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Mineral Resources of Nepal and their present status
Krishna P. Kaphle,
Former Superintending Geologist, Department of Mines and Geology, Kathmandu, Nepal
Former President, Nepal Geological Society
Nepal lies in the central part of 2500km long Himalayan belt. Almost 83% of Nepalese territory is mountainous. It is an underdeveloped country with vast natural resources such as water, minerals, forest, varieties of agricultural products and medical herbs. For the economic development of the country exploitation and proper use of such valuable resources, especially mineral resources, is extremely important. The mountainous region and the geological environment therein are suitable for metallic, nonmetallic (industrial, gemstones and energy/fuel) mineral deposits as well as huge amount of construction materials, dimension and decorative stones. Continues efforts are required to find the more mineral deposits and exploit them for the benefit of the people.
Minerals are the nonrenewable natural resources. Sustainable development of such resources helps to strengthen the national economy. Mineral exploration activities were at peak during 1974 - 1980 when Department of Mines and Geology (DMG) and UN funded Mineral Exploration Development Project (MEDP) was in action. They were able to delineate quite a few prospective areas and identify some economic, sub-economic and non-economic mineral deposits in different parts of the country (Fig.1). Now the Government of Nepal (GON) should prioritize exploration, evaluation and sustainable development of industrial minerals, high price metals, base metals, fuel minerals, precious and semi precious stones. It should also invite potential national and international investors to invest in mineral and mining sector and establish mineral based industries by giving some incentive to attract the investors in the beginning. Currently, over 500 private investors have shown their interest and taken 590 prospecting licenses to explore 27 mineral commodities and 104 mining licenses to exploit 14 mineral commodities (except river gravel and sand mines) from DMG. Few cement, marble, dead burnt magnesite (DBM), talc, agri-lime and few other industries have been established but none of them are in regular production due to some unexpected disturbances and possibly least priority of the government. Only some limestone for cement, very few coal, semi-precious stones, lead and zinc, talc, clay and dimension and construction material mines are in operation. Exploration of oil and natural gas by foreign companies, first by Shell Netherlands (already left) and later by Texana Resources Co., USA and CAIRN Energy PLC, UK (now left) and recently two Arabian Oil Companies named as Emirates Associated Business Group (EABG), UAE leased Block 8 and 9 and BBB Champions Oil Co. Inc, UAE leased block 10. This way all ten petroleum prospective blocks are leased but the output from these companies are not satisfactory.
Mineral resources play vital role in industrial development and overall increase in the national GDP. Minerals and mine contribute about 0.5% to national GDP and industries sector based on these just around 2.4% which is not encouraging. It could go above 10% if we can exploit and utilize existing mineral resources appropriately. Mining activities can damage natural environment and it should be minimized by applying various methods and immediate rehabilitation of the mined land.
Small scale historical iron, copper, lead, zinc, cobalt, nickel mines and placer gold panning in the major rivers and many slate, quartzite, dolomite and limestone quarries were operational in many districts. Old working pits, audits, smelting places, scattered slag and remnant of mine materials stand as solid proofs of such mining activities in the past. In many cases the name of the village is derived after the particular mines e.g. Taba Khani, Phalam Khani, Shisa Khani, Sun Khani etc. But at present almost all of these old workings/ mines are not in operation due to various reasons. Therefore, reassessment and evaluation of such deposits/ mines by DMG or any private sector are extremely warranted for further exploration and mining. One of the examples is Thoshe iron deposit which was reassessed by DMG and later explored in detail by a private company. Currently it is in the process of mine development to exploit iron ore in near future.
Mineral Resources in Different Geological Zones
Geology of Nepal is very complex because of continual geodynamic process in the Himalayan region that results in many thrusting, faulting, folding and metamorphic effects. Nepal Himalaya can be divided into five distinct morpho-geotectonic zones from south to north. From mineral resources point of view, the southernmost Terai Plain is potential for gravel, sand, ground water, petroleum and natural gas, and the Sub Himalaya (Churia Range/ Siwalik foot hills) for construction materials, radioactive minerals, petroleum, natural gas and minor amount of petrified coal. Lesser Himalaya (the Mahabharat Range including midlands) for metallic minerals mainly Iron, copper, lead, zinc, cobalt, nickel, tin, tungsten, molybdenum, gold, uranium, rare metals and so on, and industrial minerals like magnesite, phosphorite, limestone, dolomite, talc, clay, kaoline, graphite, mica, silica sand and quartz, and gemstones like, tourmaline, aquamarine/ beryl, garnet, kyanite and quartz crystals, and fuel minerals such as coal, lignite, methane gas, petroleum and natural gas, hot springs and radioactive minerals, and voluminous construction materials crushed gravel as well as river boulders, gravel, sand. Some of the areas in Higher Himalaya are highly promising for precious and semiprecious stones like ruby, sapphire and emerald, and metallic minerals like lead, zinc, uranium, gold silver etc. Tibetan Tethys zone is prospective for limestone, gypsum, brine water (salt), radioactive minerals and natural gas. However, because of rugged topography, difficult mountain terrain, complex geology, lack of infrastructures and financial constrain exploration and exploitation of these mineral resources is still challenging.
Mineral Deposits, Mines and Their Present Status
Geological investigations and mineral exploration activities carried out mainly by DMG, UNDP/DMG/MEDP projects, Geological Survey of India (GSI) and very few private entrepreneurs were able to identify more than 66 mineral commodities in Nepal (Fig.1). DMG has provided 590 prospecting licenses for the exploration of 27 minerals and 104 mining licenses for mining 14 mineral commodities in different parts of the country in FY 2012/13.
Fig.1: Mineral Resources Location Map of Nepal
Similarly geological, aeromagnetic and seismic survey conducted by DMG/ Petroleum Exploration Promotion Project (PEPP) and foreign oil Companies like Shell Netherlands were able to trace some promising sites for petroleum and natural gas in southern part of the country, mainly in the Terai and Siwalik Foothills. Gas and oil seepages in Padukasthan, Sirsasthan and Navisthan in Dailekh and gas seeps in Muktinath in Mustang are the direct signature of the existence of oil and natural gas in Nepal. In addition to that, shale beds of Lakharpata, Gondwana and Surkhet Groups are found to contain 2 - 20% Total Organic Carbon (TOC) which is another strong evidence of petroleum occurrences. In regional context, existence of petroleum in Potwar basin in Pakistan in the west and Aasam basin in India in the east are other positive indications that there is also a high possibility to find similar oil fields/ pools in the similar geological environment (lithological horizons) in Nepal. On these bases ten prospective blocks for exploration of petroleum and natural gas are identified. Block-10 was well explored by Shell Oil Co. but left for good after drilling one dry well of 3520m deep. Texana Resources Co. (USA) has leased Block-3 & 5; CAIRN Energy PLC, UK (left last year) has taken Block-1, 2, 4, 6 & 7 and recently two Arabian Oil Companies named Emirates Associated Business Group (EABG) and UAE and BBB Champions Oil Co. Inc, UAE have leased Block- 8 & 9 and Block-10 respectively. But they have not yet started exploration work seriously. CAIRN Energy PLC (UK) and Texana Resources Co. (USA) did some preliminary field works and laboratory works but they always remained reluctant to conduct extensive exploration, and as a result there is almost no progress in petroleum exploration sector in spite of government’s high priority.
(A) Metallic Minerals
Metallic minerals are very much used in various purposes in day to day life. They are mostly extracted from their respective ores. Gold, platinum, silver and copper also occur as native state. A numbers of metallic ore minerals are known to exist in different parts of Nepal but only the important ones are briefly described here.
Iron (Fe) is the principal metal which is used extensively in infrastructure development works, and to manufacture heavy machinery equipment, arms and agricultural tools. Iron ores like magnetite, hematite, limonite/goethite occurrences/ prospects/ deposits are known to exist in more than 85 localities. Some of these ores were extensively mined and smelted in different parts of Nepal for 150 years till 1951 (2007BS) but none of these mines are in operation since then. The well known iron ore deposits are Phulchoki (Lalitpur), Thoshe (Ramechhap, Fig.2A), Labdi Khola (Tanahun), Jirbang (Chitwan), Dhauwadi - Pokhari (Nawalparasi), Dhuwakot (Parbat), Bhedikhor and Lukarban (Baglung), Purchaundi/ Lamunigad (Bitadi), Dahabagar, Kachali, and Ekghar/ Khanigaon (Bajhang). Iron prospects and old workings are also known from different parts of Baitadi, Bajhang, Jajarkot, Rolpa, Surkhet, Myagdi, Baglung, Parbat, Chitwan, Ramechhap, Okhaldhunga and Taplejung districts. Phulchoki iron deposit still remained untransformed into commercialization due to its location in the environmentally sensitive area and shortage of power like electricity and unavailability of good quality coal in Nepal. Thoshe iron deposit was mined in small scale during Rana's regime for almost 100 years till 2006BS. But it was totally stopped after 2007BS. DMG (Kaphle & Khan 1995, 1996) did the assessment of this prospect and calculated geological reserve of about 10.5 million ton iron ore. Further detail exploration by N & C Minerals Pvt. Ltd. has estimated about 15.9million ton iron ore with an average grade 45.3%Fe. According to DMG record it has issued 40 prospecting licenses and 2 mining licenses for iron to the private/ public companies in FY 2012/13.
|Fig.2A: Iron Ore from Thoshe||Fig.2B: Bamangaon polymetallic deposit|
Copper (Cu) is another important metal which is mainly used in electrical industries to produce electrical and electronic equipments, copper wires, crafts, making alloys, utensils, and other household purposes. It was mined traditionally in Nepal since historic time but at present there is no running copper mine as such. The common copper ore found in Nepal are chalcopyrite, malachite, azurite, covellite, cuprite, bornite, and chalcocite. Copper ore occurrences/ prospects are known from more than 107 localities in the country. Small scale copper mines were in operation in Gyazi (Gorkha), Okharbot (Myagdi) and Wapsa (Solukhumbu) till the last decade and they were able to produce 20 to 50mt finished copper per year. Other copper prospects/ deposits like Kalitar (Makwanpur), Dhusa (Dhadhing), Wapsa (Solukhumbu), Bamangaon (Dadeldhura, Fig.2B), Khandeshori/ Marma (Darchula), Kurule (Udayapur), Bhut Khola (Tanahun), Pandav Khani (Baglung), Baise Khani (Myagdi), Chhirling Khola (Bhojpur), Janter Khani (Okhaldhunga) are the major ones. Old workings are also known from different parts of Darchula, Bajhang, Bajura, Parbat, Baglung, Myagdi, Gulmi, Tanahun, Gorkha, Makwanpur, Kavre, Ramechhap, Okhaldunga, Dhankuta, Solukhumbu, Ilam and Taplejung districts. Among them Siddhi Khani (Ilam), Mul Khani (Gulmi) Ningre (Myagdi) are the important ones. 28 prospecting licenses for copper exploration have been issued by DMG (source DMG, FY2012/13).
Zinc (Zn) and Lead (Pb) occurrences/ prospects/ deposits are reported from more than 54 localities in different parts of Nepal. In most cases their ore minerals e.g. Sphalerite and Galena are associated like in Ganesh Himal area (Rasuwa), Phakuwa (Sankhuwasabha), Labang- Khairang (Makwanpur), Pangum (Solukhumbu), Salimar valley (Mugu/ Humla), Daha Gulzar (Darchula), Phulchoki (Lalitpur), Sisha Khani and Kandebas (Baglung), Dhuwakot (Parbat), Barghare (Makwanpur) and Khola Khani (Taplejung). Most of them are known as old workings. Among them, only Ganesh Himal Zinc - Lead deposit (at Lari, Serkaping and Suple) has been explored in detail. Lari deposit is an economic deposit with about 2 million mt. (combined Zn+ Pb ore) and underground mine development has been done by Nepal Metal Company long time before but the deposit still remained unexploited due to some technical and financial reasons.
Cobalt (Co) prospects are not as common as iron, copper, lead and zinc in Nepal. Cobaltite, erythrite and absolite are the common ore of cobalt. Few old workings and test mining for cobalt are known from Netadarling & Tamghas (Gulmi) and Samarbhamar (Gulmi). They are also recorded from Lamadanda (Dhadhing), Nangre (Kavre), Bhorle (Ramechhap) and Bauli Gad (Bajhang). There is no cobalt mine in operation at present.
Nickel (Ni) occurrences are reported from few polymetallic deposits like in Bamangaon (Dadeldhura), Bering Khola (Ilam), Bauligad (Bajhang), Khopre Khani (Sindhuli) and old workings from Nangre, Nigre and Bhorle (Ramechhap) area. The main ore of this metal is niccolite and pentlandite which are mainly associated with chalcopyrite, pyrrhotite and pyrite.
Gold (Au) is a precious metal which has worldwide market. It is widely used in making coins, ornaments, jewelry, dental appliances, electroplating, metal coating and many other purposes. In Nepal alluvial/ placer gold are frequently wined by local dwellers (Botes) from the river gravel/ sediments deposited by the major rivers like Mahakali, Chamliya, Jamari Gad, Seti, Karnali, Bheri, Rapti, Lungri Khola (Fig.3A), Phagum Khola, Kaligandaki (Fig.3B), Myagdi Khola, Modi, Madi, Marshyangdi, Trishuli, Budhigandaki, and Sunkoshi Rivers along their high and low flood plains as well as in their terraces. Primary gold occurrences are known from Lungri Khola area (Rolpa); Bangabagar, Gorang & Jamari gad (Baitadi); Bamangaon (Dadeldhura) but they are yet to be evaluated by detail exploration
|Fig.3A: Placer gold from Lungri Khola, Rolpa||
Silver (Ag) is generally associated with zinc-lead ore and in gold. In Nepal minor amount of silver is reported in the zinc + lead ore of Ganesh Himal (Rasuwa), Barghare (Makwanpur), and polymetal sulphide of Bering Khola (Ilam), in association with cobalt ore in Netadarling (Gulmi) and Samarbhamar (Gulmi). None of them appeared as economic deposit suitable for mining.
Tin (Sn) mineralizations are normally reported in the vicinity of granitic rocks. Cassiterite is the main ore which is recorded at Meddi and Ganera (Dadeldhura), and Mandu Khola area (Makwanpur). In-situ there are irregular cassiterite – quartz or casseterite – quartz - pyrite mineralized veins, and cassiterite rich floats are seen in Meddi Khola, but there is no significant economic deposit.
Tungsten (W) is a very important element which is used in electric bulbs, making hard high speed cutting steels and tungsten cable, drilling bits, armory etc. The common ores of tungsten are scheelite and wolframite. In Nepal tungsten ores like scheelite occurrences are known from Bamangaon polymetal deposit and few minor occurrences in other places of Dadeldhura and Makwanpur districts.
Minor occurrences of Molybdenum (Mo) are reported from Khari Khola (Solukhumbu), Bamangaon (Dadeldhura), Bauli Gad (Bajhang), Lungri Khola (Rolpa), Samarbhamar (Arghakhanchi) and Chau Khola (Makwanpur). Molybdenite is the chief ore mineral.
Ilmenite and Rutile contains titanium (Ti). Minor amount of Chromium (Cr) and Titanium (Ti) are detected from the iron ore of Thoshe (Ramechhap) and Bauligad (Bajhang). Rutile grains are commonly recorded in the heavy concentrate samples from north – south flowing major rivers of Nepal.
Uranium (U) and Thorium (Th) are the two known radioactive elements in Nepal. Radioactive minerals like autonite are recorded from Thumki, Jagat, Panchmane, Gagalphedi and Chunikhel in Shivapuri area in Kathmandu. Few other ores of uranium like uranitite, tyuamunite, carnotite and cofinite are known from Tinbhangale, Chandi Khola and Chiruwa Khola (Makwanpur); Buka Khola (Sindhuli); Mardar Khola and Panpa Khola (Chitwan); Jamari Gad, Bangabagar, Baggoth, Gorang (Baitadi); and traces in different section of Chamliya River (Darchula). Recently (May – June 2014) DMG has discovered radioactive bodies in upper Mustang. Among them Upper Mustang, Gorang and Tinbhangale prospects appear quite interesting. Follow up detail work is warranted to confirm the deposits.
Bismuth (Bi) is reported from Bamangaon polymetal deposit in Dadeldhura, and Baraghare and Mandu Khola area in Makwanpur district. It is mainly used to make alloys with antimony, lead, tin and cadmium in medicine and cosmetic items.
Cinnabar is the chief ore of Mercury (Hg). It is reported from Tirche Pani/ Taruka. Talalov (1972) has also reported cinnabar from the heavy concentrate sample from Khimti River and zinc-lead ore from Pangu.
Lithium (Li) occurrences are known from the pegmatites of Hyakule and Phakuwa (Sankhuwasabha district). Petalite and spodumene are the main ores of lithium. Lepidolite (lithium mica) appears to be the source of lithium in pegmatites.
Pegmatites are the store house of Beryllium (Be) which can be extracted from beryl and aquamarine. They are known from the pegmatites of Khaptad, different parts of Manang, Kathmandu, Nuwakot, Rasuwa, Phakuwa, Hyakule, Ilam and Taplejung districts.
Arsenopyrite and realgar are the two main sources of Arsenic (As) which occur mainly in polymetallic deposits like Bamangaon and Bering Khola. Occasionally arsenopyrite is also the pathfinder mineral for gold mineralization.
In addition to above mentioned metals/ metallic ore minerals, minor occurrences of Antimony (Sb), Tantalum (Ta), Niobium (Nb), Lanthenum (La), Celenium (Ce), Cadmium (Cd), Titanium (Ti) and Venedium (V) are also reported from different parts mostly as associated minerals. Tentalum and niobium are traced form the pegmatites and granites in the Lesser Himalaya. Chemical analysis of some of the muscovites from pegmatites of Phakuwa (Sankhuwasabha) has indicated up to 140ppm Ta.
Rare Earth Elements (REEs) are set of 17 elements like Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tm, Tb, Dy, Ho, Er, Yb, Lu. They rarely exist in pure form rather they mix diffusely with other minerals. These elements are associated with alkaline rocks, granitic rocks, pegmatites, migmatized gneiss, carbonatite etc. Exploration of these very important elements has not been done in Nepal, however, possibilities of their finding is high in pegmatites, migmatized gneiss and granitic rocks of Nepal. REEs have multiple uses like in cell phones, laptops, aircrafts and hundreds of other sophisticated modern equipments
All these information indicate that Nepal is potential for metallic minerals. The exploration activities in the past have revealed that most of them are economically worthwhile deposits. Now the price of many metals has gone up significantly. Therefore, further detail investigations in the known areas, evaluation of specific deposits and exploration in the new geologically prospective areas may lead to find the potential economic deposits of metallic minerals.
(B) Nonmetallic Minerals
A number of nonmetallic minerals like limestone, magnesite, phosphorite, talc, dolomite, quartz, mica, clay, silica sand, graphite, diatomite, gemstones, decorative and dimension stones and construction materials lies in different parts of the country. Some of the important ones which are mined or explored up to certain stages are briefly described.
B-1. Nonmetallic/ Industrial Minerals
Limestone: Over 1.298 billion metric tons of cement grade limestone deposits are already known from the Lesser Himalayan region only. Exploration of limestone by DMG, in the past was able to identify a number of large to small size limestone deposits. Few cement industries are already in operation/ production, few others under construction and quite a few in the pipeline. Present domestic cement production could fulfill about 65 - 70% of the total internal demand. Six new cement industries namely Sibom, Sonapur, Ghorahi, Rolpa, Bishal and Nigale cement industries Pvt. Ltd. have started their cement production. Therefore, establishment of more cement factories based on own limestone resources is still rewarding. Some of the main cement grade limestone deposits are Sindhali & Galtar (Udaypur), Bhainse, Okhare and Nibuwatar (Makwanpur), Jogimara & Beldada (Dhadhing), Chovar, Bhattedanda (Llitpur), Balthali & Nandu (Kavre), Kakaru Khola (Sindhuli), Kajeri (Salyan), Nigale (Dhankuta), Chaukune and Lakharpata (Surkhet), Gandari (Dang), Narapani and Supa Khola (Arghakhanchi), Diyarigad (Baitadi) and few other place in Lalitpur, Kavre, Khotag, Udayapur, Syangja, Palpa, Arghakhanchi, Dang, Pyuthan, Sallyan, Rolpa, Rukum, Bajhang, Baitadi and Darchula districts. Preliminary studies indicate that there is a possibility to find more than 2.5 billion tons of cement grade limestone deposits in the Lesser Himalaya. According to DMG record (FY 2012/13) 40 mining licenses and 215 prospecting licenses of limestone have been issued to private sectors
In many cases Dolomite and limestone occur together in the same locality. From geological mapping it is known that over 5 billion tons (possible) of dolomite occur mainly in Dhankuta, Khotang, Udayapur, Sindhuli, Dolakha, Kavre, Kathmandu, Makwanpur, Dhadhing, Syangja, Palpa, Baglung, Gulmi, Arghakhanchi, Dang, Pyuthan, Sallyan, Rolpa, Rukum, Jajarkot, Surkhet, Dailekh, Jumla, Achham, Doti, Bajhang, Bajura, Baitadi and Darchula districts in the Lesser Himalayan and in some parts of Higher Himalayan region. Most of them are not yet explored in detail and still do not know their grade and quality to utilize as raw materials for industries.
Phosphorite is one of the main raw materials to manufacture chemical fertilizers like fused magnesium phosphate, triple super phosphate etc. Present annual demand of chemical fertilizer in Nepal is about 250,000mt/ year. Except three fertilizer blinding plant no other fertilizer industry based on the local phosphatrite exist in the country. Phosphorite (0.7 - 0 4.7m thick bed) is confined to massive cherty and stromatolitic dolomite of Pre-Cambrian to Lower Paleozoic age that occur in Dhik Gad, Junkuna, Morgaon, Sanagaon and Dhaubisaune areas in Baitadi, Far-western Nepal consists of 5–32 % P2O5 (Bashyal, 1984). Similar (1 to 23m thick) stromatolitic phosphorite band is also traced at Tarugad, Juilgad, Goichan - Kandechaur area in Bajhang and further east to Bajura. Detrital phosphorite fragments (<1mm - 1.5cm) are recorded from Eocene argillaceous limestone lenses and beds in Sewar Khola (Dang) and Mari Khola (Pyuthan). P2O5 content in them is <5% to 10% (Kaphle & Pradhanang, 1985). However, the phosphorite fragment itself revealed up to 25% P2O5. Exploration of phosphorite in the vicinity of MBT was able to trace few phosphatic rocks consisting of <5% P2O5. Only few phosphatic nodules/ lenses consist of up to 22% P2O5 in Takure, Barahakshetra, Tawa Khola (Kazitsyn, 1970); Gawar Khola, Sewar Khola in Midwestern Nepal and in Khulia Khola (Kaphle 1997) in Far-Western Nepal.
Magnesite: 180 million tons (66 million tons of high grade, MgO content 88 to 96% loss free basis) of magnesite deposit in Kharidhunga, Dolakha; 20 million tons of medium to low-grade magnesite deposit in Kampughat in Udayapur district; and few small size magnesite occurrences from Palpa, Baitadi and Dolakha have been identified. Kharidhunga magnesite an open cast mine has been developed to exploit magnesite as a raw material for Dead Burnt Magnesite (DBM) plant located in Lamosanghu, Sindhupalanchok district. Some technical problems appeared during test production of DBM and then the mine as well as DBM plant is remaining unproductive since more than 10 years.
Talc: Occurrences of talc bands, lenses, veins and pockets are known in magnesite, dolomite and chloritic talc schist in different parts of Lalitpur, Dolakha, Sindhupalchok, Dhadhing, Chitwan, Tanahun, Kaski, Syangja, Surkhet, Bajhang, Bajura, Baitadi and Darchula districts. DMG has issued 44 prospecting and 9 mining license to the private sector. Khari Dhunga talc mine is in operation since more than 2 decade.
Mica: Several but comparatively small occurrences of mica (muscovite and biotite) books are known from different parts of Nepal. But mineable coarse size mica books are recorded only in complex pegmatite of Langtang (Rasuwa), Bhumidanda and Kharanetar (Nuwakot), Chaukibhanjyang (Kathmandu), Nibuwagaon (Sindhupalchok), Lekhpatan, Fulbari and Tikachaur (Jajarkot), Khaptad (Bajhang), Baskot and Bhasukan (Doti), Fikal (Ilam), Chilingdin (Panchthar), Rangmale, Akabu/ Sainsabu, Dobal Pokhari, and Khanigaon (Taplejung), Phakuwa and Hyakule (Sankhuwasabha) and at few places in Gorkha and Dhadhing districts.
Ceramic Clay: Irregularly distributed scattered pockets of kaolin are known from Daman (Makwanpur), Panchmane (Kathmandu), Dalchhap and few other places.
Red Clay from Panchkhal (Kavre), Lamosure (Hetaunda), Trijuga/ Beltar (Udayapur), Chidika (Arghakhanchi), Guttu (Surkhet) are used in cement factory. Such red clay deposits are also known from different parts of Nuwakot, Dhadhing, Makwanpur, Nawalparasi, Udayapur, Palpa, Surkhet districts. Clay from Thimi/ Bhaktpur is used in small-scale pottery industries. Huge amount of siltyclay deposits in different parts of Kathmandu valley is used to manufacture bricks. In villages it is also used in house wall painting. DMG has issued six prospecting and seven mining licenses to the public/ private sector.
Pyrite is mainly used to extract sulphur and manufacture sulphur compounds e.g. sulphuric acid, ferrus sulphate etc. It is rarely used as iron ore. Pyrite is abundantly found in Bering Khola (Ilam), Chhirling Khola (Bhojpur), Pandav Khani (Baglung), Meddi and Bamangaon (Dadeldhura), and many other places mainly in almost all polymetal sulphide deposits.
Silica Sand: About 11.9 million tons of sand suitable for glass industry has been proved in Karra Khola near Hetaunda in Makwanpur district. There is a possibility to find similar sand deposits in similar deposition environment (e.g. in Dudhaura Khola) in other parts of Nepal.
Barites are known from Khanidanada (Pyuthan), Barghare (Makwanpur), Dhokadhunge (Rolpa), Phakuwa (Sankhuwasabha), Urathi, (Baitadi). True picture of barite resource is still unknown.
Graphite is one of the significant mineral in metamorphic terrain in Lesser Himalayan regions. They are reported from Ilam, Dhankuta, Sankhuwasabha, Nuwakot, Sindhupalchok, Baglung, Dadeldhura etc.
Calcite deposit as such in large size is not known, however, minor calcite veins and lenses are recorded mainly in carbonate rocks. Calcites are known at few places as stalactite and stalagmite and dog tooth spar in some of the limestone cavities/ caverns. Small scale calcite mine is under development stage in Nibuwagaon (Makwanpur).
Diatomite beds/ layers as much as 2m thick are reported from Chobhar, Thimi, Bode and few other places in Kathmandu valley. Small scale artesian mining of diatomite is in operation in Thimi and Bode of Bhaktapur district for local use. An overall assessment of quality and quantity of diatomite has not been done.
Salt: Brine water that occurs in Narsing Khola (Mustang), Chhiding Khola and Chharkabhot (Dolpa) are tapped and dried for common salt production. Brine water of these areas contains 1.5 to 3% NaCl, where as incrustation consist of up to 72.8% NaCl and 24.5% KCl. So far mineable deposit is not found.
B-2 Precious and Semiprecious stones (Gemstones)
Precious stones (Rubies and Sapphire): Gem quality but generally small crystals of light red to red ruby (Fig.4A) and light to dark blue colored sapphire are known from in Chumar, Ruyil, Shelghar, Pola, Shongla (Dhadhing) and Lari/ Ganesh Himal area (Rasuwa). They occur in highly tectonized intensely folded en-echelon lenses of sacchoroidal dolomite (dolomitic marble) within the high-grade metamorphic rocks close to MCT. At places local people are illegally mining haphazardly and destroying the precious resources.
Semiprecious stones like tourmaline, aquamarine/ beryl, garnet, kyanite, amethyst, citrine, smoky quartz (quartz crystals) etc. exist in few districts.
Tourmaline: Five distinct types of tourmaline are known from Nepal (Basset 1978, 1985, 1987). Gem quality pink (Fig.4B), and distinct multihued tourmaline (elbaite) of Hyakule and Phakuwa, pink, bright green, light orange sometimes with repeated color banding, olive green with amber colored core are known from Hyakule, Eastern Nepal. Small-scale mines of aquamarine, beryl, tourmalines are in operation. Pegmatites of Langtang valley (Rasuwa) and Naje (Manang) are also promising for tourmaline and beryl/ aquamarine. 40 prospecting license and 8mining license for tourmaline are issued by DMG. Two tourmaline mines are in operation in Daha area in Jajarkot and six mines are in developing stage.
|Fig.4A: Ruby from Dhadhing||Fig.4B: Pink Tourmalin from Hyakule||Fig.4C: Aquamarine from Taplejung|
Beryl/ Aquamarine of Taplejung (Ikabu, Lodantar (Fig.4C) area are high priced. Similarly hambergite, danburite, and ijolite are the important gemstones varieties found in Nepal. In Taplejung beryl and aquamarine mines are in operation where as the tourmaline mines are still in development stage. Gem quality clear blue aquamarine of Phakuwa (Sakhuwasabha), aquamarine/ beryl and few green colored tourmalines from Naje and few other localities in Manang district (Tamrakar, 1990, and Einfalt et al, 1995), western Nepal are reported. Lekhpatan and Tikachaur in Jajarkot; Jagat, Panchmane, Kagtigaon in Kathmandu; Baguwa, Tarkeghyang, Nibuwagaon in Sindhupalchok are the other known localities for beryl.
Garnets are recorded from strongly tectonized lenses and pods of chlorite-biotite-garnet schist within high-grade metamorphic rock sequence mainly in the Higher Himalayan region. Deep red or red colored almandine, hessonite and pyrope garnet are mined mainly in Sankhuwasabha and Taplejung districts. Small-scale garnet mines in operation in Budhekhani, Bhote Khola, Hanglaung, Khining, Sunamla, and Swachi Khani in Sankhuwasabha district are closed. Three prospecting license are issued by DMG.
Kyanites are known mainly from high grade metamorphic rocks like Kyanite schist in Dolakha, Sankhuwasabha, Taplejung, Rasuwa, Dhadhing and Jajarkot Achham districts. Four small-scale kyanite mines are in operation in Daha and Suneri in Jajarkot and Barah of Aachham districts and 4 mines are under development stage. Elongated tabular inky blue/ sapphire blue kyanite crystals are cut for gems (Fig.5A)
|Fig.5A: Kyanite (raw & cut polished) from Jajarkot||Fig.5B: Quartz Crystal from Taplejung|
Quartz Crystals (Rock Crystal): Two small-scale quartz crystals mines are in operation from pegmatites in Khejemi/ Sirku (Taplejung, Fig.5B) and Raluka (Nuwakot). Quartz crystals are also known from different parts of Jajarkot, Dailekh, Dhadhing, Rasuwa, Nuwakot, Sakhuwasabha, Ilam and Taplejung districts. Only colored verities like amethyst, citrine and smoky quartz are cut for gems. 2 Mining license and 15 prospecting license are issued by DMG.
B-3 Decorative and Dimension Stones
Marble: Pink, gray and white colored marble deposit (1.63 million ton) is located in Godavari, Lalitpur district. Based on this deposit Godavari marble industries (Pvt.) Ltd. is established. Its annual production capacity is about 80,000m2 polished marble slabs. It was producing about 50,000m2 to 70,000m2 polished marble slabs and some crazy marble, chips and aggregate as bi-products but since last 3 years mine is shot down due to some environmental and legal reason. Based on Anekot (Kavre) marble deposit Everest marble and allied industry is in operation. Recently Nawadurga Marble Industry Pvt. Ltd is developing marble quarry in Chhatre Deurali in Dhadhing. 3 prospecting license and 5 mining license are issued by DMG.
Granites of Cambrian to Ordovician age are known from, Makwanpur (Palung and Ipa), Sindhuli, Udaypur, Dadeldhura in the Lesser Himalaya. Coarse grained, massive granites are used as decorative and dimension stones. Late phase granites are also known from the Higher Himalayan and Inner Himalayan (Tethys) region. 5 prospecting licenses are issued by DMG but not a single granite quarry is in pipeline.
Quartzite is a hard metamorphic rock which consists of mainly quartz. It is abundantly known from many districts like Taplejung, Ilam, Panchthar, Solukhumbu, Dhankuta, Ramechhap, Sindhupalchok, Makwanpur, Dhadhing, Nuwakot, Tanahun, Kaski, Syangja, Parbat, Baglung, Beni, Dang, Sallyan, Rolpa, Rukum, Jajarkot, Achham, Doti, Bajhang, Bajura, Dadeldhura, Baitadi, Darchula and few other districts. It is mainly used as dimension stone.
Slate is the common roofing and pavement material that is extensively mined from different parts of Taplejung, Dhankuta, Sindhupalchok, Ramechhap, Nuwakot, Sindhupalchok, Dhadhing, Gorkha, Myagdi, Baglung, Parbat, Jajarkot, Achham, Doti, Dadeldhura, Baitadi, Bajhang, Bajura and many other districts since historic time.
B-4 Construction Minerals (Materials)
Rocks are the main construction materials since the Stone Age. Some of the rocks like marble, basalt, granite and red sandstones are cut into slabs and used in decoration; phyllite, slates, flaggy quartzite and schist are used for roofing; limestone, dolomite, quartzite, sandstone are used for aggregate in various construction works, road paving and flooring. Vast quantities of river boulders, cobbles, pebbles and sands are mined as construction materials/ aggregates. DMG (Y.P. Sharma et al 1988) has evaluated such materials (boulders=347,006,000m3, cobbles=214,261,000m3 and pebbles=229,205,000m3) in the major rivers of Terai region.
(C) Fuel Minerals
Coal: In Nepal low to medium grade coal occurrences/ deposits are known in four stratigraphic positions like (a) Quaternary peat/ lignite (b) Siwalik coal (c) Eocene Coal and (d) Gondwana coal. Peat/ lignite in Kathmandu valley is mined and used mainly in brick burning along with wood. Siwalik coal is not economically attractive because of scattered small occurrences. Eocene Coal occurs as irregular seams confined to orthoquartzite in Tosh, Siuja, Azimara and Abidhara in Dang, and few places in Sallyan, Rolpa, Pyuthan and Palpa districts. Small scale 19 coal mines are in operation in these districts. In addition to that 30 prospecting license are also issued by DMG. Present coal production in Nepal is insignificant (14,084mt in 2012).
Petroleum and Natural Gas: A number of oil and natural gas seeps are recorded in a stretch of about 14km in Padukasthan, Sirsethan and Navisthan area in Dailekh (Fig.6A) and only gas seeps in Muktinath in Mustang. GON/DMG/ PEPP have given high priority to explore and promote petroleum exploration in Nepal since 1982. DMG/ PEPP were able to identify 10 prospective blocks in the southern parts of the country (Fig.6B). Shell Company of Netherlands conducted exploration in Block no.10 (Biratnagar block) in eastern Nepal. It has drilled a test well up to 3520m deep but the hole appeared dry. It has left Nepal for good. Since last few years Texana Resources Company of USA and Cairn Energy PLC of UK have initiated the exploration works in Block no 3 & 5; and 1, 2, 4, 6 & 7 respectively. The possibility of finding oil in some of these blocks appears fairly high but these companies are reluctant to conduct extensive exploration work. Cairn Energy PLC of UK also left Nepal recently. Last year, two new petroleum companies from Middle East have taken Block-8, 9, and 10 on lease but no one has initiated the work so far.
Methane gas deposit in Kathmandu Valley is known since long time. It dissolves in water type biogenic gas. DMG explored this gas in 26 sq. km area in Kathmandu valley by exploration drilling of over 14 drill holes up to 570m depth and proved 310 million cubic meter methane gas deposit. The gas occurs at different depth from 120m to 300m. Its average calorific value is 7200kcal/m3. A model gas plant is set in Tripureshor/ Teku. Feasibility study has confirmed that the gas can be used for industrial and household purpose and the reserve is sufficient to supply gas to 21,000 families for about 30 years. The GON/ DMG is inviting for potential investor to come forward with the suitable proposal to develop the gas wells and commercialize this gas deposit for the benefit of the people. Recently DMG has initiated one more gas well drilling in Imadole (Lalitpur district) and its result is awaited.
Geothermal Hot Springs: During preliminary study 23 geothermal hot springs are identified and few more are also reported. Most of them are found to be associated with Main Central Thrust (MCT) and confined to the river banks of Mahakali, Karnali, Tila, Kaligandaki, Myagdi Khola, Marshyangdi, Trishuli, Bhotekoshi Rivers and in Kodari. The temperature of the hot spring water ranges from 40o to >60oC. It can be utilized for heating, drying fruits, hot water bath to heal skin disease etc.
Radioactive Minerals like uranium are known from Sindhuli, Makwanpur, Kathmandu, Baitadi and Mustang districts. There is a high possibility to find such minerals in the granitic terrain (granite, gneiss and pegmatite) in the Tethys, Higher, and Lesser Himalayan regions and from the Siwalik sandstone. Recently prospection of radioactive minerals by DMG in Mustang district was able to trace some prospective radioactive bodies in upper Mustang. Follow-up exploration will be able to delineate such radioactive bodies and know about the grade and tonnage of the deposit. Uranium is a major source of nuclear fuel for the production of Nuclear energy.
Minerals, Mines and Their Contribution
All the mineral resources that occur in the country are owned by the state. DMG under the Ministry of Industry is the responsible government authority which is conducting systematic geological mapping and mineral exploration in the country for last five and half decades. In course of time DMG has been successful to identify a number of metallic, nonmetallic/ industrial and fuel mineral deposits/ prospects/ occurrences and prove some economic and sub-economic mineral deposits and also promote few mineral based industries like cement, agri-lime, marble, talc, dead burnt magnesite, zinc-lead, coal, gemstones, pottery etc. Few small to medium scale mines of limestone, magnesite, marble, talc, coal, peat, clay, salt, talc, mica, quartz crystals, semiprecious and precious stones, dimension/ paving stones, roofing slates are in operation by the private entrepreneurs after obtaining the licenses from DMG. There are over 40 limestone quarries from which limestone are supplied to cement industries. Six gemstone mines are in operation and twelve are in developing stage. Few gem industries, which do cutting and polishing of semiprecious and precious stones from Nepal and abroad are established. Construction aggregates, sand, gravel, dimension stone, decorative stones, paving stones and roofing slates are the other important mineral resources which have high demand for infrastructural development works. Metallic minerals like, iron, copper, lead, zinc, cobalt, nickel, gold, are known from different parts of Nepal but they are not yet mined. Only two placer gold mining license were issued to private sector but till this time they did not show any production. A private company did detail exploration of Thoshe iron deposit in Ramechhap and obtained mining license from DMG. It is envisaged that if the GON give high priority to exploit mineral resources with liberal policy, within next few years time some more industrial minerals, base metals, precious metals, gemstones, coal and petroleum deposits will be well explored and proved, a number of mines will be operated and more mineral based industries and petroleum industries will be established in Nepal.
Department of Mines and Geology administrates and fully exercises the Mines and Mineral Act (2042BS) and Regulation (2065BS). Under the existing rules and regulations, DMG issues both Prospecting and Mining Licenses to the interested investors (national/ international) and regularly inspects and monitors the mining activities carried out by the private lease holders. According to DMG in FY 2012/13 about 104 mines/ quarries (for 14 different mineral commodities) excluding the licenses issued by District Development Committees (DDC) are either in operation or in development stage. Similarly 590 prospecting licenses for prospection/ exploration of 26 mineral commodities are issued (source DMG/ Planning section). In FY 2012/13 DMG has collected around Rs46,469,626/= as royalty and surface rental from this sector. From petroleum companies the government receives around Rs.26,000,000/annum from royalty, surface rental of lease area (10 blocks) etc. With more mines in operation, establishment of mineral industries and petroleum discoveries the country will create job opportunity to many people and contribute substantially to national GDP.
Investment Opportunity in Mineral and Mining Sectors
There are ample opportunities for the investors to invest in the commercially viable mineral commodities that deserve investment. Some of the existing economic mineral deposits have been developed and are being used in industries like cement, industrial lime, agriculture lime, dead burnt magnesite, talcum powder, and marble industries. Some small-scale industries are using local limestone, dolomite, quartz, talc, clay, coal, peat, precious and semiprecious stones, brine water (salt) etc. There is a high demand of gold, iron, copper, zinc, gypsum, phosphorite, gemstones, coal, petroleum and natural gas, construction materials such as aggregate, dimension/ decorative stones, paving stones, slates, boulders, gravel and sand. Investment in these potential mineral resources is highly rewarding.
40th Annual General Meeting (AGM) of the Nepal Geological Society was held in SaSa Banquet and Event Management, Teku, Kathmandu on Bhadra 8, 2075 (September 24, 2018)
Academic and professional development Sub Committee of the Nepal Geological Society and Nepal Geological Students’ Society in collaboration with Central Department of Geology has organized a training and interaction program entitled “Mining and Engineering Geology in field” on 23rd Asadh 2075 at the conference hall of the Central Department of Geology, Kirtipur.