Professor Emeritus
david.graham@oregonstate.edu

Office: 541-737-4140

Burt Hall

Burt Hall 255

2651 SW Orchard Avenue

2651 SW Orchard Avenue
Corvallis, OR 97331

Profile Field Tabs

At OSU
Brief Research Interests: 

Helium isotope and rare gas geochemistry
Trace element chemistry of mid-ocean ridge and ocean island basalts

Location: 
Building: 

Research Interests

Noble Gas Geochemistry

Isotope and Trace Element Chemistry of Volcanic Rocks from Mid-Ocean Ridges, Islands, and Continental Rifts

Mantle Heterogeneity

The Effects of Volatiles in Petrogenesis

Current Research

Spatial Variations in Helium Isotopes Along Mid-Ocean Ridges

Carbon and Helium Isotope Variations in Earth's Mantle

Education

B.S., Florida Institute of Technology (Oceanography) 1975
M.S., University of Rhode Island (Oceanography) 1980
Ph.D., MIT-Woods Hole Oceanographic Institution (Oceanography) 1987

Graduate Students

Attilio Giacobbe           M.S.   UCSB, 1993

Louise Douglas           M.S.   Marine Geology & Geophysics, 1998

Brennan Jordan          Ph.D.  Geosciences, 2001

Chris Russo                M.S.    Geosciences, 2001

                                    Ph.D.  MG&G, 2007

Charlotte Goddard      Ph.D.  MG&G, 2008

Kevin Konrad              M.S.   Geology, 2012

                                   Ph.D.  Geology, 2017

Publications

Peer-Reviewed Papers

Graham DW, PJ Michael, TB Truong (2023) Carbon isotope composition of basalts from Loihi Seamount:  Primordial or recycled carbon in the Hawaiian mantle plume? Earth Planet. Sci. Lett.  617, 118248. doi: 10.1016/j.epsl.2023.118248

Pitcavage E, T Furman, WR Nelson, DW Graham, S Shirey. PK Kulyanyingi, E Barifaijo (2023)  Geochemical constraints on the origin of primitive potassic lavas in the eastern Virunga Volcanic Province. Geochem. Geophys. Geosys. doi: 10.1029/2023GC010950

Graham DW, K Konrad (2022) Supernova versus cosmic ray origin for exotic nuclides in geomaterials: A test using 3He with 60Fe in marine sediments. Geochim. Cosmochim. Acta 336, 177-187. doi: 10.1016/j.gca.2022.09.016

Péron S, S Mukhopadhyay, MD Kurz, DW Graham (2021). Deep-mantle krypton reveals Earth’s early accretion of carbonaceous matter. Nature 600, 462-481. doi: 10.1038/s41586-021-04092-z

Graham DW, PJ Michael (2021). Predominantly recycled carbon in Earth's upper mantle revealed by He-CO2-Ba systematics in ultradepleted ocean ridge basalts. Earth Planet. Sci. Lett. 554, 116646. doi: 10.1016/j.epsl.2020.116646

Rowe MC, DW Graham, E Smid, L McGee (2020) Unusually homogeneous helium isotope composition of the Auckland Volcanic Field and implications for the underlying mantle. Chem. Geol. 545, 119639. doi: 10.1016/j.chemgeo.2020.119639

Fields BD, JR Ellis, WR Binns, D Breitschwerdt, GA de Nolfo, R Diehl, VVDwarkadas, A Ertel, T Faestermann, J  Feige, C Fitoussi, P Frisch, D Graham, B Haley, AHeger, W Hillebrandt, MH Israel, T Janka, M Kachelriess, G Korschinek, M Limongi, M Lugaro, F Marinho, A Melott, RA Mewaldt, J Miller, RC Ogliore, M Paul, L Paulucci, M Pecaut, BF Rauch, KE Rehm, M Schulreich, I Seitenzahl, M Sorensen, F-K Thielemann, FX Timmes, BC Thomas, A Wallner (2019). Near-Earth Supernova Explosions: Evidence, Implications, and Opportunities. The 2020 Decadal Survey on Astronomy and Astrophysics, U.S. National Academies of Sciences, Engineering, and Medicine, Committee on Astronomy and Astrophysics. arXiv:1903.04589v1 [astro-ph.SR] 11 Mar 2019. doi: arxiv.org/abs/1903.04589

Sibrant ALR, M Maia, E Mittelstaedt, DW Graham (2019) Variable crustal production originating from mantle source heterogeneity beneath the South East Indian Ridge and Amsterdam-St. Paul Plateau. Geochem. Geophys. Geosys. doi: 10.1029/2019GC008419

Nelson WR, BB Hanan, DW Graham, SB Shirey, G Yirgu, D Ayalew, T Furman (2019) Distinguishing plume and metasomatized lithospheric mantle contributions to post-flood basalt volcanism on the southeastern Ethiopian Plateau. J. Petrol. doi: 10.1093/petrology/egz024

Broadley MW, H Sumino, DW Graham, R Burgess, CJ Ballentine (2019) Recycled components in mantle plumes deduced from variations in halogens (Cl, Br, I), trace elements and 3He/4He along the Hawaiian-Emperor Seamount chain. Geochem. Geophys. Geosys. doi: 10.1029/2018GC007959

Loewen MW, DW Graham, IN Bindeman,  JE Lupton,  MO Garcia (2019) Hydrogen isotopes in high 3He/4He submarine basalts: Primordial vs. recycled water and the veil of mantle enrichment. Earth Planet. Sci. Lett. 508, 62-73. doi: 10.1016/j.epsl.2018.12.012

Graham DW, PJ Michael, KH Rubin (2018) Variations in magmatic He, CO2 and δ13C during a mid-ocean ridge eruption at 9°50'N on the East Pacific Rise. Earth Planet. Sci. Lett. 504. 84-93. doi: 10.1016/j.epsl.2018.09.040

Konrad K, DW Graham, AJR Kent, A Koppers (2018) Spatial and temporal variability in Marquesas Islands volcanism revealed by 3He/4He and the composition of olivine-hosted melt inclusions. Chem. Geol. 477, 161-176. doi: 10.1016/j.chemgeo.2017.12.025

Graham DW, PJ Michael, T Shea (2016) Extreme incompatibility of helium during mantle melting: evidence from undegassed mid-ocean ridge basalts. Earth Planet. Sci. Lett. 454, 192-202. doi: 10.1016/j.epsl.2016.09.016

Konrad K, DW Graham, CR Thornber, RA Duncan, AJR Kent, A Al-Amri (2016) Interaction of asthenospheric melts and lithospheric mantle beneath western Saudi Arabia: inferences from 3He/4He and CO2 in xenoliths and lavas from Harrat Hutaymah. Lithos 248-251, 339-352. doi: 10.1016/j.lithos.2016.01.031

Michael PJ, DW Graham (2015) The behavior and concentration of CO2 in the suboceanic mantle: inferences from undegassed ocean ridge and ocean island basalts. Lithos 236-237, 338-351. doi: 10.1016/j.lithos.2015.08.020

Sgualdo P, K Aviado, L Beccaluva, G Bianchini, J Blichert-Toft, JG Bryce, DW Graham, C Natali, F Siena (2015) Lithospheric mantle evolution in the Afro-Arabian domain: insights from Bir Ali mantle xenoliths (Yemen). Tectonophysics. doi: 10.1016/j.tecto.2014.11.025

Graham DW, BB Hanan, C Hémond, J Blichert-Toft, F Albarède (2014) Helium isotopic textures in Earth’s upper mantle. Geochem. Geophys. Geosys. 15, 2048-2074. doi: 10.1002/2014GC005264

Graham DW, BB Hanan, JE Lupton, K Hoernle, R Werner, DM Christie, JM Sinton  (2014) Helium isotope variations and mantle plume – spreading ridge interactions along the Galápagos Spreading Center. Geophysical Monograph 204. The Galápagos: A Natural Laboratory for the Earth Sciences. Eds. KS Harpp, E Mittelstaedt, N d’Ozouville, DW Graham, pp. 393-414. doi: 10.1002/9781118852538.ch18

Hanan BB, J Blichert-Toft, C Hemond,  K Sayit, A Agranier,  DW Graham, F Albarède (2013) Pb and Hf Isotope Variations along the Southeast Indian Ridge and the Dynamic Distribution of MORB Source Domains in the  Upper Mantle. Earth Planet. Sci. Lett. 375, 196-208. doi: 10.1016/j.epsl.2013.05.028

Lupton JE, RJ Arculus, LJ Evans, DW Graham (2012) Mantle hotspot neon in basalts from the Northwest Lau Back-arc Basin. Geophys. Res. Lett. 39, L08308, doi: 10.1029/2012GL051201

Rooney TO, BB Hanan, DW Graham, TH Furman, J Blichert-Toft, J-G Schilling (2012) Upper mantle pollution during Afar plume-continental rift interaction. J. Petrol. 53, 365-389. doi: 10.1093/petrology/egr065

Colin A, PG Burnard, DW Graham, Y Marocchi (2011) Plume-ridge interaction along the Galapagos Spreading Center: discerning between gas loss and source effects using neon isotopic compositions and 4He-40Ar*-CO2 relative abundances. Geochim. Cosmochim. Acta 75, 1145-1160. doi: 10.1016/j.gca.2010.11.018

Debaille V, RG Trønnes, AD Brandon, TE. Waight, DW Graham, C-TA Lee (2009) 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. doi: 10.1016/j.gca.2009.03.002

Graham DW, MR Reid, BT Jordan, AL Grunder, WP Leeman, JE Lupton (2009) Mantle source provinces beneath the northwestern USA delimited by helium isotopes in young basalts. J. Volc. Geotherm. Res. 188, 128-140. doi: 10.1016/j.jvolgeores.2008.12.004

Russo CJ, KH Rubin,  DW Graham (2009) Mantle melting and magma supply to the Southeast Indian Ridge: the roles of lithology and melting conditions from U-series disequilibria. Earth Planet. Sci. Lett. 278, 55-66. doi: 10.1016/j.epsl.2008.11.016

Goldstein SL, G Soffer,  CH Langmuir, KA Lehnert, DW Graham,  PJ Michael (2008) Origin of a “southern hemisphere” geochemical signature in the Arctic upper mantle. Nature 453, 89-94. doi: 10.1038/nature06919

VanLaningham S, RA Duncan, N Pisias, DW Graham (2008) Tracking fluvial response to climate change in the Pacific Northwest: a combined provenance approach using Ar and Nd isotopic systems on fine-grained sediments. Quat. Sci. Rev. 27, 497-517. doi: 10.1016/j.quascirev.2007.10.018

Brandon AD, DW Graham, T Waight, B Gautason (2007) 186Os and 187Os enrichments and high-3He/4He sources in the Earth’s mantle: evidence from Icelandic picrites. Geochim. Cosmochim. Acta 71, 4570-4591. doi: 10.1016/j.gca.2007.07.015

Nicolaysen KE, FA Frey, JJ Mahoney, KTM Johnson, DW Graham (2007) Influence of the Amsterdam/St. Paul hotspot along the Southeast Indian Ridge between 77° and 88°E: correlations of Sr, Nd, Pb and He isotopic variations with ridge segmentation. Geochem. Geophys. Geosys. 7. doi: 10.1029/2006GC001540

Chen Y, Y Zhang, D Graham, S Su, J Deng (2007) Geochemistry of Cenozoic basalts and mantle xenoliths in Northeast China. Lithos 96, 108-126. doi: 10.1016/j.lithos.2006.09.015

Graham DW, J Blichert-Toft, CJ Russo, KA Rubin, F Albarède (2006) Cryptic striations in the upper mantle revealed by hafnium isotopes in Southeast Indian Ridge basalts. Nature 440, 199-202. doi: 10.1038/nature04582

Agranier A, J Blichert-Toft, DW Graham, V Debaille, P Schiano, F Albarède (2005) The spectra of isotopic heterogeneities along the Mid-Atlantic Ridge. Earth Planet. Sci. Lett., 238, 96-109. doi: 10.1016/j.epsl.2005.07.011

Keller RA, DW Graham, KA Farley, RA Duncan, JE Lupton (2004) Cretaceous-to-Recent record of elevated 3He/4He along the Hawaiian-Emperor volcanic chain. Geochem. Geophys. Geosys. 5. doi: 10.1029/2004GC000739

Burnard PG, DW Graham, KA Farley (2004) Fractionation of noble gases (He, Ar) during MORB mantle melting? A case study on the Southeast Indian Ridge. Earth Planet. Sci. Lett.  227, 457-472. doi: 10.1016/j.epsl.2004.08.021

Michael PJ, CH Langmuir, HJB Dick, JE Snow, SL Goldstein, DW Graham, K Lehnert, G Kurras, W Jokat, R Mühe, HN Edmonds (2003) Magmatic and amagmatic seafloor generation at the ultraslow-spreading Gakkel ridge, Arctic Ocean. Nature 423, 956-962. doi: 10.1038/nature01704

Ito G, J Lin, D Graham (2003) Observational and theoretical studies of the dynamics of mantle plume-mid-ocean ridge interaction. Rev. Geophys. 41, 1017-1041, doi: 10.1029/2002RG000117

Edmonds HN, PJ Michael, ET Baker, DP Connelly, JE Snow, CH Langmuir, HJB Dick, R Mühe, CR German, DW Graham (2003) Abundant hydrothermal venting on the ultra-slow spreading Gakkel Ridge, Arctic Ocean. Nature, 421, 252-256. doi: 10.1038/nature01351

Detrick RS, JM Sinton, G Ito, JP Canales, M Behn, T Blacic, B Cushman, JE Dixon, DW Graham, J Mahoney (2002) Correlated geophysical, geochemical and volcanological manifestations of plume-ridge interaction along the Galápagos Spreading Center. Geochem. Geophys. Geosys. 3, Paper 2002000350. doi: 10.1029/2002GC000350

Burnard PG, DW Graham, KA Farley (2002) Mechanisms of magmatic gas loss along the Southeast Indian Ridge and the Amsterdam-St. Paul Plateau. Earth Planet. Sci. Lett. 203, 131-148. doi: 10.1016/S0012-821X(02)00828-2

Mahoney JJ, DW Graham, DM Christie, KTM Johnson, LS Hall, DL VonderHaar (2002) Between a hot spot and cold spot: isotopic variation in the Southeast Indian Ridge asthenosphere, 86°-118°E. J. Petrol. 43,  1155-1176. doi: 10.1093/petrology/43.7.1155

Graham DW (2002) Noble gas isotope geochemistry of mid-ocean ridge and ocean island basalts; characterization of mantle source reservoirs. In: Noble Gases in Geochemistry and Cosmochemistry, eds. D. Porcelli, R. Wieler and C. Ballentine. Reviews in Mineralogy and Geochemistry, Mineral. Soc. Amer., Washington, D.C., pp. 247-318. doi: 10.2138/rmg.2002.47.8

Graham DW, JE Lupton, FJ Spera, DM Christie (2001) Upper mantle dynamics revealed by helium isotope variations along the Southeast Indian Ridge.  Nature 409, 701-703. doi: 10.1038/35055529

Johnson KTM, DW Graham, KH Rubin, K Nicolaysen, DS Scheirer, DW Forsyth, ET Baker, LM Douglas Priebe (2000) Boomerang Seamount: the active expression of the Amsterdam-St. Paul hotspot, Southeast Indian Ridge.  Earth Planet. Sci. Lett. 183, 245-259. doi: 10.1016/S0012-821X(00)00279-X

Scheirer DS, DW Forsyth, JA Conder, MA Eberle, S-H Hung, KTM Johnson, DW Graham (2000) Anomalous seafloor spreading of the Southeast Indian Ridge near the Amsterdam-St. Paul Plateau. J. Geophys. Res. 105, 8243-8262. doi: 10.1029/1999JB900407

Hauff F, K Hoernle, G Tilton, DW Graham, AC Kerr (2000) Large volume recycling of oceanic lithosphere over short time scales (≤0.5 Ga): geochemical constraints from the Caribbean Large Igneous Province. Earth Planet. Sci. Lett. 174, 247-263. doi: 10.1016/S0012-821X(99)00272-1

Graham DW, JE Lupton (1999) Helium isotopes in historical lavas from Mount Vesuvius: comment on 'Noble gas isotopic ratios from historical lavas and fumaroles at Mount Vesuvius' by D. Tedesco et al.. Earth Planet. Sci. Lett. 174, 241-244. doi: 10.1016/S0012-821X(99)00268-X

Furman TH, DW Graham (1999) Erosion of lithospheric mantle beneath the East African Rift System: geochemical evidence from the Kivu volcanic province. Lithos  48, 237-262. doi: 10.1016/S0024-4937(99)00031-6

Graham DW, KTM Johnson, LM Douglas Priebe, JE Lupton (1999) Hotspot-ridge interaction along the Southeast Indian Ridge near Amsterdam and St. Paul islands: helium isotope evidence. Earth Planet. Sci. Lett. 167, 297-310. doi: 10.1016/S0012-821X(99)00030-8

Sturm M, EM Klein, DW Graham, JL Karsten (1999) Age constraints on crustal recycling to the mantle beneath the southern Chile Ridge: He-Pb-Sr-Nd systematics. J. Geophys. Res. 104, 5097-5114. doi: 10.1029/1998JB900107

Graham DW (1999) Helium Isotopes. In: The Encyclopedia of Geochemistry, ed. C. P. Marshall and R. W. Fairbridge, Kluwer Academic Publishers, pp.314-315. doi: 10.1007/1-4020-4496-8_154

Graham DW, LM Larsen, BB Hanan, M Storey, AK Pedersen, JE Lupton (1998) Helium isotope composition of the early Iceland mantle plume inferred from the Tertiary picrites of West Greenland. Earth Planet. Sci. Lett. 160, 241-256. doi: 10.1016/S0012-821X(98)00083-1

Garcia MO, KH Rubin, MD Norman, JM Rhodes, DW Graham, DW Muenow, K Spencer  (1998) Petrology and geochronology of basalt breccia from the 1996 earthquake swarm of Loihi Seamount, Hawaii: magmatic history of its 1996 eruption.  Bull. Volcanol. 59, 577-592. doi: 10.1007/s004450050211

Burnard P, D Graham, G Turner (1997) Vesicle-specific noble gas analyses of "popping rock": implications for primordial noble gases in Earth. Science 276, 568-571. doi: 10.1126/science.276.5312.568

Graham DW, P Castillo, JE Lupton, R Batiza (1996) Correlated helium and strontium isotope ratios in South Atlantic near-ridge seamounts and implications for mantle dynamics.  Earth Planet. Sci. Lett. 144, 491-504. doi: 10.1016/S0012-821X(96)00172-0

Reid MR, DW Graham (1996) Resolving lithospheric and sub-lithospheric contributions to helium isotope variations in basalts from the southwestern US. Earth Planet. Sci. Lett. 144, 213-222. doi: 10.1016/0012-821X(96)00166-5

Hanan BB, DW Graham (1996) Lead and helium isotope evidence from oceanic basalts for a common deep source of mantle plumes. Science 272, 991-995. doi: 10.1126/science.272.5264.991

Hoernle K, Y-S Zhang, D Graham (1995) Seismic and geochemical evidence for large-scale mantle upwelling beneath the eastern Atlantic and western and central Europe. Nature 374, 34-39. doi: 10.1038/374034a0

Graham DW, P Allard, CK Kilburn, FJ Spera, JE Lupton (1993) Helium isotopes in some historical lavas from Mount Vesuvius. J. Volc. Geotherm. Res. 58, 359-366. doi: 10.1016/0377-0273(93)90117-A

Graham DW, DM Christie, KS Harpp, JE Lupton (1993) Mantle plume helium in submarine basalts from the Galapagos Platform. Science 262, 2023-2026. doi: 10.1126/science.262.5142.2023

Lupton JE, DW Graham, JR Delaney, HP Johnson (1993) Helium isotope variations in Juan de Fuca Ridge basalts. Geophys. Res. Lett. 20, 1851-1854. doi: 10.1029/93GL01271

Graham DW, WJ Jenkins, J-G Schilling, G Thompson, MD Kurz, SE Humphris (1992) Helium isotope geochemistry of mid-ocean ridge basalts from the South Atlantic. Earth Planet. Sci. Lett. 110, 133-147. doi: 10.1016/0012-821X(92)90044-V

Graham DW, SE Humphris, WJ Jenkins, MD Kurz (1992) Helium isotope geochemistry of some volcanic rocks from St. Helena. Earth Planet. Sci. Lett. 110, 121-131. doi: 10.1016/0012-821X(92)90043-U

Graham D, P Sarda (1991) Reply to comment by T. M. Gerlach on "Mid-ocean ridge popping rocks: implications for degassing at ridge crests". Earth Planet. Sci. Lett. 105, 568-573. doi: 10.1016/0012-821X(91)90194-M

Lupton JE,  DW Graham (1991) Comment on "A ten-year decrease in the atmospheric helium isotope ratio possibly caused by human activity" by Y. Sano et al.. Geophys. Res. Lett. 18, 482-485. doi: 10.1029/91GL00493

Graham DW, JE Lupton, F Albarède, M Condomines (1990) Extreme temporal homogeneity of helium isotopes at Piton de la Fournaise, Réunion Island. Nature 347, 545-548. doi: 10.1038/347545a0

Sarda P, D Graham (1990) Mid-ocean ridge popping rocks: implications for degassing at  ridge crests. Earth Planet. Sci. Lett. 97, 268-289. doi: 10.1016/0012-821X(90)90047-2

Graham DW, A Zindler, MD Kurz, WJ Jenkins, R Batiza, H Staudigel (1988) He, Pb, Sr and Nd isotope constraints on magma genesis and mantle heterogeneity beneath young Pacific seamounts. Contrib. Mineral. Petrol. 99, 446-463. doi: 10.1007/BF00371936

Graham DW, WJ Jenkins, MD Kurz, R Batiza (1987) Helium isotope  disequilibrium and geochronology of glassy submarine basalts. Nature 326, 384-386. doi: 10.1038/326384a0

Hudson A, ML Bender, DW Graham (1986) Iron enrichments in hydrothermal plumes over the East Pacific Rise. Earth Planet. Sci. Lett. 79, 250-254. doi: 10.1016/0012-821X(86)90183-4

Bender ML, A Hudson, DW Graham, RO Barnes, M Leinen, D Kahn (1985) Diagenesis and advection reflected in pore water chemistry on the western  flank of the East Pacific Rise, 20 degrees south. Earth Planet. Sci. Lett. 76, 71-83. doi: 10.1016/0012-821X(85)90149-9

Rona PA, G Thompson, MJ Mottl, JA Karson, WJ Jenkins, D Graham, M Mallette, K Von Damm, J Edmond (1984) Hydrothermal activity at the Trans-Atlantic Geotraverse Hydrothermal Field, Mid-Atlantic Ridge crest at 26°N. J. Geophys. Res. 89 11365-11377. doi: 10.1029/JB089iB13p11365

Emerson S, V Grundmanis, DW Graham (1982) Carbonate chemistry in marine pore waters: MANOP sites C and S. Earth Planet. Sci. Lett. 61, 220-232. doi: 10.1016/0012-821X(82)90055-3

Klinkhammer G, DT Heggie, DW Graham (1982) Metal diagenesis in oxic marine sediments. Earth Planet. Sci. Lett. 61, 211-219. doi: 10.1016/0012-821X(82)90054-1

Graham DW, ML Bender, DF Williams, L D Keigwin Jr. (1982) Strontium-calcium ratios in Cenozoic planktonic foraminifera. Geochim. Cosmochim. Acta 46, 1282-1292. doi: 10.1016/0016-7037(82)90012-6

Graham DW, BH Corliss, ML Bender, LD Keigwin Jr. (1981) Carbon and oxygen isotopic disequilibria of Recent deep-sea benthic foraminifera. Mar. Micropaleo. 6, 483-497. doi: 10.1016/0377-8398(81)90018-9

Bender ML, DW Graham (1981) On Late Miocene abyssal hydrography. Mar. Micropaleo. 6, 451-464. doi: 10.1016/0377-8398(81)90016-5

Bender ML, DW Graham (1978) Long term constraints on the global marine carbonate system. J. Mar. Res. 36, 551-567. link

Books Edited

Harpp KS, E Mittelstaedt, N d’Ozouville, DW Graham (2014) The Galápagos: A Natural Laboratory for the Earth Sciences. Geophysical Monograph 204, AGU/Wiley. doi: 10.1002/9781118852538

News & Views

Graham DW (2014) Mantle geochemistry: Small-scale stirrings. Nature Geoscience (News & Views) 7, 556-557. doi: 10.1038/ngeo2216

Graham DW (2010) Geochemistry: Relict mantle from Earth’s birth. Nature (News & Views) 466, 822-823. doi: 10.1038/466822a

Graham DW (2005) Geochemistry: Neon illuminates the mantle. Nature (News & Views) 433, 25-26. doi: 10.1038/433025a