DOI: 10.6084/m9.figshare.30086716.v1
title: Data associated with the paper "Enriched mantle generated through persistent convective erosion of continental roots" (Gernon et al., Nature Geoscience, 2025)

description: <b>Geochemical Data:</b><b>Supplementary Data Table 1</b>: Compilation of radiometric and isotopic data for volcanic rocks from the Christmas Island Seamount Province (CHRISP)<sup>1</sup> and the Investigator Fracture Zone (IFZ)<sup>2</sup>.<b>Supplementary Data Table 2</b>: Compilation of isotope data for volcanic rocks from Kerguelen Plateau, Broken Ridge, St Paul and Amsterdam Island, Ninety East Ridge (refs.<sup>3-8</sup>), and India<sup>9</sup>.<b>Supplementary Data Table 3</b>: Compilation of isotope data for Kerguelen Plateau volcanics (refs.<sup>3,10-15</sup>).<b>Source Data References</b>:K. Hoernle, F. Hauff, R. Werner, P. van den Bogaard, A. D. Gibbons, S. Conrad, and R. D. Mu ̈ller. Origin of Indian Ocean Seamount Province by shallow recycling of continental lithosphere. <i>Nature Geoscience</i>, 4(12):883–887, 2011.A. Dürkefälden, F. Hauff, K. Hoernle, M. Portnyagin, J.-A. Wartho, D. Garbe-Scho ̈nberg, A. Gurenko, P. van den Bogaard, A. Kipf, and M. Gutjahr. Geochemical and temporal evolution of Indian MORB mantle revealed by the Investigator Ridge in the NE Indian Ocean. <i>Gondwana </i><i>Research</i>, 134:347–364, 2024.C. R. Neal, J. J. Mahoney, and W. J. Chazey. Mantle sources and the highly variable role of continental lithosphere in basalt petrogenesis of the Kerguelen Plateau and Broken Ridge LIP: Results from ODP Leg 183. <i>Journal of Petrology</i>, 43(7):1177–1205, 2002.I. G. Nobre Silva, D. Weis, J. S. Scoates, and J. Barling. The Ninetyeast Ridge and its relation to the Kerguelen, Amsterdam and St. Paul hotspots in the Indian Ocean. <i>Journal of Petrology</i>, 54(6):1177–1210, 2013.F. A. Frey and D. Weis. Temporal evolution of the Kerguelen plume: Geochemical evidence from 38 to 82 Ma lavas forming the Ninetyeast Ridge. <i>Contributions to Mineralogy and Petrology</i>, 121(1):12–28, 1995.A.D. Saunders, M. Storey, I. L. Gibson, P. Leat, J. Hergt, and R.N. Thompson. Chemical and isotopic constraints on the origin of basalts from Ninetyeast Ridge, Indian Ocean: results from DSDP Legs 22 and 26 and ODP Leg 121. In J. Weissel, J. Peirce, E. Taylor, and J. Alt et al., editors, <i>ODP, Scientific results, Leg 121, Broken Ridge and Ninetyeast Ridge</i>, volume 121. Proceedings of the Ocean Drilling Program, 1991.F. A. Frey, K. Nicolaysen, B. K. Kubit, D. Weis, and A. Giret. Flood basalt from Mont Tourmente in the Central Kerguelen Archipelago: the change from transitional to alkalic basalt at ∼25 Ma. <i>Journal of Petrology</i>, 43(7):1367–1387, 2002.S. Doucet, D. Weis, J. S Scoates, V. Debaille, and A. Giret. Geochemical and Hf–Pb–Sr–Nd isotopic constraints on the origin of the Amsterdam–St. Paul (Indian Ocean) hotspot basalts. <i>Earth and Planetary Science Letters</i>, 218(1):179–195, 2004.A. Kumar, A. M. Dayal, and V. M. Padmakumari. Kimberlite from Rajmahal magmatic province: Sr-Nd-Pb isotopic evidence for Kerguelen plume derived magmas. <i>Geophysical Research Letters</i>, 30(20):2053, 2003.F.A. Frey, M. F. Coffin, P. J. Wallace, and D. Weis. Leg 183 synthesis: Kerguelen Plateau–Broken Ridge—a large igneous province. In F.A. Frey, M.F. Coffin, P.J. Wallace, and P. G. Quilty, editors, <i>Proceedings of the Ocean Drilling Program, Scientific Results</i>, volume 183, pages 1–48, 2003.S. Ingle, D. Weis, J. S. Scoates, and F. A. Frey. Relationship between the early Kerguelen plume and continental flood basalts of the paleo-Eastern Gondwanan margins. <i>Earth and Planetary Science Letters</i>, 197(1):35–50, 2002.B. Kieffer, N. T. Arndt, and D. Weis. A bimodal alkalic shield volcano on Skiff Bank: its place in the evolution of the Kerguelen Plateau. <i>Journal of Petrology</i>, 43(7):1259–1286, 2002.D. Weis and F. A. Frey. Submarine basalts of the Northern Kerguelen Plateau: Interaction between the Kerguelen plume and the Southeast Indian Ridge revealed at ODP Site 1140. <i>Journal of Petrology</i>, 43(7):1287– 1309, 2002.F. A. Frey, D. Weis, A. Y. Borisova, and G. Xu. Involvement of continental crust in the formation of the Cretaceous Kerguelen Plateau: New perspectives from ODP Leg 120 Sites. <i>Journal of Petrology</i>, 43(7):1207– 1239, 2002.J. J. Mahoney, W. B. Jones, F. A. Frey, V. J. M. Salters, D. G. Pyle, and H. L. Davies. Geochemical characteristics of lavas from Broken Ridge, the Naturaliste Plateau and southernmost Kerguelen Plateau: Cretaceous plateau volcanism in the southeast Indian Ocean. <i>Chemical Geology</i>, 120(3):315–345, 1995.<b>Geodynamic Modelling Data Outputs</b>:<b>Simulated mantle flow velocities. </b>Statistical output showing how maximum velocities vary through the entire model run (see the Methods for details on the thermo-mechanical simulations). These ranges of length-scales and velocities of convective flow were used to estimate times taken for material entrained into these cells beneath the lithospheric discontinuity (shown) to reach the base of the oceanic plate (see Extended Data Fig. 6b of the paper).<b>SCLM flux under different extension rates.</b> Flow rate of decoupled lithospheric material—crossing a transect 200 km from the COB—into the sub-oceanic asthenosphere (SOA) over time, exhibiting pulsing behaviour. Three alternative models are shown: (1) the reference model; (2) symmetric boundary conditions, and (3) fast divergence (20 mm yr<sup>-1</sup>) (see Methods in the paper). See Fig. 3b in the paper and associated text for details. A slow divergence scenario is also considered (see "<i>SCLM flux under slow extension</i>", below).<b>SCLM flux under slow extension</b>. Flow rate of decoupled lithospheric material crossing a transect 200 km inboard of the COB into the sub-oceanic asthenosphere (SOA) over time, using a slow extension rate of 5 mm yr<sup>-1</sup> (see Extended Data Fig. 3a of the paper).<br><br><br>