scholarly journals Geology and mineral resources of Khudi-Bahundanda area of west-central Nepal along Marshyangdi Valley

2019 ◽  
Vol 58 ◽  
pp. 97-103
Author(s):  
Shashi Tamang ◽  
Sandeep Thapa ◽  
Kabi Raj Paudyal ◽  
Frédéric Girault ◽  
Frédéric Perrier
Keyword(s):  
Large Scale ◽  
Mineral Resources ◽  
Main Central Thrust ◽  
Quartz Veins ◽  
The North ◽  
Central Nepal ◽  
West Central ◽  
Geological Map ◽  
Scale Structures ◽  
Garnet Zone

Geological study was carried out along the Khudi-Bahundanda area of the Marshyangdi Valley in the west central Nepal. The area lies partly in the Main Central Thrust (MCT) zone and partly in the Higher Himalayan Crystalline Zone. The aim of the study was to prepare a detail geological map and cross section in the scale of 1:25,000 to work out on stratigraphy, metamorphism and mineral resource potential of the area. The rocks of the Higher Himalaya have been mapped under a single unit as Formation I. This unit consists of kyanite-garnet para-gneiss. The lithological units of the MCT zone are mapped into three units as the Benighat Slate, the Malekhu Formation and the Robang Formation from the bottom to the top, respectively. The Benighat Slate consists of dark grey to black schist with some carbonate beds as members. The Malekhu Formation consists of creamy white siliceous dolomite marble with parting of schist. The Robang Formation comprises of light grey psammitic schist with garnet and white micaceous quartzite in various proportion. Many secondary structures are observed in the study area, but primary structures are missing due to extreme metamorphism. The large-scale structures are the MCT, which separates the Lesser Himalayan rocks to the south from the Higher Himalaya to the north, and the Bahundanda Thrust (BT). Numerous outcrop-scale structures like meso-scale folds, quartz veins, boudinage and ptygmatic folds are abundant. Folds in the MCT zone are mostly E-W trending, and rocks have experienced multiple metamorphism and dynamic crystallization of minerals. The Lesser Himalayan rocks resemble the garnet zone while the Higher Himalayan rocks resemble to the kyanite grade of metamorphism. As in the other sections of the Himalaya, the present section also clearly shows the inverted metamorphism in the MCT zone. The MCT zone is considered as the potential site for precious and semi-precious stones, of which the most potential ones are the garnet and kyanite.

scholarly journals Geology and micro-structure analysis of the MCT zone along Khudi- Bahundanda area of Lamjung District, west-central Nepal

2019 ◽  
Vol 58 ◽  
pp. 105-110
Author(s):  
Sandeep Thapa ◽  
Shashi Tamang ◽  
Kabi Raj Paudyal ◽  
Frédéric Girault ◽  
Frédéric Perrier
Keyword(s):  
Geological Mapping ◽  
Small Scale ◽  
Main Central Thrust ◽  
Geological Structures ◽  
Quartz Crystals ◽  
Central Nepal ◽  
West Central ◽  
Ductile Shearing ◽  
Microscopic Features ◽  
Garnet Zone

Geological mapping was carried out along the Marsyangdi Valley in the Khudi-Bahundanda area of west-central Nepal covering the Main Central Thrust (MCT) zone. The main objectives of the study were to draw a clear picture of lithology, geological structures and micro-tectonics in the rocks. A detail survey on stratigraphy and correlation with central Nepal reveals geological rock units such as the Benighat Slate, the Malekhu Formation and the Robang Formation of the Lesser Himalaya and the Formation I of the Higher Himalaya. Both regional and small-scale geological structures have been studied. The MCT zone has been mapped as a major regional structure in the region. The Bahundanda Thrust (BT), which has brought the older Malekhu Formation over the younger Robang Formation, is an another significant structure mapped. The BT is marked on the basis of fault breccia, slickensides as well as large deposits of debris mass at the fault zone. The study area has undergone poly-metamorphism and dynamic crystallization of minerals. The Lesser Himalayan rocks resemble the garnet zone while the Higher Himalaya rocks resemble to the kyanite grade of metamorphism. The present section clearly shows the inverted metamorphism in the MCT zone as in the other sections of the Himalaya. Microscopic features like ribbon-quartz, polygonization of quartz crystals, grain boundary reduction, mica-fish and rotated garnet grains indicates the ductile shearing in the MCT zone suggesting the dynamic recrystallization during thrust propagation. Numerous outcrop-scale structures like meso-scalefolds, quartz veins, boudinage and ptygmatic folds are abundant folds in the MCT zone and these are mostly E-W trending.

scholarly journals Occurrences of mineral resources in Bandipur Gondrang area of Tanahun district, central Nepal, Lesser Himalaya

2014 ◽  
Vol 2 ◽  
pp. 24-35
Author(s):  
Kabiraj Paudyal
Keyword(s):  
Mineral Resources ◽  
Mineral Deposits ◽  
Lesser Himalaya ◽  
Geological Investigation ◽  
Central Nepal ◽  
Metallic Mineral ◽  
Geological Map ◽  
Geological Control ◽  
Basic Rocks

A detailed geological investigation was carried out to assess the distribution of minerals and their geological control in Bandipur-Gondrang area of Tanahu district, a part of Lesser Himalaya in central Nepal. The area is found rich in both metallic and non-metallic mineral deposits. The main metallic minerals found are iron in Phalamdada and Labdi Khola, copper in Bhut Khola and poly-metallic deposits including suspected gold in Bhangeri Khola and Jaubari Khola-Bar Khola sections. A large deposit of inorganic carbon is found around the Gondrang-Watak area. Similarly, a good quality of green marble (metabasite) is found as decorative stone in Bagar Khola area and good quality of roofing stone in Bandipur area. In addition to these economic deposits other several sub economic to non-economic mineral are also located in the geological map of the area. Categorization of these mineral deposits is based on the probable reserve and laboratory analysis of related samples. Geological control of mineral deposits is considered to be the stratigraphic, structural, metamorphic and hydrothermal. Iron mineralization of the area is found stratigraphical control, copper deposits by magmatism of basic rocks (amphibolites), and poly-metallic deposits are related to the hydrothermal processes.

scholarly journals Geology and Mineral Resources of Phalamdada-Dhuwakot Section of West-Central Nepal, Lesser Himalaya

2018 ◽  
pp. 59-64
Author(s):  
Arjun Bhattarai ◽  
Kabiraj Paudyal
Keyword(s):  
Mineral Resources ◽  
Geological Mapping ◽  
Metamorphic Rocks ◽  
Low Grade ◽  
Lesser Himalaya ◽  
Central Nepal ◽  
West Central ◽  
Metallic Mineral ◽  
Geological Control ◽  
Core Part

Geological mapping was carried out along the Phalamdanda-Dhuwakot section of west-central Nepal in the Lesser Himalaya. The aim of geological mapping was to prospect the metallic mineral resources in the area especially to assess the geological control of mineralization as prognostic mapping and study the genesis of mineralization. The area has developed low-grade metamorphic rocks of the Nawakot Group. Geological rock units like the Kuncha Formation, Fagfog Quartzite, Dandagaon Phyllite, Nourpul Formation and Dhading Dolomite are mapped in the area. Jal Bhanjyang Thrust carries the more older rocks of the Nourpul Formation over the Dhading Dolomite. The area is highly deformed as indicated by presence of folds. Outliers of Fagfog Quartzite and Dhading Dolomite are developed at the core part of the syncline. Phalamdada iron and Anbu Khaireni as well as Dharapani copper are the major metallic deposits reported in the area. Both deposits are considered as the syngenetic in nature. Bulletin of Department of Geology, vol. 20-21, 2018, pp:59-64

scholarly journals Geology of Shantipur-Wami Taksar Areas of Gulmi-Baglung Districts, Western Nepal

2020 ◽  
Vol 22 ◽  
pp. 29-32
Author(s):  
Sushant Sapkota ◽  
Pashupati Gaire ◽  
Kabi Raj Paudyal
Keyword(s):  
Regional Scale ◽  
Mineral Resources ◽  
Geological Structure ◽  
Geological Mapping ◽  
The North ◽  
Copper Mineralization ◽  
Metallic Mineral ◽  
Geological Map ◽  
Map Scale ◽  
Geological Units

The study area represents a small part of the Lesser Himalaya in western Nepal and lies about 346 km west from Kathmandu. It covers 250 km area representing some parts of Gulmi and Baglung districts. The area was selected for the present study on the impression from the previous geological map that has showed some metallic mineral resources like iron, copper and lead in the region. Similarly, studies reveal that there is very complicated geological structure which raised the interest for the study. Main objective of the study was to prepare a geological map of the area in a scale of 1:25,000 and study the possible mineral deposits. An extensive geological mapping was carried out in the field covering at one data within one centimetre of the map scale and large number of samples was collected for the petrographic as well as ore genesis studies. The rocks of the region were mapped under two geological units as the Nourpul Formation (older) and the Dhading Dolomite (younger).  There are a series of folds in the area. From regional to micro-scale all folds are trending towards east-west. The Badi Gad Fault and the Harewa Khola Thrust are the regional scale thrust mapped in the area. The Badi Gad is considered as a strike-slip in nature. The Harewa Khola Thrust is probably an imbricate fault. It has propagated to the north which is out of sequence in nature. Some metallic minerals like copper and iron along with old working mines were observed during the study. Occurrences of copper and iron mineralization has been mapped and described. Present study revealed that copper mineralization is limited within the veins and boudinage forms as hydrothermal deposit while the iron is tabular and syngenetic in nature.

scholarly journals Study of regional geological structures in Ridi-Shantipur area of Gulmi district, Lesser Himalaya, west-central Nepal

2019 ◽  
Vol 58 ◽  
pp. 111-118
Author(s):  
Shrawan Shakya ◽  
Kabi Raj Paudyal
Keyword(s):  
Regional Scale ◽  
Lesser Himalaya ◽  
The North ◽  
Central Nepal ◽  
West Central ◽  
Continuous Shear ◽  
Deformation Event ◽  
Middle Member ◽  
Geological Units ◽  
The Himalaya

The study was carried out in the Lesser Himalaya between Ridi-Shantipur area of the Gulmi District, west-central Nepal. Two geological units: the Nourpul Formation and the Dhading Dolomite were mapped in the area. These units belong to the Nawakot Group as explained by several researchers in central Nepal. The Nourpul Formation can further be divided into three members based on distinct mappable lithology, which are named as the Lower Member, the Middle Member and the Upper Member, respectively. The area is highly folded with several local and regional anticlines and synclines; Ridi Khola Anticline, Ridi-Karikot Syncline, Ruru Anticline, Baletaksar-Gwadi Syncline, Huga-Bamgha Anticline, Rimuwa-Rudrabeni Syncline, Juhan-Eksing Anticline, Juniya-Limgha Syncline, Bharse-Thaple Anticline, and Chiureko Syncline, respectively from the south to the north. All the folds are trending along to the ESE-WNW direction. The origin of these folds can be linked with the thrust propagation in the Himalaya that can be explained with the deformation event D4. The Harewa Khola Thrust is the only one regional scale thrust mapped in the area. The thrust carries the older Nourpul Formation over the Dhading Dolomite with the indications of thrust related features like slickensides and fault-breccias. The thrust seems to propagate to the north. There is a continuous shear zone mapped in the outcrops from the Tal Khola-Aslewa-Eksingh-Gudrung-Juhang- Rupakot region as an indicator of the presence of the Badi Gad Fault in the region.

scholarly journals A Short Note on the Tsergo Ri Landslide, Langtang Himal, Nepal

1995 ◽  
Vol 11 ◽  
Author(s):  
J. T. Weidinger ◽  
J. M. Schramm
Keyword(s):  
Large Scale ◽  
Mass Movement ◽  
Short Note ◽  
North Central ◽  
Central Nepal ◽  
Geological Map ◽  
Displacement Deposition ◽  
Langtang Valley

The large-scale mass movement at Tsergo-Ri (Langtang valley) in north-central Nepal was mapped in detail and an engineering geological map was prepared. Five different phases of displacement, deposition and erosion of the landslide are reconstructed. The present morphology of the area is largely the result of the above movement.

scholarly journals The Geology of the Rolwaling-Lapchi Kang Himalayas, East-Central Nepal: preliminary findings

1987 ◽  
Vol 4 ◽  
Author(s):  
Daniel Schelling
Keyword(s):  
Brittle Deformation ◽  
The South ◽  
Main Central Thrust ◽  
East Central ◽  
The North ◽  
Central Nepal ◽  
Main Boundary Thrust ◽  
Structural Discontinuity ◽  
Thrust Zone

Between the Tethyan sediments to the north and the Main Boundary Thrust to the south ten lithotectonic units have been identified in the Rolwaling-Lapchi Kang Himalayas and the Tamba Kosi region of east-central Nepal. These are (1) the Rolwaling Granites, (2) the Rolwaling Paragneisses, (3) the Rolwaling Migmatites, (4) the Alampu Schists, (5) the Khare Phyllites , (6) The Chagu-ChilangkaAugen Gneisses; (7) The Laduk Phyllites, (8) the Suri Dhoban Augen Gneisses, (9) the Rarnechap Group, and (10) the Mahabharat Crystallines. The Main Central Thrust (MCT) is a major lithologic, metamorphic and structural discontinuity separating the overthrust Higher Himalayan crystallines from the underthrust Lesser Himalayan metasediments. The Mahabharat Crystallines are an outlying klippe of Higher Himalayan rocks, underlain by the MCT, that has been thrust a minimum of 80 kilometers over the underlying Lesser Himalayan metasediments. Extending approximately 5 km below the MCT and 15 km above the MCT the Himalayas are a shear-thrust zone exhibiting ductile, brittle-ductile and brittle deformation as well as an inverted metamorphic sequence.

Contact metamorphism of the Tethyan Sedimentary Sequence, Upper Mustang region, west-central Nepal

2020 ◽  
Vol 157 (11) ◽  
pp. 1917-1932 ◽  
Author(s):  
Iva Lihter ◽  
Kyle P. Larson ◽  
Sudip Shrestha ◽  
John M. Cottle ◽  
Alex D. Brubacher
Keyword(s):  
Regional Metamorphism ◽  
Contact Metamorphism ◽  
Metamorphic Rocks ◽  
Upper Crust ◽  
Sedimentary Sequence ◽  
The North ◽  
Central Nepal ◽  
West Central ◽  
Metamorphic Temperature ◽  
Local Movement

AbstractThe Upper Mustang region of west-central Nepal contains exposures of metamorphosed Tethyan Sedimentary Sequence rocks that have been interpreted to reflect either contact metamorphism related to the nearby Mugu pluton or regional metamorphism associated with the North Himalayan domes. New monazite geochronology results show that the Mugu leucogranite crystallized at c. 21.3 Ma, while the dominant monazite age peaks from the surrounding garnet ± staurolite ± sillimanite schists range between c. 21.7 and 19.4 Ma, generally decreasing in age away from the pluton. Metamorphic temperature estimates based on Ti-in-biotite and garnet–biotite thermometry are highest in the specimens closest to the pluton (648 ± 24°C and 615 ± 25°C, respectively) and lowest in those furthest away (578 ± 24°C and 563 ± 25°C, respectively), while pressure estimates are all within uncertainty of one another, averaging 5.0 ± 0.5 kbar. These results are interpreted to be consistent with contact metamorphism of the rocks in proximity to the Mugu pluton, which was emplaced at c. 18 ± 2 km depth after local movement across the South Tibetan detachment system had ceased. While this new dataset helps to characterize the metamorphic rocks of the Tethyan Sedimentary Sequence and provides new constraints on the thickness of the upper crust, it also emphasizes the importance of careful integration of metamorphic conditions and inferred processes that may affect interpretation of currently proposed Himalayan models.

scholarly journals VIII.—Quartz Dykes Near Foxdale, Isle of Man

1903 ◽  
Vol 10 (1) ◽  
pp. 34-36 ◽  
Author(s):  
J. Lomas
Keyword(s):  
General Trend ◽  
General Direction ◽  
Quartz Veins ◽  
Isle Of Man ◽  
North East ◽  
The North ◽  
Large Size ◽  
Geological Map ◽  
Granite Mass

In the neighbourhood of Foxdale, Isle of Man, and especially on Granite Mountain, the ground is strewn with numerous blocks of quartz. Many of them are of large size, 10 feet or more in diameter.On the slopes of South Barrule similar blocks are found in great profusion, and they can be traced across the hills to the west coast. North of Foxdale other bands are found, some of which are inserted in the geological map. They lie principally in the altered slates of the Barrule Series, and have a general trend corresponding with the main axis of the island, from north-east to south-west. In places they are seen to be in sitû, and where the granite mass of Foxdale intervenes the general direction changes, and is principally tangential to the intrusion.Numerous micro-granite dykes extend along the axis of the island in the same direction.In an old quarry at Renshent on the north margin of the granite several quartz veins are seen to traverse the granite itself. They can be traced along the floor of the quarry and up the vertical face about 30 feet high.One of these, about 3 feet in width, shows perfectly sharp margins when cutting through the granite, dips at 65° W., and strikes 10° E. of S. It consists mainly of quartz, some clear and some white and opaque, but on entering the granite it changes locally to a pegmatite. The pegmatite contains, in addition to the quartz, large felspars, some over 3 inches long, perfectly formed, and showing crystal faces, and mica in crystals over an inch in diameter.

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