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This article throws light upon the top twelve minerals that are found in India in huge quantities. They are: 1. Coal 2. Petroleum 3. Iron 4. Mica Deposits 5. Gold 6. Copper 7. Lead 8. Chromite 9. Manganese 10. Bauxite 11. Tin 12. Uranium.
Mineral # 1. Coal:
Millions of years ago, the forests got submerged and then covered by sand, silt and clay. In course of time, the remains of trees were slowly transformed into coal due to heat and pressure. Coal is therefore, said to have organic origin and it is found only in sedimentary rocks.
i. Varieties of Coal:
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Coal is based on the carbon content and is of following three varieties:
1. Peat and Lignite:
Peat and lignite is known as brown coal containing about 50 per cent of carbon. They are of inferior varieties as they have more moisture and give out a lot of smoke. Together they contribute about 15 per cent of the coal mined in the world. Peat is commonly used as a fertilizer, or as a fuel in dried forms.
2. Bituminous Coal:
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Bituminous coal is known as soft coal or coking coal contains 70 per cent of carbon. It is very widely used since it is found in abundance. About 80 per cent of the coal mined is of bituminous variety.
Bituminous coal, or the ordinary coal of the market, is widely used as domestic fuel, and in metallurgy as metallurgical coal.
3. Anthracite Coal:
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The highest carbon content of 90 per cent of it is available in limited quantities and contributes only 5 per cent of the world’s output.
ii. Uses of Coal:
1. Coal is used as fuel for steam engines, railways and ships, and for smelting iron ore.
2. It may be used to generate electricity known as thermal electricity.
3. It yields a number of by-products like coal tar and chemicals like ammonia and benzene.
iii. Coal Fields of India:
Coal is considered as the primary source of energy in our country and represented the most valuable and reliable source of fuel and energy to its economy and should be exploited to the fullest advantage.
1. Coalfields of Gondwana:
(a) Raniganj
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(b) Jharia
(c) East Bokaro
(d) West Bokaro
(e) Ramgarh
(f) South Karanpura
(g) North Karanpura
(h) Rajmahal
Raniganj and Jharia are two most important coalfields in our country together constitute 40 per cent of the total reserve. All these coalfields lie in eastern India and have a potential of 300 million tones.
2. Singrauli Coal Fields:
Containing 11 per cent of the country’s coal resources that is centrally located and supplies mainly to the northern India. This coal is used for power generation and industrial training.
3. Godavari Coal Fields:
As the main source of supply of coal to the Southern states.
The main coalfields are:
i. Kothagundam,
ii. Ramagundam,
iii. Ramakrishnapur, and
iv. Bellampally areas.
Among the coal fields in the Northeastern region, the important one is a Ledomakum coalfield in Assam. The adjoining Namchick-Nampherk coal fields in Arunachal Pradesh possess considerable potentialities. Meghalaya possess sizeable coal reserves in Khasi-Jainita Garo hills. Lack of transportation here is the main difficulty in the way of large scale of exploitation. India is also a producer of lignite.
Lignite occurs at:
(a) Neyveli in South Arcot district of Tamil Nadu.
(b) Palena and Khari in Bikaner district in Rajasthan.
(c) Nichahom in Jammu and Kashmir.
(d) Kutch and Bharuch district of Gujarat.
India exports some coal to Japan, France, Belgium, Italy during 1981, 450,000 tons of coal was exported. Thus India has become an exporter of coal.
Mineral # 2. Petroleum:
i. General Aspects of Petroleum:
Petroleum is composed of various hydrocarbons we also found subtypes of sulphates associated with these hydrocarbons also found.
In organic compounds like Mg, Al, Ti, Cr, N, P, and Cu. Density is lighter than water that is 0.7 to 0. 9, colour is light to red gray or green in colour.
Based on various hydrocarbons petroleum is classified into two main types:
1. Aliphatics
2. Carbocyclic
1. Aliphatic classified into:
2. Carboyclic:
Crude oil is very important for us contains 3,500 petrochemical compounds.
If we analyse Barrel oil crude oil various compounds are:
ii. Origin of Petroleum:
Origin of petroleum is based on two important aspects:
1. Inorganic theory, and
2. Organic theory.
1. Inorganic theory
Based on two theories:
(a) Carbide theory, and
(b) Volcanic theory.
2. Organic theory:
Based on two theories:
(a) Vegetal matter theory, and
(b) Animal theory.
Various hydrocarbons derived from Carbon—Carbide theory.
Examples:
Limestone, Marble, etc.
Some proposed hydrocarbon developed due to volcanic activity—Volcanic theory. Hydrocarbons varies mainly from animals—Animal theory.
Examples:
Radiolaria.
Many algaes are important which contributes much hydrocarbon deposited along the water and with the sediment-plant theory or vegetal matter.
Petroleum mainly confined to trap rocks (which do not allow magnesium from one place to another place).
Based on the basis of this there are mainly two types:
(a) Structural—Folds (anticlinal and synclinal) and faults.
(b) Stratigraphical—Petroleum confined to particular strata.
Examples:
Unconformity, sandstone, etc.
Petroleum is associated with sedimentary sequence. No petroleum is associated with igneous sequence.
iii. Distribution of Petroleum:
Northeastern of India Assam up to the Southern part lot of sedimentary rocks all along the coastal areas. Petroleum bearing horizons are mainly associated with sedimentary sequence.
Sedimentary Basin:
Basin in the petroleum represents a unit of geological structure characterized by a particular sedimentary succession during a given geological time.
Various sedimentary basins in India based on geological structure:
1. Paleogeography of the basin indicates the nature of the sedimentation.
Structure:
Based on paleogeography and based on the structure we can classify the various sedimentary basins into five types:
1. Basins associated with geosynclines.
2. Basins associated with divergent continental margins (related to the evolution of Bay of Bengal and Arabian Sea).
3. Basins associated with convergent margins.
4. Basins associated with Himalayan folded belt.
5. Basins associated with in Craton.
1. Basins associated with geosynclines:
Depth of sedimentation is more when compared to shallow water. In India we find petroleum and petroleum horizon.
Example:
Assam.
2. Basins associated with divergent continental margins:
Here are three subdivisions:
(a) Rift type basin
Example:
Camp bay, Kerala.
(b) Pull apart:
Pull away the continental margins due to the igneous intrusion oil bearings on offshore, Mumbai.
(c) Deltaic:
Which are, associated Godavari, Ganga, and Krishna.
3. Basins associated with convergent margins:
Example:
Andaman and Nicobar islands.
4. Basins associated with Himalayan folded belt:
Example:
Himalayan belt.
5. Basins associated with in Craton:
These are not marginal basins but these represent the center of the plate it does not disturbs, it is stable.
Two types of such basins associated:
(a) Depression:
Vindhyans, Deccan plateau.
(b) Sedimentary rocks are formed Grabens.
Example:
Mahanadi, Godavari.
Distribution:
1. Assam Oil Field:
Northeastern part of India.
Various types of minor fields are:
1. Digboi oil field,
2. Naharkatiya oil field,
3. Moran.
4. Rudrasagar and
5. Lakwa oil fields.
Sedimentary rocks in the area are classified into three main types:
Digboi:
North West of Naga hills of Laxmipur district of Assam and the oil field in the area confined to asymmetrical anticline.
Rock types:
In the area belong to Tipam Series of Miocene to Pliocene age. This Tipam Series confined to ferruginous sandstone, mudstone and clays.
The sandstone of Tipam Series is principally oil horizon and there are more than thousand oil wells located in the area but only 40 oil wells are working condition.
Naharkatiya Oil Field:
It lies 40 kilometres Southwest of Digboi. The oil-bearing horizon in the area is mainly controlled by anticline, which is traversed inner fault, which seem to have fold for the movement of oil.
The oil-bearing formations of the area belong to Barail Series. The Barail Series are made up of Arenaceous rocks. Lower are sands and shales middle part and argillaceous upper part.
There are about 300 wells drilled in the area and about 220 oil wells are in working condition. This is the first major oil field discovered in India, which now produce more than 3000 million tons of crude oil per annum.
Moran Oil Field:
This oil field is situated 40 kilometres WSW of Naharkatiya area. There is a minor fault, which divides oil into two parts. The rock types in the area are much similar to that of Naharkatiya but the oil fields are covered by alluvial cover and oil fields lie at a depth of 450 metres.
Rudrasagar Oil Field:
In Rudrasagar the structure of the oil field is a gentle dome shape traversed by inner faults and the Barail Series are the oil bearing horizons in the area.
Lakwa Oil Field:
This oil field is found both in sedimentary rocks belonging to Barail Series and also Tipam Series.
2. Oil Fields of Gujarat:
In Gujarat we find:
a. Combay Oil Field:
The onshore Combay basin and its extension through gulf of Combay represent a tertiary intercratonic rift type of gravel, which opens into Mumbai offshore region. The deepest part of the basin is over 5000 metres thick consisting of shale, sandstone and siltstone associated with thin bands of limestone belonging into tertiary period. The structure of the oil field broad anticline, which is folded on either side by Deccan traps.
b. Kalol Oil Field:
The Kalol oil field is about 25 kilometres North of Ahmedabad which represents long elongated anticline finding NNW to SSW in the major strike fault. The oil producing rocks in this region are of Eocene age.
c. Nawagami Area:
Nawagami area is situated towards South of Ahmedabad and the oil is situated in an anticline of irregular shape trending EW.
d. Sanand Area:
Sanand area oil-bearing structure is about 60 kilometres WNW of Ahmedabad and here again the structure is anticline trending NNW to SSE.
e. Ankaleshwar Oil Field:
The structure in oil field is an ENE to WS Westerly trending elongated anticline doubly plunging SW.
Ankaleshwar is the largest oil field area in Combay basin and oil rocks are of Eocene age. The oil from this area has specific gravity of 0.8 per cent and rich in gasoline but low in gas content.
There are about 170 oil producing basins and about 12 gas producing wells present in Ankaleshwar region.
3. Punjab and Himachal Pradesh:
Exploratory drilling carried out Jwalamuki area in Himachal Pradesh indicates that there is a greater amount of gas in the area. The gas bearing horizons in Zira area of Punjab.
4. Rajasthan:
The large parts of western and northern part of Rajasthan consists of Mesozoic and Eocene sediments coincide an alluvium. The occurrence of oil and natural gas has been found in Jaisalmer area.
5. Oil Fields in Bengal:
Under the great thickness of alluvial power in Ganga valley. Uttar Pradesh and Bihar thick tertiary sediments have been recognized. According to Russian geologist this region is much similar between the Urals and Volga region in U.S.S.R. Prospecting the oil in Ganga valley is still under progress and no oil- bearing locations in the area.
6. Oil Fields in Coastal Areas:
The cretaceous and tertiary sediments in the east coast of peninsular India are thought to be oil bearing they include areas along Orissa coast, Andhra Pradesh coast, Godavari delta, Tamil Nadu coast, Cauvery coast. Detail work carried out in the Cauvery area as shown that about 4000 metres thick tertian type of sediment. Geophysical survey has shown oil in the area but prospecting is still in progress.
7. Oil Bearing Horizon in Andaman and Nicobar:
A complex stratigraphic succession of marine sediments ranging from cretaceous to pliocene have been recorded. Mud volcanoes are present in island and traces of paraffin and crude oil have been located in this area.
8. Offshore Oil Fields in India:
Region from the banded to low tides up to surface (high tide).
1. Bombay High:
Recognized by the Oil and Natural Gas Commission (ONGC) and this Bombay High is about 160 kilometres NW of Bombay in the Arabian Sea. Area under water represents a structural type with a natural covered of about 1500 sq. kilometres forming a glomb by shale. The oil in Bombay High has structures of the limestone deposit and such structures having greater porosity and permeability has even pores for future oil prospecting in Bombay High. The oil is light brown colour and low in same.
2. Bassein Area:
It represents a satellite of Bombay High and very recent oil.
3. Janijira Area:
It is situated 80 kilometres SW of Bombay high and the oil has been struck where an oil form of about 110 metres was met at a depth of about 1900 metres below sea level. The estimated reserves 5000 to 7000 barrels per day.
Oil Companies:
There are five oil companies engaged in the refining and marketing of petroleum products.
These are:
a. Indian Oil Corporation (IOC) Limited,
b. Bharat Petroleum Corporation Limited,
c. Hindustan Petroleum Corporation Limited,
d. Caltex Oil Refining (India) Limited and
e. Assam Oil Company Limited.
Oil Refineries:
Mineral # 3. Iron:
Iron is the backbone of the modern industry. Iron is the second most common metal in the earth’s crust. Iron is one of the ancient metal to be known by man from prehistoric days and its consumption is increasing day-by-day.
Most of the iron produced is converted into steel. Most of the iron is malleable for this eminently suited for foregoing of rolling metals like Manganese, Chromium, Titanium, Heridium, Molybdenum, Nickel which are the alloys with iron are called ferrous metals and give special qualities to steel.
The important ore minerals of iron are given in Table 12.2:
Qualities of the ore:
a. High-grade ores above
b. 60% Medium grade ores 50 to 60%
c. Low-grade ores < 50%
In nature the commercial deposits are mostly bladed type. Although deposits of magnetite contact metasomatic and replacement nature. In many cases ground water circulations of weathering have resulted concentration of ore from free source.
Sulphur, Phosphorous, Arsenic are the most objectionable impurities in iron ores while Quartz, Aluminum, Calcium, Magnesium, Titanium impurities are not objectionable.
i. Distribution of Iron:
The major iron ore producing countries in the world are former U.S.S.R, Brazil, India, U.S.A., Canada, and Australia.
ii. India’s Important Iron Ore Deposits:
India has around 60 per cent of the world’s High-grade ore reserves. Iron contributes a major share to the country’s foreign exchange earnings. In 1969, India exported 60 million tons of iron ore and earned a foreign exchange of rupees 8.3 millions (83 crores).
Iron ore occurs on large scale in India chiefly in the form of Oxides of Haematite, Magnetite and Limonite. In India the Dharwarian rocks of Bihar, Orissa, Madhya Pradesh (M.P.), Maharashtra, Karnataka, Tamil Nadu (T.N.), and Andhra Pradesh (A.P.) containing an extensive deposits of high grade in which contains 60 to 69 per cent and consists of the most important iron ore deposits.
About 43 per cent of Indian reserves are situated in Orissa and Bihar. The hill range covering a part of Singhbhoom district in Bihar state; Keonjar and Mayurbanj, Cuttack and Bonia district of Orissa are the most important deposits of iron ores. The important mining centres of this regions Noamundi, Gorumahisani, Tomka the deposits of iron ore in Bihar. Iron ore series and the ores occur in the form of banded and massive form and the ore contains an average around 60 per cent.
Madhya Pradesh:
In Madhya Pradesh iron ore deposits occurs in associations of Banded Haematite Quartzite and massive form. The important deposits are found in Durg. Bastar district and Chanda district. In Durg District consists of Haematite minerals and Bastar district contain Banded Haematite Quartzite. The average iron ore contents are 68.69 per cent and the total estimates reserve is around 120 million tons.
Maharashtra:
In Maharashtra the important deposits are in Ratnagiri district and border of Goa. In Goa economically important deposits of haematite are associated with the Banded Haematite Quartzite.
Occurs in many districts of Satara and Vasco da Gamma and are the important deposits. The deposits of Goa are mainly blue dust contains 60 per cent of iron ore.
Karnataka:
In Karnataka iron ores are widely distributed all over the districts. But there are number of districts and are economically workable deposits of iron ore chiefly haematite carrying 53 to 63 per cent of iron contents. Less per cent of purity.
Above list shows the occurrence of iron ore in Bellary district, Chikkamagalur district and in Shimoga are quiet important ore reserves. In Bellary it is about 150 million tons of which 130 million tons situated in Sundur regions. The ores occur in Banded Haematite Quartzite on the top of the series of hill ridges.
The important sources in these regions Donimalai, Devadaru, Kumaraswamy, Ramadurga, Kanivena hally and Thimmappanagudda hill ranges. Haematite ore contents 60 to 69 per cent of iron and very less percentage impurities like phosphorous and sulphur. The deposits are being developed by National Mineral Development Corporation (NMDC), and Mysore Minerals Limited (MML) and provide mine owners.
Chikkamagalur districts, Bababudan giri hills have one of the most important deposits. This ore carries 55 to 65 per cent of Iron. The deposits of Kemmangundi and Dupadar are now exploited (removal) by the (MSIL or VISL).
Kudhremuk and Gangamulai have extensive deposits of magnetite ores. In Kudhremuk project wood also produce around 7.5 million tons of concentration per year and initial stage which could be raised to 10 million tons and exports to Iran through Mangalore sea port by the modern mechanized slurry method (in liquid method).
Andhra Pradesh:
In Andhra Pradesh deposits exist at Ananthpur, Kurnool and Vishakhapatnam districts. The iron ore contains 55 to 66 per cent.
Tamil Nadu:
In Tamil Nadu the magnetite ores carrying an average of 48 per cent of iron occurs in so many places in Trichinopoly, Salem district.
The magnetite type of iron ore in India is either of igneous origin or metamorphic origin. The total reserves of iron ore in India are around 23 million tons of which haematite type contains around 85 per cent with magnetite type is about 8 per cent and the rest around.
iii. Iron and Steel Industry:
Iron and steel industry is the most important of all manufacturing industries and is considered as the basic or key industry of any nation.
For the development of an iron and steel industry the basic requirements are:
1. Availability of raw materials like iron ore, dolomites, limestones and manganese,
2. Availability of fuel that is coking coal,
3. A large supply of water for tampering of steel,
4. Availability of capital, and
5. A big market to absorb the products of the industry.
The iron and steel industry is generally described as material-oriented industry. Its best location is one where both coal and iron ore are found to close proximity. If coal and iron are not found together, then the plant is more suitably located near coal mines, iron ore mines, or at intermediate location or even near market.
In India the industry is developed in the Northeastern region, mainly at:
1. Jamshedpur in Bihar
2. Burnpur in West Bengal
3. Bhilai in Madhya Pradesh
4. Durgapur in West Bengal
5. Rourkela in Orissa
6. Bokaro in Bihar
7. Bhadravathi in Karnataka—producing special type of steel with charcoal
8. Visakhapatnam in Andhra Pradesh
9. Salem in Tamil Nadu
10. Vijaynagar in Karnataka.
Mineral # 4. Mica Deposits:
Mica, asbestos, steatite find extensively in insulating industry. Mica is generally as high dielectric properties with very low thermal conductivity for that using as a several appliances in electric and electronic industries and extensive uses in the insulating industry.
Mica is a hydrous silicate of aluminium with varying amount of K, Na, Ca, Mg. and Fe. The general formula, which explains chemical formula of mica.
X2 Y 4-6 Z8 O22(OHF)2
where X = K, Na, Ca, Ba
Y = Mg, Al, Fe
Z = Si, Ca
It is characterized by basal cleavages; mica can be separated easily into very thin sheets, which are elastic, flexible, strong and also transparent.
Different types of Micas are recognized:
1. Muscovite mica:
Colourless, transparent with potassium.
2. Biotite mica:
It is a dark colour, translucent or opaque with iron and magnesium.
3. Phlogopite:
Phlogopite is an amber colour with Magnesium (honey yellow colour or gum colour).
4. Lepidolite:
Pale coloured with Lithium.
5. Vermiculite:
Of all these Muscovite, Phlogopite, Lepidolite are great economic importance. Muscovite and Biotite are abundant in acid pegmatites, crystalline limestone and dolomites. Vermiculite is generally associated in ultrabasic.
Distribution:
India is the major world producer of black and splitting type of muscovite mica. Besides Brazil, USA and Canada are the other important producers.
Indian productions and Important Mica Deposits or Mica Belts:
India is the leading producer of superior quality sheet of mica in the world. In 1969, around 17,626 tons of crude mica were produced. Of these 43 per cent came from Bihar belt. 29 per cent was from Nellur belt and 27 per cent from Rajasthan. The remaining 1 per cent from all other states.
India exported mainly to Japan, USA, UK and Norway. In 1970, the exports were around 42,000 tons.
In India mica occurs in three important belts:
(All mica occurs in pegmatitic veins).
1. Bihar mica belt,
2. Nellur mica belt, and
3. Rajasthan mica belt.
1. Bihar Mica Belt:
Bihar is the largest producer of high quality of black mica in the world. The mica belt extended over 150 kilometres with 19 to 20 kilometres width runs in ENE-WSW directions through Gyan, Hazaribagh and Monghyr districts. In this mica belt the deposits of mica are associated with the pegmatite veins. The country rocks are Precambrian Meta sediments mainly consisting of Mica Schist, Hornblende Schist and Gneisses.
The Bihar Mica Belt consists of four types of pegmatite veins. The quality of Bihar mica varies from silver soft white to clear Ruby Muscovite. The rock about 600 individual mines are working with in this belt. The major activity is concentrated in Kodarma reserved forest area in Hazaribagh districts.
2. Nellur Mica Belt:
In Andhra Pradesh the Nellur Mica Belt is the most important producing area. The mica belt stretches for about 100 kilometres between Guddur, Rapur and Sangam districts and as an average width of 16 kilometres. In this area the productive pegmatite veins contains blocks of muscovite mica generally is light pale green colour.
3. Rajasthan Mica Belt:
In Rajasthan the mica with an average width of 100 kilometres extends from Jaipur, Udaipur and Mewar. In this Bhilvar is the important producing centre. Usual quality of mica is Ruby red variety. The mica belt Pegmatite; Rajasthan contains an appreciable quantities of Beryl.
In other states of India mica has been recorded from Karnataka, Orissa and Tamil Nadu and certain parts of Travancore.
Mica in the form of large sheet is the value type. Mica is also sold as black mica, split mica and scrap mica. The scrap mica is used in the manufacture of micanito.
Mineral # 5. Gold:
Gold is mainly associated with acid igneous rocks. When gold bearing rocks are weathered and eroded, heavier gold particles may get concentrated in streambeds. These are placer gold deposits. Gold also occurs in veins or loads where it is in the form of flecks and occasionally as octahedral crystals.
Studies bear out that gold is transported in hydrothermal solutions. Apart from occurring in the native state, gold occurs as a compound with tellurium in minerals like Sylvanite [(Au, Ag) Te2 and culverite Au, Te2]. Soviet Russia, South Africa, Canada, USA and Australia are the leading producers of gold.
The Kolar Gold Fields and the Hutti area in Karnataka produce gold in commercial quantities. Besides there are a number of prospects in several states.
In the Kolar area, the main rock types are Schists, amphibolites and ferruginous quartzites of Dharwarian age. Gold occurs in gold quartz lodes and gold bearing sulphide lodes emplaced in the above rocks. In the gold quartz lodes, the amount of sulphide is low (less than 1 per cent) and in sulphide lodes, it is high about 90%).
The main gold quartz lode in Kolar is the Champion lode along which the Mysore mine, the Champion the Ooregaum mine, the Nandidurg mine are situated. The mines are deep and it has been found that the yield of gold has decreases considerably with depth. Additionally, the increasing depth factor has led to escalation in the cost of mining. In 1981, the average gold content was reported to be less than 5 dwts/tonne.
In the Hutti Gold Field lying in the Raichur district of Karnataka, the country rocks are chlorite Schists and Phyllite. Mineralised reefs occur in intensely sheared zones and gold occupies minute cracks. The tenor of the ore is about 5 dwts/tonne.
The Gadag Gold Field and the Bisanattam gold prospects, also situated in Karnataka, have been prospected for gold.
Mineral # 6. Copper:
Copper is used in the manufacture of household utensils and wires. It is also used in the form of alloys by mixing it with other metals. Bronze, Brass and German silver are some of these alloys. Copper is a good conductor of electricity; its resistance to rusting is one of its useful properties.
It is, therefore, greatly used in the manufacture of electrical cables, like Iron. It can take any form and shape like sheets and wires. But copper is not so cheap and abundant as iron ore. Copper ore has a low metal content of about 2 per cent. Copper ore yielding 6 per cent metal is considered to be extremely rich.
The four main copper bearing tracts known in India include the:
1. Khetri copper belt in Rajasthan,
2. Malanjkhand copper deposit in Madhya Pradesh,
3. Agnigundala lead-copper deposit in Andhra Pradesh, and
4. Rakha copper belt in Bihar.
Smaller prospects are in Dariba, Alwar, Chandmari, Jhunjhunu district, Ingaldhal, Chitradurga district in Karnataka and Ambamatta in Gujarat.
1. The Khetri copper belt in Rajasthan extends over 80 kilometres in highly folded and faulted rocks. A number of branching and parallel zones is also known. The primary copper minerals are Chalcopyrite, Pyrite and Pyrrhotite and the secondary copper minerals are malachite, azurite, covellite and chalcocite. ‘Gossan’ found in some localities is locally cobaltiferous, manganiferous and argentiferous.
2. In Malanjkhand in Madhya Pradesh, copper mineralisation is associated with metamorphosed sediments. Granites, basic dykes and quartz veins of Archaean age. The major ore minerals in the rocks are Chalcopyrite and Pyrrhotite with small amount of Sphalerite, Chalcocite, Covellite and Molybdenite.
3. In the Agnigundala area in the Guntur district of Andhra Pradesh, the host rocks for mineralisation are calcareous Quartzites, Dolomites and Dolomitic Limestones. Copper is associated with Lead and Zinc. While Copper mineralisation is mainly in calcareous quartzite. Lead-Zinc mineralisation is found mostly in dolomites, Cobalt, Nickel and Silver are associated metals.
4. In the Singhbhoom copper belt, Copper mineralisation is the granite and in the Surda deposit in the belt, mineralisation is in Quartz Schist. The ore minerals are Chalcopyrite and Pyrrhotite, Pentlandite (Iron nickel Sulphide) and Arsenopyrite (Iron arsenic Sulphide) and pyrite (Iron Sulphide) are the associated minerals.
In the Singhbhoom district between the well-known Rakha mines and Jamaphar, Copper mineralisation occurs in the forms of disseminations, Stringers, clots and veins in fractured Quartz-chlorite Schists and conglomerates. According to the Geological Survey of India (GSI). The proved and estimated reserves of copper ore in the Singhbhoom district are of the order of 45 million tones and 58.5 million tonnes respectively.
Mineral # 7. Lead:
Lead is widely used in making storage batteries, cable sheathing, lead pigments, and ammunition and gasoline antiknock additives. It is also alloyed with a number of metals. Zinc find in alloying and for galvanizing iron and steel. Zinc compounds are used in die-casting textiles and rubber industry.
The operating mines for winning Lead and Zinc in India and Sikkim includes:
1. The Zawar Group, Rajasthan—Zinc and Lead
2. Raipura-Dariba, Rajasthan—Zinc and Lead
3. Sergipalli, Orissa—Lead
4. Agnigundala, Andhra Pradesh—Lead, Copper
5. Sikkim Mining Corporation at Rango, Sikkim—Zinc, Lead, Copper
The geological setting for lead and zinc mineralisation in the Zawar belt is defined by a set of rocks including Quartzites, Dolomites-Slates and Phyllite intruded by dolerite dykes and quartz veins.
Mineralisation is thought to be the result of hydrothermal activity and fissure filling. The main Sulphides are Galena (PbS) and Sphalerite (ZnS) and the other Sulphides are Pyrite, Arsenopyrite, Chalcopyrite and Pyrrhotite. According to the Indian Bureau of mines, the total lead-zinc reserves are of the order of 246 million tonnes with 0.76 to 1.46 per cent lead and 1.46 per cent zinc.
The Raipura-Dariba belt is the continuation of the Zawar belt. Lead and zinc mineralisation occurs in folded graphitic mica Schists and dolomite. Shalerite (ZnS), Galena (PbS) and Chalcopyrite (CuFeS2) are the important sulphide minerals. Here Copper, Silver, Cadmium and Antimony are the major accessory metals.
In Sargipalli in Orissa the rock types are Quartz mica Schists and dolomitic limestones in which galena occurs as Stringers, veins and lodes. The associated Sulphides are Shalerite. Chalcopyrite, Bornite, Pyrite and Pyrrhotite.
In Agnigundala, Andhra Pradesh, Lead mineralisation (PbS) occurs in veins and stringers in dolomites and dolomitic limestones. The associated Sulphides are Chalcopyrite. Shalerite and Pyrite.
The total reserves of lead ores of all grades in the country are of the order of 120 million tonnes while those of zinc are 101 million tonnes.
Mineral # 8. Chromite:
Chromite is used in metallurgical, refractory, chemical and foundry purposes.
Over 95 per cent of the known Chromite deposits in the country are in Orissa. The other states with Chromite resources are Karnataka, Maharashtra, Bihar, Andhra Pradesh, Tamil Nadu and Manipur.
In Orissa the districts of Dhenkanal, Cuttack and Keonjhar have Chromite ores of metallurgical, refractory, chemical grades.
In Sukinda area in the Cuttack district, Chromite ore occurring as veins, stringers and lenses in ultramafic rocks is mined.
In Bihar, Jojohatu is known for Chromite occurring as segregation and veins in ultrabasic rocks.
In Karnataka, a 56 kms. Long Chromite belt in ultrabasic rocks is known in the Hassan district Chromite bricks are made out of Chromite from the Byrapur area.
Chromite is also known as Bandara and Ratnagiri districts (Maharashtra), in the Kondapalli hills in the Krishna district (Andhra Pradesh), in anarthosites of Sittampundi and Karungalpatti (Tamil Nadu) and Ukhral and Tengopal districts (Manipur).
The Indian Bureau of mines made an estimate of 111.2 million tonnes of Chromite in the country of this, about 59.4 million tonnes are of metallurgical, grade.
Mineral # 9. Manganese:
The important producers of Manganese ores in the country are:
Orissa, Maharashtra, Karnataka, Madhya Pradesh, Goa, Andhra Pradesh, Gujarat and Bihar. Ferromanganese grade ore is found in Maharashtra, Madhya Pradesh and, Andhra Pradesh.
The different types of Manganese ores are:
(a) Syngenetic and Gondite deposits—Madhya Pradesh, Maharashtra and Rajasthan.
(b) Syngenetic and reef deposits—Associated with Koduritic rocks in Andhra Pradesh and Orissa.
(c) Replacement ores in Iron ores—Bihar, Orissa, Karnataka and Goa.
(d) Lateritic deposits:
Associated with (a) (b) or above.
On the whole, the Indian ore is hard and lumpy and suitable for metallurgical purposes. Orissa has the pride of place in the production of Manganese ores, its output being 30 per cent of the country’s yearly production. In the Bonai-Keonjhar belt, the minerals of the low psilomelane associated with wad.
In Bihar, Manganese ores are associated with met sediments and they contain Psilomelane, Braunite, Cryptomelane and Pyrolusite.
Perhaps, the largest and the richest Manganese ores in the country are in Madhya Pradesh and Maharashtra, where the ores occur in lenticular masses in association with manganiferous quartzites, Schists and Marbles. Small low-grade Manganese ore bodies are known in Ratnagiri in Maharashtra.
In Goa Manganese and Iron ores are in association and are mostly of low grade.
In Andhra Pradesh, Manganese ores (28 to 30 per cent Mn) have been worked for long in the Srikakulam district.
In Karnataka, Manganese ores with low phosphorous are known in Shimoga and North Canara districts.
Small Manganese ore bodies are known in Aravalli rocks in Rajasthan.
Mineral # 10. Bauxite:
Bauxite is an ore from which Aluminium is extracted. Aluminium is light, strong and good conductor of electricity. It has high industrial value and its great demand because of its varied uses in industries like transportation, electric goods, and chemical industries. Machine building and cooking utensils, extraction of Aluminium from the ore requires cheap and abundant supply of electricity. Therefore, Aluminium production is carried on in places of abundant and cheap electrical energy. It can be made stronger and more durable by mixing other metals.
India is rich in Bauxite reserves. The production has been steadily increasing since 1951. The states of Bihar, Gujarat and Madhya Pradesh are the major producers of Bauxite in India. Bihar produces Bauxite in the Ranchi and Palmau districts.
The mines of Gujarat are located in Kairo and those of Madhya Pradesh at Jabalpur, Balaghat, Bilaspur and Bastar districts.
Salem and Madurai in Tamil Nadu, Koraput and Kalahandi in Orissa, Kolhapur in Maharashtra and Chithradurga and Belgaum in Karnataka are the other Bauxite producing districts of India. Recently, deposits have also been discovered in Andhra Pradesh, Goa, Kerala, Uttar Pradesh and Kashmir and Jammu.
India produced 1,600,000 tonnes of Bauxite in 1981, out of these 20,000 tonnes were exported. The numbers of Aluminium manufacturing centres in India are not enough to use the entire Bauxite produced in the country. Therefore, most of the Bauxite is exported to other countries for the extraction of Aluminium.
Mineral # 11. Tin:
Tin resists corrosion. It is commonly used in the manufacture of tin plates, which are used to make containers, or cans, kerosene, processed food products and cigarettes are packed in theses containers. Nearly half of the tin produced in the world is used for making tin plates. Tin is also used in alloys like bronze and for galvanizing and soldering.
Malaysia is the largest producer of tin in the world. Most of the tin is consumed by non-producing nations.
Mineral # 12. Uranium:
One of the recent discoveries is the radioactive metal of Uranium and Thorium can be used to produce nuclear energy. An ounce of these nuclear fuels can produce energy equal to that produced in the burning of 100 tonnes of coal. This energy can be used for destructive purposes, as a bomb. It can be used for peaceful purposes of a well, for example, as a source of power for various industries.
India has Uranium deposits in Bihar and Rajasthan. Recent reports indicate the presence of Uranium in Madhya Pradesh and a few more districts of Rajasthan.