Annual Report 2007-2008

Earth Sciences

The scheme encourages basic research in the area of earth sciences aimed at enhancing our understanding on the evolutionary and deformation history of the landforms, the influence of climate on landforms and vice-versa, and several other factors that has far reaching impact on the survival of man kind on the planet earth. Manpower development in the area of earth sciences is also a major component of the scheme.

The Programme Advisory Committee on Earth Sciences (PAC-ES) held 3 meetings and considered around 41 project proposals. Twenty one full fledged projects and three pilot projects were recommended for financial support. Ten proposals were recommended for modification to sharpen focus, bridge the scientific gaps and attune them with the global trends. Three proposals for the award of Ramanna Fellowship were considered and one was awarded.

Highlights of On-going & Completed Projects

Projects supported in the research/ academic institutions spread over the country have generated some very exciting results and discoveries and added a wealth of information to the existing knowledgebase. Some of the significant outputs of the ongoing and recently concluded projects are reported here.

I. Water Resources

• Assessment and Management of Groundwater Resources for English Bazar Block, Malda District, West Bengal
  
  The groundwater in the study area occurs under unconfined condition with dominant flow towards east, northeast and north. Chemically, it exhibits high concentrations of HCO3 -, low SO4 2- and NO3 -, indicative of reducing condition. The major-ion chemistry seems to be controlled by weathering of silicate-minerals, rainfall-recharge, ion-exchange and anthropogenic-activities. Possible sources of arsenic in ground water appear to be the arsenicals used as pesticides in mango-orchards and multi-cropped agricultural-land, woodpreservative and arsenic-rich irrigation-water. Modelling studies indicate that at the present pumping rate of 65m3/hr/well will ensure uncontaminated supply of water till the next 25years. Further, abstracting groundwater for domestic purpose from the arsenic-free zone by placing the screens for the wells below 100m depth may not ensure permanent arsenic-free water.
  
  
• Identification of Arsenic Contamination in Ground waters in and around Varanasi Environs and its Mitigation
  
  Arsenic contamination in groundwater has been reported for the first time in Bahadurpur and Madhia villages located in the convex part of the meandering Ganga River near Varanasi. The arsenic content in the groundwater samples varies from detection limit to 80 ppb. The results of borehole sediment samples show that the arsenic content varies from 2.6 mg/kg to 11.9 mg/kg. · Analytical and inverse modeling for estimating aquifer parameters of confined aquifer The project aims to study the hydraulics of the skin layer around a well, in a confined aquifer. Towards this end, a pumping test facility with ten piezometer installations has been established inside the IIT, Guwahati Campus and about 142 sets of time dependent drawdown have been taken on these piezometers. Mathematical analysis and simulation exercise using MODFLOW package indicate profound influence of the skin layer on the overall hydraulics of the system. Seasonal groundwater quality studies are also underway.
  
  
• Analytical and inverse modeling for estimating aquifer parameters of confined aquifer
  
  The project aims to study the hydraulics of the skin layer around a well, in a confined aquifer. Towards this end, a pumping test facility with ten piezometer installations has been taken on these piezometers. Mathematical analysis and simulation exercise using MODFLOW package indicate profound influence of the skin layer on the overall hydraulics of the system. Seasonal groundwater quality studies are also underway.
  
  
• Identification of Recharge Zones through Hydrogeological Approach in Varaha River Basin, Andhra Pradesh
  
  Geomorphological, geological, hydrological and geo electrical studies carried out in the Varaha basin has indicated the occurrence of groundwater both under unconfined as well as confined conditions. Saline water and high fluoride zones had been mapped and demarcated. Recharge and discharge zones in the area are being characterised.
  
  

II. Landform Evolution & its relation to Tectonics

• Deformation and Stain Patterns in the MCT Zone of Alakhnanda Valley, Higher Garhwal Himalaya
  
  This investigation has led to the preparation of a geodynamic model for the MCT Zone. Field observations have indicated that the zone has suffered four phases of deformations viz. the D1deformation phase of Isoclinal folding (F1), followed by D2 deformation of refolding of F1, subsequent thrusting of the crystalline rocks in the D3 phase marked by Mesoscopic shear zones, followed by the Fourth phase of deformation D4, marked by faults and Joints in the region. Detailed analysis of Mesoscopic shear zones reveal that sinistral shear zones exhibit a strike variation from NNE to ENE and dextral shear zone exhibit variation from NNW-to WNW direction thus forming a conjugate pair. The bisectors of statistically preferred orientation of the two sets of the shears indicate that they are generated due to NNE-SSW horizontal compression.
  
  
  
• Neotectonic Rejuvenation in Central Kumaun, Uttaranchal: Implication to Quaternary
  Reactivation of North Almora Thrust and Transverse Faults
  
  Quaternary tectonic history and morpho-tectonics of the NAT zone in Kumaun region is a result of the co-interaction between exceptionally active and accelerating Cenozoic tectonism during the Quaternary period.
  
  The Quaternary period had witnessed disruption of widespread areas resulting in the formation of broad open valleys and blockade of several drainaige basins in the form of palaeolakes. The Quaternary deposits are the result of movements along the North Almora Thrust (NAT) zone and associated transverse faults e.g. Saryu River Fault, Simgad Fault, Gagas River Fault and Ramganga Fault. The fluvial terraces present along these features most probably formed during the time of their rejuvenation. The neotectonic activity along the North Almora Thrust (NAT) was studied along the Kali, Saryu, Jaigan, Kosi, Gagas and Ramganga valleys. The fluvial deposits along these valleys were mainly induced by tectonics environment. Presence of brecciate material at the base of the section reflects prominent tectonic activity had taken place prior to the deposition phase. A shift of fluvial domain towards the flood plain depositional environment may also mark the tectonic activity in controlling the river domain. Unpaired fluvial terraces, triangular facets and cones, waterfalls, abandoned river channel, meandering naturae of river etc. are conspicuous evidences of active tectonism undergone by the area. The abandoned three levels of fluvial terraces at certain locations near Girigad, Jaigan, Kande and Simgad suggest lateral shifting of the river channel due to the vertical upliftment of the area. The result indicates that not only the North Almora thrust is active but associated faults (Simgad Fault) are also reactivated in the Quaternary time. The movement around this area resulted in deformation of hard rocks but it has also deformed Quaternary sediments in the forms of faulting and sedimentary deformational features.
  
  
• Sedimentatological and tectonic evolution, through time and space, of the Piedmont zone of Indo-Gangetic basin between Kosi and Nandhaur rivers, Uttaranchal
  
  The remote sensing, GIS and field work based investigation in the Kota-Pawalgarh Duns have resulted in the mapping of various landforms and lineaments. The physical landscape of the Duns has been characterised in terms of the disposition and composition of various landforms. Active faults have been demarcated in the region and based on tectono-geomorphic setup of the area a model for the evolution of Duns has been proposed.
  
  
• Geometry, Kinematics and Deformation mechanisms in the Gish Transverse Zone in the Darjiling-Sikkim Himalaya, India
  
  Arc-segmenting active transverse fault in the Himalaya have been discovered for the first time. Detailobservations indicate seismogenic dextral strike-slip of ~ 3-5 mm/yr along the arc-segmenting fault and points to lateral deformation along arc segmentation.
  
  
• Structural Evolution of Gavilgarh-Tan Shear Zone, Central India: Field, Micro-structural andExperimental Approach
  
  The prime objective of this project was to understand the deformation geometry and kinematics of Gavilgarh-Tan Shear (GTS) and its bearing on the tectonics of Central Indian Tectonic Zone. Structural mapping and microscopic and Scanning Electron Microscopic studies of critical samples have indicated GTS as a sinistral strike-slip fault zone with a history of multiple re-activations. Several phases of frictioninduced pseudo-tachylyte veins indicate fault movements of contrasting character and kinematics, leading to consider that the shear/fault zone to have experienced protracted period of seismic activity in the geological past.

III. Paleo-climatic & Related Studies

• Neogene-Quaternary Phytostratigraphy of Arunachal Pradesh, Eastern Himalaya, India with palaeoenvironment and palaeogeographic considerations
  
  Twenty two new megafossil taxa, such as compressed fruit, compression and impression of fossil leaves, carbonized wood and portion of stem could be recorded from Siwalik of Arunachal Himalaya for the first time from the Indian Cenozoic strata. The palyno-assemblages from the Dafla Formation (Lower Siwalik), Kimin Formation (Upper Siwalik) and Hapoli Formation (Late Quaternary) of Arunachal Pradesh suggest a distinct change of vegetation vis-à-vis climate from subtropical pine forest (during ca.3540 YrBP) to subtropical broad-leaved forest (ca. 1370 YrBP) in the area. Stable carbon isotope data of the Late Quaternary sediments are in well conformity with palynological database.
  
  
• Late Holocene Climate Records From The Himalayan Region: High Altitude Tree Ring And Pollen Proxy Records
  
  More than 2000 years of chronology, longest ever, could be developed for the Himalayan region in India using extremely slow growing, very old trees of Himalayan pencil cedar (Juniperus macropoda) from Udaipur, Lahul, Himachal Pradesh. The climate responsive chronology, as observed from the growth pattern of the trees is a useful tool for understanding recent climate changes in longer perspective.
  
  
• Monsoon Intensification and Neogene-Quarternary Sivalik Biodiversity
  
  Monsoon variability and habitat changes in the neogene-quaternary period in the Sivaliks have been traced using dental micro-wear of apes belonging to late Miocene age, extinction pattern of amphibious Hippopotamids in early Pleistocene and an assemblage of morphologically diverse species that are reflective of lentic and swampy environment. Deciphering the climate of the Siwaliks through the pollen recovered from mammalian coprolites is being attempted for the first time.
  
  
• Analysis of palaeo-vegetation and palaeo-climate of hominin bearing Quaternary sediments of central Narmada Valley, M. P.
  
  Studies on recovered pollen, spores, faunal assemblages and the magnetic susceptibility of the BanetaFormation exposed at Hathnora inferred to be in the age bracket of 12460 to 25340 yr BP, are suggestive of cool and dry climatic regime with open vegetation of grasses and sparsely distributed trees corresponding to the climatic regime equivalent to the Last Glacial Maximum (LGM) episode, witnessed globally between 18000 to 22000 Yr BP.
  

IV. Stratigraphy & Studies Related to Evolution of Life

• Ichnology of the Mesozoic sediments of Mainland Kachchh, Western India
  
  Eight lithofacies in the Mesozoic sequences of Central Mainland Kachchh had been identified. All the lithofacies appear to be highly bioturbated and contain abundant trace fossils (78 ichnospecies of 44 ichnogenera belonging to five ethological groups - Cubichnia, Repichnia, Pascichnia, Fodinichnia and Domichnia). Paleoecological interpretations made using two ichnofacies (Skolithos & Cruziana) and twenty ichnoguilds indicate eight distinct ichnoevents where the environment of deposition is in a shallow siliciclastic and carbonate shelf related linear clastic shoreline.
  
  
• Biozonation and correlation of the Neoproterozoic Bhander Group, Central India.
  
  Two significant findings namely, (a) detection of Arumberia and Beltanelliformis minutae from the Maihar Sandstone and (b) Trace fossils of Trilobite from the Nagaur Sandstone of the Trans-Aravalli Vindhyans (Marwar Supergroup) suggest an Ediacaran age to the upper most lithostratigraphic horizon of the eastern part of the Vindhyan Basin and Lower Cambrian age to the Nagaur Group.
  
  
• Radiolarians From The Leg 119 Site745, Southern Antarctic Region: Biostratigraphy and Paleoceanography
  
  Fifty five radiolarian species, including several new taxa have been identified and well documented from the core taken from the Southern Ocean region. Further, based on the abundance of radiolarian species Cycladophora davisiana the interglacial and glacial cycles for this region is being refined.
  
  

Database Development

Database on Earth Science literature at a total cost of 10.00 lakhs has been developed at the Geological Society of India, Bangalore. In this database, all the titles along with abstracts of the published papers in the Journal of the Society has been organised in a user friendly manner for accessing and reference.


Himalayan Glaciology

The glaciers in the Himalaya lie at a formidable high altitude making them unique compared to the other glaciers in the world. Glaciers, important resource of fresh water, are known to have profound effect on environment and climate, land erosion, river discharge and consequential floods and droughts. Therefore, knowledge of glaciers is essential for formulating suitable future programmes for development and management of Himalayan Rivers and their environment.

To create the basic Research & Development base in the country for studying different aspects of Himalayan glaciers in multi-disciplinary mode, Department of Science & Technology formulated a multiinstitutional coordinated programme on Himalayan glaciers in 1986. DST is the nodal Government Department in commissioning the Research and Development activities in Himalayan Glaciology by involvement of universities and research organisations in the field of Himalayan Glaciology such as: Geological Survey of India (GSI); Wadia Institute of Himalayan Geology (WIHG); Birbal Sahni Institute of Paleobotany (BSIP); G.B. Pant Institute of Himalayan and Environment & Development; Remote Sensing Application Centre, UP; H.N.B. Garhwal University, Srinagar; National Institute of Hydrology, Roorkee (NIH); J.N.U, New Delhi; IIT, Mumbai, Jammu University, Lucknow University, I.T. College, Lucknow; Central Mining Research Institute, Dhanbad; Arunachal University etc.

Studies carried out under the on-going research programmes have contributed in understanding the various glacier phenomenon, particularly, in the areas of Glacier Geo-morphology and quaternary glacier history and palynolgical studies of Durung Durung glacier, palaeo- environmental re-construction of glacier chronology in Himachal and Garhwal Himalayas, snow cover studies of Kangriz glacier, palaeo-glaciation studies and geomorphological studies of Satopanth and Bagirath Kharak glacier, Quantification of sediment load of Thellu glacier, ablation storage and drainage of melt run-off and simulation of stream flow studies for the Gangotri glacier.

The new research and development activities were initiated on palaeo-glacier re-construction of Pindari glacier, deglaciation and associated consequences on the Gangotri glacier, Atmospheric variations and avalanche affecting Gangotri glacier, temporal variation of climate vis-à-vis glacier fluctuations in the North-East and North-West Himalayas based on multi proxy data, spatial temporal monitoring of a glacier using satellite remote sensing and luminescence measurement techniques, glacier front variation of Sonapani glacier.New initiatives have also been undertaken in implementing the research and development activities in the North-East Himalayas as geo-morphological and sedimentological studies have been initiated on Changme Kangpu glacier.

The basic infrastructural facilities have been created in laboratories as well as on selected glacier sites to facilitate the field studies by the scientists. These include permanent stations as Bhojbassa and 3 Automatic Weather Stations in Gangotri Glacier area which were established at Bhojbassa, Nandavan and Kalindi Kal for regular records of weather parameters. In order to meet the demands of scientific community to set up good dating laboratories the Optical Stimulating Luminescence Reader (OSL-Reader) facility has been set up at SASE, Chandigarh.

The new initiative in identifying vital problem areas in Himalayan Glaciology was undertaken. Glacier surge is one such area that may create a problem when advancing ice dams the side valleys, forming large lake basins from which sudden outburst may result in down stream flooding. Surging glaciers may block, destroy roads and mountains settlements, or make alphine recreation routes inaccessible for long periods. Therefore, studies have been commissioned to monitor dynamics of surging glacier in Kumdan group of glacier, North face of Karakoram range in upper reaches of Shyok valley, Jammu & Kashmir. The research outcome in the form of surging glacier maps and their statistics would have wide ranging applications and may be utilized for hydrological studies, disaster management and climate related studies.

Significant contributions have been made in understanding the glacier phenomenon through the studies supported by the Department under its Himalayan Glaciology Programme. Realising all encompassing importance of glacier studies in the national development DST has taken initiative for setting up of a National Centre for Himalayan Glaciology to give proper directions and more focused attention to glaciological research in the country. A working document is under preparation.

All India Network of ST Radar Facilities (AINSTRAF) – New Initiative

It is a new programme originated in the end of 2005 -06 as an out come of the SERC recommendations. Efforts are being made to generate the said new programme called “All India Network of ST Radar Facilities (AINSTRAF)” for setting up 10 ST Radar Facilities in different parts of the country. Separately, one ST Radar Facility has already been approved in principal for setting up the same at ARIES, Nainital in addition to the proposed 10 ST Radar Facilities under the programmme.