Geological structure and oil and gas potential of equatorial guinea. Conditions for the formation of bauxite deposits in the bokeh-kindia-tugue triangle, geochemical heterogeneity of bauxite deposits and optimization of exploration network parameters (Guinea)

Guinea (Guinee), the People's Revolutionary Republic of Guinea (Republique Populaire et Revolutionnaire de Guinee), is a state in Western. It borders in the north with Senegal, in the north and northeast with Mali, in the east with the Ivory Coast, in the south with, in the southwest with Sierra Leone, in the northwest with Guinea-Bissau. Washed in the west. The area is 245.8 thousand km 2. Population 6.4 million people (1980, est.). It is divided into 29 administrative districts. The capital is Conakry. The official language is French. The monetary unit is forces. Guinea is a member of the Organization of African Unity (OAE), is a member of the Economic Community of West African Countries (1975).

General characteristics of the economy. Guinea's GDP is $800 million (at current prices, 1978). In its structure, agriculture accounts for 21%, industry for 25% (including 18% for mining). In the structure of the fuel and energy balance, the share is 98%, hydropower 2% (1979). The total length of roads is 30.0 thousand km, the length of railways is 1.1 thousand km (1980). Major seaports - Conakry, Kamsar.

Nature. In the relief of Guinea, the following stand out: the Atlantic lowland (height up to 70 m), the stepped Futa-Jallon plateau (height 150-1300 m, maximum - 1538 m), the North Guinea highlands (average height about 800 m, maximum - 1752 m) and plains Upper Niger (height 300-400 m). The climate is equatorial-monsoon, hot, summer-humid. The average temperature of the warmest month (March or April) is 27-30°С, the coldest (August) 24-26°С. The annual amount of precipitation on the coast is over 4000 mm, in other areas 1200-1500 mm. The most significant rivers are: Niger, Cogon, Nunez, Fatala, Konkure (the mouths of some rivers are navigable). Forested vegetation predominates, the southern slope of the North Guinea Upland is covered with moist equatorial dense forests (about 4% of the territory), in the west of the country - mangroves.

The main gold reserves associated with quartz veins have been explored in the eastern part of Guinea and are small (deposits; Tinkiso, reserves 24 tons, Au content 0.4 g / m 3; Sigirini-Ko, 1 t, 17.4 g / m 3) . Diamond deposits are located in the southeast of the country in the basins of the Baule, Macon, and Diani rivers. They are confined to kimberlite pipes (content 0.6-4.5 carats/m3), dikes and small ones (0.2-4.8 carats/m3). Placers of ilmenite, zircon, rutile, and monazite (Verga deposit, etc.) are concentrated along the ocean coast in deposits of the first marine terrace, sea spits, and beaches. The width of individual placers is 250-300 m, the length is about 1.5 km. The average total content of valuable minerals is 40-60 kg/m 3 . The reserves of individual placers are estimated at 20-76 thousand tons (for example, at the Verga deposit, the total reserves of ilmenite are 60 thousand tons, zircon 10 thousand tons, rutile 5 thousand tons). Small deposits are known (Kurunde, Amaraya, Lebekere) of limestone, as well as beryl and kaolin (near the city of Kaya), graphite schists (near the village of Lola).

Mining. General characteristics. The mining industry is one of the leading industries, accounting for 60% of the employed in industry, 87% of the gross industrial output. (The location of the main mining facilities is shown on the map.) The basis of the mining industry in Guinea is the extraction of bauxite (Table 2).

There are 3 bauxite mining companies in the country: "Compagnie des Bauxites de Guinée" (49% of the shares are owned by the state), the mixed company "Friguia" (49% of the shares are owned by the state), "Office des Bauxites de Kindia" (entirely owned by the state). Mining products provide 97% of the value of exports. The country mainly exports bauxite (over 10 million tons, of which 2.9 million tons to the USA, 0.85 million tons to Canada, 4.1 million tons to socialist countries) and alumina (0.6 million tons). ), imports oil products (283 thousand tons), a small amount of coal, building materials (1978). The main trading partners of Guinea are the EEC countries,.

bauxite mining industry. In terms of bauxite mining, Guinea ranks second (17%), and in their exports, first place (30%) among industrialized capitalist and developing countries (1979). The export of bauxite in 1978 compared with 1970 (811 thousand tons) increased more than 10 times (10.3 million tons). Bauxite deposits are being developed using. The deposits are stratal in shape (layer thickness is 6-12 m), overburden thickness is on average 0.5 m. In the Fria Sodiore area (Cimbo deposit), development has been carried out since 1959. The production capacity of the quarry is over 2 million tons of ore per year. Processing since 1960 - at the alumina refinery in Fria, extraction of alumina 85-90% (1978), production of alumina over 600 thousand tons (1980). Export by rail (length 145 km) and through the port of Conakry. The deposit in Sangaredi in the Boke-Gaval region has been developed since 1973. The production capacity of the quarry is 9 million tons. By rail (length 138 km), ore is delivered to the port of Kamsar and then transported by ore carriers with a displacement of 45-60 thousand tons. Kindia (Debele deposit) began in the late 70s by open pit mining. The quarry was built with the participation of Soviet specialists. The production capacity of the open pit is 2.5 million tons of ore per year. Ore is transported by railroad (length 98 km) to the port of Conakry. To develop new bauxite deposits, 3 open-pit mining enterprises have been established: at the deposits of the Tuge region (design capacity is 8 million tons of ore per year), at the Aekoe deposit in the Boke-Gaval region (9 million tons of ore per year), where it is planned to build an alumina a plant with a capacity of 1.2 million tons and an aluminum plant, and at the deposits of the Dabola region (6.5 million tons of ore per year), on the basis of bauxite of which it is planned to build an alumina plant. The increase in alumina production is constrained by the difficulties with electricity, which will probably be overcome with the commissioning of a hydroelectric power plant on the Konkur River.

Extraction of other minerals. Iron ore mining in Guinea began in 1953 and until 1967 the Kalum deposit was developed. The development of large deposits of iron ore in the southeast in the cities of Nimba and Simandu is planned. The full development of these deposits is planned after the construction of railways from the city of Conakry to the border with Liberia.

Diamond mining in Guinea began in the 1930s and was carried out by private companies and prospectors. In the early 1960s, diamond mining enterprises were nationalized; in the mid-1970s, industrial production was suspended due to the depletion of reserves and the lack of new enrichment equipment. It is planned to resume.

Gold mining in Guinea has been carried out for a long time in an artisanal way. At the beginning of the 20th century, European entrepreneurs repeatedly tried to develop dredges (for example, 218 kg of gold was mined on the Tinkiso River in 1909-14). However, due to the insignificance of the reserves, commercial production was stopped.

Geological Survey. Personnel training. The organization of mining and geological work in Guinea is carried out by the Ministry of Mining and Geology. Mining and geological personnel are trained at the Mining and Geological Faculty (in the city of Boke) of the Polytechnic Institute in the city of Conakry.

bokeh is the largest in the world lateritic bauxite deposit. Located 135 km from the Atlantic coast in the northwestern part of Guinea. The bauxite deposits of the deposit are confined to hilly uplands (bovals), bordered by river valleys up to 100 m deep. Bauxite laterites were formed as a result of intensive weathering of Paleozoic graptolitic shales during the Paleogene-Neogene period in the conditions of a poorly dissected peneplanated plain. The thickness of the lateritic weathering crust is 10–15 m. Bauxites come to the surface and, as a rule, are overlain by ferruginous laterites (cuirass).
More than 100 bauxite deposits have been discovered at the deposit, elongated in the form of a northeast strike zone 130 km long and 30-60 km wide, with an area of over 3,500 square kilometers. According to the conditions of formation and occurrence, as well as structural and textural features, two types of bauxites are noted in the deposit: eluvial and deluvial. Genetically and spatially, they are closely related and pass into each other.
Eluvial bauxite are represented by dense stony ores with a massive, banded and slate texture. They usually form the upper part of the lateritic weathering crust. Loose and earthy varieties of bauxites are sometimes found in the lower part of the bauxite-bearing strata.
Deluvial bauxites are angular or slightly rounded fragments of eluvial bauxites ranging in size from several to 15 cm, cemented by pelitic, silty or psammite material formed due to the destruction of eluvial bauxites.

The main ore-forming minerals of bauxites are gibbsite and hematite with an admixture of boehmite (up to 10%) and kaolinite (2-3%) and titanium minerals in the upper parts of the deposit. The color of bauxites is usually light pink, brown or reddish brown, the texture is breccia, conglomerate or porous. It is characterized by a high content of alumina (51-62%), a low content of silica (1-2%), iron oxides (2-6%) and titanium (2-3%). With a cut-off grade of alumina of 50%, the total reserves of the deposit available for open-pit mining are about 3 billion tons.

V.V.Avdonin, V.E.Boitsov, V.M.Grigoriev and others. Deposits of metallic minerals, M, Academic project, 2005

Guinea

(Guinee), People's Revolutionary Republic of Guinea (Republique Populaire et Revolutionnaire de Guinee), - state in the West. Africa. It borders on C. with Senegal, on C. and C.-B. c Mali, to B. c Ivory Coast, to S. c Liberia, to S.-W. co Sierra Leone, in N.-W. c Guinea-Bissau. Ha Z. is washed by the Atlantic. OK. Pl. 245.8 thousand km 2. Hac. 6.4 million people (1980, ). It is divided into 29 administrative districts. The capital is Konakry. Official language is French. Monetary unit - forces. G. is included in the Org-tion afr. Unity (OAE), is a member of the Economic. Community of West African Countries (1975).
General characteristics of the farm. GDP in G. is 800 million dollars (in current prices, 1978). In its structure to share c. x-va accounts for 21%, industry-sti 25% (including the share of mining 18%). In the structure of fuel and energy. balance the share of oil 98%, hydropower 2% (1979). The total length of roads is 30.0 thousand km, the length of the railway. d. 1.1 thousand km (1980). Large sea. ports - Konakri, Kamsar. O. A. Lytkina.
Nature. In the relief of Georgia, the following stand out: Atlantic (up to 70 m high), Futa-Jallon stepped plateau (150-1300 m high, maximum - 1538 m), North Guinean (cp. height about 800 m, maximum - 1752 m ) and the plains of the Upper Niger (height 300-400 m). The climate is equatorial-monsoon, hot, summer-humid. cp. the temperature of the warmest month (March or April) 27-30°C, the coldest (August) 24-26°C. The annual amount of precipitation on the coast of St. 4000 mm, in other p-ns 1200-1500 mm. Most importantly, the rivers: Neger, Kogon, Nunez, Fatala, Konkure (the mouths of some rivers are navigable). Predominant forested, south. The North Guinean Upland is covered with moist equatorial dense forests (about 4% of the territory), in the west of the country - mangroves.
Geological structure. G. is located on the west of the African platform. Ha B., Y.-B. and Yu.-Z. stands out Leono-Liberian, in the center. parts of the country - south. the Taudenny syneclise and the Rockel trough, in the west - West Guinea. The Leono-Liberian shield is composed of Archean formations (gneisses, quartzites, metamorphosed ultrabasic rocks, granites) and lower. Proterozoic (, gneisses, quartzites, calcareous rocks, greywackes, volcanics and granites breaking through them). Archean ferruginous quartzites are associated with large metamorphogenic deposits of Zhel. ores South the side of the Taudenni syneclise is formed by gently sloping Proterozoic carbonate-terrigenous strata, limestone deposits are confined to Crimea. The Rockel trough is filled with Proterozoic sediments and effusives folded into carbonate-terrigenous sediments; there are metamorphic rocks (shales, quartzites), among which hematite ores are present; dolerites are found. The West Guinean syneclise is composed of gently sloping Ordovician, Silurian, and Devonian rocks (sandstones, siltstones, mudstones). Among the Ordovician sandstones, manifestations of manganese are localized, in the Devonian and Silurian rocks - small deposits of sedimentary micro-oolitic galls. ores Cenozoic (, loams, and pebbles) are developed on the Atlantic. coast (mor. terraces, beaches, spits) and numerous valleys. rec. K coastal-sea. Small zircon, ilmenite, rutile, monazite, kaolin deposits, manifestations of lignites and phosphorites are confined to the formations, placers of gold and diamonds are associated with the alluvium of river terraces. Primary (vein) gold deposits are associated with Early Proterozoic magmatism, kimberlite dikes and pipes are associated with Late Mesozoic magmatism, some with industrial. diamond content. Dunites, gabbro-norites, dolerites of Mesozoic, less often Paleozoic age are widely developed, forming massifs, sills and dikes. Meso-Cenozoic weatherings with large deposits of bauxite, zhel. ores, as well as ores of nickel and chromium. C. S. Prokofiev.
Hydrogeology. Groundwater in the territory G. have a limited distribution. Main groundwater reserves are associated with alluvium in the valleys of large pp. Heger, Tomine and others (specific flow rates of wells 1-2 l/s, sometimes up to 4 l/s) or with fractured rocks lower. parts of weathering crusts in low relief areas (0.1-1.5 l/s). B bedrocks in main. insignificant, except for the Ordovician sandstones penetrated by wells with specific flow rates of 6-7 l/s. Groundwater - ultra-fresh, with salinity up to 0.3 g/l, bicarbonate, mixed in cationic composition. Groundwater is discharged only during wet seasons. During dry periods, the flow of rivers is sharply reduced, most of the sources disappear, which creates difficulties in water supply. R. I. Tkachenko.
Minerals. G. is rich in bauxite and iron. ores (Table 1).

There are small deposits of gold, diamonds, chromium ores, nickel, ilmenite, zircon, rutile, monazite, beryl, limestone and graphite schists.
Main railway station pyd, associated with Archean ferruginous quartzites, are concentrated in the regions of the Nemba ranges (reserves 2 billion tons, iron content 60%) and Simandu (7 billion tons, 60%). B ref. parts of G. small deposits zhel. (hematite) ores are known south of the city of Forekarya and in the basin. p. Tomine (microolitic ores). On the Calum peninsula, the railway deposit ores (explored reserves of 1476 million tons, Fe 51.5%) are confined to the lateritic weathering crust along the rocks of ultrabasic and basic compositions; there are also small deposits of nickel and chromium ores.
In terms of bauxite reserves, Georgia occupies the first place among the industrially developed capitalist countries. and developing countries (approx. 40% of reserves, 1980). The largest deposits are concentrated in the center. and app. parts of the country in bauxite-bearing districts: Boke-Gaval (main deposits: Sintiuru, explored reserves of 501 million tons, Al 2 O 3 content 46.6%; Dian-Dian, 300 million tons, over 40% ; Dyubula-Tagyurata, 431 million tons, 40%); Fria Sodiore (Manga, 507 Mt, 41.3%; Sodiore, 268 Mt, 49.6%); Dongel-Sigon (Ope-Liti, 250 million tons, 47%); Bantiniel (Kasagi, 154 million tons, 46.3%); Dabola (Tekulu-Deyal, 217 million tons, 40-45%); Tuge (Pantiolo, 390 Mt, 40-45%; Fokete, 391 Mt, 40-45%); Debele - India (Debele, 44.4 million tons, over 40%). Bauxite deposits are also known in the B. of the country, near xp. Heandan-Banye. By genesis they are subdivided into lateritic and polygenic (laterite-sedimentary); main ore - gibbsite.
Main gold reserves confined to quartz veins have been explored in the east. parts of G. and are small (mines; Tenkiso, reserves 24 tons, Au content 0.4 g / m 3; Sigirini-Ko, 1 t, 17.4 g / m 3). Diamond mines are located in the south-east of the country in the basins of p. Baule, Macona, Diani. They are confined to kimberlite pipes (content 0.6-4.5 ct/m 3), dikes and small alluvial placers (0.2-4.8 ct/m 3). Placers of ilmenite, zircon, rutile, and monazite (the Verga deposit and others) are concentrated along the ocean coast in the deposits of the first sea. terraces, sea braids and beaches. Width placers 250-300 m, length approx. 1.5 km. cp. the total content of valuable minerals is 40-60 kg/m 3 . Stocks placers are estimated at 20-76 thousand tons (for example, at the Verga deposit, the total reserves of ilmenite are 60 thousand tons, zircon 10 thousand tons, rutile 5 thousand tons). There are small deposits (Kurunde, Amaraya, Lebekere) of limestone, as well as beryl and kaolin (near the city of Kaya), graphite schists (near the village of Lola). C. S. Prokofiev.
Mining. General characteristic. Mining prom-st - one of the leading industries, which accounts for 60% of those employed in prom-sti, 87% of the gross volume of prom. products. (The location of the main mining facilities is shown on the map.) G.'s industry is the extraction of bauxites (Table 2).

There are 3 bauxite dobs operating in the country. firms: "Compagnie des Bauxites de Guinee" (49% of the shares are owned by the state), the mixed company "Friguia" (49% of the shares are owned by the state), "Office des Bauxites de Kindia" (wholly owned by the state). Mining products. prom-sti provides 97% of the value of exports. Main country exports bauxite (more than 10 million tons, of which 2.9 million tons to the USA, 0.85 million tons to Canada, 4.1 million tons to socialist countries) and (0.6 million tons), imports oil products (283 thousand tons), a small amount of coal, builds. materials (1978). Ch. G.'s trading partners are the EEC countries, the USA, and the CCCP. O. A. Lytkina, S. S. Prokofiev.
Bauxite mining industry. In terms of the extraction of bauxites, Georgia ranks second (17%), and in terms of their exports, first place (30%) among the industrially developed capitalist countries. and developing countries (1979). The export of bauxite in 1978 compared with 1970 (811 thousand tons) increased more than 10 times (10.3 million tons). M-tions of bauxite are developed by an open method with the use of drilling and blasting. The form of deposits is layered (layers 6-12 m), overburden thickness in cp. 0.5 m. In the Fria Sodiore region (Cimbo deposit) development has been carried out since 1959. Production. the power of the quarry of St. 2 million tons of ore per year. Processing since 1960 - at the alumina plant in Fria, alumina 85-90% (1978), alumina production St. 600 thousand tons (1980). Export by railway (length 145 km) and through the port of Konakri. The site in Sangaredi in the Boke-Gaval region has been developed since 1973. Production. quarry capacity 9 million tons. village (length 138 km) is supplied to enrich. f-ku to the port of Kamsar and then transported by ore carriers with a displacement of 45-60 thousand tons. 70s open way. The quarry was built with the participation of owls. specialists. Production capacity of the open pit is 2.5 million tons of ore per year. Ruda by rail (length 98 km) is delivered to the port of Konakri. To develop new bauxite deposits, 3 open-pit mining enterprises have been established: at the deposits of the Tuga region (design capacity is 8 million tons of ore per year), at the Aekoe deposit in the Boke-Gaval region (9 million tons of ore). tons of ore per year), where it is planned to build an alumina plant with a capacity of 1.2 million tons and an aluminum plant, and at the deposits of the Dabola p-on (6.5 million tons of ore per year), based on bauxite which is supposed to build an alumina plant. The increase in the production of alumina is constrained by difficulties with electricity, which will probably be overcome with the commissioning of a hydroelectric power station at p. Show jumping.
Extraction of other minerals. Extraction of iron ore in G. began in 1953 and until 1967 the Kalum deposit was developed. The development of large deposits is planned. ores in the south-B. in the years Nemba and Simandu. The full development of these deposits is planned after the construction of the railroad. from Konakri to the border with Liberia.
Mining of diamonds in the territory. G. began in the 30s. and was run by private companies and prospectors. B early 60s diamond min. enterprises were nationalized, in cep. 70s prom. production has been suspended due to the depletion of reserves and the lack of new enrichment. equipment. It is planned to be renewed.
Gold mining in the territory G. has long been carried out in an artisanal way in the early 20th century. European Entrepreneurs repeatedly tried to develop the development of dredges (for example, on the river Tenkiso in 1909-14, 218 kg of gold was mined). However, due to the insignificance of reserves, commercial production has been stopped.
Geological Service. Personnel training. Organization of mining and geological. works in G. are carried out by the Ministry of Mining. affairs and geology. Mining and geol. personnel are prepared for mining and geol. f-those (in Boke) Polytechnic. in-ta in Konakri. Literature: Mikhailov B. M., Geology and the western regions of the Liberian shield, M., 1969; Prokofiev S. S., Pokryshkin V. I., Geological and economic assessment of bauxite resources in Guinea, M., 1979. C. S. Prokofiev.

Mountain Encyclopedia. - M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984-1991 .

Synonyms:

See what "Guinea" is in other dictionaries:

1) Republic of Guinea, state in 3. Africa. The name of the state of Guinea (Guinee) is taken from the name of a large geographic area. region Africa Guinea, which from the XIV century. indicated in Europe. cards in the forms of Ganua, Ginya, and from the 15th century. like Guinea. Most likely... ... Geographic Encyclopedia

Guinea- Guinea. In the upper reaches of the river Niger. Guinea (Republic of Guinea), a country in West Africa, bordering the Atlantic Ocean. The area is 246 thousand km2. The population is 7.2 million people, Fulbe, Malinka, Susu, etc. The official language is French. Over 80%… … Illustrated Encyclopedic Dictionary

- (Republic of Guinea), a state in West Africa, bordering the Atlantic Ocean. The area is 246 thousand km2. The population is 7.2 million people, Fulbe, Malinka, Susu, etc. The official language is French. Over 80% of the population are Muslims, about 1% ... ... Modern Encyclopedia

Republic of Guinea (Republique de Guinee), a state in the West. Africa. 246 thousand km². population 7.4 million (1993); Fulbe, Malinka, Susu, etc. Urban population 25.6% (1990). The official language is French. Believers 85% Muslims, ... ... Big Encyclopedic Dictionary

GUINEA- (Guinee), the Republic of Guinea (Republique de Guinee), a state in West Africa. Pl. 245.8 tons km2. Us. St. 5 million hours (1982). Capital of Conakry (700 vol., 1982). Prior to the declaration of independence in 1958, possession of France. G. agp. country with ... ... Demographic Encyclopedic Dictionary

GUINEA- Territory 246 thousand square kilometers, population 7 million people (1986). Agriculture plays a major role in the country's economy. This industry employs 70% of the population. The main food crop is rice. The main livestock breeding areas of Phuta Jallon, Upper … World sheep breeding

UDC 553.492.1

Correia ae Sa Fami Gomes

RESERVE CHARACTERISTICS OF THE BOXITE DEPOSIT IN THE BOE REGION IN GUINEA-BISSAU

An analysis was made of the calculations of the Ministry of Mineral Resources of the Republic of Guinea-Bissau and the characteristics of bauxite deposits, which make it possible to attribute Guinea-Bissau bauxite deposits to the group of complex structures according to the GKZ classification.

Key words: mineral resources, Guinean bauxite, Guinea-Bissau.

In Guinea-Bissau, the new rulers were faced with the question of carrying out fundamental structural reforms as a necessary condition for accelerated economic development. The progressive policy of the government has an important position in the main sectors of the economy is the buxite industry, which has led to further reliable development of the economy. Mineral resource complex in Guinea-Bissau. It still remains the most attractive area for attracting investments. Over the past fifteen years, the volume of capital investments in the subsoil use of various minerals has grown more than 13 times. One of the most attractive sectors of the mining industry is the extraction of bauxite. This sector has a significant impact on the development of the economy in Guinea-Bissau1.

At the same time, today there are a number of acute problems, the solution of which will determine not only the dynamics of the development of the extractive industries, but also the Guinean economy as a whole. Bauxite this industry is created to develop the economy. Bauxites are ru-

1 Ministry of Mineral Resources Guinea-Bissau 31 March 2010.

milk for aluminum production. Bauxite deposits associated with lateritic crusts are located in the southeast of the country, near the border with Guinea. 103 kilometers separate them from the port of Buba. The total bauxite deposits in Boe's single ore region are 340 Mt, including 76.9 Mt of C1+C2 category bauxite.

In the bauxite-bearing region of Boe, terrigenous rocks occur - mudstones, siltstones and sandstones of the Silurian and Devonian, separated by intrusive deposits of Mesozoic dolerites. Laterite formations up to 30 meters thick are everywhere; in their upper parts there are baksite-bearing sediments. The relief is a somewhat rugged, flat-topped hill, in some places plateau-like. It forms a watershed between the Corubal River in the north and the Coton River in the south. Bottom erosion of rivers extends for tens of meters. At one time there were hostilities in the region; mines are possible. For the first time, information about Boe bauxites appeared in the 50s. Later, Dutch experts came to the conclusion that bauxites do occur in the region. After drilling work carried out on a section of 100 x 100 meters,

bauxite reserves in the region are not estimated. They reached 109 million tons with an average content of aluminum and silicon of 46.5% and 3.5%, respectively. In 1977 and 1980 Soviet geologists conducted research and evaluation of promising bauxite deposits. The main deposits of the Boe region are Cain, Ewa, Adam, Felu Caniaje, Vendor Lady, Rachel Rebecca and Jacob. The Cain, Vendor-Lady, Eva, Rachel-Rebecca and Felu-Kaniage deposits are the most studied. The parameters of bauxite deposits in the Boe region are given in the table.

The ore reserves in these deposits have an isometric shape, following the contour of the watersheds. The thickness of bauxite layers is from 2 to 10 meters; an average of 5 meters. Overlying rocks are practically absent. Ores of medium and high quality are characterized by a new chemical composition, which improves in the direction from the bottom to the roof. On the wings, bauxite deposits are replaced by allites, low-modulus bauxites, and aluminum oxide and ferruginous rocks. Rock-forming minerals: gibbsite (69-70%), alumogethite, hematite, boehmite, kaolinite quartz, rutile. According to the VAMI Institute in Leningrad, bauxites are suitable for processing into aluminum using the Bayer process.

In the early 70s. BILLITON conducted a technical and economic assessment of the prospective deposits. It was planned to build an aluminum plant with a capacity of 1 million tons of aluminum per year, with a supply of raw materials for 25 years. The required volume of investments was estimated at 460 million dollars. Construction costs for mines and a factory were estimated at 35.5% of this amount, while infrastructure costs were to be

amount to 17%, including 7% for the construction of the railway and 4.4% for the modernization of the port of Buba. The costs, according to the plan, were to pay off in 19 years, provided that the price of aluminum remains at the level of 70 dollars. per ton. BILLITON concluded that it was not viable to develop bauxite in the Boe region. In 1982-1983 The Leningrad institute "GIPRONICKEL" came to the same conclusion. In 1984, at the request of the Guinean partners, the institute carried out the most thorough cost assessment, as a result of which construction costs decreased.

In general, the problem was not solved, although with new calculations, income from bauxite should have reached the level of 158 million dollars. that, taking into account current aluminum prices of up to $420-440 per ton, the construction of an aluminum processing plant could permanently solve the problem of bauxite in the Boe region. At the same time, representatives of the Guinean side have repeatedly expressed their desire to continue the geological study of deposits in order to increase the bauxite reserves of the Boe region. These hopes are well founded: Soviet geologists have discovered deposits of high-quality bauxite in the watershed between the Corubal and Coton rivers, in the western part of the Boe region. The aluminum content ranged from 62.83 to 77.23%2

Thus, the main task of the government of Guinea-Bissau remains to attract investment in the extraction of bauxite, which is the main priority of modern economic and social policy in Guinea-Bissau. The further development of this mining industry has a positive effect on the creation of joint ventures and new

AI2O3 SiO2 Fe2O3 TiO2

С1 954.8 5.6 11.3 46.6 2.3 24.2 2.7 23.6

С2 979.6 3.8 7.9 45.5 2.4 25.9 2.5 23.4

С1+С2 1934.4 4.7 19.2 46.2 2.3 24.9 2.6 23.5

2.Cain, S2 1557.2 4.9 16.1 46.4 1.8 24.5 2.9 23.9

3. Raschel - 1669.0 4.5 16.8 46.4 5.4 21.9 2.0 23.9

Rebecca, C2

4.Vendor Lady

C1 693.3 5.2 8.0 47.2 4.26 21.2 2.01 24.9

С2 1098.3 4.3 10.5 46.9 4.9 21.64 2.1 24.3

С1+С2 1791.6 4.7 6.22 47.1 4.6 21.4 2.1 24.5

5. Felu- 652.2 4.3 19.3 44.2 6.0 25.0 1.8 22.1