Geological mapping

Although geological study on the Nepal Himalayas was first carried out in 1854 by Hooker, the geology of the kingdom of Nepal remained unknown till 1950. Between 1951 and 1967, extensive geological mapping was carried out under the International Technical Assistance Program and by individual efforts. However, coverage of the country by systematic geological mapping was initiated only after the year 1967 by the Nepal Geological Survey.

To-date, of the total 147,181 sq. km. area of the country, various areas had been covered by geological mapping at different scales. The coverage status of geological maps available at present for the whole or part of the country is presented in the Table-1. The maps were prepared to address the regional geology and tectonics of the country as the background geological information for application in:

I. identification of targets for mineral prospecting and exploration,
II. planning of infrastructure and natural resources development activities

S. No.	Title	Scale	Coverage Sq. Km	Status	Year	Remarks
1.	Geological Map Of Nepal	1:500,000 to 1:1,000,000	Whole country	published and unpublished	1969, 1972, 1981, 1982, 1993 & 1994	Maps are available in black & white and color prints
2.	Geological Map of Development Regions	1:250,000	75,000	Published	1984 & 1987	Maps are available in 5 sheets of color print
3.	Quadrangle Geological Map	1:63,360 & 1:50,000	105,000	Published and unpublished	1996 & 1999 2000	Of the total 162 Sheets prepared 9 sheets are published in color prints

From 1995 onwards, the department has initiated a revision programme to improve and correct discrepancies in the existing original quadrangle geological maps, which will be finally upgraded to an approved standard and uniformity for publication either in a sheet wise or compiled form. Out of the existing 162 quadrangle geological maps sheets, nine sheets have been revised and published.

Engineering and Environmental Geology

In response to the increasing needs for geological inputs in infrastructure development and environmental protection in the country, the DMG established the Engineering and Environmental Geology Section in 1993. The new section was charged with carrying out the related geological studies effectively. In cooperation with the Federal Institute for Geosciences and Natural Resources (BGR), Germany, the newly created section initiated its activities with the production of engineering and environmental geological maps of the two rapidly growing urban areas, of the Kathmandu and Pokhara valleys using RS/GIS techniques. The purpose of such mapping works was to provide geo-scientific information to planners, engineers, decision-makers and other users.

The DMG has objectives to prepare similar maps for other fast growing urban areas requiring geo-scientific information for urban planning and environmental protection. Such mapping is in progress and also planned for Lumbini-Butwal, Dharan-Biratnagar and Dang valley. The published and unpublished engineering and environmental geological maps presently available are presented in the Table-2

Seismological Research

The National Seismological Network started first in 1978, November as a single seismic station established at Phulchocki hill top which is situated on the southern border of the Kathmandu valley. Today it consists of 21 short period telemetric seismic stations covering the entire country. As in other parts of the world, the seismic stations have been installed with the objectives of monitoring and evaluating seismic activity so as to better understand the causes and effects of the earthquakes and ultimately to be able to mitigate the associated destruction. The National Seismological Network was established in collaboration with the Laboratory de Geophysique Applique (LGA) and presently is functioning in colloboration with Department Analyse, Surveillance and Environment (DASE), Paris, France. The network can acquire data of magnitudes as low as 2 on the Richter Scale occurring in any part of the country. Seismic signals recorded at different stations are relayed to the National and regional Seismological Centres located at Kathmandu and Surkhet for data processing and interpretation. The National Seismological Centre disseminates earthquake data to different national and international agencies. It also makes available to agencies supporting infrastructure development activities in the country.

Based on micro-seismicity data, the DMG has prepared and published Micro-Seismicity Epicentre maps of Nepal at a scale of 1:1,000,000 to 1:2,000,000. Based on these data, the seismo-toetonic models of central and Far Western Nepal Himalaya have been prepared as part of seismo-toetonic research in the Himalaya.

In the present context of the country, such instrumentally recorded earthquake data are very important for the assessment of earthquake hazard and in disaster mitigation. Data are equally significant for planners and engineers who need to take remedial measures in designing earthquake resistant infrastructures such as dams, bridges, buildings, power transmission lines etc.

Mineral Exploration and Development

Metallic Minerals

Systematic prospecting and exploration activities have been carried out for different metallic minerals including gold, copper, lead, zinc, iron, nickel, cobalt, molybdenum and uranium since sixties. Such exploration activities with the reconnaissance geochemical survey and investigation of base metals undertaken with the assistance of United Nation Development Programme from 1975 to 1980 and subsequent similar works carried out by DMG could be considered as the major activities in the mineral exploration programme in Nepal. The activities covered the Lesser Himalayan region. As a result, some economic and sub-economic deposits of lead, zinc, copper and iron were discovered.

The activity status and development stage of identified mineral resources, production and revenue are presented in the Tables Nos. 4, 6 and 7.

The mining history of metallic minerals indicates that metals like gold, copper, lead, nickel, iron and cobalt were mined albeit at a small scale. Among these commodities, copper, iron, nickel and cobalt were even exported to Tibet and India as recently as 1950.

Today metal mining activity in Nepal has declined for all metals with exception of artisenal mining of gold placers.

However, the Department of Mines and Geology is continuously making efforts to generate new mining activities for metals like gold, copper, lead and zinc. As a result, the Nepal Metal Company, a joint venture project was established in 1975 to mine and mill the 400 tons of ore per day, which is based on lead and zinc deposit located at Ganesh Himal. The deposit contains 0.85 million tons of ore at 12.08-13.6% of zinc and 1.4-2.3 % of lead. The deposit is not currently commercially viable due to the inadequacy of the proven reserve. There is a great potential to augment substantial tonnages of new ore reserves by supplementary exploration activity which is presently hindered due to unavailability of funds.

The potential of finding primary gold resources in Nepal is quite high. Identification of gold mineralisations in the bedrock exposures in the Western and Far Western Nepal supports this perception considerably. However, the systematic exploration for an economic gold resource has not been performed due to lack of appropriate expertise and fund.

Nonmetallic Minerals

The Department of Mines and Geology conducted exploration for nonmetallic minerals such as limestone, marble, dolomite, talc, magnesite, ruby, sapphire, polychrome tourmaline, aquamarine, garnet, quartz and slate since 1965. As an outcome, commercially viable resources of cement and chemical grade limestone, marble, dolomite, talc, and magnesite are known today. The exploration activities also revealed the existence of ruby, sapphire, aquamarine, tourmaline and quartz of gem as well as industrial quality.

Three Cement Industries currently in production, namely (i) Himal Cement Company Ltd. of 400/tpd capacity (ii) Hetauda Cement Industries Ltd. of 750/tpd capacity and (iii) Udaipur Cement Industries of 800/tpd capacity are based on limestone deposits containing a total of 104.5 million tons reserve. A few mini-cement plants are also contributing to a small amount of the total cement demand. The cement industries of Nepal meet 40% of the present domestic consumption. Therefore, there is a great potential for the establishment of more cement industries in Nepal.

Recently, the Department has awarded license and negotiation is underway for the feasibility study and establishment of cement industries based on 31.6 million tons reserve of Chaukune Limestone deposit, Surkhet and 17.44 million tons reserve of Narapani limestone deposit, Arghakhanchi. One more cement grade limestone deposit identified presently at Sallyan is also in process of advertisement for the feasibility study to establish a cement industry. Surface and subsurface exploration was completed on this deposit in 1998.

A few other limestone deposits also support the agriculture and chemical lime industries.

The Godavari marble deposit is producing marble slabs demand of which is appreciably large in local market and abroad. Similarly, one talc industry produces 10,000 tons of powder talc annually from the 0.3 million ton deposit at Kharidhunga. The country needs continuation of exploration activities for the commodities like limestone, marble, dolomite, talc and magnesite. The potential areas of non-metallic minerals have not been completely examined to establish the over all resources available in the country. It is likely to discover some new resources of economic importance. Gem quality ruby, sapphire, aquamarine and tourmaline had not been satisfactorily explored in the past even though the geological condition is favorable to find commercially significant resources. These commodities particularly require the detail examination of the potential areas.

The development and production and status of some important resources identified during exploration are indicated in the table 4 and 5.

Construction Minerals

Limestone, dolomite, marble, quartzite, granite, syenite, slate, boulder, gravel, sand and clay occur extensively and are the main construction materials in the country. They are produced at different scales to fulfill mainly the domestic demand and for export to India.

Impure limestones and dolomites of chemically inferior quality but of high strength constitute important construction materials in the country. Such resources are found extensively distributed throughout the Mahabharat Range and have potentiality for future quarry development. Granite and quartzites resources of similar geographical distribution have also equal importance for the production of the construction aggregates and block stones.

Inexhaustible resources of boulder, gravel and sand are widely found in the rivers of Terai belt and Churia Range. In many rivers, the boulder are potentially productive and exportable to the neighboring countries. No conceptual frameworks has yet been designed to develop export industries based on such resources. Initial evaluation of these resources was done in all the rivers during eighties. Re-evaluation of the resources is being carried out to establish the present situation due to changing reserve after every flood and continuous removal of these materials in the past for construction purposes.

Petroleum Exploration

Petroleum is categorized as the national priority commodity for exploration and development. The Petroleum Exploration Promotion Project (PEPP) constituted under the Department of Mines and Geology in 1982, functions specifically to promote petroleum exploration and development activities in the country. The southern Terai plains and the adjoining Siwalik Range have been divided into ten different blocks, each of nearly 5000sq.km, for the petroleum exploration and development.

Composite data packages for the individual blocks are available to the potential investors at the fixed cost on fulfillment of the prescribed rules and regulations. The nature of the data packages range from the general report to borehole logs, and photo-geological, aeromagnetic, gravity and seismic interpretations. A prospective investor has to purchase the DSP-A costing US$ 5000 to be eligible for bidding the acreage, to visit the Data Center at Kathmandu and to purchase any Data Sales Packages (DSP).

His Majesty’s Government realizes that the participation of the potential investor, national or foreign, is essential to the exploration and development of petroleum in Nepal. In consideration of this fact, in April 1985 the Department of Mines and Geology initiated a global bidding process to attract the potential companies to explore and develop petroleum in the ten exploration blocks.

The Shell Company from the Netherlands conducted exploration work in the block no.10 situated in the eastern Nepal after winning award in the first bidding held in 1985. In this context, one drill hole was made up to a depth of 3,520 m after the evaluation of seismic and other surface data during 1986-90. The borehole was recorded dry. However, the data derived from the hole was utilized to update the information.

In December 1998, after fulfillment of the evaluation, negotiation and agreement process outlined for global bidding, His Majesty’s Government awarded the Texana Resources Company of USA the right to carry out the seismic and geological studies in block Nos.3 (Nepaljung) and 5 (Chitwan). Presently, the Company has initiated the activities defined in the agreement. The other blocks remain open to potential investors for exploration bidding.

Natural Gas Exploration

Natural gas associated with groundwater exists in the lake sediment of the Kathmandu valley. The Department of Mines and Geology initiated exploration for such methane gas resources in 1978 by undertaking drilling activities. The purpose was to assess the available reserve and the possibility to use it as an alternative energy. Initial drilling operations were carried out with the assistance of Japanese International Co-operation Agency (JICA). Subsequently, DMG performed further exploration activities independently. As an outcome, the presence of 300 million cubic meter of methane gas was proved over an area of 26 sq.km. The feasibility study was conducted in 1996/97 by a private consultant. The study concludes that the use of methane gas is viable for both domestic and industrial purposes.

Based on the above results, the DMG invited the potential investors to bid for the development and commercialization of the gas resources for the benefit of society. The department has received proposals in this respect which are being evaluated.

Coal Exploration

Existence of peat, lignite and coal are known in the different parts of the country. Among the various occurrences examined in the past, the coal seams identified in the Dang Valley and the surrounding area seems to be the most significant in respect of utilization as an alternative fuel in the country, though the resource is very small. Other economic coal deposits belonging to favourable formations are yet to be explored.