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Introduction

Environmental conditions during the origin and early evolution of life on Earth are intensely debated. Hydrothermal systems have long been considered critical players in this debate because they may have released essential nutrients and provided catalytic minerals for the formation of prebiotic organic molecules (e.g., Martin et al., 2008

Martin, W., Baross, J., Kelley, D., Russell, M.J. (2008) Hydrothermal vents and the origin of life. Nature Reviews Microbiology 6, 805–814. https://doi.org/10.1038/nrmicro1991

). Hydrothermal settings have been described from the early Archean rock record (Vearncombe et al., 1995

Vearncombe, S., Barley, M.E., Groves, D.I., McNaughton, N.J., Mikucki, E.J., Vearncombe, J.R. (1995) 3.26 Ga black smoker-type mineralization in the Strelley Belt, Pilbara Craton, Western Australia. Journal of the Geological Society 152, 587–590. https://doi.org/10.1144/gsjgs.152.4.0587

; Djokic et al., 2017

Djokic, T., Van Kranendonk, M.J., Campbell, K.A., Walter, M.R., Ward, C.R. (2017) Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits. Nature Communications 8, 15263. https://doi.org/10.1038/ncomms15263

) and are implicated in models for the precipitation of iron formations 3.8–1.8 Ga ago (Isley and Abbott, 1999

Isley, A.E., Abbott, D.H. (1999) Plume-related mafic volcanism and the deposition of banded iron formation. Journal of Geophysical Research: Solid Earth 104, 15461–15477. https://doi.org/10.1029/1999JB900066

; Tosca and Tutolo, 2023

Tosca, N.J., Tutolo, B.M. (2023) Hydrothermal vent fluid-seawater mixing and the origins of Archean iron formation. Geochimica et Cosmochimica Acta 352, 51–68. https://doi.org/10.1016/j.gca.2023.05.002

). However, a quantitative assessment of the intensity and fluctuations of mass fluxes originating from hydrothermal systems contributing to the elemental inventories of early oceans has so far not been attempted.

Europium can fill this gap. It occurs in a 3+ state under surface environmental conditions similar to the other rare earth elements (REE) but is reduced to the more soluble Eu²⁺ under reducing, acidic, conditions above 250 °C, and enriched relative to the neighbouring REE (Bau, 1991

Bau, M. (1991) Rare-earth element mobility during hydrothermal and metamorphic fluid-rock interaction and the significance of the oxidation state of europium. Chemical Geology 93, 219–230. https://doi.org/10.1016/0009-2541(91)90115-8

). Thus, high temperature hydrothermal fluids become enriched in Eu relative to the host rocks during fluid–rock interactions. Although Eu²⁺ immediately oxidises to Eu³⁺ in lower temperature regimes, where it behaves geochemically similar to the neighbouring, strictly trivalent REE, the precipitates of hydrothermal fluids can preserve this Eu enrichment over geologic time. In the modern fully vented and oxidised oceans, REE are particle-reactive and show residence times of only a few hundred years. Acidic fluids reaching temperatures up to ∼400 °C with positive Eu anomalies are exhaled at hydrothermal vent systems such as submarine trenches, hot spots, or rift systems into seawater, and are immediately cooled and oxidised (e.g., German et al., 1990

German, C.R., Klinkhammer, G.P., Edmond, J.M., Mitra, A., Elderfield, H. (1990) Hydrothermal scavenging of rare-earth elements in the ocean. Nature 345, 516–518. https://doi.org/10.1038/345516a0

). Subsequently, precipitating Fe- and Mn(oxy)hydroxides scavenge REE from the hydrothermal fluid and seawater. Therefore, hydrothermal Fe-Mn oxide precipitates (Bau et al., 2014

Bau, M., Schmidt, K., Koschinsky, A., Hein, J., Kuhn, T., Usui, A. (2014) Discriminating between different genetic types of marine ferro-manganese crusts and nodules based on rare earth elements and yttrium. Chemical Geology 381, 1–9. https://doi.org/10.1016/j.chemgeo.2014.05.004

) and carbonates in mussel shells proximal to black smoker vent sites show strong Eu enrichments (Bau et al., 2010

Bau, M., Balan, S., Schmidt, K., Koschinsky, A. (2010) Rare earth elements in mussel shells of the Mytilidae family as tracers for hidden and fossil high-temperature hydrothermal systems. Earth and Planetary Science Letters 299, 310–316. https://doi.org/10.1016/j.epsl.2010.09.011

). Modern submarine high temperature hydrothermal systems, where Fe-Mn oxides precipitate proximal to the vent site, act as sinks rather than sources for REE and other particle-reactive elements (German et al., 1990

German, C.R., Klinkhammer, G.P., Edmond, J.M., Mitra, A., Elderfield, H. (1990) Hydrothermal scavenging of rare-earth elements in the ocean. Nature 345, 516–518. https://doi.org/10.1038/345516a0

). In a stratified, anoxic water column, such as proposed for long periods of the Precambrian, REE could likely reach much longer residence times due to the lack of direct scavenging onto Fe- and Mn(oxy)hydroxides. Thus, REE exhaled from hydrothermal systems into Precambrian oceans should have been dispersed more widely. However, beyond computational models (Tutolo and Tosca 2023

Tosca, N.J., Tutolo, B.M. (2023) Hydrothermal vent fluid-seawater mixing and the origins of Archean iron formation. Geochimica et Cosmochimica Acta 352, 51–68. https://doi.org/10.1016/j.gca.2023.05.002

), there is no empirical constraint on the extent to which these fluids contributed to water chemistry in the different environments of early oceans, such as outer shelf or near shore environments.

Europium systematics have previously been used to investigate the impact of high temperature, hydrothermal systems on ancient local depositional environments (e.g., Bau and Dulski, 1996

Bau, M., Dulski, P. (1996) Distribution of yttrium and rare-earth elements in the Penge and Kuruman iron-formations, Transvaal Supergroup, South Africa. Precambrian Research 79, 37–55. https://doi.org/10.1016/0301-9268(95)00087-9

) and the thermal state of Earth’s mantle (Danielson et al., 1992

Danielson, A., Möller, P., Dulski, P. (1992) The europium anomalies in banded iron formations and the thermal history of the oceanic crust. Chemical Geology 97, 89–100. https://doi.org/10.1016/0009-2541(92)90137-T

; Viehmann et al., 2015

Viehmann, S., Bau, M., Hoffmann, J.E., Münker, C. (2015) Geochemistry of the Krivoy Rog Banded Iron Formation, Ukraine, and the impact of peak episodes of increased global magmatic activity on the trace element composition of Precambrian seawater. Precambrian Research 270, 165–180. https://doi.org/10.1016/j.precamres.2015.09.015

), as well as in ore geology to fingerprint the temperature of ore-forming hydrothermal fluids (Kraemer et al., 2019

Kraemer, D., Viehmann, S., Banks, D., Sumoondur, A.D., Koeberl, C., Bau, M. (2019) Regional variations in fluid formation and metal sources in MVT mineralization in the Pennine Orefield, UK: Implications from rare earth element and yttrium distribution, Sr-Nd isotopes and fluid inclusion compositions of hydrothermal vein fluorites. Ore Geology Reviews 107, 960–972. https://doi.org/10.1016/j.oregeorev.2019.03.014

). Prior studies of iron formations (IFs; Danielson et al., 1992

Danielson, A., Möller, P., Dulski, P. (1992) The europium anomalies in banded iron formations and the thermal history of the oceanic crust. Chemical Geology 97, 89–100. https://doi.org/10.1016/0009-2541(92)90137-T

; Viehmann et al., 2015

Viehmann, S., Bau, M., Hoffmann, J.E., Münker, C. (2015) Geochemistry of the Krivoy Rog Banded Iron Formation, Ukraine, and the impact of peak episodes of increased global magmatic activity on the trace element composition of Precambrian seawater. Precambrian Research 270, 165–180. https://doi.org/10.1016/j.precamres.2015.09.015

) have shown a decline of Eu anomalies between 3.8 Ga and 2.7 Ga ago, with a much more positive Eu peak at 2.6 Ga. These studies proposed variable REE fluxes from submarine high temperature systems into Archean seawater.

While these studies demonstrate that Eu signatures in chemical sediments can serve as a robust proxy for hydrothermal inputs, the previous focus on IFs limits current knowledge to the deeper continental shelf and, in some cases, to sites that were deposited in proximity to active submarine volcanic zones. A new approach is needed to track hydrothermal influences on shallow marine settings, which are known for occurrences of stromatolites from ca. ≥3.5 Ga until today (Riding, 2011

Riding, R. (2011) The nature of stromatolites: 3,500 million years of history and a century of research. In: Reitner, J., Quéric, N.-V., Arp, G., (Eds.) Advances in Stromatolite Geobiology. Springer, 29–74. https://doi.org/10.1007/978-3-642-10415-2_3

) and have been crucial for the appearance and radiation of oxygenic phototrophs that ultimately led to the oxygenation of Earth’s atmosphere at ca. 2.4 Ga (Lyons et al., 2014

Lyons, T.W., Reinhard, C.T., Planavsky, N.J. (2014) The rise of oxygen in Earth’s early ocean and atmosphere. Nature 506, 307–315. https://doi.org/10.1038/nature13068

). Shallow marine sites also host the earliest eukaryotic algae in the Proterozoic (Javaux et al., 2001

Javaux, E.J., Knoll, A.H., Walter, M.R. (2001) Morphological and ecological complexity in early eukaryotic ecosystems. Nature 412, 66–69. https://doi.org/10.1038/35083562

). Accurate reconstructions of the evolution of Earth’s biosphere and surface environments thus require an assessment to establish if, and to which extent, hydrothermal systems in these shallow marine settings affected water chemistry and the delivery of nutrients amongst other elements.

Here, we report Eu anomaly curves of IFs and marine stromatolites throughout the Precambrian to determine the influence of high temperature hydrothermal fluxes on seawater chemistry in both deep and shallow marine environments. The results allow constraint of the impact of high temperature hydrothermal systems on a range of marine habitats throughout Earth’s history.

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The Link of Eu Abundances in Iron Formations to the Geodynamic Evolution of the Earth

The compilation of chondrite-normalised Eu mass fractions (Eu_CN) in IFs (Fig. 1) and stromatolites (Fig. 2) reflects deep and shallow marine Precambrian environments. The enrichment of Eu in carbonates, where REE substitutes for Ca in the crystal lattice, is not quantitatively comparable to REE enrichments in IFs that are the result of sorption onto Fe(oxy)hydroxides. However, qualitative trends of Eu anomalies in both rock types reflect the change in concentration of Eu in the Precambrian oceans over time. Our data compilation includes new and published data, screened for sample purity. Notably, all samples used for Eu anomaly evaluation show shale-normalised, seawater-like REE patterns with positive La, Gd, and Y anomalies, as well as a heavy over light REE enrichment. This rules out significant amounts of detrital contamination and post-depositional REY mobility during diagenesis, metamorphism, or weathering that would instead result in non-seawater-like REE signatures (see Methods in the Supplementary Information). Sample details are available in the Supplementary Information.

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Our new compilation of IFs shows consistently positive Eu abundances throughout the Archean, irrespective of IF type (Algoma-type IFs are related to volcaniclastic sequences, whereas Superior-type IFs were deposited on the continental shelf and slope; e.g., Gross, (1965)

Gross, G.A. (1965) Geology of Iron Deposits in Canada, volume III: Iron Ranges of the Labrador Geosyncline. Economic Geology Report 22, Geological Survey of Canada, 162pp.

. Within the Archean, the Eu curve shows an overall decrease from the Eoarchean until ca. 2.8 Ga, followed by a strong positive Eu excess between 2.8 and 2.55 Ga that is larger than in the Eoarchean (Fig. 1). High Eu anomalies in the Eoarchean are related to a hotter upper mantle resulting from the combination of residual accretionary heat and a higher abundance of radioactive elements (Korenaga, 2008

Korenaga, J. (2008) Urey ratio and the structure and evolution of Earth’s mantle. Reviews of Geophysics 46, RG2007. https://doi.org/10.1029/2007RG000241

). At ca. 3.8 Ga, average Eu anomalies in the Isua supracrustal belt (Greenland) are more positive than those observed in Nuvvuagittuq greenstone belt (Canada), maybe due to variable upper mantle temperatures that led to local Eu enrichments and depletions in seawater at that time. The decrease in Eu anomalies from the Eoarchean until 2.8 Ga (∼80 %) is interpreted to reflect overall decreasing upper mantle temperatures and, therefore, a decreasing impact of high temperature hydrothermal systems on ocean chemistry.

A strong Eu_CN/Eu_CN* peak, on average ca. 20 % higher than initial Eoarchean values, occurs in multiple localities between 2.8 and 2.55 Ga. The starting point of this period is locally preserved in the ca. hundred-million-year older Kushtagi Shist Belt of the Dharwar Craton with up to 87 % higher Eu_CN/Eu_CN* values than in the Eoarchean; the termination of this period is recorded in the 2.55 Ga old Nanfen IF with up to 76 % higher Eu_CN/Eu_CN* values. Herzberg et al. (2010)

Herzberg, C., Condie, K., Korenaga, J. (2010) Thermal history of the Earth and its petrological expression. Earth and Planetary Science Letters 292, 79–88. https://doi.org/10.1016/j.epsl.2010.01.022

estimated upper mantle temperatures of ca. 1500 to 1600 °C between 3.0 and 2.5 Ga derived from non-arc basalts. Interestingly, the Eu_CN anomalies of Archean seawater mirror the estimated upper mantle temperature evolution (Herzberg et al., 2010

Herzberg, C., Condie, K., Korenaga, J. (2010) Thermal history of the Earth and its petrological expression. Earth and Planetary Science Letters 292, 79–88. https://doi.org/10.1016/j.epsl.2010.01.022

; Fig. 1). Their data show a progressive decrease from >1600 °C to <1550 °C between 3.4 and 2.8 Ga, followed by a return to almost 1650 °C between 2.8 and 2.5 Ga (Fig. 1). If this comparison is valid, Eu_CN systematics in IFs are a promising proxy to estimate upper mantle temperatures. Conversely, our data identify a strong linkage between solid Earth processes and global ocean chemistry.

Positive Eu_CN anomalies in IFs nearly disappear from the rock record by the onset of atmospheric oxidation at ca. 2.4 Ga, known as the Great Oxidation Event (GOE). From this point onwards, Eu_CN/Eu_CN* values are below unity and cluster around the value of modern seawater, suggesting insignificant impact of high temperature hydrothermal systems on the deep marine chemistry of REE and other particle-reactive elements. There are two possible reasons for this drop. First, mantle temperatures and resultant hydrothermal activity may have declined asymptotically (e.g., Labrosse and Jaupart, 2007

Labrosse, S., Jaupart, C. (2007) Thermal evolution of the Earth: Secular changes and fluctuations of plate characteristics. Earth and Planetary Science Letters 260, 465–481. https://doi.org/10.1016/j.epsl.2007.05.046

), so that Eu signals from hydrothermal vents became too dilute in the global ocean to leave a trace in IF. Second, travel distances of water masses carrying a hydrothermal signature declined due to the penetration of O₂ into the water column (Poulton and Canfield, 2011

Poulton, S.W., Canfeld, D.E. (2011) Ferruginous conditions: A dominant feature of the ocean through Earth’s history. Elements 7, 107–112. https://doi.org/10.2113/gselements.7.2.107

) that led to the formation of Fe- and Mn(oxy)hydroxides and scavenging of REE deeper in the oceans and a lower residence time of REE. Both scenarios, or a combination thereof, would have led to an almost complete dilution of Eu_CN anomalies in Proterozoic IFs. Periodic, local peaks in Eu_CN anomalies at 2.2 Ga and around 1.9 Ga indicate a temporary return to intense magmatic activity and higher upper mantle temperature that led to elevated REE fluxes into seawater via high temperature hydrothermal systems. Notably, these Proterozoic Eu_CN excess events and the broad Eu_CN anomaly peak between 2.8 and 2.6 Ga overlap with proposed mantle overturn events tied to supercontinent aggregation (Bédard, 2018

Bédard, J.H. (2018) Stagnant lids and mantle overturns: Implications for Archaean tectonics, magmagenesis, crustal growth, mantle evolution, and the start of plate tectonics. Geoscience Frontiers 9, 19–49. https://doi.org/10.1016/j.gsf.2017.01.005

), which are also thought to have triggered widespread IF deposition (Isley and Abbott, 1999

Isley, A.E., Abbott, D.H. (1999) Plume-related mafic volcanism and the deposition of banded iron formation. Journal of Geophysical Research: Solid Earth 104, 15461–15477. https://doi.org/10.1029/1999JB900066

). Other Proterozoic thermal peaks around 1.0 and 0.6 Ga ago (cf. Arndt, 2013

Arndt, N. (2013) Formation and Evolution of the Continental Crust. Geochemical Perspectives 2, 405–533. https://doi.org/10.7185/geochempersp.2.3

) are not recorded in IFs, probably related to the above-mentioned scenarios leading to lower REE residence times and/or IF preservation bias due to their scarcity in the Proterozoic record. Importantly, Neoproterozoic IFs show no evidence for contributions from high temperature hydrothermal systems due to widespread and deeper ocean ventilation (Baldwin et al., 2012

Baldwin, G.J., Turner, E.C., Kamber, B.S., Colpron, M. (2012) A new depositional model for glaciogenic Neoproterozoic iron formation: insights from the chemostratigraphy and basin configuration of the Rapitan iron formation. Canadian Journal of Earth Sciences 49, 455–476. https://doi.org/10.1139/e11-066

), leading to rapid REE scavenging and shorter residence times of REE in the global ocean. By this point, residence times of REE were perhaps within a few hundred years, comparable to those of modern oceans.

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Impact of High Temperature Hydrothermal Fluids on Shallow Marine Precambrian Microbial Habitats

Marine stromatolitic carbonates are mostly preserved as lime- or dolostones in worldwide occurring Precambrian stratigraphies and provide, independent of their mineralogy, a local snapshot into near shore microbial habitats within the photic zone. Eu_CN anomalies in such archives suggest that high temperature hydrothermal systems impacted these environments, which may potentially have influenced the evolution of phototrophic organisms commencing at ∼3.5 Ga (Fournier et al., 2021

Fournier, G.P., Moore, K.R., Rangel, L.T., Payette, J.G., Momper, L., Bosak, T. (2021) The Archean origin of oxygenic photosynthesis and extant cyanobacterial lineages. Proceedings of the Royal Society B: Biological Sciences 288, 20210675. https://doi.org/10.1098/rspb.2021.0675

). The largest Eu_CN anomalies are preserved in the oldest stromatolitic carbonates from the Pilbara Craton, suggesting the strongest impact of hydrothermal influx on local seawater chemistry in these habitats (Fig. 2; Van Kranendonk et al., 2019

Van Kranendonk, M.J., Djokic, T., Poole, G., Tadbiri, S., Steller, L., Baumgartner, R. (2019) Depositional setting of the fossiliferous, c. 3480 Ma Dresser Formation, Pilbara Craton: A review. In: Van Kranendonk, M.J., Bennett, V., Hoffmann, E. (Eds.) Earth’s Oldest Rocks. Second Edition, Elsevier, Cambridge, 985–1006. https://doi.org/10.1016/B978-0-444-63901-1.00040-X

).

Positive Eu_CN anomalies are also observed in some Meso- and Neoarchean stromatolites, reflecting locally or temporarily enhanced hydrothermal input to these sites. However, many Archean stromatolite locations lack positive Eu_CN anomalies, indicating that hydrothermally-derived REE from high temperature systems, as captured by IF, were efficiently scavenged in deeper marine settings or diluted by continentally derived solutes. Hence, hydrothermal REE fluxes may not always have reached near shore, shallow marine microbial habitats during the Archean. Overall, maximum Eu_CN anomalies decrease over time across the Archean, but there is no distinct enrichment between 2.8 and 2.55 Ga as recorded in the IF data, suggesting that hydrothermal fluids during this intense magmatic period had no impact on the REE budget of Neoarchean near shore, shallow marine environments.

Interestingly, the unfiltered stromatolite Eu_CN anomaly curve (Fig. S-3 in the Supplementary Information) shows positive peaks between 2.9 and 2.7 Ga, 2.1 Ga, and 1.9 Ga. Most of these positive Eu anomalies are artificial based on BaO interference on Eu concentration during analyses (see Supplementary Information); the high concentrations of Ba in the carbonates, however, may hint at temporal increased Ba-rich fluxes from hydrothermal systems into seawater. Although Eu_CN anomalies are present in some Archean stromatolites, the impact of high temperature hydrothermal systems on seawater chemistry in stromatolite-forming microbial habitats was only locally elevated. Similarly, positive Eu_CN anomalies in the Neoproterozoic are almost entirely absent in the IF record except for a few stromatolites from the Taoudeni Basin. Thus, microbial life thriving in habitats without influx from hydrothermal systems had to adapt to element delivery from different sources, such as continental solutes. This is supported by the complete absence of Eu_CN anomalies in half of the Archean stromatolite localities, providing evidence that microbial life in photic zones of near shore environments was probably not dependent on element fluxes of REE and other elements with comparable residence times from high temperature systems, but instead was reliant on solutions derived from weathering and erosion processes of already emerged landmasses.

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Significance of Bio-Essential Elements Delivered From High Temperature Systems Into Archean Oceans

Armed with a new constraint on the influence of high temperature hydrothermal vents on seawater chemistry through the Precambrian, we independently explored in a first order model the implications of hydrothermal activity for bio-essential elements, such as Mn, Co, Ni, Cu, and Zn that are enriched in hydrothermal fluids compared to seawater and river waters (Von Damm, 1995

Von Damm, K.L. (1995) Temporal and compositional diversity in seafloor hydrothermal fluids. Reviews of Geophysics 33, 1297–1305. https://doi.org/10.1029/95RG00283

). To constrain the hydrothermal flux of each of these elements, we mixed a black smoker fluid with modern and Archean seawater, respectively, using a thermodynamic model (see Supplementary Information for details). The final amount of the respective element in solution, after precipitation of hydrothermal precipitates, was multiplied by the hydrothermal water flux. To be conservative, we assumed that the hydrothermal flux was the same as today, but as shown by the Eu data, the flux may have been much higher during parts of the Archean. The riverine element flux was calculated from the river water flux multiplied by average elemental concentrations in modern and Archean river water. The results suggest that, even without additional enhancement above modern levels, hydrothermal vents would have been the dominant sources of Mn, Cu, and Zn to the Archean ocean (Fig. 3). If the river water flux was smaller due to smaller landmasses while hydrothermal water fluxes were elevated, as suggested by the Eu_CN data for extended times during the Archean (Fig. 1), also the input of Ni would likely have been dominated by hydrothermal sources.

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Today, rivers constitute the major sources of all of these dissolved elements to the ocean (Fig. 3). The first evidence of continental weathering affecting seawater chemistry is reported at ca. 3.2 Ga ago (Satkoski et al., 2016

Satkoski, A.M., Lowe, D.R., Beard, B.L., Coleman, M.L., Johnson, C.M. (2016) A high continental weathering flux into Paleoarchean seawater revealed by strontium isotope analysis of 3.26 Ga barite. Earth and Planetary Science Letters 454, 28–35. https://doi.org/10.1016/j.epsl.2016.08.032

), and it became widespread in the Neoarchean at around 2.7–2.6 Ga ago (Viehmann et al., 2014

Viehmann, S., Hoffmann, J.E., Münker, C., Bau, M. (2014) Decoupled Hf-Nd isotopes in Neoarchean seawater reveal weathering of emerged continents. Geology 42, 115–118. https://doi.org/10.1130/G35014.1

, 2018

Viehmann, S., Bau, M., Hoffmann, J.E., Münker, C. (2018) Decoupled Hf and Nd isotopes in suspended particles and in the dissolved load of Late Archean seawater. Chemical Geology 483, 111–118. https://doi.org/10.1016/j.chemgeo.2018.01.017

). We, therefore, speculate that the transition to riverine dominance in nutrient fluxes dates back to the early Proterozoic, when continental land masses were likely well established while the hydrothermal influence waned (Fig. 1). Life in the Neoarchean, in the lead-up to the Great Oxidation Event, may have benefitted from a combination of elevated hydrothermal activity (Fig. 1) and increasing continental weathering (Viehmann et al., 2014

Viehmann, S., Hoffmann, J.E., Münker, C., Bau, M. (2014) Decoupled Hf-Nd isotopes in Neoarchean seawater reveal weathering of emerged continents. Geology 42, 115–118. https://doi.org/10.1130/G35014.1

, 2018

Viehmann, S., Bau, M., Hoffmann, J.E., Münker, C. (2018) Decoupled Hf and Nd isotopes in suspended particles and in the dissolved load of Late Archean seawater. Chemical Geology 483, 111–118. https://doi.org/10.1016/j.chemgeo.2018.01.017

). In conclusion, our data suggest that the fluxes of hydrothermally sourced bio-essential elements into the Archean oceans were most potent in the Eoarchean, around the time of life’s origins, and again in the Neoarchean when nutrient fluxes drove cyanobacterial diversification and niche expansion (Fournier et al., 2021

Fournier, G.P., Moore, K.R., Rangel, L.T., Payette, J.G., Momper, L., Bosak, T. (2021) The Archean origin of oxygenic photosynthesis and extant cyanobacterial lineages. Proceedings of the Royal Society B: Biological Sciences 288, 20210675. https://doi.org/10.1098/rspb.2021.0675

). It is, therefore, conceivable that elevated mantle temperatures and resulting hydrothermal fluid flow indirectly drove biological activity and innovation by modulating nutrient supplies.

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Acknowledgements

We acknowledge the editorial handling of Tanja Bosak and the comments of two anonymous reviewers that improved the manuscript. SV and JK acknowledge funding from the FWF for project P34238. SVH acknowledges funding from NSFC (grant no. 42150610481 – The “Stromatolite Geochemical Archive”). EES acknowledges funding from a NERC Frontiers grant (NE/V010824/1) and from a Leverhulme Trust research grant (RPG-2022-313).

Editor: Tanja Bosak

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References

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Supplementary Information

The Supplementary Information includes:

• Samples and Geological Overview
• Analytical Methods, Eu Anomaly Calculation, Sample Screening for Eu_CN Seawater Curves, and Description of the Flux Model for Bio-essential Elements
• Supplementary Figures S-1 to S-6
• Supplementary Tables S-1 and S-2
• Supplementary Information References

Download the Supplementary Information (PDF)

Download Table S-1 (.xlsx)

Download Table S-2 (.xlsx)