Quaternary Tectono-climatic Records of the Ganga basin in the Mountain exits of Himalaya: An Integrated Approach

 

Major Objectives:

Study Area  Adapted form Karunakaran and Rangarao, 1979)

 

Work elements Sedimentologic and geomorphic studies OSL dating High resolution Electrical Resistivity Tomography

 

  

Results (till date)

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• Based on sediment composition and facies, the fan and fluvial terraces are divided into Axial River (ART) and Local River (LRT) terraces.

• In the Ganga Valley, north of HFT aggradation is continued till 11 ka followed by incision which is punctuated by aggradation phases in the form of three levels of terraces (T3 to T1); however, south of HFT, the aggradation continued till 6 ka or even younger till 4 ka followed by incision

• The T4 (11 ka) and T3 (9.7 ka) terraces are terminating along HFT whereas T2 (6.7 ka) and T1 terraces continue across HFT and MBT reveals tectonic activity along HFT has occurred between T3 and T2 with uplift rate of 13mm/yr. However, tectonic activity was not pronounced since the deposition of T2 and incision rate after T2 is ~ 6.7 mm/yr.

• The major incision phase in Ganga  valley is in response to climatic change from drier to wetter condition.

• In Yamuna Valley, two major phases of aggradation and incision are observed; The earlier aggradation  phase continued till ~25 ka followed by incision. The younger aggradation phase contiued till 10.7 ka followed by incision which is similar to Ganga Valley. In all six level of terraces are observed.

• Elevation variation of older terraces across imbricated Thrust reveals  tectonic activity after their deposition.

• Absence of older terraces in the sector-3 may be due to valley widening  and lateral avulsion of Yamuna River. 

• Facies distribution coupled with nature and sediment composition permit to divide the fan and alluvial terraces into Ganga River Terraces (GRT) and Local River Terraces (LRT).

                                                                                                                                       

 

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Project 2

Interfluve stratigraphy, sedimentology and geochemistry of the central and southern Ganga plains

 

 Major Objectives:

• Identification of sub-surface litho-units and alluvial architecture.

• Characterization and correlation of drill cores for sedimentology, geochemistry and magnetic properties in the Ganga-Yamuna interfluve.

•  Identification of pedogenic events in the stratigraphic record through micromorphological  study.

• Clay mineralogical studies and their implications for climatic reconstruction.

• Understanding of stratal patterns and alluvial stratigraphic development as a function of the competing influences of craton sourced river systems and Himalayan sourced river systems.

Study Area

     

 

  

Work elements

 

 

Project 3

 

Fluvial Dynamics and Sub-surface Stratigraphy of Gandak Megafan.

 

 Major Objectives

• Understanding of the River dynamics.

• Facies architecture and depositional environment of surface and subsurface deposits.

• Palaeoclimatic reconstruction.

• vA model for the megafan sedimentation in the light of  Ganga Plain foreland basin evolution.

Study Area

	Work elements Drill core data Environmental Magnetism Geochemical analysis Luminescence dating Palynology

 

Results (till date)

• §The wide valley occupied by narrow channels indicate that the discharge and so the transporting capacity of the river was very high in the past.

  • Discharge and so the size of the sediments are continuously decreasing.

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  • §The palaeo-discharge is high, palaeocurrent direction is towards south.

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  • §The rivers are entrenched not only in the older alluvium  but also in the present day alluvium (older channel bar deposits).

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    §The entrenchment of the river in the bar deposits is acting as a natural hazard .

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  • §The subsurface consist of both channel and inter-channel deposits.

    

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Project 4

 

Studies on the microbial populations present in the vadose zone in the Kanpur area of the Indo-Gangetic plains

Major Objectives

• Enumeration of total recoverable heterotrophs and direct viable counts in vadose zone core soil samples collected from a depth of around 40 m at one specific location.

• Enumeration of denitrifiers and iron reducing bacteria (which represent two major groups of anaerobic bacteria) in above soil samples using MPN procedures.

• Testing bioremediation potential of soil sample for aerobic degradation of few chosen aromatic compounds. Using MPN procedures for enumerating the specific degrades after exposing the soil to contaminant.

• Isolation and characterization of a few pure bacterial cultures.

Study Area 

Work elements Soil chemistry Total organic carbon content 16s/23s rDNA sequencing Bacterial cultures

 

Results (till date)