 

placers were formed ; these placers are mined on a small scale-total 

production is less than a hundred tons of tin metal. In the Petaca 
NORTH AMERICA 13 

district, trace amounts to small amounts of cassiterite occur in pegmatites that are valued chiefly :for their mica content. 

In California, the principal tin deposits, all small, occur in veins in 

granitic rocks or in contact-metamorphic zones nearby. A small production has come from the Gormani, Temescal, and Cima districts, and 

small deposits have been explored elsewhere, within the State. 

Elsewhere in the United States are diverse groups of deposits each 

containing a sufficient number of prospects to be of economic interest; 

these groups are principally in eastern Washington, the New England 

States, Colorado, Nevada, l\-fontana, l\1issouri, Texas, and Idaho 

(mostly placers) . 

CANADA 

Discovery of tin-bearing greisens in New Brunswick, Canada 

( Jiosking, 1963), lias increased known Canadian reserves of tin. The 

deposits at l\1ount Pleasant, New Brunswick, consist of cassiterite 

associated with base-metal sulfide minerals near or in altered silicic 

dikes (Petruk, 1964). Ore minerals occur in altered dikes along two 

main kaolinized zones, and in qua:vtz-topaz greisen around the borders 

of a siliceous "core." The Mining Journal ( 1963) announced that 

proven reserves were ca.lculated at 2,630,000 short tons of ore averaging 0.59 percent tin, 2.0 percent zinc, 0.36 percent lead, and 0.30 percent copper. Thus, known reserves of tin amount to about 14,000 long 

tons, and exploration is continuing. 

For many years byproduct cassiterite has been produced from the 

Sullivan mine in British Columbia, where it is a minor constituent 

of lead-zinc ores. Yearly production amounts to a few hundred tons 

of tin; and although lead -zinc reserves are sufficient to last for many 

years, total tin reserves are nominal. Other occurrences of tin in Canada 

are summarized by Mulligan ( 1966) ; none are large. For this report, 

all Canadian reserves are assumed to total some 20,000 long tons of 

tin. Submarginal and undiscovered resources are estimated at twice 

this figure, or 40,000 long tons of tin. 

MEXICO 

l\.fexico produces· a few hundred tons per year of tin-in-concentrate 

derived from small-scale placer mines and lodes. The placers are 

derived from lodes which consist of encrustations of cassiterite and 

specularite along small fractures in Tertiary rhyolite lavas, similar to 

the small vein deposits in New Mexico. In addition, several thousand 

tons of tin was produced from the San Antonio mine, which was also 

worked for lead, zinc, and silver. Cassiterite also occurs in altered porphyritic granite near Guadalcazar, 60 miles northeast of the city of 

327-648--69----3 
14 TIN RESOURCES OF THE WORLD 

San Luis Potosi, State of San Luis Potosi (Foshag and Fries, 1942); 

the altered granite ·also contains tourmaline, topaz, molybdenite, and 

many other minerals found in greisen tin deposits. No known deposits 

in Mexico are of sufficient size or richness to allow notable expansion 

of the long-established but small tin-mining industry. In this report, 

proven reserves are estimated at not more than 1,000 long tons of tin, 

and submarginal and undiscovered resources, at five times this amount, 

or 5,000 long tons. 

SOUTH AMERICA 

BOLIVIA 

The bulk of the lode tin of commerce comes from Bolivian mines, 

which produced about 19 percent of the 'vorld's tin output in 1964. 

The lodes lie in a belt coextensive with the Cordillera Real, or eastern 

Andes; the lodes extend fron1 Peru through Bolivia to Argentina, a 

distance of 500 miles. The deposits, classed as the subvolcanic type, 

are characterized by close association with Tertiary volcanic rock and 

older stocks of biotite granite, dacite, and quartz n1onzonite. Although 

cassiterite is the main ore mineral, many tin-bearing sulfide minerals 

and large amounts of silver are associated with it. The mineralogical 

and textural complexity of the deposits prevents preparation of highgrade concentrates and hinders the recovery of tin. In the northern 

part of the region, erosion has exposed the subjacent granite stocks, 

whereas in the south the stocks are not yet exposed. This relationship 

apparently has resulted in exposure of different zones of ore deposition and, therefore, of different mineral suites. Schneider-$cherbina 

(1964) postulated that the complexity of ores is partly caused by 

the superposition of a younger (Tertiary) silver-rich suite of sulfide 

minerals on an earlier (Mesozoic) mineral assemblage containing 

cassiterite. 

Figure 2 shows the location of the more important tin deposits in 

Bolivia; only the large deposits are discussed here. The great mine 

at Llallagua (No. 13, fig. 2), which has produced over 500,000 tons of 

tin (Ahlfeld, 1936), is developed on a network of veins that generally 

strike N. 20° E. and dip steeply. The veins are localized in and near 

a stock of quartz porphyry which has intruded graywacke, sandstone, 

and shale. The quartz porphyry is funnel shaped, contracting at depth, 

and some veins that ·are restricted to the quartz porphyry on the surface pass out of it at depth. Most of the veins are fracture fillings 

which consist of cassiterite, quartz, and many sulfide minerals, including bismuthinite, pyrite, pyrrhotite, sphalerite, galena, wurtzite, stannite, tetrahedrite, marcasite, and franckeite. "'\Volframite locally is 

abundant and is recovered. Apatite, as well as other phosphates else-
SOUTH AMERICA 15 

( 

~ \-

\ 

0 50 100 

0 50 100 150 KILOMETERS 

Principal tin mines 

1. La Fabulosa 13. Llallagua-Uncia 

2. Milluni 14. Vila Apacheta 

3. Chojila 15. Colquechaca 

4. Araca 16. Ocuri 

5. Caracoles 17. Colavi 

6. Colquiri 18. Potosi 

7. Oruro 19. Tasna 

8. Morococala 20. Chorolque 

9. Santa Fe 

10. Huanuni placer 

21. Oploca-Siete Suyos}ch 22. Animas ocaya 

11. Huanuni mine 23. Carguaicallo 

12. Monserrat 24. Monte Blanco 

25. Pirquitas (Argentina) 

FIGURE 2.-Main tin deposits of Bolivia. 
16 'IN RESOURCES OF THE WORLD 

where rare, is anundant in some veins; siderite and rhodochrosite are 

the major gangue minerals. At the Uncia mine, within the Llallagua 

district, very rich veins contained as much as 6 percent tin. Very large 

reserves of low-grade ore are known; these deposits consist chiefly of 

mineralized shear zones and poorly mineralized areas of quartz porphyry between major veins. 

Tin ores in pegmatites are mined at La Fahulosa mine, north of 

La Paz. The pegmatites are associated with granite and contain cas~ 

siterite as the main ore mineral, accompanied by molybdenite, chal~ 

copyrite, ferroan sphalerite, arsenopyrite, pyrrhotite, and stannite. 

The tin content of the pegmatites is about 1 percent, increasing 

slightly vfhere stannite is abundant. 

Tin-silver ores are mined at Oruro, Potosi, Colquechaca, and Chocaya. At Oruro, veins striking northwest are associated with three 

dacite stocks intruded into fine-grained pelitic rocks. The veins are 

fissure fillings in the dacite stock, in explosion breccias associated with 

the stocks, and in the surrounding pelitic rocks. Vein material consists 

of quartz, cassiterite, pyrite, freibergite, andorite, sphalerite, leadantimony sulfosalts, and, in the latest phase, galena, franckeite, alunite, and dickite. The mine also has millions of tons of low-grade ore 

that contains 0.2--0.4 percent tin. 

The mines at Potosi were originally ·worked for silver, but today 

they produce principally tin ores. A funnel-shaped dacite stock, narrowing at depth, has intruded sandstone, shale, conglomerate, and, 

near the surface, tuffs. An en echelon vein system extends to a depth 

of 1,100 meters and passes out of the stock at depth. The veins are 

strongly zoned; in the upper part they contain complex tin and silver 

Ininerals, in the center only tin minerals, and at depth cassiterite, 

wolframite, and bismuthinite. 

South of Potosi, Bolivia, the tin belt dies out rapidly, and the southern end contains only a few major districts (Tasna, Chorolque, OplocaSiete Suyos, Animas). However, the richest tin vein in Bolivia, which 

contained nearly 6 percent tin, was worked at the Oploca-Siete Suyos 

mine. The deposits, vein fillings and impregnations associated with 

volcanic rocks, contain cassiterite and sulfides of tin, bismuth, antimony, and silver. For more complete discussions of the tin deposits 

of Bolivia, see Ridge (1953) and Turneaure and Welker (1947). 

In spite of the abundance and richness of lode deposits in Bolivia, 

only a small a1nount of tin has been produced from associated placers, 

partly because of lack of active chemical decay in the high altitudes 

at which the tin veins occur. At Huanuni, a placer mine contained 

unweathered lode material that was separated, crushed, and treated 

in a typical lode mill (Ferron, 1941). Unquestionably, large reserves 
SOUTH AMERICA 17 

of tin will be found in Bolivia in placer deposits, many of which n1ay 

be covered by young volcanic rocks. 

The 'tin reserves of Bolivia are sun1marized in table 5, which is 

1nodified frmn Robertson's report ( 1965). It is assumed for this report 

that submarginal and undiscovered lode and placer deposits contain 

at least twice as much tin as the known reserves at the $3,080 figure, 

or about 1 million long tons. 

TABLE 5.-Estimated tin reserves of Bolivia 

[In thousands of long tons. Data from Robertson (1965, p. 81). Expressed in terms of the tin content of concentrates prepared by Bolivian concentrating plants] 

Year _________________________________________ _ 1965 1970 ---------------- Price, long ton of tilL ________________________ _ 

Measured (=positive and 

probable): Lode ________________________ _ 

Indicated (=possible) : Lode ________________________ _ 

Tailings and dumps ___________ _ Other _______________________ _ 

Total ___________________ _ 

Grand totaL _____________ _ 

At $2,520 

(£\JOO) 

361 

96 

20 

36 

152 

513 

ARGENTINA 

At $3,080 

(£1,100) 

361 

96 

At $2,520 

(£900) 

325 

160 

At $3,080 

(£1,100) 

325 

160 

20 -------------------- 36 

152 

513 

160 

485 

160 

485 

The southernmost tip of the Bolivian tin belt crosses the border into 

Argentina, where a single mine (Pirquitas, No. 25, fig. 2) has produced tin from a lode systmn and associated placers. Yea,rly production never exceeded a few hundred tons of tin. The mine is developed 

on several veins in metamorphosed shale and sandstone. The most important vein was about 3 feet wide and contained 3.5 percent tin. The 

vein minerals include quartz, cassiterite, pyrite, sphalerite, galena, 

proustite, stannite, pyrargyrite, polybasite, andorite, and marcasite. 

Near the Bolivian border, at Cerro Pululus, and far1ther south at 

Pairique Grande, cassiterite is intergrown with specularite in veinlets 

in rhyolite, occurrences similar to those in :Mexico and New Mexico. 

Southwest of Catan1arca, province of Catamarca, cassiterite occurs in 

greisen zones in granite, in a region that contains many tungsten deposits (Ahlfeld, 1958, p. 46). 

For this report, measured and indicated ore reserves are assumed 

to equal10 years' production at the 1965 rate of 343 long tons, or 3,430 

long tons of tin. Undiscovered resources are assumed to be at least twice 

the known reserves, or 7,000 long tons. 
18 TIN RESOURCES OF THE WORLD 

BRAZIL 

Production of tin in Brazil, which has recently increased notably, 

reflecting production from the new tin district in the Territory of 

Rondonia, reached 1,556 long tons in 1960 (Robertson, 1965, p. 68). 

Although Brazilian production may not become important in relrution 

to world production in the ne-ar future, the reserves in the new district 

most certainly are important. Producing areas of Brazil are shown in 

figure 1. 

In eastern Brazil, State of Rio Grande do Norte, cassiterite is a constituent of Paleozoie( ~) pegmatites that also contain beryl, amblygonite, and oolumbite-tantalite enclosed in rocks of Precambrian age. 

Plaeer deposits of ca.'3Siterite ·occur in eastern Minas Gerais, and a cassHerite-bearing pegmatitic-muscovite granite is mined there at the 

N azareno mine. The cassiterite is accompanied by tantalite and microlite. 

The Ipameri deposit, in the State of ·Goias, is a folded vein that 

contains cassiterite associated with sulfide minerals. The vein occurs in 

greisenized schist; gran]te may occur at depth. The vein contains an 

ecomonically im·portant amount of tin. 

The placer deposits of Amapa, which contain cassiterite derived 

from tin hearing pegmatites, supported a smrull tin smelter for several 

years. Reserves are now small. 

The new tin district in tthe Territory of Rondonia is large, covering 

a known area of some 60,000 square miles (fig. 1) in the drainage basin 

of the Rio Madeira (Kloosterman, 1967). Many stocks of biotite 

granite ·are intruded into the older Precambrian and lower Paleozoic 

rocks; many are crudely ~alined north-south. '.Dhe tin deposits consist 

of lodes in the granites and of many associated placeffi. For the most 

part, the known lodes consist of cassiterite locally associated with 

wolframite in topaz greisen in granite. Fluorite locally is a:bundant, 

and many lodes are localized in argillized granite. Eluvial and alluvial 

placers are rich; some contain several pounds of cassiterite per cubic 

yard. New districts are being discovered yearly, and reserves are very 

large. Kloosterman ( 1967) points out that the area contains some ring 

complexes and other features similar to those of the tin-producing a.rea 

of Nigeria. 

The other deposits of Brazil shown in figure 1 are mostly small and 

of little economic worth. Those of Ceara are principally tin-bearing 

pegmatites with a very small production of tin. 

The total tin reserves of Brazil, estimated for this report by Pieter 

Van Leeuwen, an industry geologist familiar with many of the tin 

deposits in Brazil, are given in table 6. 
EUROPE 19 

TABLE 6.-Tin reserves of Brazil, by area 

[In thousands of long tons of cassiterite containing 65 percent tin; not differentiated by class. Estimates by Pieter Van Leeuwen] 

Rondonia: At 1966 price 

Productive mines______________________________ 88. 2 

Non productive mines _______________ ----------- 50 

Tapajos---------------------------------------- 10 

lpameri 1

_ -------------------------------------- • 8 

San Joao del Rei (eastern Minas Gerais)____________ 1 

At twice the 1966 price 

543 

250 

30 

1.4 

1.9 

------------------- Total, cassiterite__________________________ 150 

Total, metallic tin_________________________ 97. 5 

t Conservative estimate. 

826 

537 

NOTE.-For purposes of this report, tin resources in submarginal and undiscovered deposits are con- sidered to equal at least twice the known reserves of the larger figure above, or 1,074,000 long tons of tin. This 

is probably a conservative estimate, possibly by a factor of 2 or 3. 

EUROPE 

ENGLAND 

The mines of Cornwall, which during their mining history produced 

more than 2 million tons of tin, are now largely exhausted. In 1860, 

some 300 mines were active and employed 100,000 workers (Ahlfeld, 

1958, p. 82). In 1964, only two mines were operating (Robertson, 1965, 

p. 71). Many fundamentals of mining geology were learned in Cornwall, where extensive underground mining gave three-dimensional 

exposures throughout the entire district. Here, the concept of zoning 

in lode deposits was developed and tested and became a fundamental 

geologic tool. Because many other deposits of cassiterite in greisen resemble the Cornwall deposits, the zoning in Cornwall, as originally 

established by Dewey ( 1925), is shown in figure 3. 

The numerous lode deposits are related to several outcropping stocks 

of biotite granite and occur in granite and in the surrounding pelitic 

rocks, which are converted to hornfels near the granites. Cassiterite 

is the main ore mineral and is accompanied by quartz, tourmaline, 

topaz, arsenopyrite, wolframite, chalcopyrite, galena, sphalerite, and, 

locally, sulfosalts. Owing to the zoning, some mines produced principally copper ores; others lead-zinc ores; and others tin, wolframite, 

and minor sulfide ores. The Dalcoath mine, one of the most productive 

lode tin mines of the world, was worked to a depth exceeding 3,000 feet; 

the veins extended 1,500 feet into the granite. The Dalcoath mine produced 80,000 tons of tin and 350,000 tons of copper. Dines (1956) presented a detailed description of the mines of Cornwall. For a recent 

discussion of the geology of the lode deposits of Cornwall and Devon, 

as well as geologic problems yet unsolved, see Hosking ( 1964). 

The tin reserves of Cornwall (Robertson, 1965, p. 88) are given as 

47,000 long tons (inferred) in 1960. Deep exploration will increase 

these reserves, perhaps by an order of magnitude. For this report, it is 

assumed that submarginal and undiscovered deposits contain twice the 
20 TIN RESOURCES OF THE WORLD 

Veinstone Thick- Approximate 

or gangue Mineral zone ness temperature of 

mineral (feet) formation (°C) 

Carbonates (such as 400 Up to 

iron and manganese) 150 

Sulfides (such as antimony) 200 

(/') 

UJ 

t: 

0:: 

~ Sulfides of lead and silver, 1800 m giving place at depth to zinc 

0:: 

~ l 

I 

a. 

(/') (/') 0:: 

0 UJ 

:::> Q 

..J Li: LL. ..J 

:::> 

(/') 

UJ 

Cl 

1 

N z 1- w Sulfides of copper intermixed 0:: (/') 

2500 500 ~ 0:: with wolfram and tin for 700ft :::> ~ 

0 (/') 

LLI 

1-

~ 

1-

(/') 

"' z 

:::> 

1-

j FEET 

w ..- 0 z 

:J 

~ 

~ 

0:: 550 :::> Oxide of tin with wolfram in 2500 0 to 1- the upper parts 575 

1---1000 

L-2000 

FIGURE 3.- Zoning in the tin deposits of Cornwall, England. (From Dewey, 1925, 

fig. 7.) 
EUROPE 21 

inferred reserves, or 94,000 long tons of tin, here classed as resources. 

As proved by the successful reopening of the South Crofty mine, 

large areas of Cornwall are as yet incompletely explored; the ultimate 

tin production from Cornwall may well exceed the quoted figure for 

resources. 

PORTUGAL AND SPAIN 

A single complex, but continuous, tin district extends southeastward 

through Portugal and Spain. For a distance of 500 miles, tin and 

tungsten deposits of diverse types are associated with plutonic rocks, 

dominantly porphyritic biotite or biotite-muscovite granites (Cotelo 

Neiva, 1944, p. 33), many of which contain tourmaline. The deposits 

consist of yeins, stockworks, and alluvial and eluvial placers. The veins 

can be further classified into pegmatite an~ hypothermal veins, with 

characteristic mineralogy. The veins may contain cassiterite and wolframite, or wolframite alone, associated with other minerals. Columbite, tantalite and beryl occur with cassiterite at some places in the 

pegmatites. The elements characteristic of the deposits are Sn, vV, As, 

Fe, Ph, Zn, Cu, Si; ·at places, Au, Ag, Ti, Sb, Li, Mo, U, Bi, Ca; more 

rarely, P, Be, Cl; and, most rarely, Nb, Y, Ta, Ni, Mn, V; Band Fare 

common in the gangue 1ninerals. Many vein deposits are transitional 

between pegmatites and high-temperature sulfide-bearing veins. 

In Portugal as in many other tin districts, the major tin deposits 

occur near the granite borders or within the granites; tungsten deposits, on the other hand, tend to occur farther from the contacts, in 

the surrounding rocks. The n1ajor districts are Porte de Lima, Borralha, Villa Real, Ervedosa, :J\'Iinas de Ribera, Viseu and the placer 

district of Belmont. (For locations, see Ahlfeld, 1958, p. 105.) In Spain, 

the main mines and producing areas are San Fiox and the area of 

Presqueiras-A vi on in the north west; Dominica, Barquilla, and Alemeclilla along the Portuguese border; and Logrosan and V aldefloresTrasquilon, about 200 kilmneters southwest of Madrid. 

The tin and tungsten resources of the Iberian Peninsula undoubtedly 

are large. Neither Spain nor Portugal estimated her reserves for the 

Robertson volume. For this report, tin reserves in measured and indicated ore are estimated to be equivalent to 10 years' average production of about 750 tons per year for each country, or 15,000 tons of tin. 

Subn1arginal resources are estimated at 10 times the measured and indicated reserves, or 150,000 tons of tin. This is probably a very conservative figure, possibly by an order of magnitude. 

FRANCE 

A small amount of tin has been mined sporadically in France since 

Phoenician times. The known lode deposits are similar to those in Spain 

327-648--69----4 
22 TIN RESOURCES OF THE WORLD 

and Cornwall; the French deposits are related to Hercynian granites 

intruded at the same time as those in England and Spain. Lodes contain cassiterite in association with the usual high-temperature sulfide 

minerals. Recent production has come mainly from a dredging operation in Brittany in ground ,that contains 0.2-0.4 kg cassiterite per cubic 

meter (Robertson, 1965, p. 71). 

Reserves of tin in France were not reported by Robertson ( 1965). 

However, it is estimated that production will continue until1970 at 

400 tons of tin-in-concentrates per year; hence, measured and indicated 

reserves are assumed to be 2,000 long tons of tin. Resources in undiscovered and marginal deposits are conservatively estimated at twice the 

measured and indicated reserves, or 4,000 long tons. 

GERMAN DEMOCRATIC REPUBLIC (EAST GERMANY) AND 

CZECHOSLOVAKIA 

The ancient metalliferous province in the Erzgebirge of East Germany and Czechoslovakia has produced tin since about 2000 B.C. 

(Janecka and Stemprok, 1967, p. 3), and although production fell to 

less than 500 tons of tin in the early 1900's, Germany was able to raise 

production to more than 1,000 tons annually during World War II. 

Present production from the region is but a few hundred 'tons of tin 

per year. Total production to 1964 was estimated by Janecka and 

Stemprok (1967, p. 3) at about 120,000 tons of tin. 

Several large granitic plutons of two distinct suites are intruded 

into metamorphic rocks along a northwest trend at right angles to 

the trend of the main range (Erzgehirge) . The earlier granites are 

poorer in alkalies than the l3!ter granites, which were intruded after 

the quartz porphyries (Janecka and Stemprok, 1967). The ore deposits 

are associated with the younger biotite granite, much of which contains tourmaline or topaz. Cassiterite, locally with wolframite, in 

typical high-,temperature veins is accompanied by numerous base-metal 

sulfides and locally by silver minerals and uranium. The grade of mined 

lodes seldom ex-ceeded 2 percent tin. 

No reserve figures are available for the deposits of the East Germany-Czechoslovakia area; however, as production has been maintained at the level of several hundred tons per year, and because 

exploration of lower grade deposits is continuing, it is assumed that 

measured plus indicated reserves of the grade being mined total at 

least 10 years' production, or about 5,000 long tons of tin. Submarginal 

resources of substantially lower grade are probably large, and are estimated here to be 10 times the measured and indicated reserves, or 

50,000 long tons of tin. These lower grade deposits consist principally of 

greisens, stockworks, and skarns; tin content of some stockworks (near 
ASIA 23 

Vernerov) is as much as 0.38-0.64 percent, and that of some skarns 

0.6-0.8 percent, according to Janecka and Stemprok (1967, p. 11-14). 

ASIA 

Asia leads the world in tin production and in tin reserves. The 

world tin supply consequently is dependent largely on Asian production. The period of high prices and world shortage in 1962-66, for 

example, was caused largely by the loss of Indonesian production, 

which fell from 35,000 long tons in 1952 to about 13,000 long tons 

in 1963. 

Throughout the tin belt of Southeast Asia, primary tin deposits are 

closely related to biotite or biotite-muscovite granite, although most 

production is from placer deposits. Most of the lode deposits consist of 

veins, disseminated deposits, and stockworks that are closely related to 

quartz-topaz greisens or quartz veins, in which cassiterite is associated 

with numerous base-metal sulfide minerals. The tin belt of Southeast 

Asia is shown in figure 4. 

Several geologic factors have contributed to the unusual size and 

richness of the Southeast Asian tin deposits: ( 1) an unusual concentration of tin granites, (2) deep and rapid tropical weathering 

that has released large amounts of primary tin from lode sources, 

(3) formation of rich and extensive placers during a complex 

geomorphic history during which rich and extensive placers formed, 

both marine and alluvial, many of which are now seaward of present 

shorelines, and ( 4) low relief and sluggish stream action that preserved the placers. 

The most productive tin belt stretches more than 1,500 miles from 

Billiton (Belitung) Island in Indonesia (fig. 4) through Malaysia and 

Thailand into northern Burma. Many placer deposits and a few important lode deposits are worked throughout the belt. The most productive areas are numbered in figure 4. 

INDONESIA 

In 1941, Indonesia (then Dutch East Indies) produced 53,370 long 

tons of tin. By 1963, after nationaliz·ation of the mines and expulsion 

of foreign capital, the output had fallen to 12,947 tons (Shelton, 1964, 

p. 1125), a situation which contributed to the present period of world 

shortage. The reduced output does not represent exhaustion of reserves, however. Indonesian production comes principally from placer 

deposits both onshore and offshore of the islands of Billiton (Belitung), Bangka, and Singkep in the Java Sea (shown in fig. 4). Bangka 

is the major source, followed by Billiton and Singkep in the ratio 

20: 10: 2. Bedrock of the islands consists of alternating beds of sand-
24 TIN RESOURCES OF THE WORLD 

30° 100" 110" 120° 

CHINA 

20" -

SOUTH VIETNAM 

10° 

BORNEO o· 

10" ~----------~------------------~--------------------~ 

1. Billiton (Belitung) Island, Indonesia 

2. Bangka Island, Indonesia 

3. Malaysia 

A. Gunong Bakau mines, Selangor 

B. Lahat pipe, Kinta Valley, Perak 

C. Beatrice mine, Selabin 

D. Pahang mines, Pahang 

4. Phuket Island, Thailand 

5-9. Burma 

5. Maulmein area 

6. Mawchi area 

7. Byingyi district 

8. Tavoy district 

9. Mergui Islands 

10. Nam Pha Tene mine, Laos 

11. Pia Oak Mountains, Tonkin, Vietnam 

12. Kochiu area, China 

13. Kwangtung-Kwangsi-Hunan Provinces, 

China 

FIGURE 4.-Tin-bearing areas of Southeast Asia. 
ASIA 25 

stone and shale intruded by batholiths and stocks that range in composition from gabbro to granite. The primary ore deposits are associated 

with biotite granite. Lodes occur in the granite and in the sedimentary 

rocks. The largest lode deposit-I{lappa l{ampit on Billiton Islandis restricted to the sedimentary rocks and consists of replacement 

bodies containing cassiterite ·and associated magnetite, pyrite, 

chalcopyrite, pyrrhotite, arsenopyrite, sphalerite, galena, bismuthinite, 

bismuth and phenakite along with fluorite, quartz, tounnaline, and 

other silicates. The deposit was mined to a depth of about 1,000 feet 

below sea level, and produced about 240 tons of metallic tin per 

month during 1934-52 ( Admn, 1960, p. 410). The mine was flooded 

during the Japanese occupation and has not been reopened. 

The placers of Bangka and Billiton Islands are widespread, and 

extend sea ward from the present shorelines. During the Pleistocene, 

lowering of sea level exposed the wide Sunda Shelf to erosion, and 

Pleistocene streams carved extensive but shallow drainages on the 

shelf. Placers were localized along these drainages as well as in older 

valleys elsewhere on the islands. Much of the alluvial material in the 

placers is cemented by iron hydroxides and forms a coherent conglomerate called kaksa, in which cassiterite is distributed between coarse 

fragments of quartz and sandstone. Much placer production is £rmn 

seagoing dredges. 

Tin reserves of Indonesia unquestionably are large. The official reserve figures furnished to the International Tin Council (Robertson, 

1965) are give in table 7. 

TABLE 7.-T-in reserves of Indonesia, 1965 

[Estimated reserves of tin-in-concentrates. Data from Robertson (p. 87)] 

Demonstrated reserves t: Alluvial 2 ________________________________________________ _ 

Lode ____________________________________________________ _ 

Disseminated primary ore (stockworks) _____________________ _ 

Total _________________________________________________ _ 

Inferred reserves: Alluvial 2 ________________________________________________ _ 

Grand Total ___________________________________________ _ 

t Closely equivalent to measured plus indicated; not differentiated by price. 2 Including tailings and dumps. 

Thousands of long tons 

516. 7 

16.6 

10.3 

543. 6 

66. 4 

610.0 

The inferred reserve figure (table 7) is considered to be conservative, 

and it excludes reserves that may be discovered by offshore exploration. 

The entire shelf area from an unknown end point east of Billiton Island to north o£ Singkep Island is geologically favorable for offshore 

placer deposits, and for the purposes of this report it is assumed that 
26 TIN RESOURCES OF THE WORLD 

resources yet to be discovered in this area will equal the measured and 

indicated reserves o:f table 7, or about 540,000 tons. This assumption 

is supported by the :fact that Indonesian placer reserves average 0.639 

pounds o:f tin per cubic yard (Robertson, 1965, p. 88), much higher 

than the grade o:f reserves in Malaysia (0.33-0.38 lb o:f tin per cu yd). 

I:£ high-grade reserves are extensive, lower grade resources also must 

be extensive. Moreover, lode resources also must be considerable. 

MALAYSIA 

Historically, Malaysia has :furnished 30-55 percent o:f the world's 

yearly tin production. All the main cities o:f the country are mining 

centers, and, according to 'Tin News o:f January 1966, 67 dredges, 975 

gravel pump mines, and 55 other mines were operating in Malaysia 

at that time; almost 45,000 people were employed in tin mining. 

Tin deposits in Malaysia include both lodes and placers, but placers 

are the dominant producers. The deposits extend through the country 

in two north-trending belts nearly parallel to the coastlines. The 

mineral belts coincide with two mountain ranges that consist o:f batholiths and stocks o:f biotite granite and related rocks, probably o:f 

Cretaceous age, which intrude a thick series o:f sedilnentary and metamorphic rocks of Cambrian to Cretaceous age. Widespread unconsolidated clays, gravels, and boulder clays (clays containing residual 

boulders) contain the placer cassiterite deposits. Marine placers are 

widespread (Fitch, 1952, p. 5) ; several were being mined in 1967. 

Athough placers are mined throughout Malaysia, the most productive area is the Kinta Valley, State o:f Perak (No. 3B in fig. 4). The 

geology o:f the valley has been described in detail by Ingham and Bradford ( 1960), :from whose report the :following description is abstracted. 

The valley is about 30 miles long and about 15 miles wide at the southern end, and narrows into the mountains to the north. Bedrock o:f the 

valley consists principally o:f crystalline limestone and is encircled 

by hill-forming biotite granite. The lode deposits are principally in 

the contact areas o:f the granite and surrounding limestone; they consist of cassiterite, quartz, arsenopyrite, and pyrite, with small amounts 

of galena, sphalerite, chalcopyrite, bismutite, scheelite, wolframite, 

and antimony sulfosalts. Fluorite, lithium mica, tourmaline, and corundum are locally abundant. At the surface numerous deep solution 

cavities in the limestone have trapped the alluvial cassiterite, which is 

recovered by dredging, gravel pump mining and hydraulicking. Trace 

amounts o:f columbite-tantalite, monazite, ilmenite, cobaltite, rutile, 
ASIA 27 

and striiverite occur in placer concentrates. During 1876-1950, the 

IGnta Valley produced 1,200,000 tons of metallic tin, which, at today's 

prices, would be worth about $2 billion. 

Other important placer areas in Malaysia are in the Selangor River 

about 100 miles south of the Kinta Valley (Roe, 1953), and in the 

Frasers Hill area, about 20'--40 miles northeast. 

Important lode mines in Malaysia include the Gunong Bakau mines, 

Selangor; the Lahat pipe, in the J{inta Valley, Perak; the Beatrice 

mine, Selabin; and the Pahang Consolidated Co. mines near Sungei 

Lembing, State of Pahang. Respectively, these are A, B, C, and D in 

fig. 4. Only the mines in Pahang are currently (1967) operating. 

The mines at Gunong Bakau produced tin at the rate of about 600 

tons per year during 1900-38. The veins consisted of quartz-topazcassiterite greisen in fractured biotite granite. The ore averaged 1.6-1.7 

percent Sn02 ; pyrite, chalcopyrite, and torbernite (a uranium 

mineral) were also present. 

The Lahat pipe, 1nined in 1903-10 to a depth of 340 feet, never exceeded a few dozen feet in cross section; yet it yielded 1,500 tons of 

tin. The pipe was in limestone; it consisted of cassiterite inter grown 

with iron oxides and secondary calcite in the weathered part, and it 

contained arsenopyrite below the weathered zone. 

The Beatrice mine, also in a replacement pipe in limestone, generally 

did not exceed 50 by 70 feet in cross section. At the surface, it consisted 

of cassiterite, arsenopyrite, iron oxides, and scorodite (a secondary 

arsenic mineral). At depth the pipe contained cassiterite, arsenopyrite, 

chalcopyrite, and bornite in a gangue of tremolite, fluorborite, fluorite, 

phlogopite, and dolomite. The pipe was mined over a slope length 

of about 850 feet and yielded almost 9,000 tons of cassiterite. 

The Pahang mines are developed upon a complex system of veins in 

an area of about 6 square n1iles in which the bedrock consists of interbedded shale and quartzite intruded by biotite granite. Most veins are 

in rocks surrounding the granite, but some extend into the granite. The 

lodes are fissure fillings and replacement veins that contain cassiterite, 

pyrite, chalcopyrite, arsenopyrite, galena, sphalerite, cobaltite, manganese minerals, 1nagnetite, and secondary minerals. The gangue in 

the veins is quartz, chlorite, calcite, fluorite, clay, and tourmaline. Some 

ores occur in greisen, and most veins are bordered by chloritized rock. 

In the period1888-1948, these mines produced 79,509 tons of cassiterite. 

The tin reserves of Malaysia, according to the official figures furnished to the International Tin Council (Robertson, 1965, p. 86), are 

listed in table 8. 
28 TIN RESOURCES OF THE WORLD 

TABLE 8.-Tin reserves and known resources of JJfalaysia 

[Estimated reserves of tin-in-concentrates. Modified from Robertson (1965 p. 86) j 

Reserves: 

Measured and indicated _____________________________________ _ 

Reserves in Malay Reservations t (first indications) [inferred reserves?] ________________________________________________ _ 

Resources (known) : Subrnarginal ________________________________________________ 1 

Old tailings and residual areas ________________________________ _ 

Areas within which mining 1 is prohibited or restricted ____________ _ 

Total, reserves plus known resources ______________________ _ 

t Lands designated as mining lands. Not differentiated by price. 

Thonsands of 

long tons 

600 

170 

230 

1, 000 

NOTE.-For the purposes of this report, it is assumed that resources in undiscovered lode~, offshore 

placers, and unknown submarginal resources will equal an additional 1 million tons of tin, a figure which 

may be conservative by a factor of 2 or 3. 

THAILAND 

Lode and placer tin deposits, continuations of the Malaysian deposits, 

are widespread in Thailand. The deposits are closely associated 

with biotite granite intrusive rocks of Late Cretaceous age (younger 

granites) which form the backbone of the main mountain system that 

:forn1s the peninsula between Malaysia and Thailand (Brown and 

others, 1951). In parts of Thailand, granites of Triassic age (older 

granites) may contain deposits; these ·are being actively studied by the 

Thailand Department of Mineral R,esources (1967) to determine i:f 

they are stanniferous. In northern Thailand, along the Burmese 

border, the mountains contain tungsten deposits as well as deposits of 

tin, which may be related to Triassic granites. The principal tin 

placers are near Phuket Island (No. 4 in fig. 4), and near Ranong, 

about 60 miles north. As elsewhere in Southeast Asia, placers are 

more important tin producers than lode deposits are. Tin production 

from Phuket Island has come from alluvial stream-channel deposits 

and their submarine extensions. After W oriel War II, Union Carbide 

Corp. installed a seagoing dredge to mine the offshore deposits, which 

probably are extensive. Lode deposits on Phuket Island consist of 

cassiterite accompanied by tourmaline, topaz, white mica, and lesser 

a1nounts of zircon, ilmenite, monazite, and garnet in quartz veins and 

pegmatite dikes. 

The lode deposits of northwestern and western Thailand consist of 

fissure veins, stockworks, and pegmatite than contain wolframite and 

cassiterite accompanied locally by arsenopyrite, scheelite, pyrite, 

chalcopyrite, and molybdenite. In several districts, more tungsten is 

produced than tin. 

In the province of Yala, adjoining the Malaysian border, several 

lode mines have produced cassiterite from veins in crystalline limestone and from other 1netamorphosed rocks near the biotite granite 
ASIA 29 

contacts. In this province, the Japanese, during vVorld 'Var II, installed the first plant designed to use the Cavaet process of tin recovery. 

In the Ca vaet process, cassiterite is converted to stannous chloride, 

which in turn is dissolved in water and the tin is then recovered 

electrolytically. 

Tin reserves of Thailand are large. Robertson ( 1965, p. 86) gave 

figures (table 9) based upon the official Thailand response to the International Tin Council questionnaire. 

TABLE 9.-Tin reserves of Thailand, 1965 

[Estimated reserves of tin-in-concentrates, in thousands of long tons. Data from Robert:::on (1965, p. 8i)J 

Price, per long ton of tin _________________ ------------------ __ 

Measured:l AlluviaL ______________________________ _ 

Tailings and dumps _____________________ _ 

At $1,9f\O 

(£iOO) 

29. 7 

1.3 

At $2,520 

(£900) 

At $3,080 

(£1,100) 

35. 9 37. 9 

1.4 1.4 

TotaL_____________________________ 31. 0 37. 3 39. 3 

Indicated plus inferred _____________________ 2 1,089. 0 __________ 2 1, 500. 0 

------------------ Grand totaL________________________ 1, 120. 0 37. 3 1, 539. 3 

J Measured reserve~ of dredging companies, excluding offshore deposits. 2 Inland, alluvial, eluvial, and offshore deposits. 

[N OTE.-As the above figures include no reserves in lode depo~its, the writer has, for the purposes of this 

report, estimated that lode resources and submarginal placer resources equal th 1965 measured, indicated, 

and inferred placer reserves at the $1,960 (£700) rate, or 1,120,000 long tons of tin.] 

BURMA 

The known tin deposits of Burma lie along the Thailand-Burma 

border and are the extension of the Indonesia-Malaysia-Thailand 

belt of deposits. The deposits are similar to those in Thailand and 

~ialaysia; they consist of lodes and placers related to biotite granite 

that intrudes slates, agglomerates, and quartzites that contain some 

interbedded limestone. The tin belt in Burma is about 750 miles long, 

extending from the Byingyi-Mawchi district on the north (Nos. 6, 7, in 

fig. 4) through the Moulmein and Tavoy districts (Nos. 5, 8 in fig. 4) 

to the Mergui Islands on the south (No. 9 in fig. 4) . 

The Mawchi mine was one of the most important tin-tungsten mines 

of the world ( Ahlfeld, 1958, p. 72) . The mine was developed along 

1nany veins that cut a tourmalinized granite and the enclosing slates. 

The veins carry quartz, tourmaline, mica, cassiterite, wolfra1nite, a 

little scheelite, and small amounts of galena, chalcopyrite, pyrite, 

arsenopyrite, molybdenite, sphalerite, bismuthinite, covellite, chalcocite, beryl, phenakite, and fluorite. In 1939, the Mawchi mine produced 3,100 tons of tin concentrate and 2,700 tons of tungsten concentrate (Ridge, 1953, p. 53). The mine closed during World War II, 

and since then it has produced only on a much smaller scale; reserves, 
30 TIN RESOURCES OF THE WORLD 

however, are probably large. Tin mining in Burma has not recovered 

from the setback of the Japanese occupation. 

In the Tavoy district, quartz veins in granite and surrounding 

sedimentary rocks contain both cassiterite and wolframite, the wolframite being preponderant (Brown and Heron, 1923}. The veins 

range in thickness from a few inches to several feet and -are most 

numerous in or near granite. In addition to wolframite and cassiterite, 

the veins contain fluorite, scheelite, molybdenite, pyrite, chalcopyrite, 

galena (rare), pyrrhotite, arsenopyrite, sphalerite, native bismuth, 

bismuthinite, ·and topaz. The walls of most veins consist of quartz-mica 

gre1sen. 

Veins containing wolframite and cassiterite are mined in the Mergui 

Islands. These veins are in most respects similar to those in the Tavoy 

district. 

Tin and tungsten have been won from many small placers in Burma, 

but no major producing placer districts are now operating. Without 

question, placer deposits will produce important ·amounts of tin, but 

the rather mountainous terrain of Burma is not as favorable for the 

occurrence of large placer fields as is the terrain of Malaysia. 

Reserves of tin in Burm.a were not estimated by the Burmese government for Robertson's report (1965}. For the present report, the 

writer assumes that proved reserves amount to 60,000 tons, calculated 

from 10 years' production at the highest pre-World War II rate 

and that the total known and undiscovered resources of submarginal 

grade must equal at least 250,000 tons of tin. 

VIETNAM AND LAOS 

Important tin deposits occur at two localities in Vietnam and Laos. 

Before World V\Tar II, the Nam Pha Tene mine (No.10 in fig. 4} was 

a large producer (914 tons of cassiterite in 1939), but figures of present production are unavailable. The deposit consists of a pipelike 

replacement body in limestone. Near the surface it contains needlelike 

crystals of cassiterite in limonite. At depth the pipe passes into veins 

in the sandstone beneath the limestone, and there the veins contain 

fine-grained cassiterite and sphalerite, galena., chalcopyrite, arsenopyrite, and jamesonite. The deposit is related to a biotite-hornblende 

granodiorite. 

In the Pia Oak 1\fountains, northern Tonkin Province of Vietnam 

(No. 11 in fig. 4), veins containing cassiterite and wolframite occur 

in and around a biotite granite or granodiorite. The deposits are in 

veins, stockworks, and veinlets in both the granite and surrounding 

rocks. The veins also contain quartz, scheelite, molybdenite, pyrite, 

pyrrhotite, sphalerite, galena, and autunite (a uranium mineral). 
AFRICA 31 

Placer cassiterite deposits also are worked in the Pia, Oak area. 

The richest placers are found in deep solution cavities in limestone, 

simila,r to deposits in the ICinta V ailey, Malaysia. 

The tin reserves of Vietnam and Laos are unknown. For the purpose 

of this report, it is assumed that measured plus indicated reserves are 

equivalent to 5 years' production at the pre-World ""\Va,r II level (about 

1,500 tons was produced in 1939), or 7,500 tons. Resources are assumed 

to be at least 10 times the measured and indicated reserves, or 75,000 

tons. 

JAPAN 

Since the 16th century, tin deposits on Honshu Island have produced 

moderate amounts of tin (Japan Geol. Survey, 1960, p. 184) . According to Takomoto (1944), the deposits occur mainly as pegmatitic and 

quartz veins associated with biotite granite intrusive rocks. Veins 

occur in both granite and the invaded country rocks. Cassiterite is 

the main tin mineral, but stannite and stanniferous tetrahedrite also 

are present. Associated minerals are wolframite, scheelite, arsenopyrite, chalcopyrite, pyrite, sphalerite, stibnite, galena, pyrrhotite, molybdenite, bismuthinite, and several gangue minerals especially topaz, 

quartz, tourmaline, and fluorite. In 1958, operating mines in three areas 

(Ikuno-Akenobe, Obira-Mitate, and Suzuyama) produced 1,126 tons 

of tin-in-concentra.te, of which the major part came from the Akenobe 

mine, where many quartz veins that contain cassiterite, wolframite, 

and numerous base-metal sulfide minerals are mined. The veins, which 

cut both diorite a.nd gahbro intrusive rocks as well as the surrounding 

sedimentary and volcanic rocks, are considered to be related to an 

underlying granite. 

Reserves of tin in Japan are moderate. According to the Japan 

Geological Survey, reserves in five working mines in 1962 were 

2,654,000 tons of ore a,veraging 1.'2 percent tin, or about 20,000 long 

tons of tin. Present reserves ( 1968) amount to about 16,000 long tons . 

. A .. s the tin deposits of Japan a.re not extensive and many a,re worked 

out, it is assumed in this report tha,t undiscovered submarginal resources amount to not more than the known reserves, or about 16,000 

long tons of tin. 

AFRICA 

Substantial producing tin deposits are found in Nigeria and the 

Democratic Republic of the Congo, and less important ones in Rwanda, 

Heprublic of South Africa, South-West Africa, Rhodesia, Tanzania, 

and Uganda. Small producing deposits occur in Burundi, Cameroon, 

Morocco, Niger, Swaziland, and Zambia (formerly Northern Rhodesia). Locations of all major producing districts are shown in figure 1. 
32 TIN RESOURCES OF THE WORLD 

NIGERIA 

Nigeria is the world's fifth largest producer of tin (9,354 long tons 

of tin-in-concentrate in 1965, U.S. Bur.l\Tines, 1966), n1ost is produced 

from placers that contain eassiterite, co1umbite, and tantalite. The 

large amount of byproduct oolmnbite produced makes Nigeria, the 

world's leading producer of that mineral. 

The geology of Nigeria is well known; the J os Plateau, from which 

about 95 percent of the placer cassiterite is produced, has been studied 

in detail ( J a,cobson and vV ebb, 19±6 ; ~iackay and others, 19-!9 ; Carter 

and others, 1963 ; and Jacobson and others, 1958) . The plateau has a 

complex history of granitic-rock intrusion. _l\;fany of the intrusive 

rocks were emplaced as ring complexes. The general order of intrusion 

for a typical eomplex has been described as follows: ( 1) Rhyolite, 

tuff, and agglomerates, which filled ring faults that bounded a large 

caldera and the caldera itself; ( 2) late intrusive rhyolites and explosion breccias; (3) quartz-pyroxene-fayalite porphyries; ( 4) basic 

dikes and semiconformable intrusions; ( 5) arfvedsonite-fayalite granite-porphyry ring dikes; ( 6) biotite granites; ( 7) riebeckite microgranites; ( 8) riebeckite-aegerine granites; ( 9) albite-riebeckite 

granite; and ( 10) minor acid dikes (Jacobson and others, 1958, p. 30). 

The various granites are collectively grouped under the term "younger 

granites"; more than 40 younger granite complexes are known in 

Nigeria. Similar complexes are known elsewhere in north and ·west 

Africa. 

Most of the tin deposits of Nigeria are associated with the biotite 

granites, which form ring dikes, bosses, and large stocks or batholiths as much as several hundred square miles in outcrop area. Tex,turally, the younger granites range from fine grained to coarsely porphyritic; their most noticeable chemical features are a rather high fluorine 

content and a paucity of boron. This paucity of boron leads to the 

complete absence of tourmaline in the ~tin deposits (Jacobson and 

others, 1958, p. 16). The younger granites intrude Precambrian rocks, 

but are themselves probably of early Paleozoic age. Lode cassiterite deposits consist principally of mineralized stockworks and quartz-topazInica greisens which are most common near the apices of granite 

stocks. Columbite and cassi~terite are most common in the albite-biotite 

granite. The tin lodes contain cassiterite, wolframite, chalcopyrite, 

bornite, galena, arsenopyrite, sphalerite, and molybdenite. 

Elsewhere in Nigeria, a suite of granites older than the younger 

granites intrudes the Precambrian rocks. Most of these older granites 

have gneissic textures and gradational contacts. Associated with the 

older granites are many pegmatites that contain cassiterite, columbitetantalite, beryl, tapiolite [ (Fe,Mn) (Nb,Ta) 20 6], and minor sulfide 
AFRICA 33 

minerals. ~lost of the cassiterite and columbite-tantalite was introduced during a late-stage albitization of the pegmatites. A few of the 

pegmatites have been mined, but 1nost tin produced from the pegmatite 

areas is won from nearby alluvial deposits. 

The rich and extensive placers of the J os Plateau were forn1ed largely 

from erosion of the basement rocks. During a period of elevated base 

level, streams aggraded their valleys and buried the placers beneath 

a blanket of clay and alluvium. Still later, extensive lava fields blocked 

valleys and buried the stream gravels; drainages reestablished on the 

lavas have intersected the buried placers, giving rise to n1odern 

placers from reworked older ones. ~lost production is from modern 

placers, but some placers beneath lava have been worked; these buried 

placers are probably very extensive. 

Reserves.-In 1962, reserves in Nigeria were estimated (Robertson, 

1965, p. 82) as 138,000 long tons of tin in a combined proved and inferred category. Undiscovered resources of economic and submarginal 

grade are estimated, for the purposes of this report, to equal at least 

the known and inferred reserves, or another 138,000 long tons. Judging 

from the known extent of deposits buried beneath lavas, this estimate 

is probably conservative. 

DEMOCRATIC REPUBLIC OF THE CONGO 

Important amounts of tin are won from both lode and placer mines 

in the Democratic Repu:blic of the Congo. Tin deposits are found in 

the provinces of ~{aniema, Katanga, and IGvu, and the former Territory of Ruanda-Urundi (now the countries of Rwanda and Burundi). 

The deposits are tin-bearing pegmatites, some of which are large, and 

tin-bearing greisens and quartz veins; the pegmatites are more important in l{atanga. 

The basement rocks consist of a group of quartzites, schists, and 

gneisses of Precambrian age, locally intruded hy mafic rocks and by 

biotite granite of younger age. The tin deposits are genetically related 

to the biotite granite. Columbite and tantalite are found in deeper 

parts of the granites and in some placers. 

The lode deposits exploited by one company ( Symetian) in Maniema 

have been described in detail by Varlamoff (1948); his descriptions 

are largely applicable to most of the area. A large granite intrusion 

has a border of coarse-grained microcline-quartz-muscovite rock, and 

an interior of medium-grained microcline-quartz-muscovite-biotitealbite granite. Following injection of the granite, several systems of 

veins and dikes formed in the following sequence: (1) Aplite-pegmatite, (2) early quartz veins containing colmnbite and tantalite, (3) 

greisen that contains columbite-tantalite and nonlithia mica, and ( 4) 
34 TIN RESOURCES OF THE WORLD 

greisen that contains lithia mica, wolframite, and cassiterite. Later 

quartz veins contain ferberite, native his1nuth, pyrite, and arsenopyrite. 

Veins are comn1onest above cupolas of granite intrusive rocks, where 

tourmalinization is often intense. 

V arlamo.ff considered the differing n1ineralogy of various veins 

mined in the Congo to be largely a function of regional mineral zoning 

com.bined with the depth of erosion. In upper (or outer) zones, greisen 

deposits that contain cassiterite and sulfide minerals are important. In 

deep zones within granite, veins contain important amounts of columbite-tantalite in addition to cassiterite. 

In J(atanga, large pegmatites are mined by open-pit methods. The 

~Ianono pegmatite is about 10 km long, as much as 400 m wide, and 

contains cassiterite throughout (Geomines Co., 1967, p. 3). Cassiterite, 

which is present in amounts averaging about 2.2 kg of tin per cubic 

meter, is accompanied by thoreaulite ( SnTa20 7 ), in the ratio one part 

thoreaulite to 20 parts cassiterite. Ore minerals recovered are cassiterite, tantalite, columbite, and thoreaulite. Spodumene is an important constituent of the pegmatite, but it is not routinely recovered. 

The Manono pegmatite produced 127,500 metric tons of cassiterite 

from about 1928 to 1967 (Geomines Co., 1967, p. 4). Other pegn1atites 

in the Congo are worked on a smaller scale. 

Placer deposits of cassiterite in the Congo are mainly small but 

rich. The deposits are localized near biotite granites, or where streams 

cross tin-bearing greisens or pegmatites. 

Reserves.-The Democratic Republic of the Congo government estimated reserves for Robertson's report ( 1965, p. 84), and these figures 

are presented in table 10. 

Robertson presented evidence to show that these reserve figures are 

extremely conservative; the writer agrees. For instance, measured and 

inferred reserves in the Manono pegmatite (Manono and IGtololo 

mines, to a depth of 125 ft) 'are estimated by the writer to be about 

900,000 short tons of tin metal. Total reserves in the Democratic Republic of the Congo therefore are estimated to be at least 1 million long 

tons of tin1netal, most of which is in the Manono pegmatite. 

Resources.-As emphasized by Ahlfeld (1958, p. 52), the Congo 

tin fields were not discovered until 1933, and tin-bearing granites and 

pegmatites are widespread over many thousand square miles. The tin 

fields therefore are not yet considered to be completely explored. For 

the present report, the writer assumes that tin resources in submarginal 

and undiscovered deposits amount to another 1 million long tons of 

tin metal. This estimate probably is conservative. Thus, the Democratic 

Republic of the Congo contains one of the major tin reserves of the 

world. 
AFRICA 35 

TABLE 10.-Estimated reserves of tin, Democratic Republic of the Congo, 1965 

[In thousands of long tons. Data from Robertson (1965). Expressed in terms of tin-in-concentrates of the 

grade produced by existing mines] 

Price, per long ton of tin 

Measured: 

$1,960 

(£700) 

Alluvial and eluviaL___________________________ 9 

Lode-------------------------------------------------

Total____________________________________ 9 

Indicated: Alluvial and eluviaL __________________________________ _ Lode ________________________________________________ _ 

Tailings and dumps____________________________ 5 

$2,520 $2,800 

(£900) (£1,000) 

29 

105 

134 

8 

2 

10 

34 

105 

139 

9 

7 

15 

Total____________________________________ 5 20 31 

Inferred: Lode_________________________________________________________ 10 

Tailings and dumps____________________________________ 5 10 

Total _____________________________________________ _ 

Grand totaL _______________________________ _ 14 

REPUBLIC OF SOUTH AFRICA 

5 

159 

20 

190 

Tin deposits of the Republic of South Africa are mainly in pipes 

and veins that occur in or near granites or granophyres of the Bushveld Complex. The mineral assemblages, which are characteritic of the 

Cornwall type, consist of abundant cassiterite accompanied by quartz, 

fluorite, pyrite, tourmaline, arsenopyrite, molybdenite, chalcopyrite, 

wolframite scheelite, sphalerite, bornite, chalcocite, tetrahedrite, tennantite, galena, covellite, and rare bismuth minerals (Strauss, 1954). 

The pipes are vertically and horizontally zoned and generally bottom 

on luxullianite (a rock consisting virtually of tourmalinized granite). 

The tin content ranges :from 0 to 70 percent and averages 12-30 percent. Most o:f the known pipes in the Potgietersrus fields were mined 

out before 1926, and the present production comes mostly :fron1 disseminated deposits of cassiterite in granite (Robertson, 1965, p 69), 

which contain an average o:f about 1.5 percent tin. Detailed descriptions o:f many of the deposits were given by Leu be and Stumpfl ( 1963). 

Important deposits occur at Rooiberg, where veins and pockets contain cassiterite, scheelite, galena, sphalerite, chalcopyrite, pyrite, and 

bismuthinite. Gange minerals are quartz, tourmaline, fluorite, ankerite, 

and sericite. Smaller deposits are known at Leeuwpoort, and at vVarmbad, cassiterite occurs in pegmatites, quartz veins, and breccia replacement bodies in granite (De Kun, 1965, p. 471). 

Reserves.-No tin-reserve figures were given for the Republic of 

South Africa in Robertson's report (1965). However, the govern-
36 TIN RESOURCES OF THE WORLD 

ment forecast for the country calls for a production of 1,100 tons of 

tin in 1970, indicating that reserves are moderate. It is assumed here 

that measured and indicated reserves equal 10 years' production at 

1,100 tons per year, or 11,000 long tons of tin. Undiscovered reserves 

and submarginal resources are assumed to equal at least twice the 

proved reserves, or 22,000 long tons. 

SOUTH-WEST AFRICA 

Tin deposits occur in four distinct northeast-trending belts in a small 

area of west-central South-vVest Africa (fig. 1). Two generations of 

biotite granite (and associated rocks) have intruded the Damara Complex of Precambrian age, which includes crystalline limestones, granulites, and crystalline schists. Many pegmatites intrude the schist and 

granite, but a single pegmatite that contains both cassiterite and 

wolframite furnishes the bulk of current production. Swarms of 

pegmatites occur in schists near the grani,te contacts, in tectonic zones 

in the schists, or where the schists change strike. The pegmatites that 

are genetically related to the younger granites contain the bulk of the 

cassiterite, and locally carry, in addition to the cassiterite, columbitetantalite, scheelite, and wolframite. The ore minerals accompanied a 

la,te-stage albitization of pegmatites and the formation of tourmaline, 

muscovite, and lepidolite. 

At the Steipelmann mine, near Arandis, a tin-bearing pipe in limestone contains herzenbergite ( SnS), arandisite (a complex tin silicate), 

and nordenskioldine ( CaSn (B03 ) 2 ) as the tin-bearing minerals (Ramdohr, 1935). Small lode deposits occur at Paukuab (greisenized pegmatites and greisen zones in granites) and in the Orange River area. 

Small placers contributed most of the tin produced in South-West 

Africa until 1962; today placers contribute only a few hundred tons 

of tin concentrates yearly. 

Reserves.-Robertson (1965, p. 70) stated that proved reserves at 

the main lode mines amount to 8 million tons of material containing 

tin and tungsten (grade unknown). He estimated that annual production will reach 900 tons of tin metal by 1970. For ~this report, it is assumed that proven reserves amount to at least 80,000 long tons of tin 

metal. Resources of submarginal grade and in undiscovered deposits 

are estimated to be at least 100,000 long tons of tin metal, a purely 

arbitrary figure that probably is conservative. 

SOUTHERN RHODESIA 

Tin-bearing pegmatites are mined on a substantial scale in the 

l(amativi area of Southern Rhodesia, principally at the l(amativi tin 

mines (Fick, 1960, p. 472). The tin-bearing pegmatites are especially 
AFRICA 37 

abundant in a northeast-trending schist belt that extends about 80 

miles across the Gwaai River in the south west corner of the country. 

The western part of the belt is called the VV ankie tin belt, and the 

eastern, the l{amativi tin belt. 

The schist and gneiss belt is part of the basement system of Precambrian metamorphosed sedimentary rocks. Biotite granite and two 

younger generations of pegmatites intrude this basement system. Fick 

(1960, p. 475) noted that an older generation of tourmaline-bearing 

pegmatites is tin free but that the younger ones contain cassiterite and 

can be classed as either lithium-poor or lithium-bearing pegmatites. 

The lithium-poor pegmatites are richer in ,tin and contain recoverable 

amounts of colun1bite-tantalite and spodun1ene. Albitized parts of 

tin-bearing pegmatities are enriched in colmnbite-tantalite. Small 

crystals of beryl occur but are not recovered. According ~to vVatson 

(1962, p. 35), the mined ores average about 0.25 percent tin. 

Reserves.-N o official reserve figures were furnished to the International Tin Council by the Rhodesian government for Robertson's 

1965 report. Because of recent plant expansion at Kamativi mines, 

however, one may assume that proved reserves are substantial. For this 

report, it is assumed that measured and indicated reserves of Rhodesia 

equal10 times the yearly production, or about 6,000 long tons of tin. 

Submarginal and undiscovered resources are estimated to be at least 10 

times the measured and indicated reserves, or 60,000 long ~tons of tin. 

RWANDA, BURUNDI, UGANDA, AND TANGANYIKA 

(TANZANIA) 

A belt of lode and placer tin deposits east of Lake Kivu stretches 

from southwestern Uganda into northern Tanganyika (Tanzania). 

In Uganda, gneissic biotite granite has intruded and domed shales and 

sandstone of the J{aragwe-Ankolean System of Precambrian age. 

Cassiterite veins are associated with the granites, but occur mostly in 

the surrounding rocks (Barnes, 1961, p. 28). The deposits are both 

hydrothermal and pegmatitic; hydrothermal deposits contain most 

of the tin, and pegmatitic deposits contain some columbite-tantalite 

and beryl. Sulfide minerals are lacking. 

The belt of lode and placer tin deposits in lT ganda continues into 

Tanganyika, where the deposits are mined, principally by a single 

large company (l{yerwa Syndicate, Ltd.), at the l{aborishoke deposit 

(Harris, 1961, p. 136). The mine is in the l{aragwe Tinfields, a belt of 

deposits about 5 miles wide and 30 miles long. Biotite granite has intruded and thermally metamorphosed phyllites, sericite schists, and 

quartzites of the Karagwe-Ankolean System. Fissuring accompanied 

the intrusion of granite; younger fissures localized quartz-mica veins 
3S TIN RESOURCES OF THE WORLD 

that carry cassiterite, hematite, and, locally, wolframite. Some veins 

occur in granite, but the majority are in the metamorphosed rocks. 

Placer deposits along the Murongo River were mined during the early 

development of the tin fields, but no extensive placers were found. 

The tin deposits in Rwanda and Burundi are an extension of the 

deposits in the Democratic Republic of the Congo (Harris, 1961, 

p. 282). Most of the tin is won from stanniferous pegmatites that also 

carry recoverable amounts of columbite-tantalite and lithium minerals. According to Thoreau (1951, p. 282), the pegmatites near 

Usumbura (now Bujumbura) in Urundi (now Burundi) contain 

larger amounts of bastnaesite (a cerium carbonate) than do Congo 

pegn1atites. 

Re8erves.-No reserve figures are available for these countries. For 

this re.port, it is assumed that measured and indicated ore is sufficient 

to sustain the 1964 rate of production for each country for 10 years. 

This leads to a reserves figure of about 20,000 long tons of tin. Undiscovered and submarginal resources are estimated to equal at least the 

proven reserves, or another 20,000 long tons. 

OTHER AREAS IN AFRICA 

Small deposits of tin are worked in Cameroon, Morocco, Niger, 

Swaziland, and Zambia (formerly Northern Rhodesia) ; small deposits are known also in the United Arab Republic (Egypt), Algeria, 

~!ali, Liberia, Sierra Leone, and Mauritania. (See fig. 1.) Present 

information indicates that none of these areas contain large proven 

reserves of tin, and for this report it is assumed that total resources 

amount to 50,000 long tons of tin, a purely arbitrary figure. 

OCEANIA 

Lode and placer tin deposits occur in Australia; each type of 

deposit has contributed roughly half of the 670,700 tons of tin concentrates produced in the country to the end of 1961 (Zimmerman, 

1965b, p. 39). The large Australian deposits are 1nainly localized 

along the tectonic belt that follows the eastern 1nargin of the continent 

(fig. 5). Several isolated occurrences, of detrital and lode cassiterite 

are known in New Zealand (Hutton~ 1950). 

AUSTRALIA 

Substantial tin deposits in Queensland and New South Wales have 

been mined since 1891, and today these sustain the main producing 

1nines of the country. The district in northern Queensland covers the 

Herberton-\Vatsonville-Mount Garnet area, where placer and lode 
N 

WESTERN 

AUSTRALIA 

OCEANIA 

NORTHERN 

TERRITORY 

0 400 800 KILOMETERS I I I 

0 100 MILES I I 

0 100 KILOMETERS 

I I 

1. Herberton district 9. Northwestern region 

2. Croydon district 10. Western region 

3. Cooktown district 11. South-West Division 

4. Stlanthorpe-Ballandean district 12. North-West Division 

5. New England district 13. Darwin-Katherine region 

6. Mount Tallenbung-Albury tin belt 14. Barrier Range 

7. Beech worth-Eldorado district 15. Middlesex district 

8. Northeastern region 

39 

FIGURE 5.-Tin-bearing areas of Australia. Modified :from Australia Bureau 

of Mineral Resources, Geology and Geophysics (1957, fig. 3). 
40 TIN RESOURCES OF THE WORLD 

deposits are associated with biotite granites intruded into metamorphic 

and sedimentary rocks. Blanchard (1947, p. 265-304) ·described the 

lode deposits in some detail. These lodes consist mainly of small- to 

moderate-sized pipes in granites or the surrounding bedded rocks. 

Those in granites contain cassiterite, wolframite, molybdenite, native 

bismuth, and smaller an1ounts of sulfide minerals. The pipes in surrounding rocks contain one or more of the following: Cassiterite, 

arsenopyrite, pyrite, pyrrhotite, tetrahedrite, sphalerite, galena, and 

stannite in a gangue of quartz, fluorite, mica, topaz, kaolinite, tourmaline, chlorite, calcite, and siderite. Some of the pipes contain sulfide 

1ninerals unaccompanied by cassiterite. The pipes in granite were classified by Blanchard (1947, p. 269) as (1) the quartz type, with abundant quartz; (2) the granite type, in which replacement by quartz is 

irregular; and ( 3) ~the garnet type, in \Yhich garnet replaces the mica. 

Garnet is found only in the molybdenite-cassiterite pipes. 

In contrast to 1nany pipes of the world, the Australian pipes (in 

granite) that containn1olybdenite ores are older than joints and fractures of the granite. The cassiterite-bearing pipes, however, are 

localized along fractures or joints, leading Blanchard to conclude 

that the 1nolybdenite-rich pipes were formed earlier. The largest pipe 

in the Herberton district (Vulcan pipe) produced 8,500 tons of tin 

from 165,000 tons of ore for a recovery of 5 percent tin. Most of the 

pipes are nnlCh smaller, however. 

In northern Queensland, alluvial deposits are derived from lodes 

associated with biotite granites. Basalt flows of Tertiary age overlie 

some ancient channels in the Herbert on area, where both dredges 

and sluices have been used. The gravels mined in the Herberton area 

in 1962 averaged about 0.5 pound of tin per cubic yard (Zimmerman, 

1965a, p. 376). In the Cooktown district, eluvial (slope) and residual 

placers are 1nined on a small scale in addition to the main alluvial 

placers. 

In southern Queensland (Stan thorpe district, fig. 5), n1ost tin has 

been won from alluvial deposits, which now seem largely worked out. 

The placers were derived from lode deposits near and in biotite 

granite. A typical lode mine (1Vatson's Show) was developed on 

quartz veins along the contact area of granite and slate, where cassiterite was accompanied by chalcopyrite, galena, arsenopyrite, pyrite, 

and minor amounts of n1olybdenite, wolframite, and sphalerite. 

Deposits of N e\v South "\Vales include both lodes and placers ; both 

types have been worked extensively. ~lain production came from 

the New England district and from Ardlethan in d1e l\fount Tallenbung-Albury belt (fig. 5). In theN ew England district, which merges 

to the north with the Stanthorpe: district of Queensland, granite, and 
OCEANIA 41 

granite porphyry intrude Paleozoic sedimentary rocks. Lode deposits 

in granite generally are more numerous in the silica-rich part of 

the granites and consist of veins, stockworks, and disseminations of 

cassiterite in altered granite. Other lodes are concentrated in the rocks 

peripheral to the granites, rarely more than 2 miles from the contact. 

The lodes at Torrington (New England district) are confined to 

granite and are localized along persistent joints. The lodes carry 

quartz, chlorite, cassiterite, ferberite, arsenopyrite, chalcopyrite, 

pyrite, n1olybdenite, sphalerite, galena, and monazite. Tungsten deposits in the same area contain quartz, topaz, cassiterite, beryl, bismuth, fluorite, and uranium 1ninerals. 

In the Mount Tallenbung-Albury tin belt, which extends southward into Victoria, lodes and placers are associated with biotite 

granite and contact rocks. Lode deposits are localized in fractures in 

granite, where it was extensively altered to quartz-tourmaline rock. 

1fost lodes contain cassiterite, arsenopyrite, pyrite, wolframite, chalcopyrite, galena, molybdenite, and bismuth minerals. Productive placers are largest in streams that flow along margins of altered granites. 

According to Robertson (1965, p. 67), a new plant erected to treat ore 

from a 1nine on a large lode deposit in granite at Ardlethan will produce 650 ~tons of tin metal annually. 

In western New South Wales, lodes in the Barrier Range (No.14 on 

fig. 5) are localized along greisenized dikes and pegmatites in the 

LmYer Precambrian schists. 

Cassiterite produced in Victoria has come largely from placer and 

lode deposits in the Beechworth-Eldorado district on the border with 

New South ""\Vales. The lodes are relat€d to Devonian biotite granites, 

and contain cassiterite associated with base-metal sulfides in greisen 

zones and quartz veins within granite and the enclosing sedimentary 

rocks .. A ..few placer deposits were large enough to sustain dredges; 

placers have yielded most of the tin produced from the district. 

Tin deposits in Western Australia occur near Green bushes in the 

South-"\Vest Division, and at the Moolyella fields in the North-West 

Division (fig. 5). At Greenbushes, ancient sand, clay, and gravel deposits (older alluvium) unrelated to present drainages are dredged 

for cassiterite. The deposits formed in a lake or shallow sea of Tertiary 

age and represent ancient beach deposits that formed around islands 

composed of Precambrian greenstones and gneisses. Recent alluvium 

along n1odern streams contains cassiterite that is derived from reworking of the older alluvium. The placers also yield small amounts of 

tantalite. Small lode deposits in the area consist of cassiterite-tantalitebearing viens in granite. 
42 TIN RESOURCES OF THE WORLD 

In the Moolyella area, buried placers have yielded the bulk of the 

tin. The placers were derived from low-grade lodes consisting of 

stanniferous quartz veins and pegmatites. 

Tin deposits in the Northern Territory are localized in a belt about 

200 miles long that extends southeastward from Darwin and coincides 

roughly with the Pine Creek geosyncline ("\Valpole and Crohn, 1965, 

p. 168) of Precambrian age. These deposits consist of cassiteritebearing greisens, quartz veins in or near granite, and cassiterite-tantalite-bearing pegmatite. Most deposits are small. 

Tasmania contains many tin deposits grouped in the northern part 

of the island (fig. 5). According 1to Solomon (1965, p. 464) most of 

the mineral deposits were formed during the Tabberabberan orogeny 

of Devonian age; none are exposed in post-Devonian sedimentary 

. rocks. Lode tin deposits are worked in the west, and placers in the 

northeast. Cassiterite is the main ore mineral, and in lodes it is accompanied by valuable amounts of copper, lead, zinc, and silver. 

The placer deposits of northeast Tasmania consist of modern 

stream placers and of "deep leads" (older alluvium) which locally are 

overlain by basalt. Some deep leads contained as much as 78 pounds of 

cassiterite per cubic yard (Jack, 1965, p. 499). Grade of currently 

mined gravels ranges from 0.32 to 1.5 pounds of cassiterite per cubic 

yard. Jack (1965, p. 497) stated that placers of northeast Tasmania 

have produced 40,000 tons of tin. 

Lode deposits in northeastern Tasmania consist of mineralized pegmatite and granite dikes, flat-lying "floors" in granite, and quartz 

and greisen veins, all localized in biotite or biotite-muscovite granite 

o£ Devonian age. Cassiterite, the main ore mineral, is accompanied by 

wolframite, scheelite, chalcopyrite, galena, and molybdenite. Tourmaline, topaz, quartz, mica, and kaolin are the main gangue minerals. In 

the Blue Tier and Branxholm-Weldborough areas, deeply weathered 

tin-bearing granite was mined as a residual deposit. The most important lode mine in northeastern Tasmania is the A'berfoyle tin mine, 

near Rossarden. The mine was developed on numerous veins in a zone 

200 feet wide and 1,600 feet long in contact-metan1orphosecl shales, 

slates, and graywackes above a cupola of biotite granite (Edwards and 

Lyon, 1957). The ore minerals include cassiterite, wolframite, arsenopyrite, pyrite, molybdenite, pyrrhotite, chalcopyrite, sphalerite, stannite, galena, tetrahedrite, matildite, native bismuth, scheelite, marcasite, magnetite, and hematite. Gangue minerals are muscovite, topaz, 

apatite, triplite, fluorite, quartz, and carbonates. Storey's Creek mine, 

2 miles distant, is similar, and drilling during 1961-62 at nearby l(ookaburra-Lutwyche disclosed another major lode system (IGngsbury 

1965, p. 506). 
OCEANIA 43 

Lode tin and base-metal deposits of primary importance in western 

Tasmania include those in Mount Heemskirk-Zeehan (tin, silver, lead, 

zinc), Dundas-Renison Bell (tin, silver, lead, zinc), Mount Cleveland- "r aratah (tin, lead, zinc), and Moina areas. 

In the Mount Heemski.rk-Zeehan area (western region of Tasmania), the Heen1skirk granite of Devonian age is intruded into a thick 

series of clastic and volcanic rocks and intercalcated limestones and 

dolomite. Within the Heemskirk granite the lodes are associated with 

transitional masses of tourmaline granite. Tin lodes occur as pipes and 

irregular fissure fillings, and those in the granite contain cassiterite in 

a gangue of quartz, mica, and tourmaline. Outward from the granite, 

zoned lodes pass from those containing cassiterite, pyrrhotite, pyrite, 

chalcopyrite, sphalerite, and galena into ores containing stannite and 

valuable amounts of silver in argentiferous galena and tetrahedrite. 

At Dundas-Renison Bell, rubout 9· miles northeast of Zeehan, mafic 

rocks and quartz porphyry intrude gently folded shale and sandstone. 

Lode tin deposits consist of fissure-fillings and concordant bedding-replacement bodies. Near quartz porphyry, cassiterite is accompanied by 

abundant tourmaline and quartz; farther away, cassiterite occurs as 

disseminated grains within massive pyrrhotite that also contains minor 

pyrite, arsenopyrite, chalcopyrite, sphalerite, and galena, and trace 

amounts of stannite, canfieldite, and franckeite. 

At Mount Cleveland, cassiterite is associated with pyrite, pyrrhotite, 

and chalcopyrite in lodes within shaly sandstone that is overlain by 

volcanic rocks and underlain by massive sandstone. Wollastonite, 

tourmaline, and fluorite, plus minor arsenopyrite, indicate that these 

lode deposits formed at high ten1perature. Recent drilling has established reserves of 2 million tons of ore containing 1 percent tin and 

0.35 percent copper. Ten miles northeast of Mount Cleveland, the 

~fount Bischoff n1ine produeed more than 54,000 tons of tin metal from 

mineralized quartz-feldspar porphyry dikes which probably lie above 

a buried granite cupola. Cassiterite occurred in pyrrhotite-talc-carbonate bodies that replaced dolomite, in fissure lodes consisting of cassiterite with pyrite, sphalerite, arsenopyrite, and minor stannite in a 

gangue of quartz, tourmaline, topaz, and fluorite. 

Elsewhere in Tasmania, lode tin has been mined at Dalcoath Hill 

in the Middlesex district of north -central Tasmania (No. 15 on fig. 5), 

and cassiterite occurs as ·an accessory mineral in silver-base-metal lodes 

at numerous localities. 

Reserves.-Robertson (1965, p. 88) gave the official Australian 

Government estimate of reserves in all categories in 1965 as 83,000 long 

tons of tin (at a price of $3,080 per long ton). As the new plant at 

Ardlethan will produce at the rate of 650 tons of tin metal per year! 
44 TIN RESOURCES OF THE WORLD 

reserves there probably can be esti1natecl to equal, at least, 10 yea,rs' 

production. 

The International Tin Council (1966, p.1628) has quoted Australian 

reserves as equal to 127,000 long tons of tin. Hence, it is possible that 

the total measured, indicated, and inferred reserves, plus undiscovered 

resources, may be equal to about 250,000 long tons of tin, assuming 

that undiscovered resources are at least equal to known reserves. 

NEW ZEALAND 

N e'v Zealand has not produced tin, and only one known lode can be 

classed as a tin deposit. North of Port Pegasus on Steward Island, a 

roof pendant of schist and quartz in biotite granite has been altered to 

quartz-topaz greisen along a system of anastomosing veinlets in a zone 

about 2 miles long and a few feet to a few hundred feet wide (Williams, 1934, p. 414). Cassiterite is accompanied by wolframite, topaz, 

iron-bearing garnet, sphalerite, and gahnite. Elsewhere in New Zealand, cassiterite is confined to noneconomic amounts in stream gravels, 

beach sands, and pegmatites at widely scattered localities. 

CHINA. 

The information on tin resources of China is incomplete, and has 

been for many years. The available recent information indicates that 

ne'v deposits have been discovered, which, in conjunction with the older 

ones, have at least maintained large reserves. 

A large tin field of China is an area about 350 miles long and 200 

miles wide covering the southern parts of the provinces of l{iangsi 

and Hunan, eastern l{ wangsi, and northern l{ wangtung (fig. 1). The 

major deposits and reserves, however, lie in the Kochiu district of 

Yunnan Province. According to Hsieh (1963, p. 374), traces of cassiterite have been found recently in Heilungkiang Province. 1\iost of the 

400 known occurrences of tin in China are, however, in the longknown tin regions. Meng (1937, p. 441) pointed out that the main tin 

deposits of China can be correlated with two structural trends which he 

called the Nanling and Coastal zones (fig. 6) . The Nanling zone parallels the east-west trend of the Nanling Ranges ; the Coastal zone 

parallels the coastline from Hainan Island northeastward. Of these 

two stanniferous zones, the Nanling is the more important. Hsieh 

(1963, p. 374) considered the Yunnan (I{ochiu) deposits to be related 

to the deposits of Southeast Asia. 

The bedrock in the l{ochiu region consists of a series of Precambrian 

gneisses and schists which are overlain unconformably by feebly metanlorphosed slates, phyllites, quartzites, and schists, also of Precambrian 

age. These in turn are overlain by lhnestones that range in age from 
CHINA 45 

110" 115" 

25" 

20" 

0 200 400 MILES 

0 200 400 KILOMETERS 

EXPLANATION ----Sn ---- -------Sn--------

N anling zone Coastal zone 

FIGuRE 6.-Tin deposits in the Nanling and Coastal zones, China. (From Meng, 

1937, fig.l.) 

Devonian to Triassic. In Kochiu valley, widespread karst topography 

is developed on Triassic limestones, which are the host rocks of most of 

the tin deposits. The geologic structure of this part of Yunnan consists 

of east-trending and northeast-trending n1ountain ranges ( Yunnanese 

A.rc), two of which come together at Iiochiu (Meng and others, 1937, 

p. 431). A.t the l{ochiu tinfields, two systems of faults striking northnortheast and northwest cross the ranges, and Meng, Chern, and Ho 

(1937) pointed out that the tin district occurs at this structural nexus. 

Biotite granite has been intruded into the limestone, which is host to 

most of the deposits; these deposits are concentrated along anticlines 

or above granite cupolas, the most important being those along the anticlines. Many granites of the area contain tourmaline and (or) topaz. 

The numerous tin deposits consist of replacement veins and pipes 

in limestone. Locally the veins reach down\vard into the underlying 

granite, where wolframite becomes important. The ore minerals consist of cassiterite, molybdenite, wolframite, bismuthinite, arsenopyrite, 

pyrite, hematite, magnetite, galena, and sphalerite. Gangue minerals are quartz, tourmaline, topaz, lithimn n1icas, fluorite, and, in 

contact deposits, diverse calc-siliciate minerals. ~{any veins have a 

marked zonation; some mines, originally opened as silver n1ines, be-
46 TIN RESOURCES OF THE WORLD 

came tin mines at depth (Meng, 1937, p. 444). The l{ochiu area is 

believed to supply 70-80 percent of Chinese tin production and to 

contain 80 percent of China's reserves. 

Tin deposits occur at irregular intervals along the Nanling zone, 

which extends eastward in l{wangsi Province, then swings northward into southern Hunan, thence eastward into Kiangsi Province, almost to the coast north of Hongkong (fig. '6). 

Both lode and placer deposits have been worked in the Hochih area 

( Sen-Shing, 1928). Lodes occur in limestone, quartzites, and biotite 

granite. Cassiterite occurs in quartz veins that also contain pyrite, 

wolframite, stibnite, and bismuthinite. The placers are both eluvial 

and alluvial. Sen-Shing noted that 10,000 miners worked in the district in 1919, and that 180 tons of metallic tin per year were produced 

by extremely crude mining methods. 

Pipe deposits in the Hohsien area are similar to those in southern 

Hunan; most consist of pipes in altered limestone near biotite or biotite-hornblende granite (\V ang and Hsiung, 1935, p. 82). Most pipes 

do not exceed a few dozen feet in width. Ore minerals consist of cassiterite, arsenopyrite, chalcopyrite, stannite, bornite, sphalerite, enargite, 

tennantite, pyrite, and pyrrhotite. Pipes and veins in granite are 

rare and contain notable amounts of wolfra1nite. Most of the current 

production comes from placer deposits associated with the lode deposits, and rich alluvial pockets in limestone are worked. 

In southwestern IGangsi Province, tungsten becomes important and 

1nost lode deposits are worked for both tin and tungsten. The lodes are 

fissure-filling quartz veins that occur in biotite granite as well as in the 

surrounding metamorphic rocks. The ore minerals include cassiterite, 

wolframite, arsenopyrite, sphalerite, chalcopyrite, molybdenite, bismuthinite, scheelite, and galena. 

The tin deposits of the Coastal zone (figs. 1, 6) are associated with 

biotite granites t!hat are widely distributed in the coastal area from 

Hainan Island to J'apan. Hsieh (1963, p. 377) stated that a common 

lode type consists of cassiterite-quartz-chlorite veins in both biotite 

granite and surrounding rocks. The cassiterite is associated with pyrite, 

pyrrhotite, chalcopyrite, sphalerite, arsenopyrite, and some wolframite. Veins in limestone tend to contain more varied and richer sulfide 

minerals, and, throughout the region, cassiterite predominates over 

wolframite. The belt of deposits is correlwtive with a late Mesozoic 

tectonic deformation and widespread intrusion of biotite granite that 

can be considered a continuation of the Malay Peninsula zone. 

Rese:rves.-The recent drop in Chinese tin production is probably 

caused by the unavailability of modern machinery 1to replace wornout 

equipment rather than by the depletion of deposits. Ahlfeld (1958, p. 
U.S.S.R. 47 

39) gave reserve figures for 1946-47 that range from 652,000 tons to 

1,873,330 tons of tin metal. The Paley Commission suggested 1.5 million ~ong tons of tin metal for Chinese reserves. Because of the great 

extent of stanniferous regions in China, the 1writer is inclined toward 

an optimistic view of Chinese reserves; known reserves are assumed to 

be 1.5 million long tons of tin, of which 500,000 tons is classed a;s 

measured plus indicated, and 1 million tons as inferred. 

Resources in submarginal and undiscovered deposits must be large. 

For this report, total resources 'are estimated to be at least twice the 

known reserves, or 3 million iong tons of tin (table 3) . This e8timate 

is proba;bly conservative. 

U.S.S.R. 

The information on tin resources of the U.S.S.R. is incomplete, 

and has been for many years. The availruble recent information indicates that new deposits have been discovered, whioh, in conjunction 

with the older ones, have at least maintained large reserves. 

Numerous technical papers dealing with tin deposits of the Soviet 

Union have been published since 1945, leading to the inference that deposits are widespread. Important new deposits have been found, principally in Siberia. Recent ~literature mentions deposits on the Kolyma 

River which are similar geologically to those on the Alaska side of tJhe 

Bering Strait (Gracheva and Zolotova, 1960). The Mining Journal 

(1960, p. 517) noted that a large tin concentrator plant was opened in 

1960 near the Bering Strait. 

'!1he area east of the Urals is favorable for the occurrence of large 

tin deposits. Major orogenic belts have been extensively intruded by 

granite; tin deposits are known in most belts. The known producing 

deposits include both lodes and placers, the lode mines being more important. The fact that Russia no longer imports large amounts of tin 

indicates that needs are met either from stockpiled tin, or hy current 

production. Robertson (1965, p. 100) suggested consumption is still 

rising relative to production. 

'Tihe major known tin-producing regions are located in figure 1 as 

accurately as descriptions allow. Large production is derived from deposits in the Yakut Republic (Ege-Khaya-Deputatskiy region, fig.1), 

and from deposits in the Anadyr Mountains, an east-trending mountain range near the Arctic coastline in easternmost Siberia (Iul'tin and 

l(rasnoarmeyskoye areas, fig. 1). The Anadyr :belt continues across the 

Bering Strait, and ·the Alaskan deposits on Seward Peninsula are 

probably along the continuation of this belt. The Ege-Klraya mine in 

Y akut Republic was opened in 1940, 'and other mines have been opened 

since 1953, including a placer mine at Deputatskiy. A large concentrating plant was installed at Iul'tin in 1954 (Mining Jour. 1960). 
48 TIN RESOURCES OF THE WORLD 

Several new deposits were developed during and after World War II 

in the Magadan region of Siberia (Ust'-Omchug, Batugychag, and 

Galimyy areas, fig. 1) along a mountainous belt trending northeast. 

Many granites are intruded along the range, and very persistent faults 

:follow the range. 

New deposits have been developed since World War II in an important district near Vladivostok on the Sea of Japan (LifudzinKhrustal'nyy fig. 1 and the Yaroshavsky and Karalerovo areas. These 

deposits are alined 'along a northeast-striking tectonic belt inrtruded 

by granitic rocks and cut by extremely numerous and persistent faults 

whioh extend landward from the Sea of Okhotsk. 

New deposits have been opened since World War II in the older, 

esta;blished mining districts of Transbaikal and Kazakstan, which lie 

along east-trending ranges along the Mongolian border. Other deposits 

have been opened along the Kolyma River (Khingansk, fig. 1). These 

deposits are described as consisting of cassiterite associated witJh tourmruline, topaz, and numerous sulfide minerals in typical greisens related to silicic intrusive rocks of Late Jurassic and Cretaceous age 

( Gracheva and Zolotova, 1960) . 

No attempt is made here to describe the individual deposits in 

Siberia. The abundant literature (mostly in Russian) indicates that 

most are high-temperature deposits associated with granite intrusive 

rocks. Cassiterite is the main ore mineral. As elsewhere in the world, 

numerous sulfide minerals, including arsenopyrite, pyrite, galena, 

sphalerite, pyrrhotite, and silver-bearing sulfosalts, are associated with 

the cassiterite. Pegmatites containing cassiterite and beryl are also 

known. For brief descriptions of the main deposits known prior to 

1952, see Ridge ( 1953). 

Reserves.-Most writers have been hesitant to assign figures toRussian tin reserves, principally because official Russian figures are not 

available. An estimate of 500,000 tons has been considered reasonable, 

but this figure seems to have persisted unchanged since 1953, and, in 

this writer's opinion, does not realistically consider either the large 

number of producing mines opened since that date, or the tremendous 

extent of geologically favorable areas in which tin deposits are known 

to occur. 

The writer takes a more optimis6c view of Russian tin reserves 

(table 3) and assumes that proved reserves (measured and indicated 

category) amount to at least 10 years' production at the 1965 level 

(about 21,000 long tons, according to U.S. Bur. Mines, 1966), and that 

inferred reserves in known deposits equal twice the known reserves. 

Hence, measured reserves are assumed to be 210,000 long tons of tin, 
REFERENCES 49 

and inferred reserves to be 420,000 long tons, probably a conservative 

estimate. 

Resources of submarginal grade, or in undiscovered deposits, are 

believed to be much larger. For the purpose of this report, resources 

are assumed to be at least twice the known reserves, or 1,260,000 long 

tons of tin. This is probably a conservation figure, for it is about equal 

to that for reserves of the same category in Thailand, and the Russian 

stanniferous areas are certainly much larger. However, the greater 

extent of the Russian deposits is in part compensated for by the severe 

Arctic climate, which is unfavorable for the formation of large and 

rich placers. 

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50 TIN RESOURCES OF THE WORLD 

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REFERENCES 51 

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52 T~ RESOURCES OF THE VVORLD 

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INDEX 

[Italic page numbers indicate major references] 

A Page Page 

Abstract. •••• ___ ------------------___________ 1 Kaksa _________________ -------------------- ___ 7, 25 

Africa __ ------ _____ ---------------_--------___ 91 Kamativi tin belt, Southern Rhodesia........ 37 

Alaska. _____ ------------_____________________ 11 

Algeria_-------------------------------_______ 38 L 

Alluvial placers, origin_______________________ 7 Laos_---------------------------------------- 90 

Asia ____ ------- __ ------------------ ____ ------- 23 Liberia.--------···--------------------....... 38 

Australia_____________________________________ 98 Lode deposits, Aberfoyle mine, Tasmania____ 42 

Appalachian region, United States ••• -·-· 12 

B Ardlethan, New South Wales, Australia.. 41 

Argentina _______ ------------------------- 17 

Beryllium, in tin district_____________________ 10 Beatrice mine, Malaysia__________________ 27 

Black Mountain, Alaska______________________ 10 beryllium________________________________ 6 

Bolivia·-------------------------------··--··· 6,14 Black Hills, S. Dak______________________ 12 

Burma._ •• ____________ •••• ----------·---_____ 29 Bolivia, silver_-------------- ____ •• ------· 14 

Burundi. ______ ••• __________ •.•• ----·-------· 37 California. ______ ---------------- __ ------- 13 

Bush veld Complex, Republic of South Africa. 35 Cornwall, England_______________________ 19 

Cupola area, Alaska______________________ 11 

C Dalcoath mine, Cornwall, England_______ 3,19 

Cameroon____________________________________ 38 Dundas-Renison Bell area, Tasmania____ 43 

Canada_------------------------------------- 13 Erzgebirge, East Germany and CzechoCavaet process. _____ .________________________ 29 slovakia .• ____ ------- ___ ---------- 22 

Chiua·--------------------------------------- 44 Gunong Bakau mines, Malaysia__________ 27 

Clarke oftin·--------------------------------- 2 Hochih area, China_______________________ 46 

Columbite___________________________________ 32 Hohsieu area, China______________________ 46 

Congo, Democratic Republic of the_--------- 38 Honshu Island, Japan____________________ 31 

Contact-metamorphic deposits_-------------- 6 Ipamera deposit, BraziL_________________ 18 

Cordillera Real, Bolivia______________________ 14 Kaborishoke deposit, Tanganyika________ 37 

Czechoslovakia_______________________________ 22 Kamativi mines, Southern Rhodesia_____ 36 

Kinta Valley, Malaysia___________________ 26 

D Klappa Kampit, Billiton Island, Indonesia··--------------------------· 25 Damara Complex, South-West Africa_________ 36 Kochiu area, China_______________________ 44 

Disseminated deposits________________________ 6 Kolyma River, U.S.S.R.................. 47 

La Fabulosa mine, Bolivia............... 16 

E Labat pipe, Malaysia_____________________ 27 Eluvial placers, origin _______________________ _ Lifudzin area, U.S.S.R.__________________ 48 

Europe_--------------·-- __________ ------_____ 19 Llallagua, Bolivia________________________ 6,14 

England._ •••••• _--------------______________ 19 Lost River area, Alaska.----------------- 11 

Magadan area, U.S.S.R__________________ 48 

F Maniema province, Congo________________ 33 

Fossil placers ••••• ·-·------------------------- 8 Manono pegmatite, Congo •• ______________ 3 

France. _____ --------------___________________ 21 Katanga, Congo______________________ 34 

Fumerole deposits____________________________ 6 Mawchi mine, Burma____________________ 29 

Mergui Islands, Burma___________________ 30 

G Mexico __________ ------------------·-·---- 13 

Mount Bischoff mine, Tasmania__________ 43 

German Democratic Republic (East Ger- Mount Cleveland area, Tasmania_________ 43 

many)_-------------------------- 22 Mount Heemskirk-Zeehan area, TasGranite, associated with tin deposits_-------- 2 mania_._------------------------- 43 

Mount Pleasant, New Brunswick, CanI,J,K ada ________ ----------------------- 13 

Indonesia_ •••• ·····---------···········------ 29 Nam Pha Tene mine, Laos.______________ 30 

International Tin Council report.----------·· 8 New England district, New South Wales, 

Australia •••• ___ ••• ---- ____ ------. 40 

Japan........................................ 31 New Mexico______________________________ 12 

53 
54 INDEX 

Page Page 

Lode deposits-Continued 

Oploca-Siete Suyos mine, Bolivia •••••••• 

Oruro, Bolivia .••• ____ -------------------- Pahang mines, Malaysia _________________ _ 

Phuket Island, Thailand ________________ _ 

Pia Oak Mountains, Vietnam ____________ _ 

PortugaL ... _________ • _____ • _____________ _ 

Potgietersrtus fields, Republic of South 

16 

16 

27 

28 

30 

21 

Africa._----- ____ ----------------- 35 

Potosi, Bolivia____________________________ 16 

Queensland, Australia____________________ 38 

Rooiberg, Republic of South Africa_______ 35 

silver _______________________________ 14,22, 45,48 

South-West Africa________________________ 36 

Spain ____________ ------ ________ ----------- 21 

Steipelmann mine, South-West Africa.... 36 

Storey's Creek mine, Tasmania___________ 42 

Sullivan mine, British Columbia, Canada. 13 

tantalum ________________________ 32, 34, 37,38, 42 

Tavoy district, Burma___________________ 30 

Territory of Rondonia, BraziL.__________ 18 

Trans-Baikal area, U.S.S.R______________ 48 

types_------------------------------------ 2, 3 

Unica mine, Bolivia______________________ 16 

uranium.------------------------------ 22, 30,41 

Victoria, Australia________________________ 41 

Vulcan pipe, Australia____________________ 40 

Watson's Show, Queensland, Australia._. 40 

Yak:ut Republic, U.S.S.R................ 47 

Yala province, Thailand .•• _------------ 28 

M 

Malayaite, possible new source of tin _________ _ 10 

Placer deposits-Continued 

Jos Plateau, Nigeria______________________ 32 

Kinta Valley, Malaysia___________________ 26 

likely location____________________________ 7 

Manley Hot Springs, Alaska______________ 12 

Moolyella area, Western Australia......... 42 

New Mexico ______________ ---------------- 12 

occurrence •. ___ ---- ___________ ----- ______ • 6 

Phuket Island, Thailand_________________ 28 

PortugaL •••. ____ ------------------------- 21 

Ranong, Thailand________________________ 28 

relation to Pleistocene sea levels ________ 7, 23,25 

Ria Oak area, Vietnam___________________ 31 

Selangor River, Malaysia_________________ 27 

Spain ________ ------ ____ ------ ____ --------- 21 

Stan thorpe district, Queensland, Australia. 40 

Tasmania. __________________ ------------- 42 

Territory of Rondonia, Brazil____________ 18 

Tozimoran Creek, Alaska________________ 10 

types ________ ----------------------------- 2,6 

Pneumatolytic-hydrothermal deposits________ 3 

PortugaL ..••• _________ -------- ____ ----------- ~1 

R 

References cited _________ ------------------___ 49 

Reserves and resources, Argentina____________ 17 

Reserves and resources, Australia_____________ 43 

Reserves and resources, Bolivia ________ ,_______ 17 

Reserves and resources, BraziL _________ ----- 19 

Reserves and resources, Burma_______________ 30 

Reserves and resources, Canada______________ 13 

Reserves and resources, China ________________ 10,47 

Reserves and resources, Democratic Republic of the Congo _____________________ _ 34 

Malaysia ___________________ ---------------- __ _ ~6 Reserves and resources, East Germany and 

MalL •... ____ --------------------.------------ 38 Czechoslovakia __________________ _ 

Marine placers _________ ------ __ --------------_ 8 Reserves and resources, England (Cornwall 

Mauritania __________________ ----------------- 38 district) ___ -----------------------

Metals associated with tin____________________ ~. 21 Reserves and resources, France ______________ _ 

Mexico .•• _.------- ____ --------------------·-· 13 Reserves and resources, Indonesia ___________ _ 

Morocco •• ____________________________________ 38 Reserves and resources, Japan _______________ _ 

Mount Tallenbung-Albury tin belt, Australia. 41 Reserves and resources, Laos ________________ _ 

Reserves and resources, Malaysia ____________ _ 

N,O Reserves and resources, Mexico ______________ _ 

New Zealand. ___________ • ___________________ _ 44 Reserves and resources, Nigeria _____________ _ 

Niger----------------------------------------- 38 Reserves and resources, PortugaL ___________ _ 

Nigeria .•• ___________________________________ • as Reserves and resources, Republic of South 

22 

19 

22 

25 

31 

31 

28 

14 

33 

21 

Africa _________ ------------------- 36 

Occurrence of tin deposits ___________________ _ S Reserves and resources, South-West Africa.... 36 

Reserves and resources, Southern Rhodesia... 37 

p Reserves and resources, Spain________________ 21 

Pegmatite deposits___________________________ 3 Reserves and resources, Thailand_____________ 29 

Placer deposits, Amapa, BraziL._____________ 18 Reserves and resources, United States........ 11 

Bangka Island, Indonesia _________________ 23,25 Reserves and resources, U.S.S.R ••••••••••••• 10,48 

Billiton Island, Indonesia_________________ 25 Reserves and resources, Vietnam_____________ 31 

Buck Creek, Alaska______________________ 11 Reserves and resources, world________________ 8 

Cape Creek, Alaska______________________ 11 Residual placers, origin .. -------------------- 6 columbite-tantalite ____________________ 26, 32,41 Rwanda .• ______ ----------------------------- 37 

Cooktown district, Qaeensland, Australia. 40 

Fraser Hills, Malaysia_____________________ 27 S 

Gorman, Calif.___________________________ 10 Sierra Leone._-------------------------------

Greenbushes, Western Australia .•• ------- 41 South Africa, Republic oL _ ------------------

Herberton area, Queensland, Australia.... 40 South America.------------------------------

Hochih area, China_______________________ 46 South-West Africa .•. -------------------------

Hohsien area, China______________________ 46 Southeast Asia tin belt, geologic factors ______ _ 

Huanuni, Bolivia_________________________ 16 Southern Rhodesia--------------------------- Indonesia ________________ •. __ .____________ ~3 Spain ___________________ • ____________________ _ 

38 

35 

14 

36 

23 

36 

S1 
INDEX 

Subvolcanlc deposits.------------------------

Swaziland ••. __ ••••. _--· •• _ •••.•• _------- ____ _ 

T 

Tanganyika (Tanzania) __ ----------------- __ _ Thailand._------·-·-·---•• __________________ _ 

Tungsten._-----·------------------------- __ _ 

u 

Uganda.·------------------------------------

United Arab Republic.----------------------

Page 

6 United States, conterminous ••••••••••••••••• 

38 U.S.S.R •• ·----------------·--·--------------

v,w 

Vietnam._. _____ •. ---. ____ ------------••••• -- 37 Wankle tin belt, Southern Rhodesia _________ _ 

!!8 World reserves·------------------------------- 29 

z 

Zambia._------------------------------------

37 Zonation of deposits·-------------------------

38 Cornwall, England •.. --------------------

U.S. GOVERNMENT PRINTING OFFICE: 1989 

55 

Page 

11 

1,7 

30 

37 

8 

38 

3 

19