New Delhi annexure-i format for inviting proposal for fresh induction under sap- (drs)

Highlights of the work done by Prof.Pankaj Srivastava

Palynology and clay mineralogy of the Deccan volcanic associated sediments of Saurashtra, Gujarat: Age and paleoenvironments: The intertrappean sediments associated with Deccan Continental Flood Basalt (DCFB) sequence at Ninama in Saurashtra, Gujarat yielded palynoassemblage comprising at least 12 genera and 14 species including Paleocene taxa such as Intrareticulites brevis, Neocouperipollis spp., Striacolporites striatus, Retitricolpites crassimarginatus and Rhombipollis sp. The lava flows of Saurashtra represent the northwestern most DCFB sequence in India. It is considered that the Saurashtra lava flows represent the earliest volcanic activity in the Late Cretaceous of the Reunion Mantle Plume on the northward migrating Indian Plate. The present finding of the Paleocene palynoflora from Ninama sediments indicate Paleocene age for the associated lava flows occurring above the intertrappean bed which suggests that the Saurashtra plateau witnessed eruption of Deccan lava flows even during Paleocene. The clay mineral investigation of the Ninama sediments which are carbonate dominated shows dominance of low charge smectite (LCS) along with the presence of mica and vermiculite. Based on the clay mineral assemblage it is interpreted that arid climatic conditions prevailed during the sedimentation. The smectite dominance recorded within these sediments is in agreement with global record of smectite peak close to the Maastrichtian–Paleocene transition and climatic aridity.

Early Oligocene paleosols of the Dagshai Formation, India: A record of the oldest tropical weathering in the Himalayan foreland: This study reports paleopedological features of the fossil soils that formed during the earliest phase of continental sedimentation in the Himalayan foreland. The fluvial sequence of the Dagshai Formation (31.6 ± 3.9 Ma to 30.3 ± 3.9 Ma) exposed along the Koshaliya River, NW Himalaya, contains four pedofacies (named Pedofacies A–D) of ferruginous paleosol sequences contained within overbank sediments. The Dagshai Formation unconformably overlies the marine Subathu Formation. Pedofacies A consists of 3–4 well-developed ferruginous paleosols overlain by gray sandstone beds. Pedofacies B–D are marked by a progressive decrease in pedogenesis. These paleosols occur as 0.5 m to 1.5 m thick Bw/Bt/Btk/Bk/Bss horizons that are marked by extensive development of rhizoliths, pedogenic carbonate, and iron-rich clay pedofeatures that correspond to modern Entisols, Inceptisols, Alfisols and Vertisols. Based on early Oligocene paleogeographic position of the northward-drifting Indian Plate, it is inferred that these paleosols were formed at ~18°N paleolatitude in the Dagshai sub-basin in the Himalayan foreland. Micromorphology, geochemical analyses, weathering indices, and stable isotope composition of paleosols indicate tropical climate (paleoprecipitation of 947–1256 mm and paleotemperature of ~25 °C) with an initial phase of monsoonal conditions during pedogenesis. These paleoclimatic conditions favored C3 paleovegetation immediately after the transition from greenhouse to icehouse conditions.

Thin-section analysis of lithified paleosols from Dagshai Formation of the Himalayan Foreland: Identification of paleopedogenic features and diagenetic overprinting and implications for paleoenvironmental reconstruction: In the present study we report micromorphology of diagenetically altered paleosols (~31 Ma old) from Dagshai Formation, Himalayan Foreland. The fluvial sequence exposed along the Koshaliya River, NW Himalaya, contains four types of paleosols with decreasing abundance of well-developed paleosols from basal to upper part of the Dagshai Formation. Burial diagenesis (at ~7.5 kmdepth) caused compaction (54–78% current thickness compared to pre-burial thickness) and cementation of the paleosols, accompanied by internal reorganization of groundmass within peds, staining of pedwallswith iron oxide, plugging of voids, disruption of textural pedofeatures, fracturing of large mineral grains and nodules, coarsening of pedogenic calcite crystals, redoximorphic features, and mineralization of root channels. Despite diagenetic alteration, evidence of paleopedogenic processes is still well-preserved in these fossil soils in the form of microstructures, b-fabrics, pedogenic calcite, bioturbation,and textural pedofeatures. Thin-section analysis helped to distinguish pedogenic and diagenetic features of lithified paleosols and to infer the paleoenvironment of the Dagshai paleosols. The paleopedological characteristics of the fossil soils suggest humid to sub-humid conditions during their formation in early Oligocene. The paleoclimate inferred here is consistent with prevalence of tropical paleovegetation (cf. Ficus L.) reported from Dagshai sediments.


Details of work proposed to be done in Major Thrust Areas
A. Petrology, Tectonics and Metallogeny
Prof. A. Chattopadhyay

Dr. A. Saikia

Prof. C.S.Dubey,

Prof. J. P. Shrivastava,

Dr. N.C. Pant

Dr.Saurabh Bhattacharya
Proposal-1: Microstructural and experimental modelling of faults

In the next phase of CAS, I intend to expand the existing analog experimental facility and strengthen its infrastructure. Air-conditioning and flooring of the experimental laboratory was not possible from the last CAS budget and these things are necessary right now for technical advancement of the laboratory. There is a plan to build a shaking table-type apparatus where we shall be able to experiment with water-sogged soil and sediments under rapid vertical and horizontal shaking, to understand the types of seismogenic soft sediment structures (water injection dykes, seismites etc.) and their relationship with the type of movement. The experimental observations can be correlated with the observed seismic structures of Gavilgarh Fault zone and the Son-Narmada South Fault in central India where a Ph.D. student is already working. Results of such earthquake-related experimental studies, yet to be taken up in India, have great societal relevance.

Apart from experimental work, I would like to start a new facility for fabric analysis in structural geology. Fabric analysis of deformed rocks essentially needs a characterization of the deformed lattice of minerals. Lattice –preferred orientations of minerals can give fundamental information on temperature and strain rate, as different glide planes are sequentially activated with increased temperature and strain rate. Analysis of LPO is done nowadays using Electron Back-Scatter Diffraction (EBSD) facility fitted with a Scanning Electron Microscope. As the Department of Geology already has an SEM in fully working condition, we should try to upgrade it with an EBSD facility.

Funds are required for field work in Central Indian Tectonic Zone, especially for post-Cretaceous tectonic movements in Gavilgarh Fault, Son-Narmada South fault and Son-Narmada North Fault which have controlled the entire landscape evolution of central Indian craton since Precambrian time. I would also need funds for chemical analyses on payment from outside agencies (e.g. EPMA from GSI, ICPMS from NGRI/WIHG, OSL data of river sediments from PRL/WIHG etc.).

Proposal 2: Constraining the age of formation of the crustal sequence of the Andaman island Ophiolite suite to understand intiation of subduction along Java-Sumatra-Andaman-Burma trench system.

Rationale: In the ophiolite suite of the Andaman Island, all the members of a classic ophiolite sequence namely the plutonic complex, intrusive, extrusive lava series and pelagic sediments except the sheeted dyke are well exhibited.

A two-fold subdivision of the ophiolite suite have been forwarded by previous workers namely a mantle sequence represented by serpentinised harzburgite and pods of altered dunite and the overlying crustal sequence marked by an assemblage of plutonic rocks and extrusives. The plutonics of the crustal section is mainly layered cumulates of peridotite –gabbro, overlain by non cumulate gabbro and high level intrusive of a Plagio-granite-diorite-andesite suite of rocks with thin dykes of basalt and diabase. Overlying the dyke complex is the pillowed and non pillowed lavas representing the upper most part of the ophiolite suite.

Two models have been proposed for occurrence of this ophiolite suite. One school of thought proposes that the subduction has continued along the western margin of the island arc since the late Mesozoic and the Andaman ophiolite suite is the upthrust oceanic crust accreted during the prolonged period of subduction (Pal et al. 2003; Curray 2005).The alternative idea suggests this suite ranges in age between Late Mesozoic and Early Eocene and were tectonically emplaced at the leading edge of the Eurasian continent during middle Eocene to Late Oligocene event, before Andaman–Java Subduction which probably initiated during the late Miocene (Sengupta et al. 1990; Acharya 2007).

No radiometric age data has been reported for these ophiolites except for two recent works. U-Pb SHRIMP age of Zircon from Plagiogranite has yielded an age of 93.6 + 1.3 Ma, interpreted as the age of its crystallization. Since the Andaman ophiolitic rocks predate the palgiogranite they were probably not generated in the currently active Late-Miocene Andaman-Java subduction zone and were obducted onto the leading edge of the Eurasian continent during early Cretaceous time (Sarma et al., 2010). U-Pb zircon dating of a trondhjemitic rock from Chriya tapu in south Andaman Island using Laser ablation inductively coupled mass spectrometery reveals an age of crustal formation of 95+ 2 Ma (Pedersen et al., 2010). This data shows that the Andaman volcanic arc was built on Cenomanian ophiolite-oceanic crust and subduction was initiated at this time along Tethys. Other than this paleontological data from oceanic sediments closely associated with ophiolites have revealed an Upper cretaceous to Early Eocene ages for these ophiolites. However, no work has reported age dates from basalts, rhyolites, dacites and ultramfic rock units of the Andaman ophiolites.

So far the tectonic evolution of the Andaman island have been modeled based on the tectonic elements recorded from the sea, seismic records and regional tectonic correlation with eastern Himalayas and no tectonic model has been built based on the petrochemistry and geochronology of the rocks from this suite.

The petrological and geochemical characteristics of the magmatic rocks of the ophiolite suite are poorly constrained. Significant insights can be gained on the tectonic environment at the time of the primary magmatic evolution through geochemical characterization. A concerted age dating of this sequence of rock both by isotopic dating will place its position precisely in the geological scale.

The proposed research has been conceived with an idea to ultimately reconstruct the events through time leading to formation of these magmatic rocks and emplacement by tectonic movements into continental setting to throw light on the geodynamic evolution of the Indian sub-continent.

Objective of the proposed study

The proposed study aims at addressing the geodynamic evolution of the Andaman Island Ophiolite suite based on geochemical and geochronological constraint. Significant insights can be gained on the tectonic setting at the time of formation of these rocks based on geochemical and geochronological data and also how the Indian sub continent has evolved to the present day configuration wherein, this ophiolite suite probably marks the eastern suture margin of Indian plate.

Proposal 3: Geochemical Flow Stratigraphy, Age and Duration of Deccan Volcano-Sedimentary Succession from Koyna Drill-Core Site

Recently drilled Koyna Bore Hole - 1 (KBH-1), located at Rasati [Survey of India Topographic sheet No. 47 G/11 and 47 G/15 (scale 1:50,000)] near Koyna (~2.5 km SSW of Koyna Dam reservoir region) is unique of its kind and represents to a deepest bore hole that extends up to the base of the Deccan Traps, however, such details are yet to be ascertained (Fig. 1). These longest drill core samples available provide unique opportunity to study sub-surface lava flow sequences flow by flow. Therefore, such a thick basaltic package is required to be constrained in to a stratigraphic framework. However, such studies have not been carried out on Koyana dill core samples. Lateral continuity of lava flows is critical for constructing a stratigraphic framework. Systematic litho-logical logging backed by detailed petrography of core specimens would be undertaken in the recognition of physically distinct lava flows and their flow boundaries. Koyna revealed a ~933 m thick pile of basaltic flows, underlain by granitic basement rocks. It is necessary to find out geochemical and isotopic characters of the ~933 m thick pile of Koyana basalt lava flows and at the same time it is also necessary to understand chemical correspondence of these lava flows with that of the 11 southwestern Deccan formations of the type-sections. To establish nature of geochemistry and Ar/Ar ages of the first lava flow and the clay-stratigraphy of the intervening intratrappen and bole sediments to find out possible level of the K/T boundary is also required. To understand the lateral continuity of lava flows and to characterize them into distinct chemical types, chemical signatures of the sampled flows are required to be examined. Presence of distinctive lava flows in the ~933 m thick lava package requires justification from the major and trace elemental chemistry. Present project proposal intends to study drill cores of the entire Deccan volcanic pile. It seems drill cores are the only possible way to make significant progress on further understanding of the Deccan Traps and its possible relationship with the K/T boundary event. The proposed stratigraphic studies, primarily based on the trace elemental abundances, their ratios and isotopic compositions constitute major component and would be undertaken in this project proposal.

Project 4: Geological investigations south of Indian Bharati Station to elucidate sub-ice geology and to establish the affinity of western Princes Elizabeth Land (PEL) with appropriate cratonic block

Our knowledge of East Antarctica continues to be ill-defined in spite of vigorous research programs conducted in this area from last two decades. This lack of knowledge not only sets a hurdle in understanding the subice geology but lack of this knowledge has a role in understanding the role of East Antarctica in the global environment now, in the past, and in the future as ice-sheet behaviour is also controlled by the geological parameters of the interaction surface.

Princess Elizabeth Land (PEL) comes under ‘poles of ignorance’ category of EAIS. It is located inland of the Chinese Zhongshan Research Station and the Indian Bharati Station. We possess a very shallow knowledge about the subsurface ice sheet, and the crust on which it flows, across PEL in East Antarctica. PEL is the focus of this proposal. The BEDMAP2 depiction of topography over PEL, used as input to ice sheet models, is based on ~100 seismic measurements acquired by Russian overland traverses in the 1950s and 1960s. Specifically, there are few bed data west of 105⁰E and no data west of 90⁰E in the PEL region, making it the last remaining frontier of Antarctic glaciological science.

These glaciological and geological data gaps can be filled through airborne geophysical profiling and correlation with rock exposures. The collection of geophysical data is planned in a major international initiative in the next two years. However, the validation of such a data requires detailed analyses of available rock exposures through ground survey. A detailed sampling thus becomes essential in this endeavour.

Recently Boger (2011) divided the Antarctic continent into 4 main categories on the basis of their affinities with Antarctica's correlatives within Gondwana. PEL lies in the area marked by category 4 (i.e., the rocks with no known affinities). Its proximity to the category-2 rocks (i.e., the rocks with Indian affinities) also requires examination. Moreover, the knowledge on its spatio-temporal evolution is either very limited or ill-defined.

A detailed geological study of this area can provide us with valuable data which would further enhance our understanding on the amalgamation of the present day Antarctica as well as its interrelationship with the Indian Craton. Participation of an Indian expedition will bring these efforts in the current global scientific context. Moreover, it would facilitate our knowledge about supercontinent cycle over the geological time and the role of Antarctic continent in it.

Hypothesis to be tested is the following;

Queen Maud Land Province which is present NE to PEL shows affinity towards Indian Craton while Wilkes Land present SSE of PEL have rocks with Australian affinity. However, there is no correlation of PEL terrain rocks with the Indian Cratonic Block till date. Extensive studies are required in PEL to infer the affinity of this region between the Indian and the Australian cratonic blocks.

Methods adopted are following:

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  Detailed field survey around PEL and collection of hard rock samples from the exposed lithologies.
  
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  Detailed petrological analysis of the samples collected, including reflected as well as transmitted light microscopy. Analysing the microfabric to infer evolutionary track of the rocks
  
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  Appropriate geochemical data will be generated to understand the geodynamics and tectonic history of PEL.
  
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  Chronology of the samples will be carried out by chemical dating of monazite grains as well as radioactive dating techniques of other suitable minerals.
  
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  Development of a petrogenetic model for the defined area.
  

First field investigation in and around Bharati Station has already been carried out during Antarctic field season 2015-16 recently by one Ph.D. student (Ms Devsamridhi) as a member of 35^th Indian Scientific Expedition to Antarctica. This will be continued in field season 2016-17 and the data will be integrated with the multinational project ICECAP-2 (International Collaborative Exploration of Central East Antarctica through Airborne geophysical Profiling) of which the undersigned is a Steering Committee member.
Proposal 4: Investigations on hydrothermal ore deposits in parts of the Indian subcontinent

In the coming years, department aims to adopt a dual approach in context of metallogenic studies. On the one hand, it involves ore genetic studies to tie-up the records of metallogeny with that of crustal evolution in parts of the subcontinent. On the other hand, we aspire to upgrade the existing laboratory facilities for research on ore fluids.

The field-based studies will emphasize on genesis of hydrothermal ore deposits in various parts of the country. From gold metallogeny point of view, the amphibolite-granulite transition zone in south India is one of the targeted regions. The key issue is decoding the links between lower crustal evolution and mid-crustal gold-enrichment processes. Besides, we anticipate the refinement of ideas on ore-forming processes in parts of the Aravalli-Delhi belt in western India. In this regard, the metallogenic belts of Degana-Tosham (W-Sn), Pur-Banera (Pb-Zn-Cu) and Khetri (Cu) would be the areas of prime focus. In addition to this, up-gradation and maintenance of the existing fluid inclusion set-up is under consideration. We desire to integrate the existing set-up with infrared facilities. This will broaden the scope of ore genetic and interdisciplinary studies in the department. With the aforesaid aims and plans, the department is perfectly positioned to grow its impact in metallogenic studies.

Implementation of proposed plans demands a significant amount of laboratory-based analytical data. The scanning electron microscopic and fluid inclusion facilities hosted in the department would be used for the purpose. The whole rock, electron micro probe and stable isotope analyses are to be carried out at various units of Geological Survey of India and in some other overseas laboratories.

B. Hydrogeology and Environmental Geology
Prof. C. S. Dubey

Prof. J. P. Shrivastava

Dr. N.C. Pant

Dr. S.K. Singh

Dr. S. Sekhar
Proposal 1:Immobilization of radionuclide (ions) and its diffusion in natural glasses for its suitability as nuclear waste glass

The immobilization of radioactive components for long-term isolation from the biosphere depends upon the performance of the material used and these materials determine its safety and hazards. It is used to immobilize HLW for more than 40 years when treated with calcinations and vitrification processes. From the nuclear waste management point of view, the long-lived radionuclides which are of great concern include fission products (Cs ^137, Cs¹³⁷, Sr⁹⁰, Tc⁹⁹ and I¹²⁹) and several actinides (Am ²⁴¹, Am ²⁴³, Np²³⁷, Pu²⁴⁴, Pu ²³⁹).Purpose of nuclear waste management is to develop highly durable waste matrix that ensures long-term stability of material for isolation of its radioactivity and to provide physically, chemically and thermally stable form to immobilize radioactive materials that resist leaching, powdering and cracking mode of degradation. Thus, an appropriate performance assessment technique is required to utilize glass as a waste form for nuclear waste disposal that assumes an understanding of alteration or corrosion mechanism of the glass.High energy irradiations on glass surface with 40-50 keV is yet to be carried out in glasses especially natural glasses (Impact and Obsidian glasses) to understand diffusion of radionuclide. However, these glasses were not studied in context with the Cs, Sr and other long-lived radionuclides. Previous work (Ceelen et al., 1995 and Tomar et al., 2005) on Cs diffusion was out carried, primarily based on depletion of ions at lesser depth. However, Cs, Sr and long lived radionuclide irradiation/ implantation on natural and synthetic nuclear waste glasses and their alteration studies in a geological repository is yet to be carried out.Main objectives to immobilize ions natural glasses for its diffusion study in hydrothermal-like conditions. To quantifythe release of immobilize ions (radionuclide) from the natural glasses for its suitability as nuclear waste containment. To compare the alteration of natural glass in natural environment with that of the natural glass treated in hydrothermal-like conditions in laboratory frame work.

Proposal 2:Geochemical modelling and CO2-basalt reactivity on Deccan basalt”

Deccan basalt in India, offers storage deport for carbon dioxide as they contain iron magnesium and calcium silicate minerals. Objective of the proposal is to understand mineral carbonation reactions under hydrothermal-like conditions.Such studies requirequantification ofcarbon-dioxide pressure, temperature and time at variable ratios of surface area and volume of grains, porosity and permeability. Laboratory scale experiments on crushed samples carried out in Delhi University necessitate their confirmation from bulk carbon dioxide-basalt reactivity for which whole core reactionexperiments will be carried out in the laboratory set-up available in Delhi University. Correlation of results is essential for the assessment of degree of immobilization of carbon dioxide in Deccan basalt.