Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

S. K. Pandita ¹, G. M. Bhat ¹

Affiliations
1 Department of Geology, University of Jammu, Jammu - 180004, IN

Abstract

This paper embodies the results on the study of depositional environment, provenance and tectonic setting of Middle Siwalik Subgroup of Jammu region. The data obtained on lithofacies, sedimentary structures and nature of contacts between various lithofacies, suggest multiple episodes of avulsion and abandonment of the channel system for a new course in braided river system. Four variable plot of quartz types shows that these sediments have been derived from low rank metamorphic source. The detrital modes (quartz, feldspar and lithic fragments) plotted on complementary ternary diagrams (QFL and Q_mFL_t) indicate that these sediments have been shed from recycled orogens, transitional arc and transitional continental provinces.

Keywords

Sedimentology, Siwalik, Jammu, Himalaya.

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S. K. Pandita ¹, G. M. Bhat ¹

Affiliations
1 Department of Geology, University of Jammu, Jammu - 180 004, IN

Abstract

This paper embodies the results of palaeocurrent analysis of two stratigraphic sections exposed at Parmandal-Uttarbani and Papar-Nad, Jammu. The general palaeoflow patterns are due south-southwesteriy with the temporal palaeoflow variations of 40°-183° and 41°-144°for the Middle and Upper Siwalik Subgroups respectively. In the Middle Siwalik Subgroup of Papar-Nad section and Upper Siwalik Subgroup of Parmandal-Uttarbani section, four palaeoflow reversals have been recorded. The temporal palaeoflow patterns and the reversals are related to the tectonic episodicity of the intrabasinal tectonic structures and the basin margin activity.

Keywords

Sedimentology, Palaeocurrents, Siwalik, Jammu, Himalaya.

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S. B. Bhatia ¹, G. M. Bhat ², S. K. Pandita ²

Affiliations
1 House No. 441, Sector 6, Panchkula-134 109, IN
2 PG. Department of Geology, University of Jammu, Jammu - 180 006, IN

Abstract

The paper records for the first time a small, but interesting microfossil assemblage from the mudstonc beds, underlying the bentonitized tuff band (2.8±0.56 Ma) of the Nagrota Formation, Upper Siwalik Subgroup, Jammu Hills at two localities - Bada Khetar and Uttarbehani. The assemblage comprising ostracodes, charophyte gyrogonites and angiosperm seeds, indicates an Upper Tatrot (Late Pliocene) age and deposition in shallow alkaline lake(s) at depth ranging from 2 to 6 m.

Keywords

Nagrota Formation, Upper Siwalik, Late Pliocene, Lacustrine, Ostracodes, Charophyta, Angiosperm Seed.

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G. M. Bhat ¹, Rajinder Singh ¹, S. K. Pandita ¹

Affiliations
1 Geology Dept., University of Jammu, Jammu - 180 004, IN

Abstract

This work, based on sedimentological data collected from two stratigraphic sections at Lambar and Malvat (Banihal area), reports the turbidite to storm influenced sedimentation of "Syringothyris Limestone" sequence, Kashmir Himalaya. An upward progresssion of the sequence reflects the depositional record of fine grained turbidite to storm - and wave - influenced sedimentation. Sedimentary structures like short wave length symmetrical ripples. flat lamination, thin graded bedding and structures in muddy siltstones suggest deposition in low energy, wave influenced settings, The storm influenced sediments display hummocky, cross stratification. skolithos ichinofacies, granule/shelly lags, mega ripples, low angle cross lamination and convolute lamination. The whole sequence is interpreted to represent episodic storm influenced sedimentation in a shallow basin, largely controlled by tectonic activity, The Markov Chain models structured for this sequence also suggest episodic sedimentation and do not show any cyclicity,

Keywords

Sedimentology, Syringothyris Limestone, Turbidites, Carboniferous, Kashmir Himalaya.

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Yudhbir Singh ¹, G. M. Bhat ¹, Vinay Sharma ¹, S. K. Pandita ¹, K. K. Thakur ¹

Affiliations
1 Department of Geology, University of Jammu, Jammu - 180 006, IN

Abstract

In February 2009, a huge landslide occurred at Assar in Doda district of Jammu and Kashmir state. The slide triggered after the reservoir level of the Baglihar dam increased from initial water level of 850 m to 870 m. The impounding of reservoir water created high angle scarps at number of fossil slide sites on either side of the river within the reservoir area. One such scarp (about 250 m long) at Assar caused a huge landslide washing out about 150 m road stretch. The sliding material is dominated by finer fraction (71.5 %) of micaceous silty sand and coarser fraction of gravel to boulder size. Over saturation of the slope forming material, weak rocks and high absorption and swelling nature of the soil, high slope angle and toe cutting by the water are the main reasons that triggered this slide.

Keywords

Landslide, Pore Water Pressure, Assar, Doda, Baglihar, Jammu.

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