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Soils consist of mechanical mixtures and chemical compounds of the materials found on the surface of the earth. They contain both inorganic and organic materials. The process of soil formation is influenced by the physical and chemical characters of the parent rock, physiography, altitude, climatic condition and plants and animals of the surrounding region. In North East India the above factors vary from place to place. For example. the parent rocks of Meghalaya and Karbi Anglong, which are mostly metamorphic, differ from those of hills and mountains, which are sedimentary. So far physiography is concerned there are very high mountains and hills, plateaus, deep gorges and valleys and wide plains dotted with water bodies and swamps. Climate also varies according to the location and situation of the places. There are hot and humid areas, cool hilly areas and very cold glaciated areas. Similarly the plant and animal life also varies from place to place. As a result of all these different types of soils generate in different part of the region.

Soil Formation : The generally heavy rainfall, high relative humidity and high temperature cause rapid weathering of rocks of North East India. As the weathering of the surface rocks of the hills and mountains proceeds, the sheet floods caused by heavy rainfall remove the weathered materials and carry then down to the head- streams of the rivers. The rapidly flowing water of the streams then carry the sediments, big and small, down to the foothills and plains. The sediments thus are spread over large areas in the foothills and plains. Such soils are known as transported soils or azonal soils . On the other hand the summits and slopes of the mountains are left with only a thin layer of soils formed due to local weathering, These soils are known as residual soils or zonal soil. The transported soils found in the region may be divided into two groups : allivium and diluvium and colluvium. The alluvium or alluvial soils are made of made of finer grains like fine sand, loam and silt. Alluvial soils are made of these finer materials which the running water can carry far into the plains. Diluvial and colluvial soils are found in the foothills and in beds of the narrow valleys and canyons inside a hill or mountain tract. Here the soil is a mixture of fine silt and carried by running water and cobles and pebbles deposited partly by gravitational pull and partly transported by running water. The residual soils are also divided into two groups : oxisol and altisol . Oxisols which are also known as red soils, are found at lower altitudes over the hills and mountains, while the altisols are found at medium altitude (above 1500 m- 2000m) and may be called as lateriate. Besides, there is a third category of residual soil, which may be called as Mountain Soil. This type is found at higher altitides where the soil forming process is influenced more by frosts and snowfall rather then by rainfall.

Regional distribution :

The plains of the Brahmaputra and Barak in Assam the Manipur plain and the plains of Tripura have alluvial soil. The hills of North East India have red soil over lower altitudes, and laterite soil over medium altitude, while the higher mountains have mountain soil. In Assam, therefore, we find alluvial soil over the plains, red soil in most of Karbi Anglong and North-Cachar Hills and only patches of laterite over the highest part in their hill ridges .

In Arunachal, the limited river valleys contain alluvial and diluvial soil, while all the lower hills contain red soil. The areas above 4500 m have mountain soil mixed with glacio-fluvial deposits. Meghalaya has red soil all over the hills except the higher central part where laterite is found to be present. The rocks of Meghalaya contain a higher quantity of iron and hence its red soils are brighter then the red soils of other hills. Mizoram has mostly residual soils weathered from shale. Red soils predominate the state with only thin patches of laterite over the higher ridges. While the Manipur plain contains alluvial soil, its hills have residual red soils which are sandy. Nagaland also has red soils, but these are, by and large, fine grained. Besides they seem to contain more organic and nitrogenous materials. Tripura has alluvial soils over the piedmont plains and red soil over the hills. There are a few small patches of laterites also over the higher hills of Tripura.

 Classification of Soil :

There are four major groups of soil in North -East India . These are as follows :

1. Alluvial Soil : As described above, alluvial soil is found in the river valleys and plains. This is a transported soil made up largely of silt, sand and clay. By the river sides, the alluvial soil is mostly sandy while away from the rivers it tend to be clayey. This soil is slightly acidic and rich in organic material . As this soil is made up of layers of silt deposited by running water, one can find about 10/12 layers of silt within a depth of 150 cm. The soil is characterised by a concentration of ferrous oxide ( FeO ) and aluminium oxide (Al2O3) in its lower layers. On the other hand silica content decreases from the top soil downward.

The alluvial soil may be divided into a few categories on the basis of its physical make up. These are sandy, sandy loam, silty loam and silty. Then again, alluvial soil is divided into new alluvium and old alluvium on the basis of period of there genesis.

The old alluvium was deposited earlier in the late Pleistocene and Sub-Recent periods. In the course of time it is raised to a relatively higher level because of local tectonic activities. This soil is more consolidated, acidic and less fertile. Further, it contains less phosphate and potash . Old alluvium is found in patches generally along the foothills In the Brahmaputra Valley there is a long patch of old alluvium along the Himalayan foothills from Kokrajhar District upto the river Subansiri of Lakhimpur district . The patch is however, criss-crossed by numerous rivers coming down from the hills. In Sonitpur district the patch of fold alluvium occurs south along the middle of the north bank plain from Dikrai river upto about Gohpur. The other patch occurs at the southern and eastern margins of the south bank plain , along the foothills of Meghalaya in Dhubri, Goalpara, Kamrup and Marigaon districts, along the foothills of Karbi Anglong, in Nagaon and Golaghat districts, along the Nagaland foothills of Golaghat, Jorhat and Sibsagar districts and along the southern and eastern foothill margins of Tinsukia districts. There are patches of old alluvium in the Semphema-Diphoma area near Kohima,along the foothills of Cachar and Hailakandi districts and along the foothills in Tripura. Old alluvium often forms distinct terraces and supports tea gardens. Only in western Brahmaputra Valley this soil is not found suitable for tea cultivation because of very low phosphorus content of it in this part.

The new alluvial soil consists of recently deposited silt and sand and is rich in organic content. Hence, this type of soil, if not purely sandy, is fertile and suitable for agriculture. This soil is generally rich in phosphate, potash, calcium, nitrogenous material and organic substances . It is less acidic and not saline. Its chemical and physical characters, however, very to some extent from place to place. New alluvium is found all over the Brahmaputra and Barak Valleys, Manipur Plain and Tripura Plain except in those areas where the old alluvium occurs. Over the hills and Plateaus this soil is confined to the narrow valley bottoms. It tends to be sandy in the immediate river banks loamy at some distance from the river beds and clayey in the areas of greater distance from the rivers . Besides, those alluvial soils which are found in the swamps and marshes contain a high quantity of putrefied organic matter and hence tend to be dark in colour. Rice, jute wheat, pulses, mustard , sugar cane, maize, etc. grow well over clayey soils. Loamy soils support finer varieties of rice, pulses, mustard and vegetables. The sandy soils of the flood plains are famous for vegetables., including potato.

2. Red Soils: Red soils are normally found on all the hill slopes and hill tops except in very high altitudes. These soils become red because of the oxidation of the iron content present in them. Red soils contain organic matter and nitrogenous material. They are also acidic but have lesser quantities of phosphate and potash. In the presence of water the red soils become sticky, while in its absence they become hard and develop cracks. Red soils may be regarded as residual.

These soils are commonly found in Meghalaya, hills of Tripura, Mizoram, hills of Manipur, Nagaland, Arunachal Pradesh and in the North Cachar hills of Assam. They are bright red in Meghalaya because of the presence of a greater proportion of oxidised iron in their parent rocks, i. e. the acidic rocks of Pre-Cambrian origin.

Although the red soils are commonly found over the hills, there are patches of these in the areas of the old alluvium also. The higher parts of old alluvium, which have not been affected by flooding and subsequent silting, contain reddish soil and are found in Darrang, Sonitpur, Golaghat, Jorhat and Sibsagar districts and the foothills of Karbi Anglong.

Red soils are suitable for growing fruits Besides, on the hills slopes these also support good crops of rice, maize and millets. If irrigated, these soils can produce cotton, rice, maize, wheat, pulses, potato, and citrus fruits, especially lemon, orange, pine apple, pear plum and grape.

3. Laterite Soil : Laterite is found only in small patches at the medium altitude of the hills. This soil contains considerable quantities of iron and aluminum and hence is hard when dry and red in colour. When wet it becomes sticky. Laterite soil contains less quantities of nitrogenous material, phosphorus and lime. It is a leached soil and hence not fertile. There are two types of laterite, viz. high altitude laterite and low altitude laterite . Both the types develop on the hill tops and slopes which have heavy rainfall, generally high relative humidity and facility for good drainage.

Laterite is distributed in small patches over higher hills tops of Karbi Anglong and North Cachar hills of Assam. Relatively extensive patches of laterite is found in the Cherrapunji region of Meghalaya over sandstone deposits.

In Manipur laterite is confined to the higher hills tops of the south-eastern region . In Mizoram and Tripura it is found on the ridges of higher altitude . In Arunachal Pradesh laterite is found in patches at mid -altitude on sand stone rocks.

Laterite is useful for growing crops only when water is supplied. Over the high altitude laterite millets and pulses can be grown well, while on low altitude laterite cotton, millets, rice, banana and citrus fruits grow well with irrigation.

4. Mountain Soil : In North-East India mountain soil is found over very high altitude (above 4500 m ). Such soil is therefore, confined to the higher altitudes in Arunachal Pradesh and over the summit region of the Patkai Range. This soil remains frosted in winter , In Arunachal this soil is mixed with fluvio -glacial deposit. Because of prevalence of low temperature, chemical decomposition is of lesser measure in the case of this soil. Hence it contains pebbles, cobbles and boulders along with sand and silt. Mountain soil is not fertile. It however. supports millets, barley and good grass for animal fodder.                          


            North East India is fairly rich in mineral resources. Apart from petroleum, coal, limestone and sillimanite, which have been regularly extracted since long, the region also has a number of other valuable minerals. The Geological Survey of India and the Department of Geology and Mining of each of the states of the region has been exploring and assessing the reserves of  various economic minerals present here. Besides, the  Oil India Limited and the Oil and Natural Gas Commission are specifically engaged in exploring and assessing the reserves of oil and natural gas  in North East India. The efforts  so far made have revealed that the region has the following minerals stored in it :

                                                  North -East India

                                       Reserves of  Some Minerals

                                               (in million tonnes)



Estimated Reserve

1. Coal


2. Petroleum


3. Limestone


4. Dolomite


5. Sillimanite


6. Iron Ore


7. Glass sand


8. Ceramic Clay (all varieties)




10 Natural Gas

114 billion m3


            The above table shows the estimated reserves of the mineral so  far estimated. There are some other economic minerals whose traces have been found here and there in the region. But their reserves have not been estimated because of inaccessibility of many parts of Arunachal Pradesh, Nagaland, North Cachar Hills, Manipur, Mizoram and even Meghalaya. The minerals, whose presence has been detected in the region include copper, chromite, nickel, cobalt, fire clay, kaolin, corundum, asbestos ,gypsum, beryl, graphite, gold, mica, alum, shale and mineral salt.

            Iron Ore : The iron one deposits so far explored in the region are found to contain a low proportion (41% and below) of iron. Besides, a very large quantity of ore has also not been found to be located at one place. In spite of such drawback iron used to be mined in the North East India in the past , especially during the medieval period. It is found that during the Ahom reign iron used to be mined from the north  western foothills of Tirap and Nagaland in the areas stretching from Jaipur in the east to Tiru Pahar and Telpung in the west. The mines were located at Jaipur, Tipam, Bosadaiyang, Tiru Pahar and Telpung, The present day explorations have revealed that these areas have ironstone nodules and shale of the Tipam and Barail Series of sedimentary rocks containing from 22.1% to 40.1% of iron.

            The second area where iron ores are found lies in Dhubri district in an around the hills of Bilasipara, especially at Chandardinga hills (estd. reserve 17 million tonnes) and at Melajgarh (26015’ 20’N and 90 0 28’00’E) near Abhayapuri. The ores here contain 30% -40% iron. The third reserve is found in the Meghalaya foothills of Kamrup and Goalpara district at Nalanga Beel, Kumri hill, Langupara hill, Khardong and at Arandanga-Raochapra area near Hahim, In the Garo Hills district iron ore has been  discovered at Athiabari and Nichangram. In the East Khasi Hills it has been found at a place 28 km north of Cherrapunji, where magnetite is present in the granite deposits. In Nagaland Laterite cappings, rich in iron are found in the north western foothills of Wokha district. In Manipur  bog iron is present in an wide area near Lauchipat. In Arunachal Pradesh iron ore has been detected in East Kameng and West Siang  districts.

            It has, however, been found that iron content in the ores of the North East India is generally low, being less than 50% Hence no entrepreneur comes forward to set up a steel plant, although other raw materials, except manganese, are not absent in the region. But if manganese is imported, a medium steel plant or a sponge iron plant may be set up  with coking coal from the reserve of the area between Namchik and Namphuk rivers of Changlang.


            Copper : Economically exploitable copper deposit has so far not been found  in North East India. Small deposits have so far been found in Assam, Meghalaya, Nagaland and Manipur. In Assam , it has been found in small proportions at Mahamaya hills of Bagribari area of Dhubri district, Barduar area of Kamrup district and in the upper reach of the  Barjuri river in Karbi Anglong. Copper is found in these hills in the from of pyrrhotite, chalcopyrite and pyrite in small proportions of 0.04% to 0.39%. In Meghalaya it is found at Umpirtha and Ranighat (25050’ N,91010’30” E). In Nagaland copper is present in the  basic and chalcocite. In Manipur it has been reported from Nungon, Kongal, Thana and Ningthi (Maklong Khing) area by the Geological Survey of India.

            Chromite and Some other related minerals : Chromite is rarely found in our country and more so in this region. Small deposits of chromite have  been found in Nagaland in the ultrabasic rocks situated near the Patkai Range. In Manipur it has been found at Siroi hill of Ukrul and Moreh of Chandel district. In Meghalaya chromite has been found in the  Sizu basin and in Arunachal it is discovered at Tiding Valley.

            Besides the above minerals, traces of the deposits of nickel, cobalt, gold, silver, lead, molybdenum, platinum, iridium and germanium have also been found in North East India.

            Traces of nickel deposits have been found at Moreh, Vungon, Kongal, Thana and Ningthi areas of Manipur in association with the ultrabasic rocks and serpentine bodies. This mineral has also been traced in Subansiri district of Arunachal Pradesh. Traces of cobalt deposits have been found in the Lower Subansiri district of Arunachal and at Pulphur village in Kiphire sub-division of Tuensang district (Nagaland). Alluvial or placer gold used to be extracted from several rivers of Assam in the ancient and mediaeval periods. There are references of gold of Assam in the Mahabharata, the Alamgirnama (written by Mohammad Kazim who accompanied Mir Zumla) and the writings of Jeau Baptist Traverneer and Mr. Wade. Alluvial gold was extracted from the beds of the Nadihing, Dibang, Subansiri, Dikrong and Bargang rivers. It is said that placers were derived from the auriferous quartz veins. Presence of gold has also been found near Haflong (25015”N and 920 8” W) of North  Cachar Hills at Tyrsad (8 km S. W of the Mawphlong) in the East Khasi Hills district and in Manipur in the quartz veins associated with oxides and sulphides. Although the  occurrence of silver has not yet  been traced, it is said that the metal may occur at  Bar Khamti  area of Luhit district  and at Nongpoh in the Ri Bhoi district of Meghalaya. Lead is said to occur in Sadiya sub-division and Molybdenum in the granite rocks of Cherrapunjee. Both Platinium and iridium are found to be present in the gravels of Noadihing river. The presence of germanium has been detected in the coal deposits of East and West Garo Hills to the extent of 0.095% to 0.122%.

            Coal : North East India has large reserves of coal, especially in  Assam and Meghalaya. The quality of coal so far found is however, not very good in that its organic sulphur content is high (upto3%) and carbon content is relatively low. Assam is said to contain about 1000 million tonnes of coal reserve, while Meghalaya also has about 1200 million tonnes. The first coal mining in the region was started in 1865 at the Makum coal-fields under the initiative of H.B. Medlicott.

            The coal reserves found in North East India  belong to Gondwana, and Tertiary ages. But the Gondwana coal present is in disjointed than lenses along the Himalayan foothills from Bhutan Duars to Sadiya. This has not been so far exploited because of the  thinness of the seams and transport difficulties. It is the Tertiary coal that  is found in thick workable seams and, therefore, mining has developed for its extraction in several places. But their impurities, as stated above, have hindered their optimum  exploitation. The workable Tertiary coal deposits are found in the following two groups of geological beds :

            (1) Lower Tertiary deposits are found in South Garo, Khasi and Jaintia Hills and in Karbi Anglong. These  deposits were laid down in the Eocene Period (Jaintia Group).


            2) Middle and Upper Tertiary deposits of coal are found in Ledo-Jaipur-Naginimara area of Assam. These deposits were laid down in the Tikak Parbat Formation of Barail Group during the Oligocene Period.

 Distribution of Coal Deposits : The  geographical distribution of the coal reserves is as follows :

  (A) Coalfields of Assam

1. Upper Assam Region : In the  Upper Assam region coal occurs from Miao Bum in Changlang district in the east to Nichuguard at the Nagaland foothills, south of Dimapur. The important  coalfields of the region are as follows : (i) Makum Field in the Margherita area, (ii) Jaipur-Dili Fields and (iii) Naginimara Fields.

            (i)  The Makum Coalfields are located in the Burhi Dihing Valley to the east and  south of Margherita. The important mines here are located at Borgolai, Ledo (27018’ : 95047’), Tipang and Namdang over an area of 30 km by 5 km. The coal of the  region is mostly of bituminous variety. The seams are generally thick with an average of 17 m thickness. These fields are estimated to hold 191 million tonnes of coal. Because of transportation facilities, these fields  have been worked upon since long.

            (ii) Jaipur -Dili Field is located at the Tirap foothills of Dibrugarh district between the rivers Burhi-Dihing (near Jaipur ) and Dili (headstream of Disang). The total reserve of this coal field is estimated to be about 28 million tonnes. The coal occurs here at a depth of about 100 metres. Lakadong is the main mining area here .

            (iii) Naginimara Field is located at Nagaland foothills just south of Nazira. The total reserve of this field is estimated at 10 million tonnes. The important mining centre here is Naginimara.

  2. Karbi Anglong Coal Deposits : The  coal deposits of Karbi Anglong are found in the following places.

            (i)  Longloi Deposit : This deposit is found at Longloi about 40 km west of Barpathar. The coal seam here is about 4 metres thick. However the quality of coal as such, is not very good with a high proportion of impurities present in it .

            (ii) Koilajan Deposit : This  deposit is located at  Kailajan about 28 km west-north-west of Dimapur. The quality of coal is fairly good and it  is commercially exploited for local use.

            (iii) Silbheta Deposit : This deposit lies towards the western side of Karbi Anglong , to the north of Dimapur -Nagaon Road and covers an area of 1.4 km2  .The coal is of fairly good quality and the total reserve is estimated at 15.7 million tonnes.

            Besides the above deposits coal is also found at  Dissoma and Kaliani river valleys of Bokakhat Sub-division.

            (iv) Kharbhaman Deposit : This deposit occurs on the western side of Kharbhaman Hills (26002’N : 93024’ E ) in the south-western part of Diphu Sub-division. There is a single seam of coal extending over 0.5 km. The estimated reserve is 0.5 million- 06 million tonnes.

  (B) Coal Fields of Meghalaya

            There are rich coal deposits along the southern part of Meghalaya in the Garo, Khasi and Jaintia hills. A broad outline of the coal deposits of the state is given below:

            (i) The Garo Hills Deposits :The Garo hills has a rich reserve of fairly good quality coal The fields of this area were first explored by Bedford in 1842 and subsequently by H.B. Medlicott of the Geological Survey of India. The G.S.I. has been still continuing their exploration, besides the Meghalaya Department of Geology and Mining for locating and assessing the  extent of the mineral reserve. The important fields so far found are located at (i) Darranggiri, (ii) Rongrengiri, (iii) Harigaon, (iv) Siju Simsang Valley and (vi) Nangalbibra (25’28 : 900 42’).

              Much attention has now been given to the development of the Darranggiri Coalfield. This field lies to the north of the Tura Range, a few km south of the Rongrenggiri field. The Simsang river, flowing through this area, exposes coal seams on both of its banks. It is said that this reserve contains about 125 million tonnes of coal. The  Darranggiri field is also very rich in reserve. It is said to continue from Darranggiri to as far east as Nongstoin of the West Khasi Hills district.

            (ii) The Khasi Hills Deposits : In Khasi hills workable deposits of coal seams are found in several places, of which Langrin (Um Blay) located in the extreme south west corner of the West Khasi Hills district,  Um Rileng, 8 km south west of Shillong , Mowbeh -Larkar, 32 km south of Shillong, Mowsynram, 19 km north west of  Shella, Mowlong, Rangsanobo and Laitryngew near Cherrapunji, and Thangjinath and Lyngkerdem near Pynursla. Of all these deposits, coal is extensively mined at (i) Um Rileng mines, (ii) Mowbeh -Larkar mines and (iii) Mowlong, Rangsanobo and Laitnyngrew mines.

            (iii) The Jaintia Hills Deposits : The workable coal seams of the  Jaintia Hills are located at Jarain, 16 km south of  Jowai, Bapung, 11 km east of Jowai, Sutunga, 24 km east -south -east of Jowai, and  Lakadong, 16 km north -east of Jaintiapur. Coal is also reported to occur in the headstream region of the Kapili River.

            (C) In Nagaland Tertiary coal is  present in the basal argillaceous beds of the Tikak Parbat formation (Barail Group) of the Oligocene Period. Because of a high content of organic sulphur and indifferent coking character, this coal has not been extensively used in the iron and  steel industry of the country. Within the state, coal deposits are  found to occur in the Dikhu (Dikhou) Valley of Mon district and Changkekong -Jopukong region of  Mokokchung district. In the latter region, Changki-Chonglymsen, Waromung -Mongchem and Lakuni-Mirinpoh are the areas where large quantities of coal occurs.

            (D) Coal Deposits of Arunachal Pradesh   In Arunachal Pradesh both Gondwana and Tertiary coal deposits occur. While the Gandwana coal deposits are found along the Himalayan foothills in the west and east Kameng districts. The Tertiary coal is present in the  Namphuk and Namchik valleys of  changlang district almost in continuation to the  Ledo-Borgolai fields.

            (E) In Manipur high grade coal has not been struck so far. However Lignite deposits occur near Kongra-Waiphei Village (240 26’35” N: 930 42’32” E), about 32 km south-west of Imphal. Lignite is also found in the Tureloo Valley in the Churachandpur district of the state.

            (F) In Tripura, coal has so far been found to occur in Kailashhar area near the Tripura-Bangladesh border in the North Tripura district This coal is of Tertiary period and contains impurities like organic sulphur. However, it is  commercially exploited for local use. Tripura also has lignite deposits at Ujan -Tangong near  Hirachara tea estate, Dertuichara and   Nattinchara. The deposits are generally small and lie under considerable rock cover. These have, therefore, not been exploited so far

           (G) Although coal has so far not  been  exploited in Mizoram, it is said that the state has some reserves, especially in Lunglei district. A sample of coal found in the Phairung river valley of the district, on analysis, is found to contain 40.40% of fixed carbon 29.14% of volatile matter, 15.97% of ash 14.49% of moisture. The presence of this sample indicates that there are coal reserves in the state.


                                                  Trend of Production :

                        Production of Coal in N.E India (million m tonnes)



































Source : (I) Statistical Handbook of Assam, 1971,’80,’82 and ‘92

            (ii) Statistical Handbook of Meghalaya, 1992

            (iii) Basis Statistics of NER. 1995

            (iv) Meghalaya at a glance, 1992.


            At present the coal of this region is used by railways, tea gardens and  birck -fields, besides being used for domestic purposes. Some amount of this coal is also sent to the iron and steel industries of the country for blending with the  high grade coking coal . Besides , some of the region’s coal is used in the local cement industries and the thermal power generating stations. It is said that the coal available in North East India , if treated properly, can be used in the fertilizer and chemical industries also.


            Petroleum : North East India is rich in petroleum deposits. In fact until the  middle of the nineteen sixties Assam was the only state in India producing some amount of oil .The presence of oil in the forests and fields of Upper Assam was  detected as back as  in 1822. Subsequently, on the advice of Mr. H.B. Medlicott an oil well was Mechanically drilled in  1867 near Namdang river  between Margherita and Jaipur by  Mr. Goodenough. Oil  could be struck there at a depth of only 37 metres. On further probe it was found that the quantity of oil there was not much and hence its exploitation or further drilling were not taken  up. Meanwhile Assam Railway and Trading Company started  lying railway track between Margherita and Makum mainly to transport coal from the  Ledo-Margherita region and  it was in the  course of their cleaning and digging works that the Company engineers detected many  oil seepages in the  Digboi area in 1889.The Company engineers then drilled a well at Barbeel in 1890 which produced about 900 litres (200 gallons )of oil every day. During the period 1890-1899 the A. R. T. Company  drilled 14 oil wells and having found them productive, a new company under  the  name  of Assam Oil Company was constituted in 1899. A refinery was set up at Namdang, near Margherita and the crude produced in the surrounding wells began to be refined. The A.O.C was a small Company and had limited resource. It could drill only 80 wells in 20 years. The Burma Oil Company then took over the A.O.C. in 1920 as a subsidiary and the former set up a new large refinery at Digboi in 1921. Up till 1920 the average annual production of  petroleum was less than  20,000 tonnes annually. But after the take over  of  the A.O.C. by the B.O.C. production started increasing. The B.O.C. explored oil in  the Barak valley also  during the first two decades of last century and found oil and natural gas in  Masimpur-Badarpur area. In the Badarpur and Patharia fields as many as 80 oil wells were dug and from these wells as much as 250,000 tonnes of oil was extracted. After that the  wells ran dry in the early nineteen thirties. The Digboi oilfields, however, continued to produce and between 1934 and  1953, these  produced on the average  600 million litres annually. The yield began to decrease after that and the A.O.C. had to  explore the neighbouring areas for more source and between 1952 and 1956 oil was struck at Naharkatia, Moran and Hoogrijan. The Oil India Limited constituted in 1958, subsequently developed and operated these  fields. The oil bearing deposits of these fields belong to the Barail and Tipan sandstone beds and lie at a depth of 3000 metres. The crude yields paraffin wax, lubricating oil, bitumen and various other by-products. Apart from the Oil India Limited, the Oil and Natural Gas Commission reconstituted in 1959, also started exploring for oil and natural gas after and after 1950 many deposits of oil and natural gas were found. The areas where these two valuable resources were discovered during the there decades following 1950, are Tengakhat , Jurajan , Rudrasagar, Geleki. Lokwa, Longsai (Dikhoumuk ), Amguri and Barhola. In almost all these  areas oil and natural gas have been found in the Barail and Tipam beds. In Barhola, however, these are found trapped in the gaps between the blocks of granitic greiss at a depth beyond 3500 m . Among all the  oil fields of Assam  the Galeki field is found to  be the largest.

            Being encouraged by the success in exploration in Upper Assam, the O.N.G.C. and  the Oil India Limited searched  for oil in other  parts of Assam and North-East India. The geological investigations have revealed  that in the  area along the 1300 km long belt, which runs from Upper Assam through Barak Valley, Tripura and  Chittang Hills to farther south, there occurs the Assam-Arakan Basin bearing immense hydro carbon potential. The Oil and Natural Gas Corpration in 1988 struck oil at  Masimpur (at a depth of 1318 metres), Panchagram and Badarpur of Barak Valley. Although commercial exploitation has not been started here, it is hoped that these will turn out to be commercially viable fields.

            Arunachal was brought into the oil map of India by the Oil India Limited by discovering oil at Kharsang in 1976, where oil occurs in the  Girujan beds of the  Oligocene Period. Further exploration has been going on in the state at Pasighat (East Siang), Ningru (Lohit), Kumchai (Lohit) and Bardumsa area and Namchik Valley including Jairampur (Changlang). Till the 31st March of 1988, the Corporation drilled 37 wells in Arunachal Pradesh and produced 2,39,623 tonnes of crude oil.

            Petroleum has also been struck at Champang in Mokekchung district of Nagaland. It is said that gas  and  oil deposits may be also available in the Satukba-Chumukedima area of Kohima district.

            Oil and gas seepage is reported from the north-central part of Mizoram also. Drilling has been carried on near Dibuia, Lakhumi and Longsamtang villages of the region.

             In 1985-86, North-East India produced 5.03 million tonnes of crude oil, of which Assam’s production was 4.97 million tonnes, the  rest having been produced by Arunachal. In that year, Assam’s production accounted for  16% of the  national production of 30.16 million tonnes. The trend of crude production in North-East India is as follows:




Production (‘000tonnes)




























            Source : Basic Statistics of NER. 1995.


            The crude oil of the region is at present used in the refineries of Digboi, Noonmati(Guwahati), Bongaigaon Petro-chemical Complex Ltd. and  Barauni to produce Kerosene, diesel, petroleum, wax, paraffin, grease, naphtha, D.M.T, xylene, synthetic fibre, synthetic rubber, plastic and various other by products.

            The crude petroleum from the oil fields is sent by a 24 cm diametre pipe lines to  the distant refineries. Thus there is a pipeline (1152 km long) linking Lakwa-Rudrasagar fields with Barauni, Moran-Naharkatiya fields with Noomati (440 km) and Bongaigaon (600 km). Similarly a  12 cm pipe takes the crude from the Naharkatiya-Hoogrijan fields to Digboi.

            Natural Gas : Like petroleum, natural gas is a valuable source of power and various other chemical by products. It is a gaseous mineral of organic origin lying locked underground. The gas contains a very high proportion of methane (85%-90%) and some proportions of ethane (8%-9%), propene (2%-3.5%) and butene (0.7%-1.7%).

            Natural gas is  normally found to remain in association with petroleum. But in certain places it may be found independently. The gas found with petroleum is known as ‘associated natural gas , associated natural gas, and  that found independently is called ‘ free natural gas.

            As the North East India is rich in petroleum, so also it is rich in natural gas. It is found in the Barail groups of rocks (of Oligo-Miocene Periods) occurring at very high pressure and temperature.

            In  North East India natural gas is mostly found in Assam  and Tripura. In Assam, almost all the petroleum producing  areas of the  upper Brahmaputra Valley, especially Naharkatiya, Moran, Lakwa and Rudrasagara, contain ‘associated natural gas’ Barak Valley, on the other hand, contains ‘free natural gas’  in the Adamtila structure at a place 60 km away from Silchar. Tripura is the other state in the region where free natural gas has been found. Wells have been dug at a place 15 km west of Agartala, from where gas flows out at the rate of 1.12 lakh cubic metres per day. It is estimated that in an area of 77 km  around Agartala, there is a reserve of 8 billion m3 of natural gas besides, Rakhiba and Baramura in the state, where also a rich gas deposit has been detected. Free natural gas is said to be  available in Turial area of Mizoram and  Chumukedima area of Nagaland. The North East Indian region is said to contain now a total reserve of 240 billion m3 of gas.

            Although the region is rich in natural gas, it has not been able to utilize the resource, because of lack of market, capital and technical know-how. In fact, for many years the gas coming from the oil wells has been under the process of flaring up. It is said that nearly 1 billion cu m of gas has already been flared up. But by using the gas so wasted, the region could have generated power and supplied raw material for production of fertilizer, petro-chemicals and other by-products.

  Production: In 1991-92 Assam produced 2082 million m3 of  natural  gas, which rose to 2056 m cu m in  1985-86. This accounts  for 25% of the total production of 8134 million m3 of gas in the country as a whole. The Tripura fields now produce 1.12 lakh cu m of gas per day.

            The important industries so far built up on the basis of the natural gas of Assam are Namrup Fertilizer Factory (F.C.I.), Namrup Thermal Power Project, production of carbon black and Assam Gas Company, which provides liquefied petroleum gas for domestic use. Besides many tea gardens in Upper Assam use it for their factories as a source of power.

            The Oil India Limited uses 0.80 lakh m3 of gas daily for its own works. It is also used by the Bongaigaon Petrochemical Ltd. as raw  material to produce various chemicals. The recently established synthetic fibre plants in Assam are going to benefit largely from the supply of natural gas. There is an ambitious project of  establishing a gas cracker plant in Assam on the basis of the natural gas. Once this is established a large number of industries can be set up based on it.

            Limestone : Limestone is an important mineral which is used in the manufacture of cement, as flux  in iron and for white-washing buildings and walls. North East India has a vast reserve of limestone totaling about 6.684 million metric tonnes. The limestone found in the  region is mostly organic, originated  from nummulite shells in those  areas which were under intermediated sea condition during the Mesozoic period.

            Of the seven states, the largest reserve of limestone  line in Meghalaya (4665.36 million tonnes) followed by Arunachal Pradesh (1504 million tonnes), Nagaland (450 million tonnes), Assam (135 million tonnes) and Manipur(4.6 million tonnes). It is also found in small quantities in Mizoram and Tripura.

            In Meghalaya limestone is found along the Southern part of the state almost all  throughout its length from the Southern Garo Hills district to the border of Meghalaya and Assam and beyond. This belt is said to be 400 km long. The limestone occurring in this belt is not only of good quality, but it is also found in thick workable layer of 7m to 230 m. In the Garo hills limestone is found exposed along the Simsang river gorge near Sizu (2503 N 90043 E). In fact the Sizu area has coal, clay, Sandstone and limestone occurring in close proximity, making the area a potential site for localisation of cement industry. In the Khasi hills area there is a 64 km long belt of limestone from the north of Lamgaon through Therriaghat (25011 N: 910450E) to Shella river. The outcrop here has a general length of 3.2 km and the total reserve is  estimated at 1000 million tonnes. In Jaintia, there is a large bed of limestone about 22 km long, near Jowai which can well support a mini cement plant.

            In Assam limestone occurs in a number  of places  in the Karbi Plateau. In the border region between Meghalaya, North Cachar Hills and Hamren sub-division there are limestone deposits in the Kopili and  Kharkhor river  valleys. The Garampani-Umrangshu area of North Cachar Hills and  has a reserve of about 154 million tonnes of good quality limestone. The Diphu and Bokajan sub-divisions of Karbi Anglong also have rich reserves of limestone. The Kailajan and Dilai area of Bokajan sub-division have high quality limestone, which is used in the  Bokajan cement factory. In the Diphu sub-division limestone is found in the  Sibheta area (26000’ N.93018’) which contains about 52 million tonnes of limestone.

            In Arunachal Pradesh Limestone has been discovered at Tela-Tidding area of Lohit district, where an  estimated reserve of 9.1 million tonnes of the mineral occurs. The Tezu area of this  district is also said to contain a reserve of high-silica and high magnesia marble containing about 74 million tonnes. Dali, Mega and Kabbu in Siang districts also have rich deposit of limestone.

            Limestone is  available in Manipur in Chandel and Ukhrul districts. The total reserve in these two districts, upto workable depth, is estimated at 4.5 million tonnes. Out of this, 2.2 m. tonnes occur in Ukhrul in lenses, while the remainder is found in isolated pockets at Hungdung, Mova and Khangoi of Chandel  district. The deposits of Manipur generally carry 34% to 53% of lime.

            In Nagaland high grade limestone deposits have been discovered in various places of Phek and Tuensaang district. Out of them, the  deposits of Wazeho in Phek district and Nimi(375 million tones) in Tuensang district are really large. There is calcareous tufa type of limestone is Chakhabam of Kohima and Dibuia of Mokokchung. The total reserve of limestone so far discovered in this state is estimated at  450 million tonnes.

            Mizoram also has limestone deposits in several in several places. Of these ones  found at Muthi, Tuirial, Vakku and Kawrthan areas are more important.

            In Tripura silicious limestone deposits have been located at Shankan Range, but no production has so far been achieved.


Production : The limestone produced in the North East India has so far been used  by local cement industries. Plans are on to use it in the paper and other chemical industries of the region. The total production of limestone in the North -East India is shown below:


                                    Limestone Production in N.E. India

                                                (‘000 tonnes)




Arunachal Pradesh





































                          Source : (i) Statistical Handbook of Assam. 1992

                                    (ii) Statistical Handbook of Meghalaya, 1987

                                    (iii) Meghalaya at a glance, 1992,

                                    (iv) Basic statistics of NER, 1995,


Reserve  : A thorough investigation of the limestone deposits of the region is yet to be made. However, the estimates made so far reveals the following reserves so far :


                                    Limestone Reserves of N.E. India

                                                (million tonnes)


1 Arunachal Pradesh


2. Assam


3. Nagaland


4. Meghalaya


5. Manipur



            Based on the limestone production of southern Meghalaya, there  came up the Mawmluh-Cherra Cement Factory as a Meghalaya state public sector undertaking. Its present production is about 250,000 tonnes per annum. The limestone deposits of Dillai hill made the basis for Bokajan Cement Factory in  Assam which produces about  400,000 tonnes of  cement annually. In Arunachal Pradesh a mini cement plant has been established near Tezu, which  produces about 30 tonnes of  cement  a day . This plant is supplied with the  limestone  of Tidding area . A mini cement plant has also been set up at Hungdung in Chandel district of Manipur, which can produce 50 tonnes of cement  daily. In Nagaland a mini cement plant of 50 tonnes  per day capacity has been established at Wazeho of Phek district. The quality of limestone of this area is so good that it can produce even white cement if so intended.

            Although North East India is rich in limestone, it has only two major and three mini cement plants which produce only about 0.6 million tonnes  of cement annually. But the region needs about 2 million tonnes of cement every year and hence there is a large gap between the requirement and production, which is met by import from other states of the country. It is therefore, desired that more cement factories be developed in the region as early as possible.

            Sillimanite : North -East India is famous for sillimanite reserves after  that of petroleum. Sillimante is a valuable mineral that is used in the manufacture of refractory materials, sparking plugs for automobiles and in glass industry. About 90% of the total production of sillimanite in India comes from this region.

            Meghalaya, and Karbi Hills of Assam are the two areas where this  mineral has been found. It was in  1922 that the occurrence of it in the Khasi Hills was first traced and subsequently, after independence, the  Karbi Anglong deposits could be discovered.

            In Meghalaya sillimanite deposits occur as outcrops associated with older gneisses over a belt of 320 km2 in the Sonapahar -lalmati area in the northwestern corner of West Khasi Hills, just south of Boko- Hahim region of Assam . The variety of sillimanite found here is of very good quality containing 61 % of allumina and 36% of silica. It is therefore, of great value as a refractory material. In fact, because of  its  massive character and absence of impurities in it, the cut and sawn blocks of it can be readily used for lining glass tanks and other furnaces without precalcinating. It is estimated that this region contains a reserve about  255,600 million metric tonnes of sillimanite accounting for 83% of the  total known reserve of the country.

            In Karbi Anglong the mineral has been discovered at Chippilangso Ingtigaon, Samenlangso, Chailangso, Amterang, Bamuni and Chelabo areas. It is estimated  that  the reserves of Chippilangso are of the order of 10 million tonnes.

            The minning of sillimanite in the early days, i.e. since 1950 was done by the Assam Sillimanite Ltd. In 1973 the  lease of the  mines was taken over  by the Hindustan Steel Ltd. and this company has been mining the mineral ever since. The mining of sillimanite in Karbi Anglong is yet to begin. The following table shows the  production of sillimanite from the Sonapahar-Lalmati quarries





81,00  tonnes


33,00  tonnes


44,00  tonnes


52,00  tonnes


2,240  tonnes


1,649  tonnes

                          Source : Basic Statistics of NER, 1995.

                                     Meghalaya at a glance, 1987, 92

                                     Statistical Handbook of Meghalaya, 1989.

  Dolomite : The  dolomite deposits of the North East India are so far found in Arunachal Pradesh and Meghalaya. In Arunachal Pradesh its deposits have been discovered at Rupa and Dedza over  an area of 1.80 km2 in West Kameng district. The reserves are  estimated at 38 million tonnes in the former and 20 million tonnes has been identified at Cherrapunji. Although no large-scale commercial exploitation of this mineral has so far been taken up, it holds out great prospect for future.

   Marble : Although no good quality marble has so far been discovered in this region, there  are deposits of green marble along with serpentine and gemstone in the Moreh region of Manipur. Marble along with limestone and graphite has also been discovered in the Lower Subansiri district of Arunachal Pradesh. The Govt. of India has sanctioned Rs.2 crores toward building the infrastructure for exploiting this minerals.

   Corundum : Corrundum, which is ranked second only to diamond in hardness and is used in refractory crucibles, occurs in North East India in association with sillimanite as a locally segregated bodies in the sillimanite bearing rocks of the Sonapahar-Lalmati area of Meghalaya. It is also found in Patarkhang area and Raindu River Valley of West Khasi Hills of the state. In the Sonapahar-Lalmati area corrundum often makes up 20% to 50% of the sillimanite ore. Sometime corundum is found to be formed as blue transparent crystals like sapphire and then it is regarded as a precious stone.

  Gypsum : Gypsum,  which is used in the chemical industries and to manufacture of the region. In Assam it is found in the Dimasa Reserve forest of Karbi Hills, near Badarpur of Cachar district and  near Haflong and Mahur of North Cachar district. In Meghalaya gypsum deposits are confined to the Garo Hills area, especially near Mahendraganji, Garobadha, Mariangpara, Mongopara  and Tarapara. In Nagaland it is discovered in Tuensang district.

   Asbestos : Asbestos is a  fibrous mineral, that is used to manufacture roofing sheets, fireproof garment, curtains, brake-linings, insulating mats filter-pads for acids besides various chemicals.

            No economically exploitable deposits of asbestos  has so far been found in North -East India. Silky Chrysolite (a variety of  asbestos ) has, however, been found in the Tizu Valley between Punchini and Kurani (250 40’ N, 940 40’ E) and near the Gedu river close to Myanmar border in  the Phek district of  Nagaland. The deposits of this mineral has also been reported from Moreh, Nepalibasti and  Kwatha areas of the Chandel district of Manipur. Besides these two states, there are some asbestos deposits near Payani in the Mishimi Hills Arunachal Pradesh.

  Mica : In North East India mica is found mainly in the rocks of the  Meghalaya-Karbi Plateaus. As white mica (muscovite) it is available in the Dholamara Hills of Goalpara district adjoining the  Meghalaya Plateau and as lepidolite or lithium mica it is present at is present at the northern tip of the Dhir Beel (26025’N, 930 44E) and Mukjan areas of the Kaliani river valley.          

  Sulphur : Sulphur  deposits have not been found independently in North -East India. However, the Tertiary coals in the Dili-Jaipur and Makum areas contain sulphur to the extent of 6% along with other impurities. Thus ammonium sulphate can be extracted from the coal and sulphur can be isolated from the compound.

  Beryl: Beryl is an important mineral. It  is used to extract beryllium, which, in its turn is used in the preparation of a special alloy with copper. This mineral has become very important of  late, as  beryllium is used in the  nuclear reactors as a moderator. A small quantity of it is also used in chemical industry for  manufacturing beryllium salt and ceramic glaze. Besides, a verity of beryl turns into a precious stone, called emerald.       

            Occurrence of beryl suitable for working on a commercial scale has not so far been found in North -Eastern region. Small quantities of it have been discovered in Garo Hills, Karbi Anglong and at Darka, Kharmajua and Rangsali of southern Goalpara embedded in the pegmatite veins of the gneissic rocks.

  Mercury: Very recently a deposit of mercury has been found at a small zone in Bangswar river in Tripura by the  Geological Survey of India and Science & Technonogy Department of Tripura.

  Graphite : Although no graphite has commercially been mined in North East India, the region is rich in  this mineral Almost all the deposits of graphite of the region are confined to Arunachal Pradesh. There are rich deposits of it at La Lamdak (23,777 tonnes of flaky variety and 3.3 million tonnes of  amorphous variety) Lalpani (71 million tonnes of amorphous variety) and Lanchidhouri (10,35 million  tonnes of amorphous type) of Subansiri, Siang and Lohit districts of the state.

   Quartz and Feldspar : Quartz and feldspar commonly used in large quantities in the  region. However, a good quantity of these minerals is found to occur at Hahim (25050’52” N, 910 0940’’E) in Kamrup and Rangsali hill of Goalpara district. The total reserve of quartz at Pancharatna hill of Goalpara district. The total reserve of quartz at Hahim, Rangsali and Silbheta is estimated at 8500 tonnes and that of feldspar at 6200 tonnes.

   Glass Sand : In North-East India, glass sand has so far been found in Assam, Meghalaya and Tripura. The Jiajuri and  Thanajuri hills of Karbi Anglong contain about 11.78 million tonnes of glass sand. In  Meghalaya Laitryagew, Umstow and Alugumadam areas of Khasi Hills and  Siju and Tura areas of Garo Hills contain 2.3 million tonnes of it. Tripura’s reserve is small(187127tonnes) and distributed over Bijoynandi Cherra, Jogendranagar, Kalinagar and Purba Champamura.

   Alum Shale : Alum is used in dyeing and tanning  industries. It is also used as an antiseptic, Alum is extracted from pyrite. In North -East India pyrite is found  associated mostly with shale in the coal bearing horizons of  Upper Assam and Khasi and Jaintia Hills. This shale can be used for extracting  aluminium sulphate and alum. Apart from the coal bearing horizons, pyrite is also found in the southern foothill region of Goalpara in quartz-feldspathic gneiss. In  Karbi  Hills it is found as  nodules  in the coal and  shale beds in Silbheta and Kailajan area and as carbonaceous shale in the area between Lunggit and Takhi villages. In Nagaland also coarse grained pyrite is found in the Zunki Valley of Tuensang district.

   Clay : North-East India, especially Assam, is very rich in various types of clay used in industries. Following are the important types of clay found in the region.

   (A) Fuller’s Earth : It is a dull white to light grey-white mineral used in oil industries  and in removing stain, fats and grease. A low grade Fuller’s earth is found at Bhutankhuti and Subankhata in the northern part of Nalbari district of Assam. This clay covers an area of 9.2 km2 . The deposit of Bhutankhuti amounts to 5.67 million tonnes and that of Subankhata 13 million tonnes. The clay is mixed with sand and its presence in the mixture varies between 53% to 72%.         

   (B) Fire Clay : Fire clay is used to manufacture firebricks for lining furnaces. It  is also used in glass and cement industry. In North-East India it is found in association with the coal seams of Upper Assam, Karbi Anglong and Jaintia hills. In Karbi Anglong it exists in huge quantities in the Lakadang coal seams of Kailajan (1,678,680 metric tonnes and Silbheta (7,624,500 metric tonnes). The Kailajan clay a white to buff coloured, sticky and argillceous, which can be used in  refractories and ceramic industries. The Silbheta deposit is white to dull white in colour and argillaceous. It is suitable to manufacture aluminium sulphate, apart from using in ceramic industries and refractories.

  (C) Kaolin or China Clay : Kaolin is used to manufacture crockeries, sanitary wares and in electrical goods (insulator) industries. In North East India it is found in Karbi Anglong, Golaghat and  Lakhimpur districts of Assam and at Mawphlong of Meghalaya. In Karbi Anglong good  quality Kaolin deposits have been discovered at Silbheta, Silonijan and Deopani areas. The white to dull white china clay found in this area can be used in ceramic industry, which is so far altogether  absent in the region.

  Mineral Salt : Salt was produced in North East India by collecting saline water from the salt-spring found in certain fault-zones of the region. The salt water so collected used to be dried over fire in bamboo cylinders. But as the salt  so produced was inadequate, it used to be imported from other parts of India. Salt-springs are found  in Sadiya, Jaipur, Mohong and Barhat of the Brahnaputra Valley along the  foothills. In Cachar they occur at the Hilakandi Valley in the north-western corner of the  district. In Nagaland the salt-springs are located in Kohima, Tuensang and Phek districts and in Manipur they are present along the foothills in the eastern part of the Manipur basin and in Ukhrul district. In fact, salt is still prepared for domestic use in some of the hill areas of North East India.

  Mineral Water : There are many hot springs in North -East India. A good number  of them  are located in the northern and north-eastern part of the Karbi Plateau and eastern part of Jaintia hills. Of all these, the two more famous ones are  located in Golaghat district and North Cachar Hills. The one in Golaghat district is located in the Nambar Reserve Forest about 19 km southwest of  Golaghat town. The water of this spring contains hydrogen sulphide and  its temperature is 530C to 580C. The  other hot-spring, located at the  headstream of Kapili is at a distance of 33 km east of Jowai. Its water is 350C warm. Both the springs have clear water and are known as Garampani.

  Building Materials : Granite, granite-gneiss, sandstone, quartzite, slate etc. are often used in constructing buildings, roads, dams and factories. In the North -East India, these materials are found in almost all the states.

            Granite and granitic gneisses are found all over the Meghalaya Plateau and in the Karbi Plateau of Assam. Besides, the outlying hillock of the  Karbi -Meghalaya  Plateau scattered over the lower Brahmaputra Plain have also these rocks. Khasi greenstone, used as road-metal are found abundantly in the central and southern part of the Meghalaya Plateau. Blocks of Sylhet trap are found along the southern margin of the Meghalaya Plateau and in  the  Kailajan, Jamuna, Hariahjan and Deopani river beds of Karbi Anglong. In Arunachal Pradesh this rock is found in West Siang district. Quartzite is found in and around Shillong, Naga-Patkai ranges and Arunachal Pradesh .Slate used for roofing purposes are found in the north-eastern part of Shillong and in the Tizu and Tepe river Valley of Nagaland . Massive coloured sandstone used as bricks, slabs and posts can be found in Khasi and Garo hills, in Wokha, Mokokchung and Kohima districts of Nagaland and in the  headstream areas of Ledo, Lekhapani, Namdang, Tipam and Tirap rivers of Arunachal.


            Power is one of the most important infrastructural element for economic development of a region. The traditional sources of power  are coal, petroleum, natural gas and running water and the form in which the modern civilization receives power is electricity. North-East India has almost all the sources, but development of power in the region is one of the lowest. The coal that is present in the region contains a high proportion  of sulphur, phosphorus and other volatile and non-volatile impurities and without their removal local coal is not directly suitable for electricity production. Diesel, an end product of petroleum is used to produce thermal electricity but it cannot be used extensively, as its demand in other spheres is too high. There is abundant natural gas in  the region and it is slowly being used to produce thermal electricity in the area. The dearth of  huge capital and  technical know-how needed have so far hindered power generation from natural gas. So far hydro-electricity is concerned, the region is rich in water resources but the huge initial capital needed to construct dams and barrages and install the required machinery are some of the stumbling blocks in generating hydroelectricity.

            The region is, however, extremely rich in hydro-electric power potential. The total potential (more than 40,000 mw) of the region accounts for about 30% of that of the whole country. The river Brahmaputra, Barak, Manipur and Kaladan and their numerous tributaries receive enormous quantity of water from rainfall and melting snow. It is said that Brahmaputra alone can produce more than 30 m. kw of electricity. Besides, there are such large tributaries as the Ranganadi, Dikrong, Burai, Jia Bharali, Jia, Dhansiri, Pagladia, Manas, Saralbhanga and Gadadhar in the north bank and Na Dihing, Burhi Dihing, Disang, Dikhou, Dhansiri, Kopili, Digaru, Kulsi, Krishnai, etc. in the south bank which contain large volumes of water throughout the year and which pass through hilly terrain in their upper courses, providing conditions suitable for damming them and generating electricity. The Barak, Manipur River and Koladan and their tributaries also have similar physical setting. But the factors stated above have largely hindered the development of hydroelectric power generation in the region.

            Small thermal power stations were first set up at the large towns in this part of the country during the first few decades in order to supply electricity to the limited urban area. The first ever hydroelectric power production in North-East India started in 1922 with the help of water turbine set up at Bidon Falls. It had an installed capacity of 300 kw. Before 1950, the region had 7 small stations generation electricity with an installed capacity of 3,362 kw, besides a few stations run by the then railway companies. All these stations largely catered to the domestic demand of a few towns. In 1956 the installed capacity of electricity in the whole region was 5.3 MW. In 1957, the Umtru Hydel project was commissioned. Subsequent to that new thermal and hydroelectric A brief  projects were taken up . A few of them have been completed while a large number is either yet to be completed or yet to be started. Of these six (5 hydel and 1 thermal) are in Meghalaya, fifteen (all hydel including 1 NEC and 2 micro ) are in Manipur, three  (all hydel including two gas based thermal )are in  Nagaland, eleven (all hydel two micro and one in two separate stages) are in Mizoram, four (two hydel and two gas based thermal) are in Tripura, fourteen (all hydel including three micro ) are in Arunachal and sixteen (eight hydel including  three micro and eight thermal including five gas based) are in Assam.


            Installed capacity of power in N.E Region

                       (in MW) as on 31.3. 1994.  






Arunachal Pradesh





































Loktak (Hydel)        





Khandong (Hydel)





Kopili (Hydel)





N.E. India






                                                Source : Basic statistics of N.E.R 1995.

Tabular introduction  of the major projects are given below :  

Name of Project


Installed capactity (MW)






1.UmtruHydro project

On Umtru river in Ri Bhoi    


Completed in 1957

2. Umium (Barapani ) (Hydro. Project in 1963           

On Umium river in E. Khasi Hill dist


Completed in 1963

3. Kyrdemkalai Hydro pro.




4.Nangalbibra Themal

West Garo Hills dist.near Tura 



Manipur (Total : 15)




1. Loktak Hydel

35 km sw. of Imphal



2. Leinmakhong Hydel Project

On Leimakhong river in Manipur Central dist



  3. Nunghangkhong Hydel Project

On Nunghang- khong river in Ukrul dist





4.Tipaimukh Hydel Project

An NEC Project at Manipur-Mizoram border







1.Juja Mini Hydel Project

On Juja river in Kohima dist.


Commissioned in 1978

2.Daiyang Hydel Project

On Daiyang river in Wokha dist.


Under Construction

3.Dikhow Hydel Project

On Dikhow river in Mon-Tuensang dist.


Under Construction





1.Dhaleswari Hydel Project

On Tlawng River







1.Gomti Hydel Project

On Gomti Valley



2.Rukhia Thermal (Gas Based)Project

At Rukhia in W.Tripura dist.



3.Baramura Thermal(Gas Based)Project

At Baramura,near Agartala



4.Maharani Hydel Project




Arunachal Pradesh(Total:13)




1.Kameng Hydel Project

On Kameng River nearBhalukpung


Construction to be started

2.Ranga Nadi Hydel Project

On Ranga Nadi near Yazali in Lower Subansiri dist.


Construction  under way

3.Damwe Hydel Project

On Lohit river


Under Construction

4.Pakke Hydel Project

In East Kameng dist.


Under Construction





1.Kopili HydelProject

On Kapili River at Umrangso


Partly completed

2.Karbi-Langpi Hydel Project

At Amtreng in Hamren sub-Divn.


Under Construction





4.Namrup thermal

At Namrup


Under cons.

Power (gas based) project




5.Namrup West Heat(th)




6.Chandrapur Thermal Power (Furnace Oil based)Project

At Chandrapur


Commission-ed in 1973

7.Lakwa Thermal Power (Gas Based)Project

At Lakwa



8.Bangaigaon Thermal Power(CoalBased) Project

At Salekati



9.Borgolai Thermal Power(Coal Based)Project

At Borgolai near Margherita



10.Amuguri Thermal Power (gas Based)Project

At Amuguri Sibsagar dist.



11.Gelaki Thermal Power(Gas Based)Project

At Gelaki in Sibsagar dist.



12.Kothalguri thermal power (Gas &Steam based)Project

At Balulani 15 km. away from Duliajan



           As mentioned earlier, apart from the 41 major power projects shown above there are 38 other medium and micro scale project. While work in some of them is yet to be started, some are under construction. It is however, important to not that none  of the power stations in North-East India has been able to produced its full installed capacity of electricity for various reasons. The total power production in the whole region comprising seven states now  stands at 2144.80 M.U. and thermal 1046. 26 M.U. (1993-94) which is definitely very low. This also deters industrial and general economic growth of the  region.


            Actual generation and Utilisation of Power (In M.U.)

















Imported 44.22



Imported 1169.85

From Locktak 275.78


Imported 90.12

Imported 124.70


Imported 102.15















66 kwh


104 “


 129 ‘’

136 ‘’

112 ‘’

59 ‘’

66 ‘








                        Source : (I) Basic Statistics of NER. 1995

                                     (ii) Percapita consumption -- Central Electricity Authority of  India The Assam Tribune Dec. 30 1997.


            Attempts have been made by the concerned state governments and North -Eastern Electric Power Corporation, sometimes with the help of the National Hydroelectric Power Corporation and the World Bank, to build power stations. But nothing much has so far materialised as construction of such stations need enormous resource. The natural gas provides an easy source for power. Hence as many as 5 major projects have already been taken up to produce electricity. Tripura has already completed two more to produce 580 MW of additional electricity of thermal power plant in Tripura.

            The necessity of setting up of power generating units based on non-conventional sources  of energy has, of late, been felt throughout the  country in view of limited reserve of conventional energy sources of coal and oil and very high cost of establishment of hydroelectric stations. The states of North East are trying to utilise  gobar-gas and wind and solar energy to generate electricity, especially in the less accessible hilly areas. The state government of Meghalaya, for example, has  taken up the project of a wind mill at Cherapunji by installing a cluster of SMW aero generators. The Department of energy under the New and Renewable Energy Programme has also identified the Smit-Nongrem Belt near Shillong for installation of four aero generators each of 1 KV potential to harness wind energy.

            Under the Solar Energy Programme the Meghalaya Government proposes to install solar energy heating units at Tura and Byrnihat Primary Health  Centres. Such units have already been installed at a Government run hotel in Shillong and  at Civil Hospital of Willamnagar. Three more solar heating  units in the West Garo Hills, West Khasi hills and Jaintia Hills districts  have already been completed and eight more solar P.V. pumping systems are  under construction in Meghalaya.

            The Government of  Mizoram has  installed two wind mills, one at Khawbung and the other at  Sankawrdal near Aizawl with a capacity of 5 KW and 3 KW respectively under the Renewable Resource Energy project. Two other wind power generators, one each at Chaltlang  and Seleih are also going to be installed within a short period.

            In Tripura one solar -cum wind power generating  unit was commissioned on July 6,1989, at an interior village called Fuldung Seih (North Tripura District ). This project is supplying power to nearly 50 families.

            In Assam, the generation of  power from the non-conventional sources has been slow. Efforts are however, being made to harness wind energy to produce power. The Government of Assam, as  also the Meteorological Department of the Govt. of India are investigating wind velocity in various parts of the state for finding out suitable locations of installing aero generators. Efforts are also on. the way to convert solar energy to heat energy and to generate power from solar energy, especially from those places like the remote villages of the North Cachar Hills district and Majuli.

            In Arunachal the first photo voltaic power plant was installed at Akkar Yangam, a hill-top village 60 km away from Along in the West Siang district. Some similar projects  have also been undertaken to electrify remote inaccessible villages of the state.


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