Annual Report 2005-2006

Science & Engineering Research Council

Earth System Sciences

Research Programmes in Earth System Science include basic research in Earth and Atmospheric Sciences and focused activities on Deep Continental Studies, Himalayan Glaciology, Indian Climate Research Programame etc. The highlight of the achievements made under the above programme are given below:

Earth Sciences

The emphasis of this programme is to study the various aspects of Indian crust, namely, its evolution, nature of its deformation to the exogenic & endogenic geological process, its effect on climate and several other factors. Out of 40 projects fifteen full fledged projects and three pilot projects were recommended for financial support and an equal number was recommended for modification.

New R&D Projects

Following projects were supported during the year:

• Deformation and strain patterns in the MCT Zone of Alakhnanda valley, Higher Garhwal Himalaya.
• Topographic change detection using In SAR Technique - A case study in Erattupetta -Vagamon area, Kerala.
• An Experimental Investigation on the Garnet and Sapphirine Forming Reactions of Calc-Silicate Rocks in CM (F)AS(V) System.
• Tectonothermal evolution of the Granulite-Amphibolite facies rocks along the Namakkal-Alambadi corridor across the Palghat-Cauvery suture zone and its significance to Indo-Antarctic-Madagascar Connection.
• A study of Structure, tectonics, Petrology and resources of unexplored Vaikrita thrust of North of Yamunotri Area, Uttarkashi, District Uttaranchal.
• An integrated Approach for assessment of potential ground water zones in Varaha River Basin, Andhra Pradesh.
• Sedimentological and tectonic evolution, through time and space, of the Piedmont zone of Indo- Gangetic basin between Kalagarh and Tanakpur, Uttaranchal.
• Quantification of Artificial Recharge mound migration towards the Cuddalore Coast in Tamilnadu and feasibility study of artificial recharge to arrest the migration through hydro-chemical and mathematical modeling approach.
• Analysis of Paleovegetation and Paleoclimate of Hominin bearing Quaternary sediments of Central Narmada Valley, MP.
• Radiolarians From the Leg 119 Site 745 Southern Antarctic Regions: Biostratigraphy and Paleoceanography.
• Metamorphic evolution of Podiform in the Shillong Plateau, Assam, Meghalaya and an attempt to correlate Metamorphism, in time by EPMA Monazite Dating.
• Biozonation and Correlation of the Bhander Group with Special Reference to Neoproterozoic Glaciation.
• Neotectonic Rejuvenation in Central Kumaun, Uttaranchal: Implications to Quaternary Reactivation of North Almora Thrust and Transverse Tear faults.
• Harvesting of Natural Springs in Dasholi Block of Chamoli District Uttaranchal.
• Quarternary Climate and Tectonics in Ladakh Karakoram Himalaya.

Pilot Research Projects

• Variations in Tectonic Geomorphology Along North of 16 30' Konkan Coastal Belt of Maharashtra, India.
• Isotope and Chemical tracer analysis to infer late Quaternary climate vulnerability form lake sediments and terrestrial deposits of eastern India.
• Geomorphology and Sedimentation History of the Alaknanda Valley from Rudraprayag - Devaprayag (Uttranchal).

Tsunami Related R&D Projects

After the great tsunami on 26th December, 2004 the following themes were studied in detail to understand the various phenomena/ changes taken place related to geological aspects in the coasts of Andhra Pradesh, Kerala, Andaman & Nicobar Islands and Tamil Nadu:

• Tsunami Inundation zone mapping and Geomorphological analysis
• Tsunami Sediment analysis
• Surface and Groundwater Quality Assessment in Tsunami affected areas
• Ecosystem Analysis in the East Coast including Micro-paleontological analysis (Determine the provenance of sediments & Characterization of Tsunami Sediments)

Important achievements made during the year under ongoing projects

Himalayan Region

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

• The evolutionary trend of Kangra basin has been studied using advanced techniques like magnetic polarity stratigraphy, lithofacies analysis, clast compositional data, detrital framework of the sandstone, REE pattern of the samples. This study has suggested episodic tectonic pulsations between 12 - 5 Ma, as the major cause for basin evolution and climatic fluctuations for prominent changes in the fluvial architecture.
• Study on the rock magnetic properties of the paleosols of Siwalik Foreland Basin in the N.W. Himalaya have indicated clearly the interplay of the variability of upliftment of the Himalayan- Tibetan Plateau system and the rate of sedimentation and basin subsidence to be the controlling factors for the development of soils.
• Recovery of rich and diverse palyno taxa from the Neogene-Quaternary sediments of the Arunachal Himalaya has helped in understanding the depositional environment, history of vegetation and variation in climate including change in palaeo-atmospheric CO₂ concentration with periodic phases of Himalayan uplift. Further determination of pCO₂ concentration during Neogene-Quaternary has indicated possible future trend of rising CO₂ level in the atmosphere.
• The orbitolinid taxa from the arc sequence, comprising of volcanics and intra-arc basin sediments of Shyok tectonic belt has suggested the existence of transgressive Neo-Tethys Sea during Early Cretaceous times, north of Indian plate.

Landform Evolution & its relation to Tectonics & Climatic Variation

Tectonics and the degree of climatic variation in the past have affected the rates and nature of evolution of landforms. In the recent years, studies have been supported to examine and establish the relations through different approaches as follows:

• Micro-Vertebrate faunal findings in thick sequences of lignite suggest that the western Rajasthan has witnessed a very short duration (Late Palaeocene to Late Eocene) marine transgression and regression in the Early Tertiary times under fresh water lagoon environment. Signatures of repeated transgressions also indicate the tectonic instability in western Rajasthan, which correlates with the India-Asia collision and a complete withdrawal of the sea, by the Late Eocene, from the Rajasthan.
• The first ever recovery of magnetic spherules, magnetic dust, micro-tectites and micro-bracciated matrix along with bones, teeth and phosphatic dung of dinosaurs, crocodiles, mammals and turtles from the Late cretaceous phosphorite facies of the Barmer Basin, western Rajasthan, India have indicated the possibility of their emplacement due to a high temperature catastrophic event such as the extra terrestrial impact or volcanism.
• Study of palynofacies, phytolith, clay mineralogy and magnetic susceptibility on the Late Quaternary sediments from the Itola section shows that the mainland Gujarat experienced considerable variation in the monsoonal pattern during 3660-2850 yrs BP. The interval between 3600 - ~3400 yrs BP corresponds to the weakening phase of SW monsoon in this region. It is inferred that the winter precipitation due to active western disturbances, around 3650yrs BP was much more pronounced and spread over larger parts of western India which later on declined around ~3400 yrs BP. During this period SW monsoon also declined gradually and had almost ceased. This was the phase when population of the Indus valley civilization declined completely and migrated to more humid areas to sustain their livelihoods. The SW monsoon regains its strength with a brief pulse of enhanced precipitation around 3320 yrs BP along with minor fluctuation later on.
• Studies on decadal scale variability in the Indian Ocean summer monsoon during Holocene suggest that the multi-decadal variability in the summer monsoon was driven by solar activity. Dry phases in the summer monsoon (summer monsoon weakening) were found aligned with low sun spot numbers and vice versa indicating a direct solar - monsoon link. The summer monsoon strength reached its peak in the Early Holocene when sunspot activity was also high.
• Integrated geomorphological analysis revealed that the aeolian sand ridges of the Ganga - Ramganga plains show a clear association with the older floodplains, possibly correspond to a floodplain reorganization event driven by a wet to dry climatic change event in the terminal part of the Late Pleistocene.
• Faunal Studies of the Cretaceous dinnosaurian coprolites (excreta) from Maharashtra deciphered that Palm trees was a part of their diet and they lived in the tropical - subtropical climate. Recovery of grass seeds (Cyperaceae) from the intertrappean sediments also indicates the origin and development of grasslands during the Upper Cretaceous.

In addition to the above, several projects in various other geological settings for resource assessment and management, emplacement history, structural evolution etc. are also being supported under the programme.