scholarly journals Magnetic-Polarity Stratigraphy of Siwalik Group Sediments of Tinau Khola Section In West Central Nepal, Revisited

1994 ◽  
Vol 117 (1) ◽  
pp. 223-234 ◽  
Author(s):  
Pitambar Gautam ◽  
Erwin Appel
Keyword(s):  
Magnetic Polarity ◽  
Central Nepal ◽  
West Central ◽  
Siwalik Group

scholarly journals Paleohydrological reconstruction of the Siwalik Group along the Tinau Khola section, west-central Nepal Himalaya

2009 ◽  
Vol 39 ◽  
Author(s):  
Prakash Das Ulak
Keyword(s):  
Slope Gradient ◽  
Nepal Himalaya ◽  
Sedimentary Sequences ◽  
Central Nepal ◽  
Frontal Part ◽  
West Central ◽  
Channel Slope ◽  
Siwalik Group ◽  
The Himalaya ◽  
Velocity Channel

Neogene fluvial sedimentary sequences of the Siwalik Group are extensively accumulated in the southern frontal part of the Himalaya and well exposed in the Tinau Khola section of the west-central Nepal Himalaya. The group reveals a coarsening­ upwards succession in general but many fining-upwards fluvial successions on a scale from several to tens of metres is established in each lithological unit. The paleohydrological characteristics have been estimated using thickness of fining upwards fluvial successions, their grain diameters, and bedforms. The paleohydrology suggests an increase in flow velocity, channel slope gradient, and discharge of the fluvial system. Paleovelocity varies from 0.17 to 5.31 m/s, paleochannel gradient and paleodischarge change from l.13x10-5 to 7.33x10-4 m/m and 101 to 104 m3/s, respectively towards the stratigraphic top. These progressively changing paleohydrological characteristics reflect the southward propagation of thrusts caused by the upheaval of the Himalaya.

scholarly journals Neogene fluvial systems in the Siwalik Group along the Tinau Khola section, west central Nepal Himalaya

2001 ◽  
Vol 25 ◽  
Author(s):  
Prakash Das Ulak ◽  
Katsuhiro Nakayama
Keyword(s):  
System Development ◽  
Major Change ◽  
Fluvial System ◽  
Facies Association ◽  
The North ◽  
Central Nepal ◽  
Main Boundary Thrust ◽  
West Central ◽  
Facies Associations ◽  
Siwalik Group

Along the Tinau Khola section of west central Nepal, the Siwalik Group is a 4 km thick pile of fluvial sedimentary sequence of mudstone, sandstone and conglomerate. It is exposed between the Main Boundary Thrust (MBT) to the north and the Frontal Churia Thrust (FCT), also known as the Main Frontal Thrust (MFT), in the south. The Siwalik Group is lithologically divided into the Arung Khola, Binai Khola and Chitwan formations, in ascending order. Six facies associations (FA1 to FA6) are recognised within the group based on grain size distribution, nature of bedforms, and sandstone-mudstone ratio. The fine-grained sediments of the Lower and Middle members of the Arung Khola Formation belong to the FA1-facies association and were interpreted to have deposited by a low-discharge, low -relief meandering fluvial system. The multiple accumulated thin-layered muddy sandstone sequence in the Upper Member of the Arung Khola and the Lower Member of the Binai Khola formations belong to FA2 and FA3- facies associations and were deposited by a flood flow-dominated meandering fluvial system. The deep sandy braided facies association (FA4) and shallow sandy braided facies association (FA5) are well developed in the Middle and Upper members of the Binai Khola Formation, respectively. The gravelly braided facies association (FA6) is recognised in the Chitwan Formation. The palaeomagnetically well-studied section of the Tinau Khola allows precise dating of the major change of fluvial system during the deposition of the Siwalk Group. The environment of predominantly shallow meandering rivers with low­ relief and low-discharge during the time of deposition of the Arung Khola Formation changed at 9.9 Ma and flooding in the rivers dramatically increased due to the intensification of monsoon precipitation. This hydrographic change also brought the change in facies from the earlier FA1 facies to FA2 and FA3 facies. Change from meandering to braided system occurred at 8.2 Ma because of the obvious regional tectonic upliftment of the Higher Himalaya bringing into FA4 and FA5-facies associations. Finally the FA6-facies association was developed due to the large gravelly braided system development at 2.5 Ma as a result of the Main Boundary Thrust movement along the frontal part of the Himalaya.

scholarly journals Petrography of the Siwalik sandstones, Amlekhganj-Suparitar area, central Nepal Himalaya

2003 ◽  
Vol 28 ◽  
Author(s):  
Naresh Kazi Tamrakar ◽  
Shuichiro Yokota ◽  
Suresh Das Shrestha
Keyword(s):  
Middle Miocene ◽  
Foreland Basin ◽  
Early Pleistocene ◽  
Nepal Himalaya ◽  
Central Nepal ◽  
Present Study Area ◽  
Mean Grain Size ◽  
Siwalik Group ◽  
Variation Trends ◽  
The Himalaya

Middle Miocene to early Pleistocene sedimentary sequence deposited in the foreland basin of the Himalaya is represented by the Siwalik Group. In the present study area the Siwalik Group extends in a NW-SE direction and well-exposed. Forty­four sandstone samples were studied for texture, fabric and composition in order to assess their petrographic properties and variation trends of these properties in stratigraphic levels. Sandstones were classified into sublitharenite, subarkose, lithic arenite, arkosic arenite and feldspathic graywacke and further thirteen sub-clans. Mean grain size (M) and Trask sorting coefficient (So) increase up-section. Recalculated quartz, matrix, modified maturity index (MMI), total cement (Ct), cement versus matrix index (CMI) and ratio of strong cement over total cement ((Cfc/Cs)/Ct) also increase, whilst packing proximity (PP), packing density (PD) and consolidation factor (Pcc) decrease up-section showing distinct trends, and therefore, these properties are promising in recognizing the older sandstones from the younger ones.

Structural and microtectonic analyses of Barpak of Gorkha district, west-central Nepal

2020 ◽  
Vol 60 ◽  
pp. 163-179
Author(s):  
Sameer Poudel ◽  
Lok Mani Oli ◽  
Lalu P. Paudel
Keyword(s):  
Dynamic Recrystallization ◽  
Geological Mapping ◽  
Dolomitic Marble ◽  
Rock Types ◽  
Central Nepal ◽  
Phase Deformation ◽  
West Central ◽  
Shear Sense ◽  
Shear Sense Indicators ◽  
Cylindrical Folds

Geological mapping was carried out in the Barpak-Bhachchek area of the Daraudi River valley, Gorkha district, West-Central Nepal for structural analysis. The area comprises rocks of the Higher Himalayan Crystalline and the Lesser Himalayan Sequence.  Pelitic and psammitic schist, quartzite, calc-quartzite, dolomitic marble, graphitic schist, gneiss are the main rock types within the Lesser Himalayan Sequence,  whereas banded gneiss and quartzite form a significant portion of the Higher Himalayan Crystalline in the study area. The area is affected by poly-phase deformation. Lesser Himalayan Sequence has suffered five deformational phases (DL1-DL2, D3-D5) whereas the Higher Himalayan Crystalline has suffered four deformational events (DH1, D3-D5). The Lesser Himalayan Sequence lying to the northern limb of the Gorkha-Kuncha Anticlinorium is contort into doubly plunging to dome-and-basin-like en echelon type of non-cylindrical folds as Baluwa Dome and Pokharatar Basin (DL2 and D4). The direction of shearing as indicated by shear sense indicators (C' Shear band and Mica fish) is top-to-south coinciding with regional sense of shear related to the MCT propagation. The dynamic recrystallization direction, obtained from rock dominant with phyllosilicate minerals is top-to-south and coincides with mineral lineation and indicate the mineral lineation is contemporary with dynamic recrystallization during the MCT propagation.

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

Variation and change in fertility in West Central Nepal

Human Ecology ◽  
1992 ◽  
Vol 20 (2) ◽  
pp. 225-248 ◽  
Author(s):  
Steven Folmar
Keyword(s):  
Central Nepal ◽  
West Central

scholarly journals Lithofacies and depositional environment of the Siwalik Group in Samari-Sukaura River area, Central Nepal

2013 ◽  
Vol 16 ◽  
pp. 53-64 ◽  
Author(s):  
Dev Kumar Syangbo ◽  
Naresh Kazi Tamrakar
Keyword(s):  
Depositional Environment ◽  
Foreland Basin ◽  
River System ◽  
Nepal Himalaya ◽  
Meandering River ◽  
Fine Grained ◽  
Architectural Elements ◽  
Central Nepal ◽  
Eastern Zone ◽  
Siwalik Group

Thick sedimentary sequence deposited in the foreland basin of the Nepal Himalaya is represented by the Siwalik Group. The Siwalik Group is well exposed in the Samari-Sukaura River area. The present study is focused in southern portion of the MBT around the Samari-Sukaura area for its depositional environment. The Middle Siwaliks of the Sukaura Road sections is overlained by the Lower Siwaliks which is separated by the Karki Khola Thrust. Extension of the Lower Siwaliks in the Jyamire Khola and the Bundal Khola becomes wider in the eastern Zone. Repetition of the Lower Siwaliks along the southern margin of the MBT is recognized. Depending on lithofacies assemblage and facies analysis, the two broad facies assemblages FA1 and FA2 have been distinguished. FA1 shows SB, FF, LA, LS and CH architectural elements and is interpreted as a product of the fine-grained meandering river system. FA2 shows SB, FF, LA, DA and CH architectural elements and is interpreted as a product of sandy mixed-load meandering river system. DOI: http://dx.doi.org/10.3126/bdg.v16i0.8884   Bulletin of the Department of Geology Vol. 16, 2013, pp. 53-64

scholarly journals Land cover change in Himalaya with special reference to forest disturbance: A case of Bharse area, Lesser Himalaya, West Central Nepal

2008 ◽  
Vol 2 (4) ◽  
pp. 138-139
Author(s):  
Chinta Mani Gautam ◽  
Teiji Watanabe
Keyword(s):  
Land Cover ◽  
Special Reference ◽  
Land Cover Change ◽  
Forest Disturbance ◽  
Lesser Himalaya ◽  
Special Issue ◽  
Central Nepal ◽  
West Central

Himalayan Journal of Sciences Vol.2(4) Special Issue 2004 pp.138-9

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