Dr. Thounaojam Dhanakumar Singh
@pondiuni.edu.in
Post Doctoral Fellow/ Department of Earth Sciences
Pondicherry University
EDUCATION
UGC-DS Kothari Post Doctoral Fellow, Department of Earth Sciences, Pondicherry University
PhD in Geology, CSIR-NGRI, Hyderabad
MSc Geology, University of Mysore
RESEARCH INTERESTS
Mantle geochemistry, intraplate magmatism-hotspots/plumes linkage, subduction zone magmatism and role of magmatism in evolution of sedimentary basins.
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
G. Harshitha Reddy, C. Manikyamba, and Th. Dhanakumar Singh
Springer Science and Business Media LLC
Arijit Pahari, Th Dhanakumar Singh, C Manikyamba, and K S V Subramanyam
Springer Science and Business Media LLC
The Meso-Neoarchean Kudremukh greenstone belt (KGB) of Western Dharwar craton comprises predominant metabasalts associated with banded iron formations (BIFs). The metabasalts are characterized by moderate MgO (7.23–8.97 wt.%), Ni (48–374 ppm), Cr (33–188 ppm) with a wide variation in ∑\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sum $$\\end{document}PGE (21.8–215.7 ppb) contents with 15.8–115.9 ppb Pd, 3.7–105.2 ppb Pt and 0.7–8.5 ppb Rh. Among IPGE group, Iridium, Osmium and Ruthenium range from 0.2–5.9, 1.4–7 and 1.8–7.8 ppb, respectively. These metabasalts are relatively enriched in ∑\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sum $$\\end{document}PPGE (21.8–215.7 ppb) than ∑\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sum $$\\end{document}IPGE contents (3.6–18.6 ppb). Their Pd/Ir (7.6–100.7) and Pd/Pt (0.8–5.5) ratios correspond to moderate to lower degree of melting. The abundance of PGEs in Kudremukh metabasalts is dominantly controlled by sulphide and chromite fractionation trend of the parent magma. Sulphur undersaturated nature of the parent magma is evidenced through the relationship of Pd vs. Cu. Further,̄ the Cu/Pd ratios of the studied volcanics (Cu/Pd = 1277–5747) is lower than primitive mantle (Cu/Pd = 7000), indicating early sulphide removal and S-undersaturation during magmatic differentiation. PGEs geochemistry of the studied rocks suggest early removal of sulphide melts followed by pronounced sulphide fractionation and the mantle melting episode is followed by metasomatism of the refractory mantle wedge by the fluids/melts derived from the subducting slab in a convergent margin setting. PGE systematics on the metabasalts from Kudremukh greenstone belt, western Dharwar Craton, India. The KGB metabasalts are characterised by low- moderate degrees of partial melting and high degrees of sulphide fractionation. PGE geochemistry of the KGB metabasalts infers the early sulphur undersaturated nature of magmas. PGE systematics on the metabasalts from Kudremukh greenstone belt, western Dharwar Craton, India. The KGB metabasalts are characterised by low- moderate degrees of partial melting and high degrees of sulphide fractionation. PGE geochemistry of the KGB metabasalts infers the early sulphur undersaturated nature of magmas.
C. Manikyamba, Sohini Ganguly, M. Santosh, Li Tang, C.S. Sindhuja, Arijit Pahari, Th. Dhanakumar Singh, and Abhishek Saha
Elsevier BV
Arubam C. Khelen, C. Manikyamba, Li Tang, M. Santosh, K.S.V. Subramanyam, and Th Dhanakumar Singh
Elsevier BV
Abstract Oldest rocks are sparsely distributed within the Dharwar Craton and little is known about their involvement in the sedimentary sequences which are present in the Archean greenstone successions and the Proterozoic Cuddapah basin. Stromatolitic carbonates are well preserved in the Neoarchean greenstone belts of Dharwar Craton and Cuddapah Basin of Peninsular India displaying varied morphological and geochemical characteristics. In this study, we report results from U-Pb geochronology and trace element composition of the detrital zircons from stromatolitic carbonates present within the Dharwar Craton and Cuddapah basin to understand the provenance and time of accretion and deposition. The U-Pb ages of the detrital zircons from the Bhimasamudra and Marikanve stromatolites of the Chitradurga greenstone belt of Dharwar Craton display ages of 3426 ± 26 Ma to 2650 ± 38 Ma whereas the Sandur stromatolites gave an age of 3508 ± 29 Ma to 2926 ± 36 Ma suggesting Paleo- to Neoarchean provenance. The U-Pb detrital zircons of the Tadpatri stromatolites gave an age of 2761 ± 31 Ma to 1672 ± 38 Ma suggesting Neoarchean to Mesoproterozoic provenance. The Rare Earth Element (REE) patterns of the studied detrital zircons from Archean Dharwar Craton and Proterozoic Cuddapah basin display depletion in light rare earth elements (LREE) and enrichment in heavy rare earth elements (HREE) with pronounced positive Ce and negative Eu anomalies, typical of magmatic zircons. The trace element composition and their relationship collectively indicate a mixed granitoid and mafic source for both the Dharwar and Cuddapah stromatolites. The 3508 ± 29 Ma age of the detrital zircons support the existence of 3.5 Ga crust in the Western Dharwar Craton. The overall detrital zircon ages (3.5–2.7 Ga) obtained from the stromatolitic carbonates of Archean greenstone belts and Proterozoic Cuddapah basin (2.7–1.6 Ga) collectively reflect on ∼800–900 Ma duration for the Precambrian stromatolite deposition in the Dharwar Craton.
Th. Dhanakumar Singh, C. Manikyamba, Li Tang, Sohini Ganguly, M. Santosh, K.S.V. Subramanyam, and Arubam C. Khelen
Elsevier BV
Abstract Magmatic pulses in intraplate sedimentary basins are windows to understand the tectonomagmatic evolution and paleaoposition of the Basin. The present study reports the U–Pb zircon ages of mafic flows from the Cuddapah Basin and link these magmatic events with the Pangean evolution during late Carboniferous–Triassic/Phanerozoic timeframe. Zircon U–Pb geochronology for the basaltic lava flows from Vempalle Formation, Cuddapah Basin suggests two distinct Phanerozoic magmatic events coinciding with the amalgamation and dispersal stages of Pangea at 300 Ma (Late Carboniferous) and 227 Ma (Triassic). Further, these flows are characterized by analogous geochemical and geochronological signatures with Phanerozoic counterparts from Siberian, Panjal Traps, Emeishan and Tarim LIPs possibly suggesting their coeval and cogenetic nature. During the Phanerozoic Eon, the Indian subcontinent including the Cuddapah Basin was juxtaposed with the Pangean LIPs which led to the emplacement of these pulses of magmatism in the Basin coinciding with the assemblage of Pangea and its subsequent breakup between 400 Ma and 200 Ma.
E. Shaji, M. Santosh, Shan‐Shan Li, C. Manikyamba, T. Tsunogae, S.G. Dhanil Dev, Arathi G. Panicker, Th. Dhanakumar Singh, and K.S.V. Subramanyam
Wiley
Th. Dhanakumar Singh, C. Manikyamba, K.S.V. Subramanyam, Sohini Ganguly, Arubam C. Khelen, and N. Ramakrishna Reddy
Elsevier BV
Arubam C. Khelen, C. Manikyamba, Sohini Ganguly, Th. Dhanakumar Singh, K.S.V. Subramanyam, S. Masood Ahmad, and M. Ramakrishna Reddy
Elsevier BV
Abstract Spectacular stromatolitic dolomites with varied morphological features are preserved in the Vempalle and Tadpatri Formations of the Proterozoic Cuddapah basin, eastern Dharwar Craton. They exhibit stratifera, columnar, conical, domal and spheroidal/lobate morphologies in which columns are branched at some places (in Tadpatri Formation). Based on their trace elements such as REY and stable isotope compositions (carbon and oxygen) the Vempalle stromatolites have been classified as three types. Vempalle I stromatolites exhibit pronounced positive Eu anomalies with small scale positive Ce anomalies whereas Vempalle II counterparts have slight negative to positive Eu, feeble positive Ce and positive Gd anomalies. Vemaplle III stromatolites display positive Ce, Eu and Gd anomalies. The Tadpatri Formation stromatolites have pronounced Gd anomalies with low order positive Ce and Eu anomalies. Significant depletion in δ18O is observed in Vempalle ranging from – 10.70‰ to −7.07‰ and 20.73‰ to −11.87‰ in Tadpatri Formations. The Tadpatri stromatolites display negative δ13C varying from −4. 56‰ to −1.26‰. Contrarily, the Vempalle stromatolites recorded both positive and negative δ13C ranging from −0.24‰ to 2.00‰ thereby reflecting their deviation from the popular belief of the boring billion concept of displaying Midproterozoic δ13C stasis. The flat REE patterns along with Ce, Eu and Gd anomalies, chondritic to superchondritic Y/Ho ratios collectively reflect on marine water conditions for their deposition with variable inputs of siliciclastic/terrigenous materials and hydrothermal signatures. These cherty dolomitic stromatolites were deposited in subtidal-intertidal-supratidal zones of a shallow shelf of Proterozoic open ocean under warm, alkaline and anoxic conditions.
M. Rajanikanta Singh, C. Manikyamba, Sohini Ganguly, Jyotisankar Ray, M. Santosh, Th. Dhanakumar Singh, and B. Chandan Kumar
Elsevier BV
Abstract The Singhbhum Craton of eastern India preserves distinct signatures of ultramafic-mafic-intermediate-felsic magmatism of diverse geodynamic affiliations spanning from Paleo-Mesoarchean to Proterozoic. Here we investigate the 2.25 Ga Malangtoli volcanic rocks that are predominantly clinopyroxene- and plagioclase-phyric, calc-alkaline in nature, display basalt-basaltic andesite compositions, and preserve geochemical signatures of subduction zone magmatism. Major, trace and rare earth element characteristics classify the Malangtoli volcanic rocks as arc basalts, boninites, high magnesian andesites (HMA) and Nb enriched basalts (NEB). The typical LILE enriched-HFSE depleted geochemical attributes of the arc basalts corroborate a subduction-related origin. The boninitic rocks have high Mg# (0.8), MgO (>25 wt.%), Ni and Cr contents, high Al 2 O 3 /TiO 2 (>20), Zr/Hf and (La/Sm) N (>1) ratios with low (Gd/Yb) N ( 2 , and Zr concentrations. The HMA samples are marked by moderate SiO 2 (>54 wt.%), MgO (>6 wt.%), Mg# (0.47) with elevated Cr, Co, Ni and Th contents, depleted (Nb/Th) N , (Nb/La) N , high (Th/La) N and La/Yb ( pm = 0.28–0.59 and (Nb/La) pm = 0.40–0.69 and Nb/U = 2.8–34.4 compared to normal arc basalts [Nb = pm = 0.10–1.19; (Nb/La) pm 0.17–0.99 and Nb/U = 2.2–44 respectively] and HMA. Arc basalts and boninites are interpreted to be the products of juvenile subduction processes involving shallow level partial melting of mantle wedge under hydrous conditions triggered by slab-dehydrated fluid flux. The HMA resulted through partial melting of mantle wedge metasomatized by slab-dehydrated fluids and sediments during the intermediate stage of subduction. Slab-melting and mantle wedge hybridization processes at matured stages of subduction account for the generation of NEB. Thus, the arc basalt-boninite-HMA-NEB association from Malangtoli volcanic suite in Singhbhum Craton preserves the signature of a complete spectrum of Paleoproterozoic active convergent margin processes spanning from subduction initiation to arc maturation.
C. Manikyamba, M. Santosh, B. Chandan Kumar, S. Rambabu, Li Tang, Abhishek Saha, Arubam C. Khelen, Sohini Ganguly, Th. Dhanakumar Singh, and D.V. Subba Rao
Elsevier BV
Abstract The Bastar Craton of Central India has a thick sequence of volcano–sedimentary rocks preserved in Kotri–Dongargarh belt that developed on a tonalite-trondhjemite-granodiorite (TTG) basement followed upwards by the Amgaon, Bengpal, Bailadila, and Nandgaon Groups of rocks. Here, we report the U-Pb geochronology and Lu-Hf isotope systematics and whole rock geochemistry of volcanic rocks and associated granitoids belonging to the Pitepani basalts, Bijli rhyolites, and Dongargarh granite in the Nandgaon Group of the Kotri belt. The volcanic rocks of the Nandgaon Group are bimodal in nature in which the basalts exhibit intergranular, porphyritic to spherulitic texture composed of pyroxenes, plagioclase, tremolite, actinolite, and chlorite ± Fe oxides. The rhyolites display porphyritic texture consisting of K-feldspar, quartz, and plagioclase as phenocrysts. The associated porphyritic granitoids have K-feldspar, microcline, plagioclase, and biotite phenocrysts within a groundmass of similar composition. The bimodal suite displays LILE, LREE enrichment, and HFSE depletion with significant negative Nb-Ta anomalies combined with slightly fractionated REE patterns in the basalts and highly fractionated patterns and prominent negative Eu anomalies in the rhyolites endorsing their generation in an island-arc/back-arc tectonic setting. The geochemical features of the associated granitoids indicate that these are potassic and classify as within-plate A-type granites. Zircons from the basalts show clear oscillatory zoning in their CL images. They cluster as a coherent group with 207Pb/206Pb spot ages ranging from 2446 to 2522 Ma and weighted mean age of 2471 ± 7 Ma. Zircons from the rhyolite samples are subhedral to euhedral and show simple oscillatory zoning with some heterogeneous fractured domains. The data from two samples define upper intercept ages of 2479 ± 13 Ma and 2463 ± 14 Ma. Zircon grains in the granite show clear oscillatory zoning and their U-Pb data define an upper intercept age of 2506 ± 50 Ma. The Lu-Hf isotopic data on the zircons from the basalts show initial 176Hf/177Hf ratios from 0.280925 to 0.281018. Their eHf(t) values are in the range of − 10.0 to − 6.7. The Hf-depleted model ages (TDM) are between 3038 Ma and 3171 Ma, and Hf crustal model ages (TDMC) vary from 3387–3589 Ma. The zircons from the rhyolites show initial 176Hf/177Hf ratios from 0.280919 to 0.281020 and from 0.281000 to 0.281103, respectively, with eHf(t) values varying from − 10 to − 6.4 and from − 7.5 to − 3.9. Among these, one sample shows TDM between 3038 Ma and 3182 Ma, and TDMC varies from 3377 to 3596 Ma, whereas the other sample shows ages of 2925 Ma and 3072 Ma with TDMC varying from 3208 to 3432 Ma. The initial 176Hf/177Hf ratios of the granites range from 0.280937 to 0.281062 with eHf(t) values of − 8.8 to − 4.3. The TDM shows a range of 2979 Ma and 3170 Ma, and TDMC varies from 3269 to 3541 Ma. The predominant negative eHf(t) values of zircons from these rocks suggest that the source material was evolved from the Paleoarchean crust. The geological, geochemical, and geochronological evidence suggests coeval tectonic and magmatic episodes of volcanic and plutonic activity in an island-arc setting where the arc migrated toward the continental margin and played a significant role in the Neoarchean–Paleoproterozoic crustal growth of the Kotri belt of Central India.