The Isotope Geochemistry Laboratory (IGL) is part of the Department of Geology, University of Maryland (UMd). The IGL was created in 1991 by Profs. R. J. Walker and E. J. Krogstad to pursue state of the art isotopic and trace element analysis of terrestrial and extraterrestrial materials. Currently, the IGL comprises a set of five laboratories for the preparation and isotopic analysis of a wide range of geological materials. These laboratories include separate mass-spectrometry, chemistry, mineral separation and rock preparation facilities. The IGL began operations in 1991 with the acquisition of a 12 inch radius of curvature National Bureau of Standards single-collector, solid source mass spectrometer. In 1992, a VG Sector 54 mass spectrometer, with 7 Faraday collectors, was added to the complement of analytical tools. A third thermal ionization mass spectrometer, a Thermo Fisher Triton, with 9 Faraday cups, was installed in 2007. The NBS and VG mass spectrometers were retired from UMd service during the summer of 2014, ending their careers with us with 10,261 and 14,479 individual analyses, respectively. In their place, a Thermo Fisher Triton Plus was installed in the fall of 2014.

A second mass-spectrometry laboratory, shared with the Plasma Laboratory, houses a Thermo Fisher Neptune Plus multi-collector inductively-coupled plasma mass-spectrometer, as well as an Element 2 single collector ICP-MS. An overview of the types of research conducted within the IGL at UMd can be found at our research homepage.

The mission of the IGL is to produce the highest quality isotope data, to innovate in techniques development and applications, to train students and visitors in the techniques involved in gathering such data, and to maintain itself as a world-class isotope measurement facility.

The Thermal Ionization Mass Spectrometry Laboratory (CHEM 0218) of the IGL currently houses two solid source mass spectrometers, two filament degassing apparatuses, and laminar flow clean benches for sample loading operations. Each mass spectrometer has dedicated ion optics sources for Re and Pt filaments.

Photo shows the UMd Thermo Fisher Triton mass spectrometers.

The Thermo Fisher Tritons were installed in 2007 and 2014. These instruments are primarily used for high precision measurements of W, Nd, Sr, Os, Ru, and Mo isotopes as applied to geological/cosmochemical projects.

The Neptune Plus multi-collector ICP-MS uses high temperature plasma to ionize elements that have been either chemically separated and purified from a material, or liberated from a solid matrix via laser ablation. The relative intensities of the different isotopes of a given element are quantified using either the multiple Faraday cups or an electron multiplier. This instrument is commonly used to measure the isotopic compositions of U, Mo, Li, W, Pt, Ru, Ir, Pd, and Re.

Photo of Neptune Plus multi-collector ICP-MS, part of the UMd Plasma Laboratory.

Most samples for isotopic analysis are processed (elements of interest are purified from matrix) in the Chemistry Clean Laboratories. Two 500 sq. ft. laboratories are supplied with HEPA-filtered air. Each contains class-10 vented laminar flow hoods, chemical fume hoods and multiple work stations (with fume extraction). The facility also utilizes two Milli-Q water purification systems, and currently operates three sub-boiling stills (quartz- and teflon).

Air-lock entrance foyer to the "new" and "old" clean rooms (CHEM0216A & CHEM 0216B).

Vented work stations (foreground) and 2 of 4 class 10 laminar flow hoods (background) present in the "old" chemical Clean Laboratory.

A 500 ft² clean lab in CHEM 0216A was opened in 2007. Photo shows the all-plastic cabinetry and work stations.

A 500 ft² clean lab in CHEM 0216A was opened in 2007. Photo shows the perchloric acid scrubber hood.

Photo of a first stage rhenium elution accomplished using disposable anion exchange columns.

The Sample Digestion Laboratory (CHEM0221) and Rock Preparation (CHEM0219) laboratories were last renovated in 2002-2003. The Rock Preparation lab houses short-term sample storage, a ceramic jaw crusher and disk mill, alloy mortar and pestle, rock splitter, SPEX Industries Shatterbox and Mixer Mill (both with agate and alumina grinding chambers), and a Leco diamond slow-speed saw for cutting iron meteorites. The Sample Digestion lab houses two ovens (one can achieve temperatures as high as 380°C), one muffle furnace, both oxy-propane and oxy-hydrogen torches (for sealing Pyrex and quartz Carius tubes) and an Anton-Paar high pressure asher (HPA). The HPA can be used for high temperature digestions of samples for Os isotope and highly siderophile element measurement.

Images of the Anton Paar high-pressure asher (HPA) at the University of Maryland. (a) The HPA as installed beneath its custom built extraction hood. The bench-top size of the HPA (b) and simple operational controls make it ideal for processing precious materials, where time and simple methods are of the essence. (c) Wrapping tool for closing the optically perfect caps to high-purity 50mL capacity quartz digestion vessels prior to loading in the HPA. (d) Rack containing 6 quartz vessels being prepared for cleaning. 7 high purity quartz digestion vessels can be loaded into the HPA for digestion at a time.

Sample Digestion Laboratory. This lab is used for flux fusions, HPA digestions, oven digestions, and torch work associated with the sealing of Carius tubes.

Torchbox for sealing Carius tubes. An oxygen-propane torch is used for sealing Pyrex tubes, and an oxygen-hydrogen torch is used to seal quartz tubes.

Rock crushing/short-term storage room.

Nickel-sulfide fire assays are used for concentrating highly siderophile elements from large quantities of silicate matrix.

Some of the main thrusts of research in the IGL include studies of the Earth's mantle and crust, and the evolution of the early solar system. Applications also target tectonic and environmental problems. The range of specific research topics currently active in the IGL include:

• The evolution of siderophile elements in Earth's mantle and crust through time. Recent targets of interest include mafic-ultramafic rocks from South Africa (Barberton and Belingwe Greenstone Belt komatiites), Western Australia (komatiites of various ages from the Pilbara and Yilgarn Cratons), Colombia (Gorgona komatiites), Fennoscandia (komatiites and ophiolites of various ages), Canada (Abitibi Greenstone Belt komatiites), UnstChile (Taitao Ophiolite), Finland (Jormua Ophiolite), Norway (Leka ophiolite), as well as modern oceanic rocks including abyssal peridotites and ocean island basalts.
• Use of ¹⁸²Hf-¹⁸²W, ¹⁸⁷Re-¹⁸⁷Os, ¹⁹⁰Pt-¹⁸⁶Os, and ^146,147Sm-^142,143Nd isotope systems to study mantle heterogeneities resulting from primordial planetary differentiation processes and possible interactions between the Earth's core and lowermost mantle. Targeted rocks include ancient komatiites, kimberlites and modern ocean island basalts.
• The chronology and chemical evolution of early solar system materials. Specific targets include iron meteorites, pallasites, chondrites, lunar mare volcanic glasses and basalts, lunar highland impact melt breccias, martian meteorites, and presolar grains. These studies include the application of short- and long-lived chronometers based on radioactive decay, and research on isotopic heterogeneities in meteorites and their implications for stellar nucleosynthesis, nebular mixing and early evolution of the solar system.
• Study of peridotite xenoliths plucked from the subcontinental lithospheric mantle as a means of constraining the age of lithospheric mantle creation, assemblage and possible destruction (in some regions, such as underlying the North China Craton).

A more detailed overview of the types of research conducted within the IGL at UMd can be found at our research homepage.

The faculty/staff presently engaged in research in the IGL currently include: Val Finlayson, Jay Kaufman, Sarah Penniston-Dorland, Igor Puchtel, Richard Walker.

Past members of the IGL have included (with present affiliation): Harry Becker (Freie University, Berlin), Al Brandon (retired), Erik Krogstad (Pacific Northwest Laboratory), Christina Gallup (Univ. Minnesota, Duluth), Mary Horan (Carnegie Institution), Thomas Meisel (Leoben University), Seung Ryeol Lee (Korea Institute of Geoscience and Mineral Resources), Diane McDaniel (Montgomery College), Bill Minarik (McGill University), Tim Mock (Carnegie Institution), Sonia Esperança (retired), John Morgan (retired), Paul Tomascak (SUNY Oswego), Tod Waight (University of Copenhagen), Tetsuya Yokoyama (Tokyo Institute of Technology), James Day (Scripps Instituion of Oceanography), Mathieu Touboul (ENS de Lyon), Richard Gaschnig (UMass Lowell), Roberta Rudnick (U.C. Santa Barbara), Andrea Mundl-Petermeier (IAEA), Katherine Bermingham (Rutgers University), Nao Nakanishi (Waseda University), Soumya Ray (Los Alamos), Jan Hellmann (MPI Göttingen).

Thomas Meisel (1995-1996) (University of Leoben)
Alan Brandon (1997-1999) (retired)
Tod Waight (1998-1999) (University of Copenhagen)
Harry Becker (1998-2001) (Freie University, Berlin)
Diane McDaniel (2000-2003) (Montgomery College)
Aaron Pietruszka (2002-2003) (University of Hawaii Manoa)
Seung Ryeol Lee (2004-2006) (Korea Institute of Geoscience and Mineral Resources)
Tetsuya Yokoyama (2006-2008) (Tokyo Institute of Technology)
James Day (2006-2010) (Scripps Institution of Oceanography)
Jingao Liu (2011-2012) (China University of Geosciences)
Mathieu Touboul (2009-2014) (CNRS Lyon)
Hanika Rizo (2015) (Carleton University)
Katherine Bermingham (2012-2018) (Rutgers University)
Andrea Mundl-Petermeier (2015-2018) (IAEA)
Nao Nakanishi (2018-2022) (Waseda University)
Soumya Ray (2023) (Los Alamos)
Jan Hellmann (MPI Göttingen)

Theses/dissertations completed:

• Jerry L. Burgess (M.S., 1994-with LCP) Pressure-temperature-time-deformation (P-T-t-D) history of high-grade gneisses of the Port aux Basques area, southwest Newfoundland, Canada.
• Jeffrey D. Jarriel (M.S., 1994) Use of Sr isotopic, hydrophysical, and other Geochemical data to delineate catchment flow paths during baseflow and storm events.
• Paul B. Tomascak (Ph.D., 1995) The petrogenesis of granitic rocks in southwestern Maine.
• Alison B. Schwab (M.S., 1995) Li isotope variability in ground and surface water in a first order agricultural catchment, eastern Maryland.
• Michael I. Smoliar (Ph.D., 1996) Re-Os isotopic studies of magmatic iron meteorites.
• Asuka Tsuru (M.S., 1997) The Os isotopic evolution of the upper mantle: the Jormua ophiolite complex, Finland.
• Sarah E. Libeau (M.S., 1997) Pb isotope tracers in oyster shells from historic native American middens around the Chesapeake Bay.
• Rachel A. Pressley (M.S.-with LCP, 1997) Petrogenesis of the Phillips pluton, Maine.
• Gary S. Solar (Ph.D.-with LCP, 1999) Tracing melt migration and dating deformation, west-central Maine.
• Donna Gunderson (M.S., 1999) Paleorecords of climate change.
• Jinmei Tian (M.S.-with LCP, 2000) Petrogenesis of the Moose-lookmeguntic plutonic complex, Maine.
• Ji Li (M.S., 2001) Use of the Re-Os isotope system to trace the origin of gold mineralizing fluids in the Allegheny District, California.
• David Cook (M.S., 2001) Re-Os and Pt-Os isotopic systematics of evolved iron meteorites.
• Stephen Lynton (Ph.D.-with LMDR, 2003) An experimental study of the isotopic fractionation and partitioning of lithium among quartz, muscovite, and fluids.
• Amitava Gangopadhyay (Ph.D., 2004) Petrologic, geochemical and Os isotope studies of selected Precambrian komatiites.
• Feng-Zhen Teng, (Ph.D., 2005) Quantifying the Li isotope composition of the upper continental crust.
• Jacqueline L. Mann (Ph.D., 2005) Determination of sulfur isotope composition in sulfate from two high elevation snowpits by multi-collector thermal ionization mass spectrometry using a double spike.
• Nick Geboy (M.S., 2006) Re-Os geochronology of organic-rich sediments.
• Ruth Thompson Schulte (M.S., 2007) Isotopic systematics of mafic-ultramafic rocks of the Taitao ophiolite, Chile.
• Tom Ireland (Ph.D., 2009) Highly siderophile element and tungsten systematics of Hawaiian picrites.
• Kathleen Scheiderich (Ph.D., 2010) Stable Mo isotopes as tracers of redox conditions in modern and ancient oceans and estuaries.
• Jingao Liu (Ph.D., 2011) Investigations of the history of the lithospheric mantle underlying the North China Craton.
• Gregory Archer (M.S., 2012) Highly siderophile elements and the rhenium-osmium system in chondritic components.
• Caitlin Brown (M.S., 2013) Petrogenesis of peraluminous granites from the Fosdick Mountains, Marie Byrd Land, West Antarctica
• Julia Gorman (M.S., 2013) The role of mechanical mixing in the formation of reaction zones in subduction-related mélange.
• Miriam Sharp (Ph.D., 2014) Determination of siderophile element characteristics throughout lunar history: implications for the lunar magma ocean and late heavy bombardment.
• Huan Cui (Ph.D., 2015) Authigenesis, biomineralization, and carbon-sulfur cycling in the Ediacaran ocean
• Emily Worsham (Ph.D., 2016) Siderophile elements and molybdenum, tungsten, and osmium isotopes as tracers of planetary genetics and differentiation: Implications for the IAB iron meteorite complex.
• Gregory Archer (Ph.D., 2016) Highly siderophile elements, ¹⁸⁷Re-¹⁸⁷Os and ¹⁸²Hf-¹⁸²W Isotopic systematics of early solar system materials: constraining the early evolution of chondritic and achondritic parent bodies.
• Mitchell Haller (M.S., 2017) Meter scale heterogeneities in the oceanic mantle revealed in ophiolite peridotites
• Willie Nicklas (Ph.D., 2019) The redox history of the Earth's mantle: evidence from ultramafic lavas
• Tracey Centorbi (M.S., 2020) Re-Os and oxygen systematics of variably altered ultramafic rocks, North Carolina.
• Hope Tornabene (M.S., 2020) Insights to the genetics, age and crystallization of group IC iron meteorites
• Connor Hilton (Ph.D., 2020) Genetics, age and chemical compositions of iron meteorites
• Emily Chiappe (M.S., 2022) Insights to the genetics, age and crystallization of group IIIE and the iron meteorite Lieksa

Theses/dissertations in progress:

• Emily Chiappe (Ph.D.) Insights to the genetics, age and crystallization of ungrouped iron meteorites
• Lori Willhite (Ph.D.) Spatiotemporal variability of tungsten-182 in the Hawaiian plume
• Kiran Almas (Ph.D.) Search for correlated nucleosynthetic effects in Pt and Os

As of 2024, the IGL has hosted research for more than 30 senior undergraduate student theses.

Guest Users of the IGL have included (with affiliation at the time of visit):

Peter Ashley (Johns Hopkins University), Julie Bartley (West Georgia College), Lars Borg (Johnson Space Center), Chris Fedo (Virginia Tech), Robert Frei (Geologisk Institut Kobenhavns Universitet), Shan Gao (Key Laboratory of Continental Dynamics, Department of Geology, Northwestern University, Xi’an), Jenny Hall (Yale University), Eero Hanski (Geological Survey of Finland), Debra Hassler (Harvard University), Melissa Hicks (University of Nevada, Las Vegas), Steve Lev (Towson University), Gabriela Mora-Klepeis (University of Vermont), Brent Owens (College of William and Mary), Marcio Pimentel (Universidade de Brasilia), John Rakovan (Miami University of Ohio), Paula Shafer (Indiana University), Susanna Sichel (Universidade Federal Fluminense, Brazil), Michael Smoliar (Carnegie Institution of Washington), Ilona Suominen (University of Helsinki), Yasutaka Terakado (Kobe University), Malissa Washburn (University of Maine), Manuel Schilling (University of Chile), Elizabeth Widom (Miami University of Ohio), Lukas Ackerman (University of Prague), Curtis Williams (Indiana University), Joyashish Thakurta (Indiana University), Fu-yuan Wu (Changchun Univ. of Science and Tech., and Institute of Geology and Geophysics, Chinese Academy of Sciences), Hong-Lin Yuan (Key Laboratory of Continental Dynamics, Department of Geology, Northwestern University, Xi’an), Zhu-Yin Chu (Institute of Geology and Geophysics, Chinese Academy of Sciences), David van Acken (Freie University, Berlin), Brian O’Driscoll (Keele University, Manchester University), Robert Vocke (NIST), Zu Watanabe (Miami University of Ohio), Lorne Loudin (Keene State University), Yulia Larionova (IGEM, Russian Academy of Sciences), Svetlana Tessalina (Curtin University), Christophe Robin (Univ. of Grenoble), Frederick Moynier (Washington University), Lynnette Pitcher (Stony Brook University), Eduardo Rocha-Júnior (University of São Paulo), Amy Riches (University of Tennessee), Iva Gerasimenko (Randolph College), Eric Stifter (Indiana University), Brittany Sacco (James Madison University), Alex McCoy-West (Australian National University), Donald Ngonge (University of São Paolo), Kang Chen (China University of Geosciences, Wuhan), Wendy Nelson (Towson University), Hanika Rizo (Carleton University), Brad Peters (Carnegie), Lizette Miranda (Poolesville High School).

Peer-reviewed publications produced as a consequence of work partially or wholly conducted in the IGL since its creation in 1991.

1992
1. Horan M.F., Morgan J.W., Walker R.J. and Grossman J.N. (1992) Re-Os isotope constraints on the age of iron meteorites. Science 255, 1118-1121.
2. Morgan J.W., Walker R.J. and Grossman J.N. (1992) Rhenium-osmium isotope systematics in meteorites I: Magmatic iron meteorite groups IIAB and IIIAB. Earth Planet. Sci. Lett. 108, 191-202.
1993
3. Krogstad E.J., Walker R.J., Nabelek P.I. and Russ-Nabelek C. (1993) Pb isotopic constraints on the origin of Archean and Proterozoic granites, Black Hills, South Dakota. Geochim. Cosmochim. Acta 57, 4677-4685.
1994
4. Walker, R.J., Morgan, J.W., Hanski, E.J. and Smolkin, V.F. (1994) The role of the Re-Os system in the study of magmatic sulfide ores: A tale of three ores. Proceedings of Sudbury-Norilsk Symposium, Ontario Geological Survey Spec. Pub. 5, 343-355.
5. Horan M.F, Morgan J.W., Grauch R.I., Coveney R., Murowchick J., Hulbert L. (1994) Re-Os isotopes in black shales and Ni-Mo-PGE-rich sulfide layers, Yukon Territory, Canada and Guizhou and Hunan, China. Geochim. Cosmochim. Acta. 58, 257-265.
6. Krogstad E.J. and R.J. Walker (1994) High closure temperatures of the U-Pb system in large apatites from the Tin Mountain pegmatite, Black Hills, South Dakota. Geochim. Cosmochim. Acta 58, 3845-3853.
7. Walker, R.J., Morgan J.W., Horan M.F., Czamanske G.F., Krogstad E.J., Fedorenko V. and Kunilov V.E. (1994) Re-Os isotopic evidence for an enriched-mantle source for the Noril'sk-type ore-bearing intrusions, Siberia. Geochim. Cosmochim. Acta 58, 4179-4197.
8. Lambert D.D., Walker R.J., Morgan J.W., Shirey S.B., Carlson R.W., Zientek M.L., Lipin B.R., Koski M.S. and Cooper R.L. (1994) Re-Os and Sm-Nd isotope geochemistry of the Stillwater Complex, Montana: Implications for the petrogenesis of the J-M Reef. Journ. Petrol. 35, 1717-1753.
1995
9. Morgan J.W., Horan M.F., Walker R.J. and Grossman J.N. (1995) Rhenium-osmium concentration and isotope systematics in group IIAB iron meteorites. Geochim. Cosmochim. Acta 59, 2331-2344.
10. Shirey S.B. and Walker R.J. (1995) Carius tube digestion for low-blank rhenium-osmium analysis. Anal. Chem. 34, 2136-2141.
11. Krogstad E.J., Hanson G.N. and Rajamani V. (1995) Sources of continental magmatism adjacent to the later Archean Kolar Suture Zone, south India:distinct isotopic and elemental signatures of two late Archean magmatic series. Contrib. Mineral. Petrol. 122, 159-173.
12. Walker R.J., Morgan J.W. and Horan M.F. (1995) ¹⁸⁷Os enrichment in some mantle plume sources: Evidence for core-mantle interaction? Science 269, 819-822.
13. Horan M.F., Walker R.J., Fedorenko V.A. and Czamanske G.K. (1995) Os and Nd isotopic constraints on the temporal and spatial evolution of Siberian flood basalt sources. Geochim. Cosmochim. Acta 59, 5159-5168.
14. Burgess, J.L., Brown, M., Dallmeyer, R.D. and van Staal, C.R. (1995) Microstructure, metamorphism, thermochronology and P-T-t-deformation history of the Port aux Basques Gneisses, Southwest Newfoundland, Canada. Journal of Metamorphic Geology, 13, 751-776.
1996
15. Smoliar M.I., Walker R.J. and Morgan J.W. (1996) Re-Os ages of group IIA, IIIA, IVA and IVB iron meteorites. Science 271, 1099-1102.
16. Meisel T., Biino G.G. and Nagler T. (1996) Re-Os, Sm-Nd and rare earth element evidence for Proterozoic subcontinental and oceanic lithosphere in tectonized ultramafic lenses from the Swiss Alps. Geochim. Cosmochim. Acta 60, 2583-2593.
17. Tomascak P.B., Krogstad E.J. and Walker R.J. (1996) U-Pb monazite geochronolgy of granitic rocks from Maine:implications for late Paleozoic tectonics in the northern Appalachians. J. of Geol. 104, 185-195.
18. Koide M., Goldberg E.D. and Walker R. (1996) The analysis of seawater osmium. Deep-Sea Res. 43, 53-55.
19. Walker R.J., Hanski E.J., Vuollo J. and Liipo J. (1996) The Os isotopic composition of Proterozoic upper mantle:evidence for chondritic upper mantle from the Outokumpu ophiolite, Finland. Earth Planet. Sci. Lett. 141, 161-173.
20. Krogstad E.J. and Walker R.J. (1996) Evidence of heterogeneous crustal sources: the Harney Peak Granite, South Dakota, U.S.A. Trans. Roy. Soc. Edinburgh; Earth Sciences 87, 331-337.
21. Meisel T., Walker R.J. and Morgan J.W. (1996) The osmium isotopic composition of the Earth's primitive upper mantle. Nature 383, 517-520.
22. Fedo C.M., Eriksson K.A. and Krogstad E.J. (1996) Geochemistry of shales from the Archean (~3.0 Ga) Buhwa Greenstone Belt, Zimbabwe: implications for provenance and source-area weathering. Geochim. Cosmochim. Acta 60, 1751-1764.
23. Tomascak P.B., Krogstad E.J. and Walker R.J. (1996) Nature of the crust in Maine, USA: evidence from the Sebago batholith. Contrib. Mineral. Pet. 125, 45-59.
24. Carlson R.W., Esperança S. and Svisero D.P. (1996) Chemical and Os isotopic study of Cretaceous potassic rocks from southern Brazil. Contrib. Mineral. Pet. 125, 393-405.
1997
25. Terakado Y., Fujitani T. and Walker R.J. (1997) Nd and Sr isotopic constraints on the origin of igneous rocks resulting from the opening of the Japan Sea, southwestern Japan. Contrib. Mineral. Pet. 129, 75-86.
26. Walker R. J., Morgan J.W., Hanski E.J. and Smolkin V. (1997) Re-Os systematics of Early Proterozoic ferropicrites, Pechenga Complex, NW Russia:evidence for ancient ¹⁸⁷Os-enriched plumes. Geochim. Cosmochim. Acta 61, 3145-3160.
27. Meisel T., Lange J.-M. and Krähenbühl U. (1997) The chemical variation of moldavite tektites: simple mixing of terrestrial sediments. Meteoritics & Planetary Science 32, 493-502.
28. Walker R.J., Morgan J.W., Smoliar M.I., Beary E., Czamanske G.K. and Horan M.F. (1997) Application of the ¹⁹⁰Pt-¹⁸⁶Os isotope system to geochemistry and cosmochemistry Geochim. Cosmochim. Acta 61, 4799-4807.
29. Meisel T., Melcher F., Tomascak P., Dingeldey C. and Koller F. (1997) Re-Os isotopes in orogenic peridotite massifs in the eastern Alps, Austria. Chemical Geology 143, 217-229.
30. Esperança S, Carlson R.W., Shirey S.B. and Smith D. (1997) Dating crust-mantle separation: Re-Os isotopic study of mafic xenoliths from central Arizona. Geology 25, 651-654.
31. Ashley, P., Krogstad, E., Lees, P., Silbergeld, E., and Smith, D. (1997) The use of stable lead isotopes to identify and apportion sources of lead in urban house dust. in: Hazardous Waste: Impacts on Human and Ecological Health, (B. Johnson, C. Xintaras, and J. Andrews, eds.), Princeton Science Publications, p. 139-150.
1998
32. Horan M.F., Smoliar M. and Walker R.J. (1998) ¹⁸²W and ¹⁸⁷Re-¹⁸⁷Os systematics of iron meteorites: chronology for melting, differentiation and crystallization of asteroids. Geochim. Cosmochim. Acta 62, 545-554.
33. Shirey S.B. and Walker R.J. (1988) Re-Os isotopes in cosmochemistry and high-temperature geochemistry. Annual Reviews of the Earth and Planetary Sciences 26, 423-500.
34. Asmerom Y. and Walker R.J. (1998) Pb and Os isotopic constraints on the composition and rheology of the lower crust. Geology 26, 359-362.
35. Brandon A., Walker R.J., Morgan J.W., Norman M.D. and Prichard H. (1998) Coupled ¹⁸⁶Os and ¹⁸⁷Os evidence for core-mantle interaction. Science 280, 1570-1573.
36. Tomascak P.B., Krogstad E.J. and Walker R.J. (1998) Nd isotope systematics and the derivation of granitic pegmatites in southwestern Maine, USA. Can. Min. 36, 327-337.
1999
37. Tomascak P.B., Krogstad E.J. and Walker R.J. (1999) Clues to the significance of the Norumbega Fault Zone in southwestern Maine from the geochemistry of granitic rocks. In, The Norumbega Fault Zone, eds. A. Ludman and D.P. West, G.S.A. Special Paper 331, 105-119.
38. Pressley, R.A. and Brown, M. (1999) The Phillips Pluton, Maine, USA: Evidence of heterogeneous crustal sources, and implications for granite ascent and emplacement mechanisms in convergent orogens. Lithos 46, 335-366.
39. Brown, M. and Pressley, R.A. (1999) Crustal melting in nature: Prosecuting source processes. Physics and Chemistry of the Earth 24, 305-316.
40. Walker R.J., Storey M., Kerr A. and Tarney J. (1999) Implications of ¹⁸⁷Os heterogeneities in mantle plumes: evidence from Gorgona Island and Curaçao. Geochim. Cosmochim. Acta 63, 713-728.
41. Tomascak P.B., Tera F., Helz R. and Walker R.J. (1999) The absence of lithium isotope fractionation during basalt differentiation: New measurments by multicollector sector ICP-MS. Geochim. Cosmochim. Acta 63, 907-910.
42. Brandon A.D., Norman M.D., Walker R.J. and Morgan J.W. (1999) ¹⁸⁶Os-¹⁸⁷Os systematics of Hawaiian picrites. Earth Planet. Sci. Lett., 172, 25-42.
2000
43. Tsuru A., Walker R.J., Kontinen A., Peltonen P. and Hanski E. (2000) Re-Os isotopic systematics of the Jormua Ophiolite Complex, NW Finland. Chemical Geology 164, 123-141.
44. Böhlke J.K. and Horan M. (2000) Strontium isotope geochemistry of groundwaters and streams affected by agriculture, Locust Grove, MD. Applied Geochemistry 15, 599-609.
45. Righter K., Walker R.J. and Warren P.H. (2000) Significance of highly siderophile elements and Os isotopes in the lunar and terrestrial mantles. in Origin of the Earth and Moon, R. Canup and K. Righter eds., Univ. of Arizona Press, Tucson, 291-322.
46. Borisov A. and Walker R.J. (2000) Os solubility in silicate melts: new efforts and results. American Mineralogist 85, 912-918.
47. Brandon A.D., Snow J.E., Walker R.J., Morgan J.W. and Mock T.D. (2000) ¹⁹⁰Pt-¹⁸⁶Os and ¹⁸⁷Re-¹⁸⁷Os systematics of abyssal peridotites. Earth Planet. Sci. Lett. 177, 319-335.
48. Borg L.E., Brandon A.D., Clynne M.A. and Walker R.J. (2000) Re-Os isotopic systematics of primitive basalts from the Lassen region of the Cascade arc, California. Earth Planet. Sci. Lett. 177, 301-317.
49. Helz G.R., Adelson J.M., Miller C.V., Cornwell J.C., Hill J.M., Horan M. and Walker R.J. (2000) Osmium isotopes demonstrate distal transport of contaminated sediments in Chesapeake Bay. Environmental Science and Technology 34, 2528-2534.
50. Becker H. (2000) Re-Os isotopic systematics of eclogites: Implications for crustal recycling. Earth Planet. Sci. Lett. 177, 287-300.
51. Walker R.J. (2000) News & Views: The extraterrestrial wedding ring. Nature 406, 359-360.
52. Brandon A.D., Walker R.J., Morgan J.W. and Goles G.G. (2000) Re-Os isotopic evidence for early differentiation of the Martian mantle. Geochim. Cosmochim Acta. 64, 4083-4095.
53. Czamanske G.K., Wooden J.L., Walker R.J., Fedorenko V.A., Simonov O.N., Budahn J.R. and Siems D.F. (2000) Geochemical, isotopic and SHRIMP age data for Precambrian basement rocks, Permian volcanic rocks, and sedimentary host rocks to the ore-bearing intrusions, Noril'sk-Talnakh District, Siberian Russia. International Geology Review, 42, 895-927.
2001
54. Begemann F., Ludwig K.R., Lugmair G.W., Min K.W., Nyquist L.E., Patchett P.J., Renne P.R., Shih C.-Y., Villa I.M. and Walker R.J. (2001) Towards and improved set of decay constants for geochronological use. Geochim. Cosmochim Acta 65, 111-121.
55. Meisel T., Walker R.J., Irving A.J., and Lorand J.-P. (2001) Osmium isotopic compositions of mantle xenoliths: a global perspective. Geochim. Cosmochim Acta. 65, 1311-1323.
56. Walker R.J. and Stone W.R. (2001) Os isotope constraints on the origin of the 2.7 Ga Boston Creek flow, Ontario, Canada. Chemical Geology 175, 567-579.
57. Hanski E., Walker R.J., Huhma H. and Suominen I. (2001) The Os and Nd isotopic systematics of the 2.44 Ga Akanvaara and Koitelainen mafic layered intrusions in northern Finland. Precambrian Research 109, 73-102.
58. Horan M.F., Morgan J.W., Walker R.J. and Cooper R. (2001) Re-Os isotopic constraints on magma mixing in the peridotite zone of the Stillwater Complex, Montana. Contrib. Mineral. Petrol. 141, 446-457.
59. Becker H., Walker R.J., MacPherson G.J., Morgan J.W. and Grossman J.N. (2001) Rhenium-osmium systematics of calcium-aluminum-rich inclusions in carbonaceous chondrites. Geochim. Cosmochim. Acta 65, 3379-3390.
60. Morgan J.W., Walker R.J., Brandon A.D. and Horan M.F. (2001) Siderophile elements in Earth's upper mantle and lunar breccias: Data synthesis suggests manifestations of the same late influx. Meteoritics and Planetary Science 36, 1257-1275.
61. Waight T.E., Wiebe R.A., Krogstad E.J. and Walker R.J. (2001) Isotopic responses to basaltic injections into silicic magma chambers: a whole rock and microsampling study of macrorhythmic units in the Pleasant Bay layered gabbro-diorite complex, Maine, USA. Contrib. Mineral. Petrol. 142, 323-335.
62. Becker H., Shirey S.B. and Carlson R.W. (2001) Effects of melt percolation on the Re-Os systematics of peridotites from a Paleozoic convergent plate margin. Earth Planet. Sci. Lett. 188, 107-121.
63. Meisel T., Moser J. and Wegscheider W. (2001) Recognizing heterogeneous distribution of platinum group elements (PGE) in geological materials by means of the Re-Os isotope system. Fresenius J. Anal. Chem. 370, 566-572.
64. Dorais, M. J., Wintsch, R. P., Becker H. (2001) The Massabesic gneiss complex, New Hampshire: a study of a portion of the Avalon terrane. American Journal of Science 301, 657-682.
2002
65. Morgan J.W., Walker R.J., Horan M.F. and Beary E.S. (2002) ¹⁹⁰Pt-¹⁸⁶Os and ¹⁸⁷Re-¹⁸⁷Os systematics of the Sudbury Igneous Complex, Ontario. Geochim. Cosmochim. Acta 66, 273-290.
66. Walker R.J., Prichard H.M., Ishiwatari A. and Pimentel M. (2002) The osmium isotopic composition of convecting upper mantle deduced from ophiolite chromitites. Geochim. Cosmochim. Acta 66, 329-345.
67. Tomascak P.B., Widom E., Benton L.D., Goldstein S.L. and Ryan J.G. (2002) The control of lithium budgets in island arcs. Earth Planet. Sci. Lett. 196, 227-238.
68. Owens B.E. and Tomascak P.B. (2002) Mesoproterozoic lamprophyres in the Labrieville Massif, Quebec: Clues to the origin of alkalic anothosites? Can. J. Earth Sci. 39, 983-997.
69. Zack T., Tomascak P.B., Rudnick R.L., Dalpe C. and McDonough W.F. (2003) Extremely light Li in orogenic eclogites: The role of isotope fractionation during dehydration in subducted oceanic crust. Earth and Planetary Science Letters 208, 279-290.
70. Walker R.J. and Nisbet E. (2002) ¹⁸⁷Os isotopic constraints on Archean mantle dynamics. Geochim. Cosmochim. Acta 66, 3317-3325.
71. Walker R.J., Horan M.F., Morgan J.W., Becker H., Grossman J.N. and Rubin A. (2002) Comparative ¹⁸⁷Re-¹⁸⁷Os systematics of chondrites: Implications regarding early solar system processes. Geochim. Cosmochim. Acta 66, 4187-4201.
72. Becker H., Dalpe C. and Walker R.J. (2002) High precision Ru isotopic measurements by multi-collector ICP-MS. The Analyst 127, 775-780.
2003
73. Brandon A.D., Walker R.J., Puchtel I.S., Becker H, Humayun M. and Revillon S. (2003) ¹⁸⁶Os-¹⁸⁷Os systematics of Gorgona Island komatiites: implications for early growth of the inner core. Earth Planet. Sci. Lett. 206, 411-426.
74. Horan M.F., Walker R.J., Morgan J.W., Grossman J.N. and Rubin A. (2003) Highly siderophile elements in chondrites. Chem. Geol. 196, 5-20.
75. Becker H. and Walker R.J. (2003) The ⁹⁸Tc-⁹⁸Ru and ⁹⁹Tc-⁹⁹Ru chronometers: new results on iron meteorites and chondrites. Chem. Geol. 196, 43-56.
76. Wu F., Walker R.J., Ren X-w, Sun D-y and Zhou X-h. (2003) Osmium isotopic constraints on the age of lithospheric mantle beneath northeastern China. Chem. Geol. 196, 107-129.
77. Gangopadhyay A. and Walker R.J. (2003) Re-Os systematics of the ca. 2.7 Ga Alexo komatiites, Ontario, Canada. Chem. Geol. 196, 147-162.
78. Tomascak P.B., Hemming N.G., and Hemming S.R. (2003) The lithium isotopic composition of waters of the Mono Basin, California. Geochim. Cosmochim. Acta 67, 601-611.
79. Arndt N.T., Czamanske G.K., Walker R.J., Chauvel C. and Fedorenko V.A. (2003) Geochemistry and origin of the intrusive hosts of Noril'sk-Talnakh Cu-Ni-PGE deposits. Econ. Geol. 98, 495-515.
80. Becker H. and Walker R.J. (2003) Efficient mixing of the solar nebula from uniform Mo isotopic composition of meteorites. Nature 425, 152-155.
2004
81. Lazar G.C., Walker D. and Walker R.J. (2004) Experimental partitioning of Tc, Mo, Ru and Re between solid and liquid during crystallization in Fe-Ni-S. Geochim. Cosmochim. Acta 68, 643-651.
82. McDaniel D.K., Walker R.J., Hemming S.R., Horan M.F., Becker H. and R. I Grauch (2004) Sources of osmium to the modern oceans: New evidence from the ¹⁹⁰Pt-¹⁸⁶Os system. Geochim. Cosmochim. Acta 68, 1243-1252.
83. Cook D.L. Walker R.J., Horan M.F., Wasson J.T. and Morgan J.W. (2004) Pt-Re-Os systematics of group IIAB and IIIAB iron meteorites. Geochim. Cosmochim. Acta 68, 1413-1431.
84. West, D.P., Jr., Coish, R.A., and Tomascak, P.B. (2004) Tectonic setting and regional correlation of Ordovician metavolcanic rocks of the Casco Bay Group, Maine: Evidence from trace element and isotope geochemistry: Geol. Mag. 141, 125-140.
85. Hanski E.J., Walker R.J. Huhma H., Polyakov, G.V., Glotov, A.I., Tran Trong Hoa, Ngo Thi Phuong (2004) Origin of Permo-Triassic komatiites, northwestern Vietnam. Contrib. Mineral. Petrol. 147, 453-469.
86. Balykin, P.A., Polyakov, G.V., Hanski, E., Walker, R.J., Huhma, H., Glotov, A.I., Trang Trong Hoa, Ngo Thi Phuong, Hoang Huu Thanh, Tran Quoc Hung, Petrova, T.E. (2004) Late-Permian komatiite-basalt complex in the Song Da rift, northwestern Vietnam. Journal of Geology (Vietnam), Series B, No. 23, 52-64.
87. Gornostayev S.S., Walker R.J., Hanski E.J. and Popovchenko S.E. (2004) Evidence for the emplacement of ca. 3.0 Ga lithospheric mantle in the Ukrainian Shield. Precamb. Res. 132, 349-362.
88. Gelinas A., Kring D.A., Zurcher L., Urrutia-Fucugauchi J., O. Morton and Walker R.J. (2004) Osmium isotope constraints on the proportion of bolide component in Chicxulub impact meltrocks. Meteoritics Planet. Sci. 39, 1003-1008.
89. Teng F.Z., McDonough W.F., Rudnick R.L., Dalpé C., Tomascak P.B., Gao S., Chappell B.W. (2004) Lithium isotopic composition and concentration of the upper continental crust. Geochim. Cosmochim. Acta 68, 4181-4192.
90. Tomascak P.B. (2004) Developments in the understanding and application of lithium isotopes in the Earth and planetary sciences. In: Johnson CM, Beard BA, and Albarede F (eds) Geochemistry of Non-Traditional Isotope Systems, Min. Soc. Amer. Reviews Mineralogy Geochemistry. 55, 153-195.
91. Walker R. J., Horan M.F., Shearer C.K. and Papike J.J. (2004) Depletion of highly siderophile elements in the lunar mantle: evidence for prolonged late accretion. Earth Planet. Sci. Lett. 224, 399-413.
92. Rudnick R.L., Tomascak P.B., Njo H.B. and Gardner L.R. (2004) Extreme lithium isotopic fractionation during continental weathering revealed in saprolites from South Carolina. Chem. Geol. 212, 45-57.
2005
93. Hulbert L.J., Hamilton M.A., Horan M.F. and Scoates R.F.J. (2005) U-Pb zircon and Re-Os isotope geochronology of mineralized ultramafic intrusions and associated nickel ores from the Thompson nickel belt, Manitoba, Canada. Econ. Geol. 100, 29-41.
94. Tomascak P.B., Brown M., Solar G.S., Becker H., Centorbi T.L., and Tian J. (2005) Source contributions to Devonian granite magmatism near the Laurentian border, New Hampshire and Western Maine, USA. Lithos 80, 75-99.
95. Walker R. J., Brandon A.D., Bird J.M., Piccoli P.M., McDonough W.F. and Ash R.D. (2005) ¹⁸⁶Os-¹⁸⁷Os systematics of Os-Ir-Ru alloy grains, southwestern Oregon. Earth Planet. Sci. Lett 230, 211-226.
96. Brandon A. D. and Walker R.J. (2005) The debate over core-mantle interaction. Earth Planet. Sci. Lett. Frontiers 232, 211-225.
97. Terakado Y. and Walker R.J. (2005) Nd, Sr and Pb isotopic and REE geochemical study of Miocene submarine hydrothermal deposits (Kuroko deposits), Japan, Contrib. Mineral. Petrol. 149, 388-399.
98. Walker R.J. and Walker D. (2005) Does the core leak? EOS 86, 237-242.
99. Lynton S.J., Walker R.J. and Candela P.A. (2005) Lithium isotopes in the system Qz-Ms-fluid. Geochim. Cosmochim. Acta 69, 3337-3347.
100. Puchtel I.S., Brandon A.D., Humayun M., and Walker, R.J. (2005) Evidence for the early differentiation of the core from Pt-Re-Os isotope systematics of 2.8-Ga komatiites. Earth Planet. Sci. Lett. 237, 118-134.
101. Gangopadhyay A., Sproule R.A., Walker R.J. and Lesher M. (2005) Re-Os systematics of komatiites and komatiitic basalts at Dundonald Beach, Ontario, Canada: Evidence for a complex alteration history and implications of a late-Archean chondritic mantle source. Geochim. Cosmochim. Acta 69, 5087-5098.
102. Mann J.L. and Kelly W.R. (2005) Measurement of sulfur isotope composition (δ³⁴S) by multiple-collector thermal ionization mass spectrometry using a ³³S-³⁶S double spike. Rapid Commun. In Mass Spectrom. 19, 3429-3441.
2006
103. Brandon A.D., Humayun M., Puchtel I.S., Leya I. and Zolensky M. (2006) Osmium isotope evidence for an s-process carrier in primitive chondrites. Science 309, 1233-1236.
104. Pietruszka A.J., Walker R.J. and Candela P.A. (2006) Determination of mass dependent molybdenum isotopic variations by MC-ICP-MS: an evaluation of matrix effects. Chem. Geol. 225, 121-136.
105. Gangopadhyay A., Walker R.J., E. Hanski, and P. Solheid (2006) Origin of Paleoproterozoic Ti-enriched komatiitic rocks from Jeesiörova, Kittilä Greenstone Complex, Finnish Lapland. Journal of Petrology 47, 773-789.
106. Teng F.-Z., McDonough W.F., Rudnick R.L. and Walker R.J. (2006) Diffusion-driven extreme lithium isotopic fractionation in country rocks of the Tin Mountain pegmatite. Earth Planet. Sci. Lett. 243, 701-710.
107. Brandon A.D., Walker R.J. and Puchtel I.S. (2006) Platinum-Os isotope evolution of the Earth's mantle: constraints from chondrites and Os-rich alloys. Geochim. Cosmochim. Acta 70, 2093-2103.
108. Lee S. R., Horton J.W. and Walker R.J. (2006) Osmium-isotope and platinum-group element systematics of impact melt rocks, Chesapeake Bay Impact Structure, Virginia, USA. Meteoritics Planet. Sci. 41, 819-833.
109. Teng F.-Z., McDonough W.F., Rudnick R.L. and Walker R.J. (2006) Lithium isotopic systematics of granites and pegmatites from the Black Hills, South Dakota. Am. Min. 91, 1488-1498.
110. Lee S. R. and Walker R. J. (2006) Re-Os isotope systematics of mantle xenoliths from South Korea: evidence for complex growth and loss of lithospheric mantle beneath East Asia. Chem. Geol. 231, 90-101.
111. Becker H., Horan M.F., Walker R.J., Gao S., Lorand J.-P. and Rudnick R.L. (2006) Highly siderophile element composition of the Earth's primitive upper mantle: Constraints from new data on peridotite massifs and xenoliths. Geochim. Cosmochim. Acta 70, 4528-4550.
112. Wu F-Y., Walker R.J., Yang Y-H., Yuan H-L., and Yand J-H. (2006) The chemical-temporal evolution of lithospheric mantle underlying the North China Craton. Geochim. Cosmochim. Acta 70, 5013-5034.
2007
113. Yuan H., Gao S., Rudnick R.L., Jin Z., Liu Y., Puchtel I., Walker R.J. and Yu R. (2007) Re-Os evidence for age and origin of peridotites from the Dabie-Sulu ultrahigh pressure metamorphic belt, China. Chem. Geol. 236, 323-338.
114. West Jr. D.P., Tomascak P.B., Coish R.A., Yates M.G. and Reilly M.J. (2007) Petrogenesis of the ultrapotassic Lincoln syenite, Maine: late Silurian-early Devonian melting of a source region modified by subduction-driven metasomatism. Amer. J. Sci. 307, 265-310.
115. Yokoyama T., Rai V.K., Alexander C.M.O'D., Lewis R.S., Carlson R.W., Shirey S.B., Thiemens M.H. and Walker R.J. (2007) Osmium isotope evidence for uniform distribution of s- and r-process components in the early solar system. Earth and Planet. Sci. Lett. 259, 567-580.
116. Puchtel I., Humayun M. and Walker R.J. (2007) Os-Nd-Pb isotope and lithophile and siderophile trace element systematics of komatiitic rocks from the Volotsk suite, SE Baltic Shield. Precambrian Res. 158, 119-137.
117. Walker R.J., Böhlke J.-K., McDonough W.F. and Li J. (2007) Combined Re-Os isotope, gold and platinum-group element study of epigenetic gold ores, Alleghany District, California. Economic Geology 102, 1079-1089.
2008
118. Walker R.J., McDonough W.F., Honesto J., Chabot N.L., McCoy T.J., Ash R.D. and Bellucci J.J. (2008) Modeling fractional crystallization of group IVB iron meteorites. Geochim. Cosmochim. Acta 72, 2198-2216.
119. Van Acken D., Becker H. and Walker R.J. (2008) Mantle refertilization processes and their impact on the Re-Os systematics of peridotites: a case study from the Totalp ultramafic massif, eastern Switzerland. Earth Planetary Sci. Lett. 268, 171-181.
120. Gao S., Rudnick R.L., Xu W-L., Yuan H-L., Liu Y-S., Walker R.J., Puchtel I.S., Liu X., Huang H. and Wang X-R. (2008) Recycling deep cratonic lithosphere and generation of intraplate magmatism in the North China Craton. Earth Planet. Sci Lett. 270, 41-53.
121. Puchtel I.S., Walker R.J., James O.B. and Kring D.A. (2008) Osmium isotope and highly siderophile element systematics of lunar impact melt rocks: Implications for the late accretion history of the Moon and Earth. Geochim. Cosmochim. Acta 72, 3022-3042.
122. Sichel S.E., Espernca S., Motoki A., Maia M., Horan M.F., Szartman P., Alves E.dC. and Mello S.M. (2008) Geophysical and geochemical evidence for cold upper mantle beneath the equatorial Atlantic Ocean. Revista Brasileira de Goefisica 26, 69-86.
2009
123. Day J.M.D., Ash R.D., Liu Y., Bellucci J.J., Rumble D., McDonough W.F., Walker R.J. and Taylor L.A. (2009) Early formation of evolved asteroidal crust. Nature 457, 179-182.
124. Ireland T., Walker R.J. and Garcia M.O. (2009) Highly siderophile element and ¹⁸⁷Os isotopes systematics of Hawaiian picrites: Implications for parental melt composition and source heterogeneity. Chemical Geology 260, 112-128.
125. Pitcher L., Helz R.T., Walker R.J. and Piccoli P.M. (2009) Fractionation of the platinum-group elements and Re during crystallization of basalt in Kilauea Iki lava lake, Hawaii. Chemical Geology 260, 196-210.
126. Yokoyama D., Walker D. and Walker R.J. (2009) Low osmium solubility in silicate at high pressures and temperatures. Earth Planetary Sci. Lett. 279, 165-173.
127. Basu A., Day J.M.D., Liu Y., Rumble D. and Taylor L.A. (2009) Petrogenesis of olivine-phyric shergottite Larkman Nunatak 06319: Implications for enriched components in Martian basalts. Geochim. Cosmochim. Acta 73, 2190-2214.
128. Walker R.J. (2009) Highly siderophile elements in the Earth, Moon and Mars: Update and implications for planetary accretion and differentiation. Chemie der Erde 69, 101-125.
129. Ackerman L., Walker R.J., Puchtel I.S., Pitcher L., Jelínek E. and Strnad L. (2009) Effects of melt perolation on highly siderohile elements and Os isotopes in subcontinental lithospheric mantle: a study of the upper mantle profile beneath Central Europe. Geochim. Cosmochim. Acta 73, 2400-2414.
130. Ireland T.J., Arevalo R.D., Walker R.J. and McDonough W.F. (2009) Tungsten in Hawaiian picrites: a compositional model for the source of Hawaiian lavas. Geochim. Cosmochim. Acta 73, 4517-4530.
131. Puchtel I.S., Walker R.J., Anhaeusser C.R. and Gruau G. (2009) Re-Os isotope systematics and HSE abundances of the 3.5 Ga Schapenburg komatiites, South Africa: evidence for hydrous melting or prolonged survival of primordial heterogeneities in the mantle? Chemical Geology 262, 355-369.
132. Rudnick R.L. and Walker R.J. (2009) Ages from Re-Os isotopes in peridotites. Proceedings of the 9th Kimberlite Conference, Lithos 112S, 1083-1095.
133. Chu Z-Y., Wu F-Y., Walker R.J., Rudnick R.L., Pitcher L., Puchtel I.S., Yang Y-H. and Wilde S.A. (2009) Temporal evolution of the lithospheric mantle beneath the eastern North China Craton. Journ. Petrol. 50, 1857-1898.
134. Schulte R.F., Schilling M., Horan M.F., Anma R., Komiya T., Farquhar J., Piccoli P.M., Pitcher L. and Walker R.J. (2009) Chemical and chronologic complexity in the convecting upper mantle: evidence from the Taitao Ophiolite, southern Chile. Geochim. Cosmochim. Acta 73, 5793-5819.
135. O'Driscoll B., Day J.M.D., Daly J.S., Walker R.J. and McDonough W.F. (2009) Rhenium-osmium isotopes and platinum-group elements in the Rum Layered Suite, Scotland: implications for Cr-spinel seam formation and the longevity of the Iceland mantle anomaly. Earth Planet. Sci. Lett. 286, 41-51.
136. Horan M.F., Alexander C.M.O'D. and Walker R.J. (2009) Highly siderophile element evidence for early solar system processes in components from ordinary chondrites. Geochim. Cosmochim. Acta 73, 6984-6997.
137. Puchtel I.S., Walker R.J., Brandon A.D. and Nisbet E.G. (2009) Pt-Re-O isotope and HSE systematics of the 2.7 Ga Belingwe and Abitibi komatiites. Geochim. Cosmochim. Acta 73, 6367-6389.
138. Liu Y., Floss C., Day J.M.D., Hill E. and Taylor L.A. (2009) Petrogenesis of lunar mare basalt meteorite Miller Range 05035. Meteoritics and Planet. Sci. 44, 261-284.
2010
139. Van Acken D., Becker H. and Walker R.J., McDonough W.F., Wombacher F., Ash R.D. and Piccoli P.M. (2010) Formation of pyroxenite layers in the Totalp ultramafic massif (Swiss Alps) – insights from highly siderophile elements and Os isotopes. Geochim. Cosmochim. Acta 74, 661-683.
140. Scheiderich K., Helz G.R. and Walker R.J. (2010) Century-long record of Mo isotopic composition in sediments of a seasonally anoxic estuary (Chesapeake Bay). Earth Planet. Sci. Lett. 289, 189-197.
141. Day J.M.D., Walker R.J., James O.B. and Puchtel I.S. (2010) Osmium isotope and highly siderophile element systematics of the lunar crust. Earth Planet Science Lett. 289, 595-605.
142. Yokoyama T., Alexander C.M.O'D. and Walker R.J. (2010) Osmium isotope anomalies in chondrites: results for acid residues enriched in insoluble organic matter. Earth Planet. Sci. Lett. 291, 48-59.
143. Van Acken D., Becker H., Hammerschmidt K., Walker R.J. and Wombacher F. (2010) Highly siderophile elements and Sr-Nd isotopes in refertilized mantle peridotites – a case study from the Totalp ultramafic massif, Swiss Alps. Chem. Geol. 276, 257-268.
144. Yang J-H., O'Reilly S., Walker R.J., Griffin W., Wu F-Y., Zhang M. and Pearson N. (2010) Diachronous decratonization of the Sino-Korean Craton: geochemistry of mantle xenoliths from North Korea. Geology 38, 799-802.
145. Liu J., Rudnick R.L., Walker R.J., Gao S., Wu F. and Piccoli P. (2010) Processes controlling highly siderophile element fractionations in xenolithic peridotites and their influence on Os isotopes. Earth Planet. Sci. Lett. 297, 287-297.
146. Scheiderich K., Zerkle A.L., Helz G.R., Farquhar J. and Walker R.J. (2010) Molybdenum isotope, multiple sulphur isotope, and redox-sensitive element behaviour in early Pleistocene Mediterranean sapropels. Chemical Geology 279, 134-144.
147. Bottke W.F., Walker R.J., Day J.M.D., Nesvorny D. and Elkins-Tanton L. (2010) Stochastic late accretion to Earth, the Moon and Mars. Science 330, 1527-1530.
148. Hanghøj K., Kelemen P.B., Hassler D., and Godard M. (2010) Composition and genesis of depleted mantle peridotites from the Wadi Tayin Massif, Oman Ophiolite; major and trace element geochemistry, and Os isotope and PGE systematics. Journ. of Petrol. 51, 201-227.
149. Day J.M.D., Pearson D.G., Macpherson C.G., Lowry D. and Carracedo J.C. (2010) Evidence for distinct proportions of subducted oceanic crust and lithosphere in HIMU-type mantle beneath El Hierro and La Palma, Canary Islands. Geochim. Cosmochim. Acta 74, 6565-6589.
150. Blichert-Toft J. and Puchtel I.S. (2010) Depleted mantle sources through time: evidence from Lu-Hf and Sm-Nd isotope systematics of Archean komatiites. Earth Planet. Sci. Lett. 297, 598-606.
2011
151. Riches A.J.V., Liu Y., Day J.M.D., Puchtel I.S., Rumble D., McSween H.Y., Walker R.J. and Taylor L.A. (2011) The petrology and geochemistry of Yamato 984028: a cumulate lherzolitic shergottites with affinities to Y 000027, Y 000047, and Y 000097. Polar Sci. 4, 497-514.
152. Yokoyama T., Alexander C.O'D. and Walker R.J. (2011) Assessment of nebular versus parent body processes on presolar components in chondrites: evidence from Os isotopes. Earth Planet. Sci. Lett. 305, 115-123.
153. Liu J., Rudnick R.L., Walker R.J., Gao S., Wu F-y., Piccoli P.M., Yuan H., Xu W-L. and Xu Y-G. (2011) Mapping lithospheric boundaries using Os isotopes of mantle xenoliths: an example from the North China Craton. Geochim. Cosmochim. Acta 75, 3881-3902.
154. Ireland T.J., Walker R.J. and Brandon A.D. (2011) ¹⁸⁶Os-¹⁸⁷Os systematics of Hawaiian picrites revisited: additional insights into the causes of Os isotopic variations in ocean island basalts. Geochim. Cosmochim. Acta 75, 4456-4475.
155. Moskovitz N. and Walker R.J. (2011) Size of the group IVA meteorite core: constraints from the age and composition of Muonionalusta. Earth Planet. Sci. Lett. 308, 410-416.
156. Hanski E.J., Luo Z-Y., Oduro H. and Walker R.J. (2011) The Pechenga Ni-Cu sulfide deposits, NW Russia: a review with new constraints from the feeder dikes. In: Li., C., Ripley, E.M. (eds.) Magmatic Ni-Cu and PGE Deposits: Geology, Geochemistry, and Genesis. Reviews in Economic Geology 17, 145-162.
157. Connolly B.D., Puchtel I.S., Walker R.J., Arevalo R., Piccoli P.M., Byerly G., Robin-Popieul C. and Arndt N. (2011) Highly siderophile element systematics of the 3.3 Ga Weltevreden komatiites, South Africa: implications for early Earth history. Earth Planet. Sci. Lett. 311, 253-263.
2012
158. McCoy T.J., Walker R.J., Goldstein J.I., Yang J., McDonough W.F., Rumble D., Chabot N.L., Ash R.D., Corrigan C.M., Michael J.R. and Kotula P.G. (2011) Group IVA irons: new constraints on the crystallization and cooling history of an asteroidal core with a complex history. Geochim. Cosmochim. Acta 75, 6821-6843.
159. Touboul M. and Walker R.J. (2012) High precision tungsten isotope measurement by thermal ionization mass spectrometry. International Journal of Mass Spectrometry 309, 109-117.
160. Brandon A.D., Puchtel I.S., Walker R.J., Day J.M.D., Irving A.J. and Taylor L.A. (2012) Evolution of the martian mantle inferred from the ¹⁸⁷Re-¹⁸⁷Os isotope and highly siderophile element systematics of shergottites meteorites. Geochim. Cosmochim. Acta 76, 206-235.
161. Day J.M.D., Walker R.J., Ash R.D., Liu Y., Rumble D., Irving A.J., Goodrich C.A., Tait K., McDonough W.F. and Taylor L.A. (2012) Origin of Graves Nunataks 06128 and 06129, brachinites and brachinite-like achondrites by partial melting of volatile-rich primitive parent bodies. Geochim. Cosmochim. Acta 81, 94-128.
162. Penniston-Dorland S. C., Walker R.J., Pitcher L. and Sorensen S. S. (2012) Mantle-crust interactions in a paleosubduction zone: evidence from highly-siderophile element systematics of eclogite and related rocks. Earth Planet. Sci. Lett. 319-320, 295-306.
163. Touboul M., Puchtel I.S. and Walker R.J. (2012) ¹⁸²W evidence for long-term preservation of early mantle differentiation products. Science 335, 1065-1069, DOI: 10.1126/science.1216351.
164. O'Driscoll B., Day J.M.D., Walker R.J., Daly S., McDonough W.F. and Piccoli P.M. (2012) Chemical heterogeneity in the upper mantle recorded by peridotites and chromitites from the Shetland Ophiolite Complex, Scotland. Earth Planet. Sci. Lett. 333-334, 226-237.
165. Hibbert K.E.J., Williams H.M. and Puchtel I.S. (2012) Iron isotopes in ancient and modern komatiites: evidence in support of an oxidised mantle from Archean to present. Earth Planet. Sci. Lett. 321-322, 198-207.
166. Rocha E.R.V., Puchtel I.S., Marques L.S., Walker R.J., Machado F.B., Nardy A.J.R., Babinski M. and Figueiredo A.M.G. (2012) Re-Os isotope and highly siderophile element systematics of the Paraná continental flood basalts (Brazil). Earth Planet. Sci. Lett. 337-338, 164-173.
167. Day J.M.D., Walker R.J., Qin L. and Rumble D. (2012) Early timing of late accretion in the solar system. Nature Geoscience 5, 614-617.
168. Walker R.J. (2012) Evidence for homogeneous distribution of osmium in the protosolar nebula. Earth Planet. Sci. Lett. 351-352, 36-44.
169. Riches A.J.V., Day J.M.D., Walker R.J., Simonetti A., Liu Y., Neal C.R., and Taylor L.A. (2012) Rhenium-osmium isotope and highly-siderophile element abundance systematics of angrite meteorites. Earth Planet. Sci. Lett. 353-354, 208-218.
170. Moynier F., Day J.M.D., Okui W., Yokoyama T., Bouvier A., Walker R.J. and Podosek F.A. (2012) Planetary-scale strontium isotopic heterogeneity. Astrophys. Journ. 758, 45.
171. Liu J., Carlson R.W., Rudnick R.L., Walker R.J., Gao S. and Wu F-y. (2012) Comparative Sr-Nd-Hf-Os-Pb isotopic systematics of xenolithic peridotites from Yangyuan, North China Craton: additional evidence for a Paleoproterozoic age. Chem. Geol. 332-333, 1-14.
172. Jenniskens P., Fries M.D., Yin Q-Z., Zolensky M., Krot A.N., Sandford S.A., Sears D., Beauford R., Ebel D.S., Friedrich J.M., Nagashima K., Wimpenny J., Yamakawa A., Nishiizumi K., Hamajima Y., Cafee M.W., Welten K.C., Laubenstein M., Davis A.M., Simon S.B., Heck P.R., Young E.D., Kohl I.E., Thiemens M.H., Nunn M.H., Mikouchi T., Hagiya K., Ohsumi K., Cahil T.A., Lawton J.A., Barnes D., Steele A., Rochette P., Verosub K.L., Gattacceca J., Cooper G., Glavin D.P., Burton A.S., Dwrorkin J.P., Elsila J.E., Pizzarello S., Ogliore R., Schmitt-Koppin P., Harir M., Herkorn N., Verchovsky A., Grady M., Nagao K., Okazaki R., Takechi H., Hiroi T., Smith K., Silber E.A., Brown P.G., Albers J., Klotz D., Hankey M., Matson R., Fries J.A., Walker R.J., Puchtel I., Lee C-T. A., Erdman M.E., Eppich G.R., Roeske S., Gabelica Z., Lerche M., Nuevo M., Girten B. and Worden S.P. (2012) Radar enable recovery of the Sutter's Mill meteorite, a carbonaceous chondrite regolith breccia. Science 338, 1583-1587. DOI: 10.1126/science.1227163.
2013
173. Ackerman L., Pitcher L., Strnad L., Puchtel I.S., Jelínek E. and Walker R.J. (2013) Highly siderophile element geochemistry of peridotites and pyroxenites from Horní Bory: implications for HSE behaviour in subduction-related upper mantle. Geochim. Cosmochim. Acta 100, 158-175.
174. McCoy-West A.J., Puchtel I.S., Bennett V.C. and Walker R.J. (2013) Extreme persistence of cratonic lithosphere in the Southwest Pacific: Paleoproterozoic Os isotopic signatures in Zealandian mantle xenoliths. Geology, doi:10.1130/G33626.1.
175. Puchtel I.S., Blichert-Toft J., Touboul M., Walker R.J., Byerly G.R., Nisbet E.G. and Anhaeusser C.R. (2013) Insights into early Earth from Barberton komatiites: evidence from lithophile isotope and trace element systematics. Geochim. Cosmochim. Acta 108, 63-90.
176. Arevalo Jr. R., McDonough W.F., Stracke A., Willbold M., Ireland T.J. and Walker R.J. (2013) Simplified mantle architecture and distribution of radiogenic power. Geochem. Geophys Geosyst. 14, 2265-2285.
177. Geboy N.J., Kaufman A.J., Walker R.J., Misi A., de Oliviera T.F., Miller K.E., Azmy K., Kendall B. and Poulton S. (2013) Re-Os age constraints and new observations of glacial deposits in the Mesoproterozoic Vazante Group, Brazil. Precamb. Res. 238, 199-213.
2014
178. Walker R.J. (2014) Rhenium-Osmium Dating (Meteorites), Encyclopedia of Scientific Dating Methods. (W.J. Rink and J. Thompson eds.), Springer Science. 9 pp. DOI 10.1007/978-94-007-6326-5_85-1.
179. Puchtel I.S., Walker R.J., Touboul M., Nisbet E.G. and Byerly G.R. (2014) Insights into early Earth from the Pt-Re-Os isotope and highly siderophile element abundance systematics of Barberton komatiites. Geochim. Cosmochim. Acta 125, 394-413.
180. Sharp M., Gerasimenko I., Loudin L.C., Liu J., James O.B., Puchtel I.S. and Walker R.J. (2014) Characterization of the dominant impactor signature for Apollo 17 impact melt rock. Geochim. Cosmochim. Acta 131, 62-80.
181. Archer G.J., Bullock E.S., Ash R.D. and Walker R.J. (2014) ¹⁸⁷Re-¹⁸⁷Os isotopic and highly siderophile element systematics of the Allende meteorite: evidence for primary nebular processes and late-stage alteration. Geochim. Cosmochim. Acta 131, 402-414.
182. Kruijer T.S., Touboul M., Fischer-Gӧdde M., Bermingham K.R., Walker R.J. and Kleine T. (2014) Protracted core formation and rapid accretion of protoplanets. Science 344, 1150-1154.
183. Touboul M., Liu J., O"Neil J., Puchtel I.S. and Walker R.J. (2014) New insights into the Hadean mantle revealed by ¹⁸²W and highly siderophile element abundances of supracrustal rocks from the Nuvvuagittuq Greenstone Belt, Quebec, Canada. Chem. Geol. 383, 63-75.
184. Penniston-Dorland S.C., Gorman J.K., Bebout G.E., Piccoli P.M. and Walker R.J. (2014) Reaction rind formation in the Catalina Schist: deciphering a history of mechanical mixing and metasomatic alteration. Chem. Geol. 384, 47-61.
185. Walker R.J. (2014) Siderophile element constraints on the origin of the Moon. Phil. Trans. Roy. Soc. A 372, 20130258, DOI:10.1098/rsta.2013.0258.
186. Stepanova A.V., Samsonov A.V., Salnikova E.B., Puchtel I.S., Larionova O., Larionov A.N., Stepanov V.S., Shapovalov Y.B. and Egorova S.V. (2014) Palaeoproterozoic continental MORB-type tholeiites in the Karelian Craton: petrology, geochronology, and tectonic setting. Journ. Petrol. 55, 1719-1751.
187. González-Jiménez J.M., Barra F., Walker R.J., Reich M. and Gervilla F. (2014) Geodynamic implications of ophiolitic chromitites in the La Cabaña ultramafic bodies, Central Chile. Internat. Geology Rev. 56, 1466-1483.
188. Brown S., Elkins-Tanton L. and Walker R.J. (2014) Effects of magma ocean crystallization and overturn on the development of ¹⁴²Nd and ¹⁸²W isotopic heterogeneities in the primordial mantle. Earth Planet. Sci. Lett. 408, 319-330.
189. Antonelli M.A., Kim S-T., Peters M., Labidi J., Cartigny P., Walker R.J., Lyons J.R., Hoek J., and Farquhar J. (2014) An early inner Solar System origin for anomalous sulfur isotopes in differentiated protoplanets. Proc. Natl. Acad. Sci. 111, 17749-17754.
190. Tackett L.S., Kaufman A.J., Corsetti F., and Bottjer D.J. (2014) Strontium isotope stratigraphy of the Gabbs Formation (Nevada): implications for global Norian-Rhaetian correlations and faunal turnover. Lethaia 47, 500-511.
2015
191. Liu J., Rudnick R.L., Walker R.J., Xu W-l, Gao S. and Wu Y-y. (2015) Big insights from tiny peridotites: evidence for persistence of Precambrian lithosphere beneath the eastern North China Craton. Tectonophysics 650, 104-112.
192. Sharp M., Righter K. and Walker R.J. (2015) Estimation of trace element concentrations of the lunar magma ocean using mineral-melt and metal-silicate partition coefficients. Meteoritics and Planet. Sci. 50, 733-758.
193. McCoy-West A.J., Bennett V.C., O’Neill H.St.C., Hermann J. and Puchtel I.S. (2015) The interplay between melting, refertilization and carbonatite metasomatism in off-cratonic lithospheric mantle under Zealandia: an integrated major, trace and platinum group element study. Journal of Petrology 56, 563-604 (doi: 10.1093/petrology/egv011).
194. Savage P.S., Moynier F., Chen H., Shofner G., Siebert J., Badro J., and Puchtel I.S. (2015) Isotopic evidence for large-scale sulfide fractionation during Earth’s differentiation. Geochemical Perspectives Letters 1, 53-64 (doi: 10.7185/geochemlet.1506).
195. Puchtel I.S. (2015) When was the Earth’s conveyor belt set in motion? American Mineralogist 100, 2369-2370 (doi: 10.2138/am-2015-5468).
196. Liu J., Sharp M., Ash R.D., Kring D.A. and Walker R.J. (2015) Diverse impactors in Apollo 15 and 16 impact melt rocks: evidence from osmium isotopes and highly siderophile elements. Geochim. Cosmochim. Acta 155, 122-153.
197. Cui H., Kaufman A.J., Xiao S., Zhu M., Zhou C. and Liu X-M. (2015) Redox architecture of an Ediacaran ocean margin: integrated chemostratigraphic (δ¹³C-δ³⁴S-⁸⁷Sr/⁸⁶Sr-Ce/Ce*) correlation of the Doushantuo Formation, South China. Chem. Geol. 405, 48-62.
198. Touboul M., Puchtel I.S. and Walker R.J. (2015) Tungsten isotopic evidence for disproportional late accretion to the Earth and Moon. Nature 520, 530-533.
199. Greber N.D., Puchtel I.S., Nägler T.F., Mezger K. (2015) Komatiites constrain molybdenum isotope composition of the Earth’s mantle. Earth Planet. Sci. Lett. 421, 129-138.
200. Day J.M.D. and Walker R.J. (2015) Highly siderophile element depletion in the Moon. Earth Planet. Sci. Lett. 423, 114-124.
201. Walker R.J., Bermingham, K., Liu J., Puchtel I.S., Touboul M. and Worsham E. (2015) In search of late-stage planetary building blocks. Chem. Geol. 411, 125-142.
202. Carlson R.W., Boyet M., O’Neil J., Rizo H. and Walker R.J. (2015) Early differentiation and its long term consequences for Earth evolution. In: The Early Earth: Accretion and Differentiation (eds. J. Badro and M. Walter), American Geophysical Union Geophysical Monograph 212, John Wiley & Sons, Inc., pp. 143-172.
203. O’Driscoll B., Walker R.J., Day J.M.D., Ash R.D. and Daly S.J. (2015) Generations of melt extraction, melt-rock interaction and high-temperature metasomatism preserved in peridotites of the ~497 Ma Leka Ophiolite Complex, Norway. Journ. Petrol. 56, 1797-1828.
2016
204. Yokoyama T. and Walker R.J. (2016) Nucleosynthetic isotope variations of siderophile and chalcophile elements in the Solar System. Reviews in Mineralogy & Geochemistry. v. 81, pp. 107-160.
205. Day J.M.D., Brandon A.D. and Walker R.J. (2016) Highly siderophile elements in Earth, Mars, the Moon, and asteroids. Reviews in Mineralogy & Geochemistry. v. 81, pp. 161-238.
206. Rizo H., Walker R.J., Carlson R.W., Touboul M., Horan M.F., Puchtel I.S., Boyet M., Rosing M.T. (2016) Early Earth differentiation investigated through ¹⁴²Nd, ¹⁸²W, and highly siderophile element abundances in samples from Isua, Greenland. Geochim. Cosmochim. Acta 175, 319-336.
207. Day J.M.D., Waters C.L., Schaefer B.F., Walker R.J. and Turner S. (2016) Use of hydrofluoric acid desilicification in the determination of highly siderophile element abundances and Re-Pt-Os isotope systematics in mafic-ultramafic rocks. Geostand. Geoanalyt. Res. 40, 49-65.
208. Trinquier A., Touboul M. and Walker R.J. (2016) High-precision tungsten isotope analysis by multicollection N-TIMS. Analytical Chemistry 88, 1542-1546.
209. Puchtel, I.S., Touboul, M., Blichert-Toft, J., Walker, R.J., Brandon, A.D., Nicklas, R.W., Kulikov, V.S. and Samsonov, A.V. (2016) Lithophile and siderophile element systematics of Earth’s mantle at the Archean-Proterozoic boundary: evidence from 2.4 Ga komatiites. Geochim. Cosmochim. Acta 180, 227-255.
210. Rizo H., Walker R.J., Carlson R.W., Horan M.F., Mukhopadhyay S., Manthos V., Francis D., Jackson M.G. (2016) Memories of Earth formation in the modern mantle: W isotopic compositions of flood basalt lavas. Science 352, 809-812.
211. Liu J., Touboul M., Ishikawa A., Walker R.J. and Pearson D.G. (2016) Widespread tungsten isotope anomalies and W mobility in crustal and mantle rocks of the Eoarchean Saglek Block, northern Labrador, Canada: implications for early Earth processes and W recycling. Earth Planet. Sci. Lett. 448, 13-23.
212. Bermingham K., Walker R.J. and Worsham E.A. (2016) Refinement of high precision Ru isotope analysis using negative thermal ionization mass spectrometry. International Journal of Mass Spectrometry 403, 15-26.
213. Puchtel I.S., Blichert-Toft J., Touboul M., Horan M.F. and Walker R.J. (2016) The Coupled ¹⁸²W-¹⁴²Nd record of the early terrestrial mantle differentiation of Earth’s mantle. Geochemistry, Geophysics, Geosystems 17, 2168-2193. DOI:10.1002/2016GC006324.
214. Worsham E.A., Bermingham K.R. and Walker R.J. (2016) Modelling crystallization of IAB complex iron meteorites using siderophile elements: New insights into the formation of an enigmatic group. Geochim. Cosmochim. Acta 188, 261-283.
215. Walker R.J. (2016) Osmium. Encyclopedia of Geochemistry (W. White ed.), Springer Science, DOI:10.1007/978-3-319-39193-9_127-1.
216. Walker R.J. (2016) Rhenium-Osmium Isotope System. Encyclopedia of Geochemistry (W. White ed.), Springer Science, DOI 10.1007/978-3-319-39193-9_128-1.
217. Walker R.J. (2016) Siderophile elements in tracing planetary formation and evolution. Geochemical Perspectives 5-1, 1-143.
218. Chen K., Walker R.J., Gao S., Rudnick R.L., Gaschnig R.M., Puchtel I.S., Tang M. and Hu Z. (2016) Platinum-group element abundances and Re-Os isotopic systematics of the upper continental crust through time: evidence from glacial diamictites. Geochim. Cosmochim. Acta 191, 1-16.
219. Nicklas R.W., Puchtel I.S., and Ash R.D. (2016) High-precision determination of the oxidation state of komatiite lavas using vanadium liquid-mineral partitioning. Chemical Geology 433, 36-45 (doi:10.1016/j.chemgeo.2016.04.011).
220. Puchtel I.S. (2016) The Platinum Group Elements. Encyclopedia of Geochemistry. Elsevier, Amsterdam (doi: 10.1007/978-3-319-39193-9_274-1).
221. Cui H., Grazhdankin D.V., Xiao S., Peek S., Rogov V.I., Bykova N.V., Sievers N.E., Liu X-M. and Kaufman A.J. (2016) Redox-dependent distribution of early macro-organisms: Evidence from the terminal Ediacaran Khatyspyt Formation in Arctic Siberia. Palaeography, Palaeodimatology, Palaeoecology 461, 122-139.
222. Worsham E.A., Walker R.J. and Bermingham K.R. (2016) High-precision molybdenum isotope analysis by negative thermal ionization mass spectrometry. International Journal of Mass Spectrometry 407, 51-61.
2017
223. Day J.M.D., Walker R.J. and Warren J.M. (2017) 186Os-187Os and highly siderophile element abundance systematics of the mantle revealed by abyssal peridotites and Os-rich alloys. Geochim. Cosmochim. Acta 200, 232-254.
224. Day J.M.D., O’Driscoll B., Strachan R.A., Daly J.S. and Walker R.J. (2017) Identification of mantle peridotite as a possible Iapetan ophiolite sliver in south Shetland, Scottish Caledonides. The Journal of the Geological Society of London, Special 174, 88-92, doi:10.1144/jgs2016-074
225. Archer G.J., Mundl A., Walker R.J., Worsham E.A. and Bermingham K.R. (2017) High-precision analysis of 182W/184W and 183W/184W by negative thermal ionization mass spectrometry: per-integration oxide corrections using measured 18O/16O. International Journal of Mass Spectrometry 414, 80-86.
226. Mundl A., Touboul M., Jackson M.G., Day J.M.D., Kurz M.D., Lekic V., Helz R.T. and Walker R.J. (2017) Tunsten-182 heterogeneity in modern ocean island basalts. Science 356, 66-69.
227. Worsham E.A., Bermingham K.R. and Walker R.J. (2017) Molybdenum and tungsten isotope evidence for diverse genetics and chronology among IAB iron meteorite complex subgroups. Earth Planet. Sci. Lett. 467, 157-166.
228. Kleine T. and Walker R.J. (2017) Tungsten isotopes in planets. Ann. Rev. Earth and Planet. Sci. 45, 389-417.
229. Bermingham K.R. and Walker R.J. (2017) The ruthenium isotopic composition of the oceanic mantle. Earth Planet. Sci. Lett. 474, 466-473.
230. Kato C., Moynier F., Foriel J., Teng F.-Z., and Puchtel I.S. (2017) The gallium isotopic composition of the Bulk Silicate Earth. Chemical Geology 448, 164-172.
231. Greber N.D., Dauphas N., Puchtel I.S., Hofmann B.A., and Arndt N.T. (2017) Titanium Stable Isotope Fractionation in Chondrites, Achondrites and Lunar Rocks. Geochimica et Cosmochimica Acta 213, 534-552.
2018
232. Marchi S., Canup R.M. and Walker R.J. (2018) Heterogeneous delivery of silicate and metal to the Earth by large planetesimals. Nature Geoscience 11, 77-81. doi:10.1038/ s41561-017-0022-3.
233. Horan M.F., Carlson R.W., Walker R.J., Jackson M., Garçon M. and Norman M. (2018) Tracking Hadean processes in modern basalts. Earth Planet. Sci. Lett. 484, 184-191.
234. Bermingham K.R., Worsham E.A. and Walker R.J. (2018) New insights into Mo and Ru isotope variation in the nebula and terrestrial planet accretionary genetics. Earth Planet. Sci. Lett. 487, 221-229.
235. O’Driscoll B., Walker R.J., Clay P.L., Day J.M. and Daly S.J. (2018) Length-scales of chemical and isotopic heterogeneity in the mantle section of the Shetland Ophiolite Complex, Scotland. Earth and Planet. Sci. Lett. 488, 144-154.
236. Puchtel I.S., Blichert-Toft J., Touboul M. and Walker R.J. (2018) 182W and HSE constraints from 2.7 Ga komatiites on the heterogeneous nature of the Archean mantle. Geochim. Cosmochim. Acta 228, 1-26.
237. Walker R.J., Yin Q.-Z. and Heck P. (2018) Rapid effects of terrestrial alteration on highly siderophile elements in the Sutter’s Mill meteorite. Meteoritics and Planetary Science 53, 1500-1506. doi: 10.1111/maps.13102.
238. Nicklas R.W., Puchtel I.S., and Ash R.D. (2018) Redox state of the Archean mantle: Evidence from V partitioning in 3.5–2.4 Ga komatiites. Geochimica et Cosmochimica Acta 222, 447-466.
239. Amsellem E., Moynier F., Day J.M., Moreira M., Puchtel I.S., Teng, F.-Z. (2018) Stable strontium isotopic composition of OIB, MORB, komatiites and Kilauea Iki lava lake samples. Chemical Geology 483, 595-602.
240. Mundl A., Walker R. J., Reimink R. J., Rudnick R. L. and Gaschnig R. M. (2018) Tungsten-182 in the upper continental crust: evidence from glacial diamictites. Chem. Geol. 494, 144-152.
241. Cook D.L., Smith T., Leya I., Hilton C. and Walker R.J. (2018) Excess ¹⁸⁰W in IIAB iron meteorites: Identification of cosmogenic, radiogenic, and nucleosynthetic components. Earth and Planet. Sci. Lett. 503, 29-36.
242. Hibiya Y., Archer G.J., Tanaka R., Sanborn M.E., Sato Y., Iizuka T., Ozawa K., Walker R.J., Yamaguchi A., Irving A.J., Yin Q-Z., Nakamura T. (2019) The origin of the NWA 6704 ungrouped achondrite: Constraints from petrology, chemistry and Re–Os, O and Ti isotope systematics. Geochim. Cosmochim. Acta 245, 597-627.
2019
243. Archer G. J., Walker R.J., Tino J., Blackburn T., Kruijer T.S. and Hellmann J. (2019) Siderophile element constraints on the thermal history of the H chondrite parent body. Geochim. Cosmochim. Acta 245, 556-576.
244. Wu F.-Y,m Yang J.-H., Xu Y.-G., Wilde S.A., and Walker R.J. (2019) Destruction of the North China Craton in the Mesozoic. Annual Reviews of Earth and Planetary Sciences 47, 173–195.
245. Archer G.J., Walker R.J. and Irving A.J. (2019) Highly siderophile element and ¹⁸⁷Re-¹⁸⁷Os isotopic systematics of ungrouped achondrite Northwest Africa 7325: evidence for complex planetary processes. Meteor. Planet. Sci. 54, 1042–1050.
246. Peters B.J., Mundl A., Horan M.F., Carlson R.W. and Walker R.J. (2019) A framework for chemical separation of tungsten and other metals for high-precision mass spectrometry using organic acids. Geostandards and Geoanalytical Research 43, 245-259.
247. Mundl-Petermeier A., Walker R.J., Jackson M.G., Blichert-Toft J., Kurz M.D., and Halldórsson S.A. (2019) Temporal evolution of primodial tungsten-182 and ³He/⁴He signatures in the Iceland mantle plume. Chem. Geol. 525, 245-259.
248. Hilton C.D., Bermingham K.R., Walker R.J. and McCoy T.J. (2019) Genetics, age, and crystallization sequence of the South Byron Trio and the potential relation to the Milton pallasite. Geochim. Cosmochim. Acta 251, 217-228.
249. Nicklas R.W., Puchtel I.S., Ash R.D., Piccoli P., Hanski E., Nisbet E.G., Waterton P., Pearson D.G., and Anbar A.D. (2019) Secular Mantle Oxidation across the Archean-Proterozoic Boundary: Evidence from V partitioning in Komatiites and Picrites. Geochimica et Cosmochimica Acta 250: 49-75 (doi: 10.1016/j.gca.2019.01.037).
250. Qi Y., Wu F., Ionov D.A., Puchtel I.S., Carlson R.W., Nicklas R.W.**, Yu H., Kang J., Li C., Huang F. (2019) The vanadium isotopic composition of the Bulk Silicate Earth: constraints from peridotites, komatiites, and picrites. Geochimica et Cosmochimica Acta 259: 288-301 (doi: 10.1016/j.gca.2019.06.008).
251. Amsellem E., Moynier F., Puchtel I.S. (2019) Evolution of the Ca isotopic composition of the mantle. Geochimica et Cosmochimica Acta 258: 195-206 (doi: 10.1016/j.gca.2019.05.026).
252. Deng Z., Chaussidon M., Guitreau M., Puchtel I.S., Dauphas N., and Moynier F. (2019) An oceanic subduction origin for Archean granitoids revealed by silicon isotopes. Nature Geoscience 12 (9): 774-778 (doi: 10.1038/s41561-019-0407-6).
253. Locmelis M., Arevalo R.D.Jr., Puchtel I.S., Fiorentini M.L., Nisbet E.G. (2019) Transition metals in komatiitic olivine: Proxies for mantle composition, redox conditions, and sulfide mineralization potential. American Mineralogist 104: 1143-1155 (doi: 10.2138/am-2019-6914).
254. Ngonge E.D., de Hollanda M.H.B.M., Puchtel I.S., Walker R.J., and Archanjo C.J. (2019) Characteristics of the lithospheric mantle beneath northeastern Borborema Province, Brazil: Re–Os and HSE constraints on peridotite xenoliths. Journ. S. Amer. Earth Sci. 96, 102371.
255. Gorman J. K., Penniston-Dorland S.C., Marschall H.R. and Walker R.J. (2019) The roles of mechanical mixing and fluid transport in the formation of reaction zones in subduction-related mélange: Evidence from highly siderophile elements. Chem. Geol. 525, 96-111.
2020
256. Mundl-Petermeier A., Walker R.J., Fischer R.A., Lekic V., Jackson M.G. and Kurz M.D. (2020) Anomalous ¹⁸²W in high ³He/⁴He ocean island basalts: Fingerprints of Earth's core? Geochim. Cosmochim. Acta 271, 191-214.
257. Marchi S., Walker R.J. and Canup R.M. (2020) The role of large collisions in forming early compositional heterogeneities on Mars. Science Advances 6, eaay2338.
258. Hilton C.D., Ash R.D., Piccoli P.M., Kring D.A., McCoy T.J. and Walker R.J. (2020) Origin and age of metal veins in Canyon Diablo graphite nodules. Meteor. Planet. Sci. 55, 771-780.
259. Hilton C.D. and Walker R.J. (2020) New implications for the origin of the IAB main group iron meteorites and the isotopic evolution of the noncarbonaceous (NC) reservoir. Earth Planet. Sci. Lett. 540, 116248.
260. Reimink J.R., Mundl-Petermeier A., Carlson R.W., Shirey S.B., Walker R.J., Pearson D.G. (2020) Tungsten isotope composition of Archean crustal reservoirs and implications for terrestrial μ¹⁸²W evolution. Geochem. Geophys. Geosyst., 10.1029/2020GC009155.
261. Tornabene H.A., Hilton C.D., Bermingham K.R., Ash R.D. and Walker R.J. (2020) Genetics, age and crystallization history of group IIC iron meteorites. Geochim. Cosmochim. Acta, 288, 36-50
262. Puchtel I.S., Mundl-Petermeier A., Horan M.F., Hanski E., Blichert-Toft J., Walker R.J. (2020) Ultra-depleted 2.05 Ga komatiites of Finnish Lapland: Products of grainy late accretion or core-mantle interaction? Chem. Geol. 554, 119801
263. Kadoya S., Catling D.C., Nicklas R.W., Puchtel I.S., Anbar A.D. (2020) Mantle cooling causes more reducing volcanic gases and gradual reduction of the atmosphere. Geochemical Perspectives Letters 13: 25-29 (doi: 10.7185/geochemlet.2009)
264. Kadoya S., Catling D.C., Nicklas R.W., Puchtel I.S., Anbar A.D. (2020) Mantle data imply a decline of oxidizable volcanic gases could have triggered the Great Oxidation. Nature Communications 11 (1): 2774 (doi: 10.1038/s41467-020-16493-1)
265. Jerram M., Bonnand P., Kerr A.C., Nisbet E.G, Puchtel I.S., and Halliday A.N. (2020) The δ⁵³Cr isotope composition of komatiite flows and implications for the composition of the BSE. Chemical Geology 551: 119761 (doi: 10.1016/j.chemgeo.2020.119761)
266. Crossley S.**, Ash R.D., Sunshine J.M., Corrigan C.M., McCoy T.J., Mittlefehldt D.W., and Puchtel I.S. (2020) Sulfide-dominated partial melting pathways in brachinites. Meteoritics & Planetary Science 55 (9): 2021-2043 (doi: 10.1111/maps.13558)
267. Malitch K.N., Puchtel I.S., Belousova E.A., and Badanina I.Yu. (2020) Contrasting Platinum-Group Mineral Assemblages of the Kondyor Massif (Russia): Implications for the Sources of HSE in Zoned-Type Ultramafic Massifs. Lithos 376-377: 105800
268. Tian S., Moynier F., Inglis E.C., Creech J.B., Bizzarro, M., Siebert J., Day J.M.D., and Puchtel I.S. (2020) Zirconium isotopic composition of the mantle through time. Geochemical Perspectives Letters 15: 40-43 (doi: 10.7185/geochemlet.2033)
269. Hilton C.D., Ash R.D. and Walker R.J. (2020) Crystallization histories of the group IIF iron meteorites and Eagle Station pallasites. Meteor. Planet. Sci. 55, 2570-2586
2021
270. Peters B., Mundl-Petermeier A., Carlson R.W., Walker R.J., Day J.M.D. (2021) Combined lithophile-siderophile isotopic constraints on Hadean processes preserved in ocean island basalt sources. Geochemistry, Geophysics, Geosystems 22 (3), e2020GC009479 (doi: 10.1029/2020GC009479).
271. Nakanishi N., Giuliani A., Carlson R.W., Horan M.F., Woodhead J., Pearson D.G. and Walker R.J. (2021) Tungsten-182 evidence for an ancient kimberlite source. Proceedings of the National Academy of Sciences 118 (23), e2020680118 (doi: 10.1073/pnas.2020680118).
272. Haller M. B., O'Driscoll B., Day J.M.D., Daly J.S., Piccoli P.M. and Walker R.J. (2021) Meter-scale chemical and isotopic heterogeneities in the oceanic mantle, Leka Ophiolite Complex, Norway. Journal of Petrology, 62 (12), egab061 (doi: 10.1093/petrology/egab061).
273. Nicklas R.W., Brandon A.D., Waight T.E., Puchtel I.S. and Day J.M.D (2021) High-precision Pb and Hf isotope and highly siderophile element abundance systematics of high-MgO Icelandic lavas. Chemical Geology 582, 120436 (doi: 10.1016/j.chemgeo.2021.120436).
2022
274. Puchtel I.S., Nicklas R.W., Slagle J., Horan M., Walker R.J., Nisbet E.G., and Locmelis M. (2022) Early global mantle chemical and isotope heterogeneity revealed by the komatiite-basalt record: The Western Australia connection. Geochimica et Cosmochimica Acta 320: 238-278 (doi: 10.1016/j.gca.2021.11.030).
275. Puchtel I.S., Blichert-Toft J., Horan M., Touboul M., and Walker R.J. (2022) The komatiite testimony to ancient mantle heterogeneity. Chemical Geology 594: 120776 (doi: 10.1016/j.chemgeo.2022.120776).
276. Puchtel I.S. (2022) Re-Os isotope and HSE abundance systematics of the 2.9 Ga komatiites and basalts from the Sumozero-Kenozero greenstone belt, SE Fennoscandian Shield: Implications for the mixing rates of the mantle. Petrology, Special Issue (in press).
277. Hilton C.D., Ash R.D. and Walker R.J. (2022) Chemical characteristics of iron meteorite parent bodies. Geochim. Cosmochim. Acta 318, 112-125.
278. Corrigan C.M., Nagashima K., Hilton C., McCoy T.J., Ash R.D., Walker R. J., McDonough W.F. and Rumble D. (2022) Nickel-rich, volatile depleted iron meteorites: relationships and formation processes. Geochimica et Cosmochimica Acta 333, 1-25.
2023
279. Tornabene H.A., Ash R.D., Walker R.J. and Bermingham K.R. (2023) Genetics, age and crystallization history of group IC iron meteorites. Geochimica et Cosmochimica 340, 108-119.
280. Nakanishi** N., Puchtel I.S., Walker R.J. and Nabelek P.I. (2023) Dissipation of Tungsten-182 Anomalies in the Archean upper mantle: evidence from the Black Hills, South Dakota, USA. Chemical Geology, in press.
281. Peters D., Rizo H., Carlson R.W., Walker R.J., Rundnick R.L. and Luguet A. (2023) Tungsten in the (upper) mantle: less incompatible and more abundant. Geochimica et Cosmochimica Acta 351, 167-180.
282. Chiappe E.M., Ash R.D. and Walker R.J. (2023) Age, genetics, and crystallization sequence of the Group IIIE iron meteorites. Geochimica et Cosmochimica Acta 354, 51-61.
283. Chiappe E.M., Ash R.D., Luttinen A., Lukkari S., Kuva J, Hilton C.D. and Walker R.J. (2023) Chemical and genetic characterization of the ungrouped pallasite Lieksa. Meteoritics and Planetary Sciences, doi: 10.1111/maps.14095.
284. Finlayson V.A., Haller M., Day J.M.D., Ginley S., O’Driscoll B., Kontinen A., Hanski E., and Walker R.J. (2023) Oceanic and continental lithospheric mantle in the 1.95 Ga Jormua Ophiolite Complex, Finland: implications for mantle and crustal evolution. Journal of Petrology 64, 1-27.
285. Walker R.J., Mundl-Petermeier A., Puchtel I.S., Nicklas R.W., Hellmann J.L., Echeverría L.M., Ludwig K.D., Bermingham K.R., Gazel E., Devitre C.L. and Jackson M.G. (2023) ¹⁸²W and ¹⁸⁷Os constraints on the origin of siderophile isotopic heterogeneity in the mantle. Geochimica et Cosmochimica Acta 363, 15-39.
286. Nakanishi N. and Hayabusa2 Science Team. (2023) Nucleosynthetic s-process depletion in Mo from Ryugu samples returned by Hayabusa 2. Geochemical Perspectives Letters 28, 31-36.