Jaganmoy Jodder

• Krayer, Johanna; Kienle, Sandra; Jodder, Jaganmoy; Pakulla, Josua J.; Münker, Carsten & Hofmann, Axel [Vis alle 10 forfattere av denne artikkelen] (2026). Effect of submarine hydrothermal activity and emerged landmasses on Paleoarchean Ocean chemistry: Insights from the Tomka iron formation, Daitari Greenstone Belt, Singhbhum Craton, India. Chemical Geology. ISSN 0009-2541. 705. doi: 10.1016/j.chemgeo.2026.123252. Fulltekst i vitenarkiv
• Jodder, Jaganmoy; Hofmann, Axel; Elburg, Marlina A.; Ngobeli, Rebeun & Torsvik, Trond Helge (2025). Reply to comment on “Debunking the myth of a single Iron Ore Group in the Singhbhum Craton, India”. Precambrian Research. ISSN 0301-9268. 427. doi: 10.1016/j.precamres.2025.107884. Fulltekst i vitenarkiv
• Jodder, Jaganmoy; Hofmann, Axel; Elburg, Marlina A.; Ngobeli, Rebeun & Torsvik, Trond Helge (2025). Debunking the myth of a single Iron Ore Group in the Singhbhum Craton, India. Precambrian Research. ISSN 0301-9268. 423. doi: 10.1016/j.precamres.2025.107800. Fulltekst i vitenarkiv Vis sammendrag

  Archaean cratonic cover successions with well-preserved banded iron-formations (BIF) and shales provide a crucial window into early Earth surface processes. Here, we report on the intra-cratonic volcano-sedimentary sequences of the Koira and Simlipal groups of the Singhbhum Craton of India, regarded by some to be equivalent of Palaeoarchaean BIF-bearing greenstone successions collectively referred to as Iron Ore Group. However, field relationships and precise LA-Q-ICP-MS U-Pb detrital zircon ages from basal siliciclastic units of the Koira Group, non-conformably overlying Palaeo- to Mesoarchaean granitoid-greenstone basement, record a maximum depositional age of ca. 2.86 Ga. Sandstone intercalated with shale and banded iron formation of the Koira Group yields a maximum depositional age of ca. 2.68 Ga, placing the deposition of the iron formation and correlative units firmly into the Neoarchaean. The data therefore call for separate BIF–bearing sequences of Palaeoarchaean and Neoarchaean age, thus debunking the persistent myth of a single Iron Ore Group in the Singhbhum Craton of India. It further underscores similarities in the evolution of the Kaapvaal, Pilbara and Singhbhum cratons, which emerged in Mesoarchaean times to accommodate shallow-marine strata and sub-aerial flood basalts in an intra-continental setting.

• Tarduno, John A.; Zhou, Tinghong; Huang, Wentao & Jodder, Jaganmoy (2025). Earth’s magnetic field and its relationship to the origin of life, evolution and planetary habitability. National Science Review. ISSN 2095-5138. 12(5). doi: 10.1093/nsr/nwaf082. Fulltekst i vitenarkiv Vis sammendrag

  Earth’s magnetic field history can provide insight into why life was able to originate and evolve on our planet, and how habitability has been maintained. The magnetism of minute magnetic inclusions in zircons indicates that the geomagnetic field is at least 4.2 billion years old, corresponding with genetic estimates for the age of the last universal common ancestor. The early establishment of the field would have provided shielding from solar and cosmic radiation, fostering environments for life to develop. The field was also likely important for preserving Earth’s water, essential for life as we know it. Between 3.9 and ca. 3.4 billion years ago, zircon magnetism suggests latitudinal stasis of different ancestral terrains, and stagnant lid tectonics. These data also indicate that the solid Earth was stable with respect to the spin axis, consistent with the absence of plate tectonic driving forces. Moreover, these data point to the existence of low-latitude continental nuclei with equable climate locales that could have supported early life. Near the end of the Precambrian (0.591 to 0.565 billion years ago), the dynamo nearly collapsed, but growth of the inner core during earliest Cambrian times renewed the magnetic field and shielding, helping to prevent drying of the planet. Before this renewal, the ultra-weak magnetic shielding may have had an unexpected effect on evolution. The extremely weak field could have allowed enhanced hydrogen escape to space, leading to increased oxygenation of the atmosphere and oceans. In this way, Earth’s magnetic field may have assisted the radiation of the macroscopic and mobile animals of the Ediacara fauna. Whether the Ediacara fauna are genetically related to modern life is a matter of debate, but if so, magnetospheric control on atmospheric composition may have led to an acceleration in evolution that ultimately resulted in the emergence of intelligent life.

• Pfennig, M.L.; Pakulla, J.J.; Hasenstab-Dübeler, E.; Wombacher, F.; Jodder, Jaganmoy & Hofmann, A. [Vis alle 7 forfattere av denne artikkelen] (2025). Young oxygenation of the Archean Keonjhar Palaeosol, India, from 138La-138Ce chronometry. Geochemical Perspectives Letters. ISSN 2410-339X. 33, s. 51–55. doi: 10.7185/geochemlet.2503. Fulltekst i vitenarkiv Vis sammendrag

  Though there is increasing evidence from different geochemical proxies for intermittent oxygenation prior to the Great Oxidation Event (GOE), it remains ambiguous whether post-depositional processes altered these proxy signals. In this regard, the ca. 3.0 Ga old Keonjhar Palaeosol in the Singhbhum Craton in India has received particular attention, as the presence of Ce anomalies in this Archean palaeosol has been interpreted to reflect oxic surface weathering conditions during the Mesoarchean. Trace element analyses from this study revealed only small or no Ce anomalies and depleted REE patterns relative to the protolith. Most importantly, 138La-138Ce chronometry constrains a 138La-138Ce age of <620 Ma. This result precludes previous claims for Archean atmospheric oxygenation preserved in the Keonjhar palaeosol. Corresponding 147Sm-143Nd data yielded an isochron age of 1765 ± 180 Ma and 176Lu-176Hf data do not define an isochron. Altogether, these results indicate post-Archean REE mobilisation. Our findings emphasise the importance of combining palaeo-redox-proxies with radiogenic isotope analysis to validate their significance.

• Krayer, J.; Jodder, Jaganmoy; Hofmann, A.; Weyer, S.; Willbold, M. & Schulz, T. [Vis alle 8 forfattere av denne artikkelen] (2025). The influence of mafic and felsic crust on the seawater chemistry ca. 3.0 billion years ago: Evidence from Nd isotopes in banded iron formations from the Murchison Greenstone Belt. Precambrian Research. ISSN 0301-9268. 418. doi: 10.1016/j.precamres.2025.107701. Fulltekst i vitenarkiv Vis sammendrag

  Banded iron formations (BIFs) are marine chemical sedimentary rocks that serve as prime archives for Precambrian paleo-environmental reconstructions. However, due to the scarcity of well-preserved Archean rocks, the aquatic environments of early Earth remain poorly constrained. In particular, fluxes derived from continents and submarine hydrothermal systems that affected Archean seawater chemistry are crucial for the understanding of the evolution of marine environments. To fill this gap, we present major- and trace element data in combination with Sm-Nd isotopes of individual BIF layers from the ca. 3.0 Ga old Murchison Greenstone Belt (MGB) of South Africa. BIF layers with low immobile element concentrations show seawater-like shale-normalized (subscript SN) rare earth and yttrium (REYSN) patterns with heavy over light REYSN enrichment and positive LaSN, EuSN, GdSN, and YSN anomalies, implying an anoxic marine depositional setting with contributions from high-temperature, hydrothermal systems. These BIF samples yield a Sm-Nd age of 2993 ± 97 Ma that overlaps with the proposed depositional age suggesting negligible post-depositional alteration. In contrast, BIF layers with non-seawater-like REYSN patterns yield a Sm-Nd age of 2504 ± 161 Ma, which can be linked to post-depositional alteration during the ca. 2.7 Ga Limpopo orogeny. The range of initial εNd values from −1.74 to + 0.15 in pristine BIF samples suggests that elements of mixed juvenile and evolved material from emerged continents and/or hydrothermal systems affected Murchison seawater and indicates potential oceanic water mixing in the Murchison region with water masses derived from the northern Pietersburg and the southern Kaapvaal regions.

• Messling, N.; Jodder, Jaganmoy; Hegner, E.; Hofmann, A.; Wemmer, K. & Willbold, M. (2023). Mobilization of Tungsten in Greenstone Belts of the Archean Kaapvaal and Singhbhum Cratons. Geochemistry Geophysics Geosystems. 24(12). doi: 10.1029/2023GC011161. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Due to the inherently fluid‐mobile nature of W, the 182 W record of the early Earth may have been obscured by fluid‐induced mobilization of W. To investigate W mobilization in Archean greenstone sequences, we analyzed 182 W isotope systematics and major and trace element concentrations in samples from the 3.53 Ga old Onverwacht Group of the Kaapvaal Craton (South Africa) and the &gt;3.51 Ga old Badampahar Group of the Singhbhum Craton (India). Our results for mafic and ultramafic metavolcanic rocks show W/Th ratios significantly higher than primary magmatic values, which suggests fluid‐induced W enrichment. Samples least affected by secondary W enrichment (W/Th &lt; 0.26) show no resolvable W isotope anomalies from modern mantle values in both cratons. Samples from the Kaapvaal Craton with elevated W/Th exhibit deficits in 182 W as low as −8.1 ± 4.3 ppm compared to the modern mantle. Covariations of μ 182 W with W/Th, and Ce/Pb suggest that negative isotope signatures were introduced during secondary fluid‐mediated processes. The enrichment of W is most evident in altered ultramafic rocks comprising serpentine, resulting in additional covariations between MgO, LOI, and W/Th. The W isotope composition of serpentinized komatiites reflects the composition of younger intruding granitoids. We therefore infer the latter as a possible source of W‐rich fluids. The Badampahar Group samples exhibit little W isotope variability. A well‐resolved 182 W deficit of −6.2 ± 2.9 ppm was determined in a single komatiite sample, which indicates an unknown fluid source, currently not represented in any other unit of the Singhbhum Craton.

• Hofmann, Axel; Bolhar, Robert; Kuznetsov, Anton B.; Jodder, Jaganmoy; Butler, Mike & Nguyen, Ai (2023). A craton-wide geochemical study of Neoarchaean carbonate rocks of Zimbabwe. Chemical Geology. ISSN 0009-2541. doi: 10.1016/j.chemgeo.2023.121587. Fulltekst i vitenarkiv
• Jodder, Jaganmoy; Hofmann, Axel; Xie, Hangqiang; Elburg, Marlina & Wilson, Allan (2023). Geochronology of the Daitari Greenstone Belt, Singhbhum Craton, India. Precambrian Research. ISSN 0301-9268. 388. doi: 10.1016/j.precamres.2023.106997. Fulltekst i vitenarkiv
• Tarduno, John A.; Cottrell, Rory D.; Bono, Richard, K.; Rayner, Nicole; Davis, William J. & Zhou, Tinghong [Vis alle 13 forfattere av denne artikkelen] (2023). Hadaean to Palaeoarchaean stagnant-lid tectonics revealed by zircon magnetism. Nature. ISSN 0028-0836. doi: 10.1038/s41586-023-06024-5. Fulltekst i vitenarkiv
• Hofmann, Axel; Jodder, Jaganmoy; Xie, Hangqiang; Bolhar, Robert; Whitehouse, Martin, J. & Elburg, Marlina A. (2022). The Archaean geological history of the Singhbhum Craton, India – a proposal for a consistent framework of craton evolution. Earth-Science Reviews. ISSN 0012-8252. 228. doi: 10.1016/j.earscirev.2022.103994. Fulltekst i vitenarkiv Vis sammendrag

  The Singhbhum Craton of East India has a remarkably well-preserved Archaean geological record that rivals those of the Kaapvaal and Pilbara cratons. Based on a critical literature review, and aided by new field and geochronological data, a consistent framework of craton evolution during the Archaean is proposed that aims to put to rest some of the uncertainties on its geological history. The oldest rock assemblage so far identified in the Singhbhum Craton consists of ~3.5 to 3.3 Ga old greenstones of the Badampahar Group that are in tectonic contact with, or intruded by, broadly contemporaneous tonalite-trondhjemite-granodiorite of the Champua Suite, representing the precursor of grey gneisses of the Singhbhum Granitoid Complex. A reported Eoarchaean to Hadean detrital and xenocrystic zircon record suggests an even older onset of craton evolution, the details of which remain to be deciphered. Following >200 Ma of submarine volcanism and sedimentation, concomitant with granitoid emplacement of the Singhbhum Suite in the evolving craton, a regional event of deformation and metamorphism took place at ~3.3 Ga ago. It gave rise to syn-tectonic deposition of coarse siliciclastic successions of the Dhosrapahar Group, tight to isoclinal upright folding of the supracrustal rocks, and a greenschist to amphibolite facies metamorphic overprint. Starting at around 3.35 Ga, but overlapping with this regional event, was a broad change in the composition of felsic plutons towards more K-rich compositions, which culminated in the emplacement of granites of the Mayurbhanj Suite at 3.1 Ga that led to stabilization of the craton. Following tectonic uplift, erosion, and peneplanation, the intracontinental to continental margin volcano-sedimentary successions of the Koira Group and the correlative Simlipal Group were deposited on granitoid-greenstone basement between 3.0 and 2.75 Ga. Subsidence may have been related to extension of the craton that gave rise to the extrusion of largely subaerial basalts that may have been fed by a prominent mafic dyke swarm at ~2.80 Ga. At the same time, deformation and high-grade metamorphism affected the southwestern part of the craton. This event gave rise to widespread emplacement of granites that heralded the onset of tectonic reworking of the craton along its margins, which continued well into the Proterozoic.

• Jodder, Jaganmoy; Hofmann, Axel & Ueckermann, Henriëtte (2021). 3.51 Ga old felsic volcanic rocks and carbonaceous cherts from the Gorumahisani Greenstone Belt – Insights into the Palaeoarchaean record of the Singhbhum Craton, India. Precambrian Research. ISSN 0301-9268. doi: 10.1016/j.precamres.2021.106109. Fulltekst i vitenarkiv

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• Krayer, Johanna; Viehmann, Sebastian; Mayer, Alina; Schulz, Toni; Koeberl, Christian & Hofmann, Axel [Vis alle 8 forfattere av denne artikkelen] (2024). Elemental fluxes into 3.0-billion-year-old marine environments: evidence from trace elements and Nd isotopes in banded iron formations from the Murchison Greenstone Belt, South Africa. EGU General Assembly. doi: 10.5194/egusphere-egu24-5245. Fulltekst i vitenarkiv
• Jodder, Jaganmoy; Hofmann, Axel; Elburg, Marlina & Ngobeli, Rebeun (2024). Archaean record of the Singhbhum Craton, India: new insights from greenstone belts and cratonic cover sequences. EGU General Assembly Conference Abstracts. doi: 10.5194/egusphere-egu24-10889. Fulltekst i vitenarkiv
• Messling, Nils; Hegner, Ernst; Jodder, Jaganmoy; Hofmann, Axel; Wemmer, Klaus & Willbold, Matthias (2023). Remobilization of Tungsten in Archean Cratons: Insights from W Isotope Compositions of Volcanic Rocks from the Kaapvaal and Singhbhum Cratons. Goldschmidt Conference Abstracts. Fulltekst i vitenarkiv
• Jodder, Jaganmoy; Hofmann, Axel & Stüeken, Eva E. (2023). Earliest Evidence of Life Preserved in ca. 3.5 Ga Old Marine Sediments of the Daitari Greenstone Belt, Singhbhum Craton, India. Goldschmidt Conference Abstracts. doi: 10.7185/gold2023.15843. Fulltekst i vitenarkiv

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