Annual Report 2004-2005

Scientific Research

Earth System Sciences

Earth System Sciences comprise several programmes including basic research in earth and atmospheric sciences and focused activities on Deep Continental Studies, Himalayan Glaciology, Indian Climate Research Programme etc. The highlights of achievements under the above programmes are given below:

Earth Sciences

Under the scheme, research that enhances our basic understanding of the Indian crust, namely, its evolution, nature of its deformation due to the exogenic & endogenic geological process, its effect on climate and several other factors that have a far reaching impact on the mankind are supported. The Programme Advisory Committee on Earth Sciences (PAC-ES) held 4 meetings and considered 50 project proposals. Sixteen proposals were recommended for financial support and an equal number was recommended for modification to sharpen focus, bridge the scientific gaps and attune them with the global trends. The Committee also discussed a number of policy issues and identified goals & strategies to bring about improvements in the quality of research to achieve international competence. Following are some of the significant recommendations:

• International participation to be strengthened to encourage multi-directional flow of information/ personnel.
• Top priority to be given to initiate research in societally relevant areas of earth sciences, in addition to the focus on emerging areas.
• Encourage co-ordinated research programmes to bring together complementary groups and gain insight into specific problems.
• Increase the number of contact programs in emerging areas to sensitise the younger group of scientists / researchers.
• Periodic ‘audit of labs’ to evaluate and improve the status of infrastructure facility in accordance with the world standards.

Some of the highlights of the progress/achievements related to this programme are as follows:

New projects sanctioned

The following new projects on various topics/themes were sanctioned:

• Assessment and Management of Ground Water Resource for English Bazar Block, Malda District, West Bengal;
• Deformation and volume change during Ductile Shearing in the Kumaon Lesser Himalaya of Amritpur-Bhimtal area;
• Crystal growth & characterisation of Rare Earth Vanadate Laser Crystal;
• Neogene - quaternary palynostratigraphy of Arunachal Pradesh, Eastern Himalaya, India with Palaeo-environment and palaeogeographic consideration;
• Geoelectric Studies for Hydrological Characterization of Sagar Island Region, South 24 Parganas, West Bengal;
• Depositional environment and sequence stratigraphy of Bajocian-Callovian sediments of Jaisalmer Basin, Jaisalmer, Rajasthan;
• Sub Surface Cavity Detection by Inversion of Geophysical Data using Global Optimization Technique;
• Environment of deposition and Biostratigraphy of Early Tertiary Lignites of Rajasthan and Adjoining Areas;
• Pedosedimentary Reconstruction of Alluvial Fan Deposits of the Kangra Intermontane Basin;
• Sedimentology, Geochemistry and Evolution of Certain Coral Islands of the Gulf of Mannar;
• Laboratory Culture Experiments on Foraminifera for Paleoclimatic Studies and Pollution Monitoring; and
• Organic walled Microfossil Characterization of Palaeozoic Litho Units of Garhwal Tethyan Himalaya with Special Reference to the High Resolution Biostratigraphy.
  Research Highlights

Himalayan Region

Himalaya and its adjoining regions have always remained interesting for geological investigations for understanding their tectonic evolution as well as its climate forcing on the entire Indian mass.

• A study on the geochemical evolution of the Lohit Plutonic Complex and the kinematics of the thrust sheets around the eastern syntaxis (Arunachal Pradesh) led to the delineation of a major thrust namely the Walong Thrust that divides the plutonic complex into granite dominated eastern belt and basic rock dominated western belt that correlates with Po Qu fault in the north and Sagaing Fault in Central Myanmar.
• Sedimentological studies in the foreland basins of Kangra valley in the lesser Himalaya along Chail thrust indicated episodic tectonic pulsation between 12 – 5 Million years ago.
• Morphometric and Statistical application used for the first time in trilobite taxonomy for the Cambrian sedimentary sequence in Zanskar- Spiti regions of Himalaya, was found significantly important for high-resolution biostratigraphic zonation. Further, the observed variation in the ichnofacies distribution is attributed to the availability of oxygen and nutrient influx.
• Rock magnetic studies on paleosols of Indo-Gangetic foreland basin in the N.W. Himalaya indicated a highly transgressive phase followed by a stable period of sedimentation under a dominantly semi – humid climatic regime tending to semi-arid and cold climatic events during the Late Miocene and early Pliocene periods.
• Multi-proxy paleoclimatic records inferred from 1.25 m. thick peat sequence from the NW Kumaoun Higher Himalaya indicates variability in the climate with a predominantly wet climatic regime with intervening periods of dry climate. The past 200 years record display a striking synchronicity with the instrumental data.
• Climatic inferences from tree ring analysis has led to believe that the potential of Tsuga dumosa in understanding the impact of little ice age on SW monsoon variability in the Eastern Himalayan Region.

Analogue Model Experiments – Understanding Himalayan Tectonics

Projects on experiments with analogue models were supported to gain insight in to the behaviour of the Indian crust and its deformation.

• In a study on Cenozoic Deformation in and around India due to Collision with Asia (Figure 2.12) it was noticed that the strength and weight of the oceanic crust flanking India to be the reason for the unusual efficiency of the Indian plate to act as an indenter. Further, thinskinned thrusting of the Indian plate and presence of a weak passive margin in the northern portion, to be the causes, for localized crustal thickening leading to the formation of the Himalaya. The straight edges of the Eastern and the Western Ghats are the locus of strike slip faulting.
• To understand the regional tectonic set up and seismicity of the frontal and oblique ramps in the western Himalaya, laboratory model deformation studies were carried out basing it on observed field structural fabric. This led to inferring that the rate, amount, and pattern of displacement along the trailing, oblique and frontal ramps further leading to envisage the zones of seismic activity in the region.
• In another study, using the Sandbox analogue modeling technique, efforts were made to understand the mechanism and growth of thrust wedges in the marginal parts of Himalaya and its impact in the evolution of the Ganga plain foreland basin.

Quaternary Studies in Kutch, Gujarat

• The discovery of well preserved specimens Metagoniolithon fossils from Chhasra Formation (Late Lower Miocene/Burdigalian) outcropping at Ramwada Mandir in Kutch district of Gujarat, suggests that the climatic change undergone by the Indian subcontinent from relatively cold conditions to warm tropical conditions, leading to the extinction of Metagoniolithon antiquum sp. nov. beyond this time.
• Studies on the Narmada valley indicated a large catchment with higher discharge being maintained by the river ever since the last 100 ka and its evolution due to tectonic activity. The sediment records indicate (Figure 2.13) deposition in a slowly subsiding basin during the Late Pleistocene, followed by inversion during the Holocene period due to a significant increase in compressive stresses along the NSF.

Participation in Asia-Oceania Geoscience Society (AOGS) Meeting

20 Indian earth scientists were supported to participate in the First AOGS meeting held at Singapore during 5-9 July 2004. The conference provided a forum for not only to exchange ideas but also to get acquainted with the new and advanced techniques and offered the scope to pursue collaborative research in Earth System Sciences.