Plume magmatism and continental breakup led to the opening of the northeast Atlantic Ocean during the globally warm early Cenozoic. This warmth culminated in a transient (170 thousand year, kyr) hyperthermal event associated with a large, if poorly constrained, emission of carbon called the Palaeocene–Eocene Thermal Maximum (PETM) 56 million years ago (Ma). Methane from hydrothermal vents in the coeval North Atlantic Igneous Province (NAIP) has been proposed as the trigger, though isotopic constraints from deep sea sediments have instead implicated direct volcanic carbon dioxide (CO2) emissions. Here we calculate that background levels of volcanic outgassing from mid-ocean ridges and large igneous provinces yield only one-fifth of the carbon required to trigger the hyperthermal. However, geochemical analyses of volcanic sequences spanning the rift-to-drift phase of the NAIP indicate a sudden ~220 kyr-long intensification of magmatic activity coincident with the PETM. This was likely driven by thinning and enhanced decompression melting of the sub-continental lithospheric mantle, which critically contained a high proportion of carbon-rich metasomatic carbonates. Melting models and coupled tectonic–geochemical simulations indicate that >104 gigatons of subcrustal carbon was mobilized into the ocean and atmosphere sufficiently rapidly to explain the scale and pace of the PETM.
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All data generated or analysed during this study are provided in the online version of this article (Supplementary Data File S1) and in Extended Data Tables 1–6. The map in Fig. 1b was plotted with open source plate tectonic application software GPlates (https://www.gplates.org/; licensed for distribution under a GNU General Public License). Any new geochemical data generated in this study are also available to download via the figshare repository at: https://doi.org/10.6084/m9.figshare.19732948. Source data are provided with this paper.
More details on the computational methods and tools used for this study are available from the corresponding author upon reasonable request.
Storey, M., Duncan, R. A. & Swisher, C. C. Paleocene–Eocene Thermal Maximum and the opening of the northeast Atlantic. Science 316, 587–589 (2007).
Storey, M., Duncan, R. A. & Tegner, C. Timing and duration of volcanism in the North Atlantic Igneous Province: implications for geodynamics and links to the Iceland hotspot. Chem. Geol. 241, 264–281 (2007).
Steinberger, B., Bredow, E., Lebedev, S., Schaeffer, A. & Trond, H. T. Widespread volcanism in the Greenland–North Atlantic region explained by the Iceland plume. Nat. Geosci. 12, 61–68 (2019).
Eldholm, O. & Grue, K. North Atlantic volcanic margins: dimensions and production rates. J. Geophys. Res. 99, 2955–2968 (1994).
Saunders, A. D., Fitton, J. G., Kerr, A. C., Norry M. J. & Kent, R. W. in Large Igneous Provinces Vol. 100 (eds Mahoney, J. J. & Coffin, M. F.) 45–94 (AGU, 1997).
White, R. S. et al. Lower-crustal intrusion on the North Atlantic continental margin. Nature 452, 460–464 (2008).
Mitchell, R. N., Kilian, T. M. & Evans, D. A. D. Supercontinent cycles and the calculation of absolute palaeolongitude in deep time. Nature 482, 208–211 (2012).
Zeebe, R. E. & Lourens, L. J. Solar system chaos and the Paleocene–Eocene boundary age constrained by geology and astronomy. Science 365, 926–929 (2019).
Frieling, J. et al. Extreme warmth and heat-stressed plankton in the tropics during the Paleocene–Eocene Thermal Maximum. Sci. Adv. 3, e1600891 (2017).
Zachos, J. C., Dickens, G. R. & Zeebe, R. E. An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics. Nature 451, 279–283 (2008).
Gutjahr, M. et al. Very large release of mostly volcanic carbon during the Palaeocene–Eocene Thermal Maximum. Nature 548, 573–577 (2017).
Röhl, U., Westerhold, T., Bralower, T. J. & Zachos, J. C. On the duration of the Paleocene–Eocene Thermal Maximum (PETM). Geochem. Geophys. Geosyst. 8, Q12002 (2007).
Haynes, L. L. & Hönisch, B. The seawater carbon inventory at the Paleocene–Eocene Thermal Maximum. Proc. Natl Acad. Sci. USA 117, 24088–24095 (2020).
Dickens, G. R., O’Neil, J. R., Rea, D. K. & Owen, R. M. Dissociation of oceanic methane hydrate as a cause of the carbon isotope excursion at the end of the Paleocene. Paleoceanography 10, 965–971 (1995).
Svensen, H. et al. Release of methane from a volcanic basin as a mechanism for initial Eocene global warming. Nature 429, 542–545 (2004).
Jones, S. M., Hoggett, M., Greene, S. E. & Dunkley Jones, T. Large igneous province thermogenic greenhouse gas flux could have initiated Paleocene–Eocene Thermal Maximum climate change. Nat. Commun. 10, 5547 (2019).
Self, S., Thordarson, T. & Widdowson, M. Gas fluxes from flood basalt eruptions. Elements 1, 283–287 (2005).
Chavrit, D., Humler, E. & Grasset, O. Mapping modern CO2 fluxes and mantle carbon content all along the mid-ocean ridge system. Earth Planet. Sci. Lett. 387, 229–239 (2014).
Morton, A. C. & Keene, J. B. in Initial Reports DSDP Vol. 81 (eds Roberts, D. G. et al.) Ch. 19 (US Government Printing Office, 1984).
Brown, S. & Downie, C. in Initial Reports DSDP Vol. 81 (eds Roberts, D. G. et al.) Ch. 13 (US Government Printing Office, 1984).
Sluijs, A. et al. Subtropical Arctic Ocean temperature during the Palaeocene/Eocene thermal maximum. Nature 441, 610–613 (2006).
Backman, J. et al. in Initial Reports DSDP Vol. 81 (eds Roberts, D.G. et al.) Ch. 38 (US Government Printing Office, 1984).
Larsen, L. M., Fitton, J. G. & Pedersen, A. K. Paleogene volcanic ash layers in the Danish Basin: compositions and source areas in the North Atlantic Igneous Province. Lithos 71, 47–80 (2003).
Fitton, J. G., Larsen, L. M., Saunders, A. D., Hardarson, B. S. & Kempton, P. D. Palaeogene continental to oceanic magmatism on the SE Greenland continental margin at 63 °N: a review of the results of Ocean Drilling Program Legs 152 and 163. J. Petrol. 41, 951–966 (2000).
Stokke, E. W., Jones, M. T., Tierney, J. E., Svensen, H. H. & Whiteside, J. H. Temperature changes across the Paleocene–Eocene Thermal Maximum—a new high-resolution TEX86 temperature record from the Eastern North Sea Basin. Earth Planet. Sci. Lett. 544, 116388 (2020).
Larsen, L. M., Waagstein, R., Pedersen, A. K. & Storey, M. Trans-Atlantic correlation of the Palaeogene volcanic successions in the Faeroe Islands and East Greenland. J. Geol. Soc. London 156, 1081–1095 (1999).
Gariépy, C., Ludden, J. & Brooks, C. Isotopic and trace element constraints on the genesis of the Faeroe lava pile. Earth Planet. Sci. Lett. 63, 257–272 (1983).
Hansen, J., Davidson, J., Jerram, D., Ottley, C. & Widdowson, M. Contrasting TiO2 compositions in early Cenozoic mafic sills of the Faroe Islands: an example of basalt formation from distinct melting regimes. Earth Sci. 8, 235–267 (2019).
Millett, J. M., Hole, M. J., Jolley, D. W., Passey, S. R. & Rossetti, L. Transient mantle cooling linked to regional volcanic shut-down and early rifting in the North Atlantic Igneous Province. Bull. Volcanol. 82, 61 (2020).
Jolley, D. W., Millett, J. M., Schofield, N., Broadley, L. & Hole, M. J. Stratigraphy of volcanic rock successions of the North Atlantic rifted margin: the offshore record of the Faroe–Shetland and Rockall basins. Earth Environ. Sci. Trans. R. Soc. Edinburgh 112, 61–88 (2021).
Holm, P. M., Hald, N. & Waagstein, R. Geochemical and Pb–Sr–Nd isotopic evidence for separate hot depleted and Iceland plume mantle sources for the Paleogene basalts of the Faroe Islands. Chem. Geol. 178, 95–125 (2001).
Schilling, J.-G. & Noe-Nygaard, A. Faeroe–Iceland plume: rare-earth evidence. Earth Planet. Sci. Lett. 24, 1–14 (1974).
Jourdan, F. et al. Major and trace element and Sr, Nd, Hf, and Pb isotope compositions of the Karoo Large Igneous Province, Botswana–Zimbabwe: lithosphere vs mantle plume contribution. J. Petrol. 48, 1043–1077 (2007).
Aulbach, S., Sun, J., Tappe, S., E Höfer, H. & Gerdes, A. Volatile-rich metasomatism in the cratonic mantle beneath SW Greenland: link to kimberlites and mid-lithospheric discontinuities. J. Petrol. 58, 2311–2338 (2018).
Bastow, I. D. & Keir, D. The protracted development of the continent–ocean transition in Afar. Nat. Geosci. 4, 248–250 (2011).
Thirlwall, M. F., Upton, B. G. J. & Jenkins, C. Interaction between continental lithosphere and the Iceland Plume—Sr–Nd–Pb isotope geochemistry of tertiary basalts, NE Greenland. J. Petrol. 35, 839–879 (1994).
Nøhr-Hansen, H. Palynostratigraphy of the Cretaceous–lower Palaeogene sedimentary succession in the Kangerlussuaq Basin, southern East Greenland. Rev. Palaeobot. Palynol. 178, 59–90 (2012).
Holm, P. M. Nd, Sr and Pb isotope geochemistry of the Lower Lavas, E Greenland Tertiary Igneous Province.Geol. Soc. Spec. Publ. 39, 181 (1988).
Muirhead, J. D. et al. Displaced cratonic mantle concentrates deep carbon during continental rifting. Nature 582, 67–72 (2020).
Foley, S. F. Rejuvenation and erosion of the cratonic lithosphere. Nat. Geosci. 1, 503–510 (2008).
Foley, S. F. & Fischer, T. P. An essential role for continental rifts and lithosphere in the deep carbon cycle. Nat. Geosci. 10, 897–902 (2017).
Sobolev, S. V. et al. Linking mantle plumes, large igneous provinces and environmental catastrophes. Nature 477, 312–316 (2011).
Gorczyk, W. & Gonzalez, C. M. CO2 degassing and melting of metasomatized mantle lithosphere during rifting—numerical study. Geosci. Front. 10, 1409–1420 (2019).
Darbyshire, F. A. et al. A first detailed look at the Greenland lithosphere and upper mantle, using Rayleigh wave tomography. Geophys. J. Int. 158, 267–286 (2004).
Nielsen, T. F. D. Tertiary alkaline magmatism in East Greenland: a review. Geol. Soc. Spec. Publ. 30, 489 (1987).
Guimarães, A. R., Fitton, J. G., Kirstein, L. A. & Barfod, D. N. Contemporaneous intraplate magmatism on conjugate South Atlantic margins: a hotspot conundrum. Earth Planet. Sci. Lett. 536, 116147 (2020).
Currie, C. A. & van Wijk, J. How craton margins are preserved: insights from geodynamic models. J. Geodyn. 100, 144–158 (2016).
King, S. D. & Anderson, D. L. Edge-driven convection. Earth Planet. Sci. Lett. 160, 289–296 (1998).
Debaille, V. et al. Primitive off-rift basalts from Iceland and Jan Mayen: Os-isotopic evidence for a mantle source containing enriched subcontinental lithosphere. Geochim. Cosmochim. Acta 73, 3423–3449 (2009).
Torsvik, T. H. et al. Continental crust beneath southeast Iceland. Proc. Natl Acad. Sci. USA 112, E1818 (2015).
Hanan, B. B. & Schilling, J. G. The dynamic evolution of the Iceland mantle plume: the lead isotope perspective. Earth Planet. Sci. Lett. 151, 43–60 (1997).
Lee, H. et al. Massive and prolonged deep carbon emissions associated with continental rifting. Nat. Geosci. 9, 145–149 (2016).
Wieczorek, R., Fantle, M. S., Kump, L. R. & Ravizza, G. Geochemical evidence for volcanic activity prior to and enhanced terrestrial weathering during the Paleocene Eocene Thermal Maximum. Geochim. Cosmochim. Acta 119, 391–410 (2013).
Reynolds, P. et al. Hydrothermal vent complexes offshore Northeast Greenland: a potential role in driving the PETM. Earth Planet. Sci. Lett. 467, 72–78 (2017).
Westerhold, T. et al. An astronomically dated record of Earth’s climate and its predictability over the last 66 million years. Science 369, 1383–1387 (2020).
Boynton, W. V. and Henderson, P. in Cosmochemistry of the Rare Earth Elements: Meteorite Studies Vol. 2. Ch. 3 (Elsevier, 1984).
Müller, R. D. et al. Ocean basin evolution and global-scale plate reorganization events since Pangea breakup. Ann. Rev. Earth Planet. Sci. 44, 107–138 (2016).
Karlsen, K. S., Conrad, C. P. & Magni, V. Deep water cycling and sea level change since the breakup of Pangea. Geochem. Geophys. Geosyst. 20, 2919–2935 (2019).
Karlsen, K. S., Domeier, M., Gaina, C. & Conrad, C. P. A tracer-based algorithm for automatic generation of seafloor age grids from plate tectonic reconstructions. Comput. Geosci. 140, 104508 (2020).
Merdith, A. S., Atkins, S. E. & Tetley, M. G. Tectonic controls on carbon and serpentinite storage in subducted upper oceanic lithosphere for the past 320 Ma. Front. Earth Sci. 7, 332 (2019).
Merdith, A. S. et al. Pulsated global hydrogen and methane flux at mid-ocean ridges driven by Pangea breakup. Geochem. Geophys. Geosyst. 21, e2019GC008869 (2020).
Fitton, J., Saunders, A., Larsen, L., Hardarson, B. & Norry, M. Volcanic rocks from the southeast Greenland Margin at 63 °N: composition, petrogenesis, and mantle sources. Proc. Ocean Drill. Prog. Sci. Results 152, 331–350 (1998).
Fitton, J. G. & Godard, M. Origin and evolution of magmas on the Ontong Java Plateau. Geol. Soc. Spec. Publ. 229, 151–178 (2004).
Norrish, K. & Hutton, J. T. An accurate X-ray spectrographic method for the analysis of a wide range of geological samples. Geochim. Cosmochim. Acta 33, 431–453 (1969).
Reynolds, R. C. Matrix corrections in trace element analysis by X-ray fluorescence: estimation of the mass absorption coefficient by Compton scattering. Am. Mineral. 48, 1133–1143 (1963).
Govindaraju, K. 1994 compilation of working values and sample description for 383 geostandards. Geostand. Newsl. 18, 1–158 (1994).
Jochum, K. P., Seufert, H. M. & Thirlwall, M. F. High-sensitivity Nb analysis by spark-source mass spectrometry (SSMS) and calibration of XRF Nb and Zr. Chem. Geol. 81, 1–16 (1990).
Imai, N., Terashima, S., Itoh, S. & Ando, A. 1994 compilation of analytical data for minor and trace elements in seventeen GSJ geochemical reference samples, “igneous rock series”. Geostand. Newsl. 19, 135–213 (1995).
Murton, B. J., Taylor, R. N. & Thirlwall, M. F. Plume–ridge interaction: a geochemical perspective from the Reykjanes Ridge. J. Petrol. 43, 1987–2012 (2002).
Tanaka, T. et al. JNdi-1: a neodymium isotopic reference in consistency with LaJolla neodymium. Chem. Geol. 168, 279–281 (2000).
Jacobsen, S. B. & Wasserburg, G. J. Sm–Nd isotopic evolution of chondrites. Earth Planet. Sci. Lett. 50, 139–155 (1980).
Munro, L. E., Longstaffe, F. J. & White, C. D. Effects of heating on the carbon and oxygen-isotope compositions of structural carbonate in bioapatite from modern deer bone. Palaeogeogr. Palaeoclimatol. Palaeoecol. 266, 142–150 (2008).
Macintyre, R. M. & Hamilton, P. J. in Initial Reports DSDP Vol. 81 (eds Roberts, D. G. et al.) Ch. 30 (US Government Printing Office, 1984).
Roberts, D. G., Backman, J. Morton, A. C., Murray, J. W. & Keene, J. B. in Initial Reports DSDP Vol. 81 (eds Roberts, D. G. et al.) Ch. 39 (US Government Printing Office, 1984).
Berggren, W. A., Kent, D. V., Swisher, C. C. & Aubrey, M. P. A revised Cenozoic geochronology and chronostratigraphy. Soc. Sediment. Geol. Spec. Publ. 54, 129–212 (1995).
Lund, J. A late Paleocene non-marine microflora from the interbasaltic coals of the Faeroe Islands, North Atlantic. Bull. Geol. Soc. Denmark 37, 181–203 (1988).
J. G., Ogg. in Geomagnetic Polarity Time Scale. Ch. 5 (Elsevier, 2012).
Hirschmann, M. M., Renne, P. R. & McBirney, A. R. 40Ar/39Ar dating of the Skaergaard intrusion. Earth Planet. Sci. Lett. 146, 645–658 (1997).
Jakobsen, J. K. et al. Parental magma of the Skaergaard intrusion: constraints from melt inclusions in primitive troctolite blocks and FG-1 dykes. Contrib. Mineral. Petrol. 159, 61–79 (2009).
Waagstein, R. Structure, composition and age of the Faeroe basalt plateau. Geol. Soc. Spec. Publ. 39, 225–238 (1988).
Fitton, J. G., Williams, R., Barry, T. L. & Saunders, A. D. The role of lithosphere thickness in the formation of ocean islands and seamounts: contrasts between the Louisville and Emperor–Hawaiian hotspot trails. J. Petrol. 61, egaa111 (2020).
McKenzie, D. & O'Nions, R. K. Partial melt distributions from inversion of rare earth element concentrations. J. Petrol. 32, 1021–1091 (1991).
Baker, M. B. & Stolper, E. M. Determining the composition of high-pressure mantle melts using diamond aggregates. Geochim. Cosmochim. Acta 58, 2811–2827 (1994).
Walter, M. J. Melting of garnet peridotite and the origin of komatiite and depleted lithosphere. J. Petrol. 39, 29–60 (1998).
Hastie, A. R. et al. The composition of mantle plumes and the deep earth. Earth Planet. Sci. Lett. 444, 13–25 (2016).
Hart, S. R. & Dunn, T. Experimental cpx/melt partitioning of 24 trace elements. Contrib. Mineral. Petrol. 113, 1–8 (1993).
Hauri, E. H., Wagner, T. P. & Grove, T. L. Experimental and natural partitioning of Th, U, Pb and other trace elements between garnet, clinopyroxene and basaltic melts. Chem. Geol. 117, 149–166 (1994).
Johnson, K. T. M. Experimental determination of partition coefficients for rare earth and high-field-strength elements between clinopyroxene, garnet, and basaltic melt at high pressures. Contrib. Mineral. Petrol. 133, 60–68 (1998).
McDade, P., Blundy, J. D. & Wood, B. J. Trace element partitioning on the Tinaquillo Lherzolite solidus at 1.5 GPa. Phys. Earth Planet. Int. 139, 129–147 (2003).
Salters, V. J. M., Longhi, J. E. & Bizimis, M. Near mantle solidus trace element partitioning at pressures up to 3.4 GPa. Geochem. Geophys. Geosyst. 3, 1–23 (2002).
Skulski, T., Minarik, W. & Watson, E. B. High-pressure experimental trace-element partitioning between clinopyroxene and basaltic melts. Chem. Geol. 117, 127–147 (1994).
Tuff, J. & Gibson, S. A. Trace-element partitioning between garnet, clinopyroxene and Fe-rich picritic melts at 3 to 7 GPa. Contrib. Mineral. Petrol. 153, 369–387 (2007).
Irving, A. J. A review of experimental studies of crystal/liquid trace element partitioning. Geochim. Cosmochim. Acta 42, 743–770 (1978).
Perfit, M. R. in Encyclopedia of Ocean Sciences 2nd edn (ed. Steele, J. H.) 815–825 (Academic Press, 2001).
Müller, R. D. & Dutkiewicz, A. Oceanic crustal carbon cycle drives 26-million-year atmospheric carbon dioxide periodicities. Sci. Adv. 4, eaaq0500 (2018).
O’Reilly, S. Y. & Griffin, W. L. Imaging global chemical and thermal heterogeneity in the subcontinental lithospheric mantle with garnets and xenoliths: geophysical implications. Tectonophysics 416, 289–309 (2006).
Tappe, S. et al. Craton reactivation on the Labrador Sea margins: 40Ar/39Ar age and Sr–Nd–Hf–Pb isotope constraints from alkaline and carbonatite intrusives. Earth Planet. Sci. Lett. 256, 433–454 (2007).
Tappe, S. et al. Sources and mobility of carbonate melts beneath cratons, with implications for deep carbon cycling, metasomatism and rift initiation. Earth Planet. Scie. Lett. 466, 152–167 (2017).
Harrison, R. K. and Merriman, R. J. in Initial Reports DSDP Vol. 81 (eds Roberts, D. G. et al.) Ch. 29 (US Government Printing Office, 1984).
Gernon, T. M. et al. Complex subvolcanic magma plumbing system of an alkali basaltic maar–diatreme volcano (Elie Ness, Fife, Scotland). Lithos 264, 70–85 (2016).
Le Bas, M. J., Le Maitre, R. W., Streckeisen, A. & Zanettin, B. A chemical classification of volcanic rocks based on the total alkali–silica diagram. J. Petrol. 27, 745–750 (1986).
Chambers, L. M. Age and Duration of the British Tertiary Igneous Province: Implications for the Development of the Ancestral Iceland Plume. PhD thesis, Univ. of Edinburgh (2000).
Brodie, J. A. & Fitton, J. G. Data report: composition of basaltic lavas from the seaward-dipping reflector sequence recovered during Deep Sea Drilling Project Leg 81 (Hatton Bank). Proc. Ocean Drill. Prog. Sci. Res. 152, 431–435 (1998).
Fitton, J. G., Mahoney, J. J., Wallace, P. J. & Saunders, A. D. Origin and evolution of the Ontong Java Plateau: introduction. Geol. Soc. Spec. Publ. 229, 1–8 (2004).
McDonough, W. F. & s. Sun, S. The composition of the Earth. Chem. Geol. 120, 223–253 (1995).
This study was supported by a Natural Environment Research Council (NERC) grant (NE/R004978/1) to T.M.G., which also supported T.K.H. T.M.G. and T.K.H. received funding from The Alan Turing Institute under the EPSRC grant EP/N510129/1. J.L. was supported by NERC grant NE/K00543X/1 awarded to M.R.P. and T.M.G. T.M.G. acknowledges the Distinguished Geologists’ Memorial Fund of the Geological Society of London to sample the Rockall tuffs at the International Ocean Discovery Program (IODP) Bremen Core Repository (BCR). R.N.M. was supported by a National Natural Science Foundation of China grant (41888101) and a Key Research Programme of the Institute of Geology & Geophysics, Chinese Academy of Sciences (CAS), grant (number IGGCAS-201905). A.S.M. was supported by the Deep Carbon Observatory, Richard Lounsbery Foundation and MCSA Fellowship NEOEARTH, project 893615. We are grateful to the staff of the BCR, especially W. Hale, for their assistance, and to M. Cooper, A. Michalik and A. Milton (University of Southampton) for laboratory assistance. We thank G. Hincks for illustrating the Late Palaeocene northeast Atlantic ridge (Fig. 4).
The authors declare no competing interests.
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Extended Data Fig. 1 Schematic stratigraphic log of Palaeocene–Eocene volcanic and sedimentary lithofacies at DSDP Leg 81 Site 555, and the composition of tuff layers.
The corresponding plots show the major-element composition, and Mg#, of tuff layers, shown as horizontal red lines (and labelled by lithology; see also Extended Data Fig. 3a) on the log. The Mg# of a number of basalt lavas and tuffs from Harrison and Merriman99 are also shown as filled grey symbols.
Total alkali-silica (TAS) diagram (after ref. 101) showing the composition of volcanic tuffs of PETM age (approximately 700-600 mbsl; see Extended Data Fig. 2), in addition to Danish ashes of the ‘negative series’23. b, Nb versus Zr of tuffs from Site 555, shown alongside tuffs of the Danish Ash Series23 and Balder Formation in the North Sea102, and lavas from the Rockall/Hatton Bank103. The fields shown for OIB, N-MORB and Iceland rift-zones are from ref. 104. c, Incompatible element patterns of Rockall tuffs from the upper section (700-600 mbsl) normalized to primitive mantle105. The corresponding depths in the core are provided in Extended Data Table 3. For comparison, some Danish ashes (negative series) are also shown23.
Extended Data Fig. 4 Input distributions for sampled variables used in carbon outgassing simulations.
a, Fraction of CO2 present in mid-ocean ridge basalts and those of large igneous provinces (LIPs); b, Fraction of CO2 lost from the ocean crust via degassing at mid-ocean ridges; c, Fraction of CO2 lost from LIP basalt eruptions; d, Thickness of the sub-continental lithospheric mantle (SCLM); e, Width of the SCLM melting zone beneath the mid-ocean ridge system; f, Fraction of CO2 present in the SCLM. Note that the red line denotes the mean. See the Methods for further information on these variables.
143Nd/144Nd and associated εNd measurements of tuffs, lavas and hyaloclastites from DSDP Leg 81 Site 555. The sample ID number includes the site number (555), core box reference (e.g., 65-1), and the depth from the top of a given core (in cm). The 143Nd/144Nd ratios and associated εNd values are corrected to an age of 55 Ma. Also provided are published 143Nd/144Nd and associated εNd measurements from Site 555 lavas73. Errors on discrete measurements are 2 and 1 standard error (SE).
Trace element compositions by ICP-MS of selected PETM-age tuffs from Site 555. The associated recoveries of trace elements from standard reference materials are provided in Supplementary Table 2.
Distribution coefficients (D) used in the construction of Fig. 2e. Note that n = number of individual values of D.
Description of inputs used in modelling of CO2 fluxes from mid-ocean ridges, large igneous provinces (LIPs), and melting of the sub-continental lithospheric mantle (SCLM). See the Methods for further details and model description.
Description of variables used in the carbon flux simulations (Fig. 3) given best estimates of the minimum, maximum and mean for each variable, based on data and observations (see Methods). We fixed the standard deviation, SD = 0.2 x range. See the Methods for further details and model description.
Supplementary Tables 1–2.
143Nd/144Nd and associated ϵNd measurements of tuffs, lavas and hyaloclastites from DSDP Leg 81 Site 555. The sample ID number includes the site number (555), core box reference (for example, 65-1) and the depth from the top of a given core (in cm). The 143Nd/144Nd ratios and associated ϵNd values are corrected to an age of 55 Ma. Also provided are published 143Nd/144Nd and associated ϵNd measurements from Site 555 lavas73. Errors on discrete measurements are 2 and 1 standard error.
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Gernon, T.M., Barr, R., Fitton, J.G. et al. Transient mobilization of subcrustal carbon coincident with Palaeocene–Eocene Thermal Maximum. Nat. Geosci. 15, 573–579 (2022). https://doi.org/10.1038/s41561-022-00967-6