Dr. EVSSK. Babu
@ngri.res.in
Chief Scientist & Project Leader, Geochronology & Isotope Studies
CSIR-National Geophysical Research Institute, India
EDUCATION
Ph.D. University of Cambridge (Advisers: Prof. TJB. Holland, FRS and Prof. D.M. Pyle)
RESEARCH INTERESTS
Mineralogy, Petrology, Geochemistry, Geochronology and Geodynamics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Hadi Mohammaddoost, Majid Ghaderi, T. Vijaya Kumar, Jamshid Hassanzadeh, Saeed Alirezaei, and E.V.S.S.K. Babu
Elsevier BV
Ankita Nandi, T. Vijaya Kumar, E.V.S.S.K. Babu, and Ravikant Vadlamani
Elsevier BV
Bulusu Sreenivas, T. Vijaya Kumar, E.V.S.S.K. Babu, Y.J. Bhaskar Rao, A.V. Chugaev, V.A. Lebedev, and A.B. Vrevsky
Elsevier BV
E.V.S.S.K. Babu, W.L. Griffin, Roger Norris, Elena Belousova, Suzanne Y. O'Reilly, and Y.J. Bhaskar Rao
Elsevier BV
E.V.S.S.K. Babu, Sarbajit Dash, G.H.N.V. Santhosh, and Abhijeet Mukherjee
Elsevier BV
Jyoti P. Sharma, Prabodha R. Sahoo, and E. V. S. S. K. Babu
Cambridge University Press (CUP)
AbstractScapolite occurrences are widely observed in the metasedimentary rocks exposed around the Khetri Copper Belt and adjoining Nim ka Thana copper mineralized area in western India. Amoeboidal to well-developed and rounded/elliptical-shaped marialitic scapolite (Na-rich end-member) rich zones with variable Cl contents ranging from 1.0 wt % to 2.9 wt % have been identified in proximity to the ore-bearing hydrothermal fluid activity zones. Although scapolite is formed as a product of regional metamorphism in many places, in this study, we propose a strong possibility that scapolite was formed by hydrothermal ore-bearing fluid interaction with metasediments. The evidence of hydrothermal activity and Cl sourcing is attributed to (i) the absence of evaporite beds in the area and no Na-rich plagioclase as inclusions within the scapolite suggesting the formation of marialitic scapolite from sodic plagioclase in the metasediments with the interacting hydrothermal fluid; (ii) an epithermal to mesothermal hydrothermal fluid with moderate salinity responsible for the Cu mineralization that is ascribed to be the source of Cl for the formation of marialitic scapolite; (iii) diffusion of SO2 in the scapolite in close association with the sulfide mineral phase (chalcopyrite) supporting the involvement of ore-bearing fluid in the development of scapolite; (iv) the absence of zoned scapolite, the spatial distribution of scapolite in a particular lithology, the occasional incorporation of sulfur into marialitic scapolite and the texture/geometry in the scapolite suggesting a broad hydrothermal linkage instead of a pure metamorphic origin.
Waseem Raza, Sariput Sawant, Syed Masood Ahmad, Drona Srinivasa Sarma, and E.V.S.S.K. Babu
Elsevier BV
Monalisa Mallick, Barnita Banerjee, Tanveer Hassan, Teeda Vijaya Kumar, E.V.S.S.K. Babu, Keshav Krishna, and Rohit Kumar
Elsevier BV
Ch. Ashok, E. V. S. S. K. Babu, Sarbajit Dash, and G. H. N. V. Santhosh
Springer Science and Business Media LLC
Prateek Singh, Rajat Ujjainiya, Satyartha Prakash, Salwa Naushin, Viren Sardana, Nitin Bhatheja, Ajay Pratap Singh, Joydeb Barman, Kartik Kumar, Saurabh Gayali,et al.
Elsevier BV
Ch. Narshimha, V. V. Sesha Sai, U. V. B. Reddy, T. Vijaya Kumar, E. V. S. S. K. Babu, B. Sreenivas, and K. S. V. Subramanyam
Cambridge University Press (CUP)
AbstractWe report a new zircon U–Pb age of 1257 ± 6 Ma for the Punugodu granite (PG) pluton in the Eastern Dharwar Craton (EDC), Southern India. The Mesoproterozoic PG is alkali feldspar hypersolvus granite emplaced at shallow crustal level, as evident from the presence of rhyodacite xenoliths and hornfelsic texture developed in the metavolcanic country rocks of the Neoarchaean Nellore Schist Belt (NSB). Geochemically, the PG is metaluminous, ferroan and alkali-calcic, and is characterized by high SiO2 and Na2O + K2O, Ga/Al ratios >2.6, high-field-strength elements and rare earth element (REE) contents with low CaO, MgO and Sr, indicating its similarity to anorogenic, alkali (A-type) granite. The highly fractionated REE patterns with negative europium anomalies of PG reflect its evolved nature and feldspar fractionation. Mafic (MME) to hybrid (HME) microgranular enclaves represent distinct batches of mantle-derived magmas that interacted, mingled and undercooled within the partly crystalline PG host magma. Felsic microgranular enclaves (FME) having similar mineralogical and geochemical characteristics to the host PG most likely represent fragments of marginal rock facies of the PG pluton. The PG appears to be formed from an oceanic island basalt (OIB)-like source in an anorogenic, within-plate setting. The emplacement of PG (c. 1257 Ma) in the vicinity of Mesoproterozoic Kanigiri Ophiolite (c. 1334 Ma) shows an age gap of nearly 77 Ma, which probably suggests PG emplacement in an extensional environment along a terrain boundary at the western margin of the Neoarchaean NSB in the EDC.
Nihar Ranjan Kar, Devleena Mani, Soumyajit Mukherjee, Swagato Dasgupta, Mohit Kumar Puniya, Ashish Kumar Kaushik, Mery Biswas, and E.V.S.S.K. Babu
Elsevier BV
T. Vijaya Kumar, Y. J. Bhaskar Rao, E. V. S. S. K. Babu, and B. Sreenivas
Springer Science and Business Media LLC
Zircon age-Hf isotopic data on the Archean Singhbhum and Dharwar cratons and the Archean-Proterozoic Southern Granulite Terrain (SGT) obtained at the CSIR-NGRI and by others elsewhere are in focus here. These data are used to decipher episodes of juvenile crust formation in the protracted (collectively spanning ∼3.7 billion years) geologic history of the three terranes in the light of their regional geology, structure and deep-crustal architecture based on recent geophysical experiments as well as current perspectives on early Earth crust forming processes and geodynamics. Our important observations and inferences include: (1) the Hf-isotopic compositions of the Hadean-Eoarchean aged (ca. 4.2–3.6 Ga) zircon grains from the Singhbhum craton have distinctly unradiogenic Hf-isotopic compositions quite similar to the Jack Hills Hadean-Eoarchean detrital zircons, suggesting derivation from TTG-like melts generated by the internal reworking of a long-lived, geochemically enriched mafic reservoir formed around ca. 4.5 Ga; (2) a shift to strongly radiogenic zircon Hf isotope compositions during the early Paleoarchean around ca. 3.6–3.5 Ga (Singhbhum craton) and ca. 3.5–3.4 Ga (Western Dharwar craton) is conspicuous. This may relate to the time of development of depleted mantle reservoirs, the source of the voluminous Paleo-Mesoarchean juvenile felsic magmatism and crust formation events that extended for ca. 400–300 million years; (3) in the entire Dharwar craton and the northern parts of the SGT there is clear evidence for widespread juvenile magmatic episodes during the Neoarchean, around ca. 2.7 Ga and ca. 2.55 Ga, the latter being predominant and widespread; (4) in the southernmost part of the SGT, prominent juvenile magmatic episodes are also evident during the Paleoproterozoic (ca. 2.0 Ga, Trivandrum block) and early Neoproterozoic (ca. 1.0–0.9 Ga, in parts of the Madurai block); (5) onset of plate tectonic processes in the Singhbhum and Western Dharwar cratons during early Paleoarchean (ca. 3.6–3.5 Ga) cannot be ruled out, but there is clear evidence for the operation of plate tectonics, significant crustal growth and terrane amalgamation only after ∼3.0 Ga in the Dharwar craton and the SGT and (6) regional dome and basin structural pattern of the pre-3.0 Ga crust attests to the role of internal differentiation processes (Rayleigh-Taylor Inversions) and vertical tectonics for the Paleo-Mesoarchean crust of the Singhbhum and Dharwar cratons. Together with other lines of evidence; changes in bulk crustal composition, deep crustal architecture, zircon age-Hf isotope distribution etc., we infer a transition to plate tectonics around 3.0 Ga in the Singhbhum and Dharwar cratons.
Ankeeta AMONKAR, Sridhar D. IYER, Elapavalooru V.S.S.K. BABU, Natarajan SHAILAJHA, Areef SARDAR, and S. MANJU
Wiley
Prantik Mandal, Prakash Kumar, B. Sreenivas, E.V.S.S.K. Babu, and Y.J. Bhaskar Rao
Elsevier BV
Abstract Changes in the dominant tectonic regimes and the modes of formation and maturation of the continental crust during the Precambrian are a subject of active debate. Here, we discuss these issues in terms of new information on the crustal and lithospheric architecture of the different terranes in the Eastern part of the Indian Shield (EIS). We present well-constrained estimates of the crustal and lithospheric thickness characterizing different terranes of the EIS through the joint inversion of P-receiver functions (PRF) and fundamental mode group velocity dispersion data of Rayleigh waves (10–100 s). The lithospheric thicknesses are also computed independently using the S-receiver function (SRF) modeling. The study involved 2167 PRFs and 100 SRFs from 15 broadband stations. Our modeling detects a marked crustal (~4–8 km) and lithospheric (~15–20 km) thinning beneath the Singhbhum-Odisha-Craton (SOC), spatially correlating with the central part of the craton comprising the gneissic terrain contrasted by a crustal thickening (~2–6 km) beneath the horseshoe-shaped Iron Ore Group. We propose that such a crustal configuration beneath the Paleoarchean craton may suggest the dominance of vertical tectonic processes such as thickening of an oceanic mafic plateau and recurrent melting producing the TTGs and the Singbhum Granite suite. Infra-crustal reworking involving Rayleigh-Taylor instabilities and gravitational processes could explain the crustal architecture of the SOC much similar to a few other Paleoarchean cratons such as Pilbara (Australia), Barberton and Kappvaal (South Africa). Our modeling has also revealed a relatively smaller degree of crustal (2–4 km) and lithospheric thinning (4–10 km) beneath the Eastern Ghat Mobile Belt, south of the SOC. We observe a relatively thicker crust (~42 km) characterized by a flat Moho over a large area (~40,000 sq. km) encompassing the Chota Nagpur Granite Gneiss Terrane (CGGT). Such thickening is consistent with the convergence and collision tectonics involving the SOC and CGGT. However, we note a 15–20 km lithospheric thinning associated with the CGGT. Such thinning may mainly relate to Phanerozoic rifting along the Damodar graben and Rajmahal magmatism. Broadly, our model of the crustal and lithospheric architecture of the EIS reflects the imprints of northward subduction of SOC beneath the CGGT.
Abhijeet Mukherjee, Pankaj Tiwari, C. B. Verma, E. V. S. S. K. Babu, and Jena Partha Sarathi
Springer Science and Business Media LLC
The paper pertains to the studies carried out on the eclogitic xenoliths of KL-2 kimberlite of Kalyandurg kimberlite cluster in south India. Petrographic studies revealed bi-mineralic and kyanite-bearing eclogitic xenoliths in KL-2 kimberlite. The bimineralic and kyanite-bearing eclogites of Kalyandurg KL-2 kimberlite pipe show variation in modal proportion of garnet, omphacite, clinopyroxene and kyanite. The paper reports discovery of native gold grains and Au-Pt alloy in the kyanite-bearing eclogite xenoliths of KL-2 kimberlite. The flaky gold grains occurring in the matrix of kyanite-bearing eclogite are homogeneous and two grains of Au-Pt alloy with Au and Pt in the proportion of 9.8:1.2 are also present. This is the first report of gold and gold-platinum alloy specs from eclogitic xenoliths of Indian kimberlites.
Waseem Raza, Syed Masood Ahmad, Drona Srinivasa Sarma, and E V S S K Babu
Springer Science and Business Media LLC
Carbon isotopes of stalagmites are influenced by various factors operating in a cave, like evaporation, vegetation, drip rate and changes in partial pressure of carbon-di-oxide (pCO2) inside and around a cave system. Consequently, interpretation of δ13C record becomes a bit complicated. However, the vegetation changes at a given cave location are generally considered as the dominating factor influencing δ13C values of a stalagmite. The δ13C records can provide useful information regarding changes in the class of vegetation over a cave due to dissimilar pathways of photosynthesis linking C3 and C4 vegetation. Here we present a high-resolution δ13C record from a 180 mm long VSPM1 stalagmite collected from the Valmiki cave in Kurnool district of southern India. This study is mainly based on high-resolution δ13C measurements of 263 subsamples. The data has been used to infer vegetation and climatic variations for the last deglacial period starting from 15,607 to 13,161 years BP. The StalAge modelling was employed on eight U–Th dates to reconstruct the age model of the stalagmite sample. The stalagmite grew at the rate of 0.07 mm per year with varying growth rate from around 0.03 to 0.8 mm per year. X-ray diffraction analysis reveals absolute aragonite mineralogy of the sample. The record exhibits a weak positive relationship between δ13C and δ18O values. The main factors influencing δ13C values were associated with local hydroclimate. The δ13C record suggests vital evidence of rapid alterations in vegetation changes from ~15,607 to 13,161 yr BP. A major shift in vegetation activity occurred from 15,607 to 15,105 yr BP with an episode of highly poor vegetation cover around 15,460 yr BP, followed by a gradual decline in vegetation conditions between 15,105 and 14,722 yr BP. This study reveals importance of stable carbon isotopes in stalagmites to understand regional hydroclimate and paleo-vegetation changes. The δ13C record from a stalagmite sample of Valmiki cave located in South India indicates rapid vegetational changes controlled mainly by ISM variability during the last deglacial period. Three major phases have been observed; first a wet period from 15,607 to 15,105 yr BP, followed by a dry period between 15,105 and 14,722 yr BP and finally another wet event from 14,722 to 13,161 yr BP. This study reveals importance of stable carbon isotopes in stalagmites to understand regional hydroclimate and paleo-vegetation changes. The δ13C record from a stalagmite sample of Valmiki cave located in South India indicates rapid vegetational changes controlled mainly by ISM variability during the last deglacial period. Three major phases have been observed; first a wet period from 15,607 to 15,105 yr BP, followed by a dry period between 15,105 and 14,722 yr BP and finally another wet event from 14,722 to 13,161 yr BP.
Salwa Naushin, Viren Sardana, Rajat Ujjainiya, Nitin Bhatheja, Rintu Kutum, Akash Kumar Bhaskar, Shalini Pradhan, Satyartha Prakash, Raju Khan, Birendra Singh Rawat,et al.
eLife Sciences Publications, Ltd
To understand the spread of SARS-CoV2, in August and September 2020, the Council of Scientific and Industrial Research (India) conducted a serosurvey across its constituent laboratories and centers across India. Of 10,427 volunteers, 1058 (10.14%) tested positive for SARS-CoV2 anti-nucleocapsid (anti-NC) antibodies, 95% of which had surrogate neutralization activity. Three-fourth of these recalled no symptoms. Repeat serology tests at 3 (n = 607) and 6 (n = 175) months showed stable anti-NC antibodies but declining neutralization activity. Local seropositivity was higher in densely populated cities and was inversely correlated with a 30-day change in regional test positivity rates (TPRs). Regional seropositivity above 10% was associated with declining TPR. Personal factors associated with higher odds of seropositivity were high-exposure work (odds ratio, 95% confidence interval, p value: 2.23, 1.92–2.59, <0.0001), use of public transport (1.79, 1.43–2.24, <0.0001), not smoking (1.52, 1.16–1.99, 0.0257), non-vegetarian diet (1.67, 1.41–1.99, <0.0001), and B blood group (1.36, 1.15–1.61, 0.001).
M.S. Kalpana, E.V.S.S.K. Babu, Devleena Mani, R.P. Tripathi, and N. Bhandari
Elsevier BV
Abstract Soluble polycyclic aromatic hydrocarbons (PAHs) have been measured in Mukundpura (MK) CM2 carbonaceous chondrite using Gas Chromatography-Mass Spectrometry (GC-MS). The data show high yields of PAHs with the presence of 2, 3, and 4 ring polycyclic aromatic hydrocarbons along with heterocyclic nitrogen and sulfur-containing compounds. MK also shows the presence of significant amount of alkylation products. The distribution and relative abundances of PAHs in the MK are discussed in context of its petrographic grade and correlation with aqueous alteration.
Ankeeta Amonkar, Sridhar D Iyer, E V S S K Babu, and S Manju
Springer Science and Business Media LLC
We report the widespread extent of Toba volcanic glass shards in the Central Indian Ocean Basin. Investigation of four sediment cores (7º–17ºS) revealed several shard-rich horizons (SRH) that provide the first detailed tephrochronology for volcanic glass shards in the CIOB. A comparative study of surface sediments floored with Youngest Toba Tuff (YTT), indicate that irrespective of the rate of sedimentation, YTT in the basin is restricted to a depth of <35 cm-bsf. We utilized microtektites (0.77 Ma), associated with the Oldest Toba Tuff (OTT) glass shards, as a proxy for age calculation of the SRH. The results are comparable with well-established ages derived from paleomagnetic and δ18O methods for the Leg 21 ODP Site 758. The other significant finding of this study includes the first report of Middle Toba Tuff (equivalent to Layer C) and Layer D that are present between YTT and OTT (Layer E) and also Layers G, H, h, I, J, K, L and M. All these layers correspond with those reported for ODP Site 758. Furthermore, two SRH between layers G and H show signatures of localized in-situ phreatomagmatic origin, suggesting that CIOB is apparently more active – tectonically and volcanically than it is presumed.
Babita Rani Choudhary, M. Santosh, S. Ravi, and E.V.S.S.K. Babu
Elsevier BV
Abstract Kl-4 and P-5 mesoproterozoic kimberlite pipes along with several other well-known diamondiferous (ca. 1110 Ma) kimberlites in the Wajrakarur kimberlite field (WKF) intruded into the cratonic roots of Eastern Dharwar craton (EDC) in southern India. The groundmass minerals of the kimberlites exhibit inequigranular texture contain spinel, Ti-rich schorlomite garnet, two generations of olivine (macrocrysts and groundmass microphenocrysts), phlogopite, perovskite, clinopyroxene (diopside), ilmenite (low Mn) and rare apatite. We identified three distinct spinel associations in Kl-4 and P-5: (i) fine-grained ( 500 μm). The schorlomite garnet in both P-5 and Kl-4 represents solid solution of schorlomite-pyrope-almandine-grossular. Additionally, Kl-4 contains another Cr-rich schorlomite-pyrope-almandine-uvarovite solid solution. Macrocrystic spinel exhibits distinct composition of chromium (Cr2O3 up to 59.62 wt%), and poor in TiO2 (
Y J Bhaskar Rao, Sundeep Chopra, Pankaj Kumar, P K Mukherjee, Saurabh Singhal, Vikas Adlakha, T Vijaya Kumar, B Sreenivas, and E.V.S.S.K. Babu
Indian National Science Academy
New Initiatives to Bolster Analytical Facilities in India for in situ U-ThPb Geochronology, Hf and O Isotope Systematics in Zircon: A Focus on Laboratories at the IUAC,WIHG and CSIR-NGRI Y J BHASKAR RAO, SUNDEEP CHOPRA, PANKAJ KUMAR, P K MUKHERJEE, SAURABH SINGHAL, VIKAS ADLAKHA, T VIJAYA KUMAR, B SREENIVAS and E V S S K BABU CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, India National Geochronology Facility, Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067, India Wadia Institute of Himalayan Geology (WIHG), Dehradun, India
Y.J. Bhaskar Rao, T. Vijaya Kumar, B. Sreenivas, and E.V.S.S.K. Babu
International Union of Geological Sciences
Jyoti Priyam Sharma, Prabodha Ranjan Sahoo, Haraman Mahanta, A.S. Venkatesh, E.V.S.S.K. Babu, and Manish M. John
Elsevier BV
Abstract The copper mineralization at the southeastern fringe of the Khetri copper belt in western India is primarily hosted within the metapelites and dolomite units of the Mesoproterozoic Ajabgarh Group of rocks. The copper mineralization is well exposed along a NE-SW trending basinal part around Nim ka Thana area where a few of the prospects namely Dokan, Baniwala-ki-Dhani, Dariba, and Nanagwas primarily consist of abundant bornite, chalcopyrite, covellite, digenite, and chalcocite as disseminated phases hosted within a wide-ranging litho units and along quartz-calcite-barite veins. An integrated approach has been adopted to understand the metallogenetic evolution of this bornite dominated copper mineralization. δ13CV-PDB and δ18OV-SMOW results of the carbonate veins ranging from 0.57‰ to −3.75‰ and δ18O range from 15.01‰ to 20.74‰ respectively suggest the influx of hydrothermal fluid in shaping up the deposit. δ13C (CO2) of the ore-bearing fluid ranges from −1.67‰ to 2.65‰ and δ18O (H2O) from 7.11‰ to 12.84‰ respectively also suggest the input of hydrothermal source. The S-isotopic values of Cu-mineralized barite samples range between 16‰ and 20‰, which are lower than that of seawater (δ34S‰ = 20–22‰). This provides the evidence that the barite mineralization could have formed from the hydrothermal fluid that is cogenetic with the late-stage mineralization in a phase-wise separation as an associated mineral assemblage in the system progressively enriching the bornite-rich copper deposit. Based on the field data and evidences, petrographic characteristics, mineral chemistry, fluid inclusion, and stable isotopic signatures, a three-stage mineralization event is proposed as 1) syngenetic precipitation of dispersed bornite-pyrite in a euxinic environment; 2) hydrothermal vein-type mineralization dominated by chalcopyrite-bornite phase, and 3) supergene enrichment of the vein filled mineralization with the development of wide-scale chalcocite-digenetite-covellite mineral phases. Fluid inclusion microthermometry suggests a temperature range from 225°-320 °C with moderate salinity fluid representing epithermal mineralization which is coherent with the stable isotope data (C, O and S isotopes) of the mineralized carbonate and barite veins suggesting the involvement of large scale hydrothermal fluid influx. Te content of various Cu-bearing sulfide phases shows a gradual change in the concentration from chalcopyrite (2.21% to 2.31%), bornite (2.31% to 4.50%), chalcocite (2.77% to 2.87%), digenite (2.57% to 3.70%) and covellite (2.53% to 3.13%) suggesting their evolution from hydrothermal to supergene process. The studied area has experienced wide-scale alterations and Na-metasomatism with the development of associated minerals such as scapolite, tremolite, and sericite. Occurrence of primary and secondary copper sulfides in the metasedimentary sequence, alteration assemblages affected by Na-metasomatism, association of magnetite and specularite in the study area is affiliated to the hydrothermal system akin to IOCG clan as noted from the adjoining Khetri Copper Deposit.